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This chapter describes the commands used to manage the system and its performance on the network. In general, system or network management falls into the following categories. The commands that perform the tasks in these management categories are described in this chapter unless specified otherwise.
For system management configuration tasks and examples, refer to the chapter entitled "Managing the System" in the Configuration Fundamentals Configuration Guide.
To enable AAA accounting of requested services for billing or security purposes when using TACACS+, use the aaa accounting global configuration command. Use the no form of this command to disable accounting.
aaa accounting {system | network | connection | exec | command level} {start-stop || system | Performs accounting for all system-level events not associated with users, such as reloads. |
| network | Runs accounting for all network-related service requests, including SLIP, PPP, PPP NCPs, and ARAP. |
| connection | Runs accounting for outbound Telnet and rlogin. |
| exec | Runs accounting for EXECs (user shells). This keyword might return user profile information such as autocommand information. |
| command | Runs accounting for all commands at the specified privilege level. |
| level | The command level that should be accounted for. Valid entries are 0-15. |
| start-stop | Sends a start record accounting notice at the beginning of a process and a stop record at the end of a process. The start accounting record is sent in the background. The requested user process begins regardless of whether or not the start accounting record was received by the accounting server. |
| wait-start | As in start-stop, sends both a start and a stop accounting record to the accounting server. However, if you use the wait-start keyword, the requested user service does not begin until the start accounting record is acknowledged. A stop accounting record is also sent. |
| stop-only | Sends a stop record accounting notice at the end of the requested user process. |
| tacacs+ | Mandatory. Enables the TACACS-style accounting. |
| radius | Enables the radius-style authorization. |
AAA accounting is not enabled.
Global configuration
The aaa accounting command allows you to set start-stop accounting for any or all of the functions listed in "Syntax Description." For minimal accounting control, issue the stop-only keyword, which sends a stop record accounting notice at the end of the requested user process. For additional accounting control, you can issue the start-stop command, so that TACACS+ sends a start accounting notice at the beginning of the requested process and a stop accounting notice at the end of the process. For even more accounting control, you can issue the wait-start command, which ensures that the start notice is received by the TACACS+ server before granting the user's process request. Accounting is done only to the TACACS+ server.
In the following example, accounting is set for outbound Telnet and rlogin, and both a start and stop accounting notice is sent to the TACACS+ server:
aaa accounting connection start-stop tacacs+
In the following example, accounting is set for privilege level 15 commands with a wait-start restriction:
aaa accounting command 15 wait-start tacacs+
aaa authentication username-prompt
aaa new-model
To enable an AAA authentication method for AppleTalk Remote Access (ARA) users using TACACS+, use the aaa authentication arap global configuration command. Use the no form of this command to disable this authentication.
aaa authentication arap {default | list-name} method1 [...[method4]]| default | Uses the listed methods that follow this argument as the default list of methods when a user logs in. |
| list-name | Character string used to name the following list of authentication methods tried when a user logs in. |
| method | One of the keywords described in Table 61. |
If the default list is not set, only the local user database is checked. This version has the same effect as the following command:
aaa authentication arap default local
Global configuration
The list names and default that you set with the aaa authentication arap command are used with the arap authentication command. These lists can contain up to four authentication methods that are used when a user tries to log in with ARA. Note that ARAP guest logins are disabled by default when you enable AAA/TACACS+. To allow guest logins, you must use either the guest or auth-guest method listed in Table 61. You can only use one of these methods; they are mutually exclusive.
Create a list by entering the aaa authentication arap list-name method command, where list-name is any character string used to name this list, such as MIS-access. The method argument identifies the list of methods the authentication algorithm tries in the given sequence. You can enter up to four methods.
To create a default list that is used if no list is specified in the arap authentication command, use the default keyword followed by the methods you wish to be used in default situations.
The additional methods of authentication are used only if the previous method returns an error, not if it fails.
Use the show running-config command to view lists of authentication methods.
| Keyword | Description |
|---|---|
| Method | Description |
| guest | Allows guest logins. This method must be the first method listed, but can be followed by other methods to try if it does not succeed. |
| auth-guest | Allows guest logins only if the user has already logged in to EXEC. This method must be the first method listed, but can be followed by other methods to try if it does not succeed. |
| line | Uses the line password for authentication. |
| local | Uses the local username database for authentication. |
| tacacs+ | Uses TACACS+ authentication. |
| radius | Uses Radius authentication. |
The following example creates a list called MIS-access, which first tries TACACS+ authentication and then none:
aaa authentication arap MIS-access tacacs+ none
The following example creates the same list, but sets it as the default list that is used for all ARA protocol authentications if no other list is specified:
aaa authentication arap default tacacs+ none
aaa authentication local-override
aaa new-model
arap authentication
To enable AAA authentication to determine if a user can access the privileged command level with TACACS+, use the aaa authentication enable default global configuration command. Use the no form of this command to disable this authorization method.
aaa authentication enable default method1 [...[method4]]| method | At least one and up to four of the keywords described in Table 62. |
If the default list is not set, only the enable password is checked. This version has the same effect as the following command:
aaa authentication enable default enable
On the console, the enable password is used if it exists. If no password is set, the process will succeed anyway.
Global configuration
Use the aaa authentication enable default command to create a series of authentication methods that are used to determine if a user can access the privileged command level. You can specify up to four authentication methods. Method keywords are described in Table 62. The additional methods of authentication are used only if the previous method returns an error, not if it fails. To specify that the authentication should succeed even if all methods return an error, specify none as the final method in the command line.
If a default authentication routine is not set for a function, the default is none and no authentication is performed. Use the show running-config command to view currently configured lists of authentication methods.
| Keyword | Description |
|---|---|
| enable | Uses the enable password for authentication. |
| line | Uses the line password for authentication. |
| none | Uses no authentication. |
| radius | Uses Radius authentication. |
| tacacs+ | Uses TACACS+ authentication. |
| radius | Uses Radius authentication. |
The following example creates an authentication list that first tries to contact a TACACS+ server. If no server can be found, then AAA tries to use the enable password. If this attempt also returns an error (because no enable password is configured on the server), the user is allowed access with no authentication.
aaa authentication enable default tacacs+ enable none
aaa authentication local-override
aaa authentication username-prompt
aaa new-model
enable password
To have the router check the local user database for authentication before attempting another form of authentication, use the aaa authentication local-override global configuration command. Use the no form of this command to disable the override.
aaa authentication local-overrideThis command has no arguments or keywords.
Override is disabled.
Global configuration
This command is useful when you want to configure an override to the normal authentication process for certain personnel such as system administrators.
When this override is set, the user is always prompted for the username. The system then checks to see if the entered username corresponds to a local account. If the username does not correspond to one in the local database, login proceeds with the methods configured with other aaa commands (such as aaa authentication login). Note when using this command that Username: is fixed as the first prompt.
The following example enables AAA authentication override:
aaa authentication local-override
aaa authentication arap
aaa authentication enable default
aaa authentication login
aaa authentication password-prompt
aaa new-model
To set AAA authentication at login when using TACACS+, use the aaa authentication login global configuration command. Use the no form of this command to disable AAA authentication.
aaa authentication login {default | list-name} method1 [...[method4]]| default | Uses the listed authentication methods that follow this argument as the default list of methods when a user logs in. |
| list-name | Character string used to name the following list of authentication methods activated when a user logs in. |
| method | At least one and up to four of the keywords described in Table 63. |
If the default list is not set, only the local user database is checked. This version has the same effect as the following command:
aaa authentication login default local
Global configuration
The default and optional list names that you create with the aaa authentication login command are used with the login authentication command.
Create a list by entering the aaa authentication list-name method command, where list-name is any character string used to name this list, such as MIS-access. The method argument identifies the list of methods that the authentication algorithm tries, in the given sequence. Method keywords are described in Table 63.
To create a default list that is used if no list is assigned to a line, use the login authentication command with the default argument followed by the methods you want in default situations.
The additional methods of authentication are used only if the previous method returns an error, not if it fails. To ensure that the authentication succeeds even if all methods return an error, specify none as the final method in the command line.
If authentication is not specifically set for a line, the default is to deny access--no authentication is performed. Use the show running-config command to view currently configured lists of authentication methods.
| Keyword | Description |
|---|---|
| enable | Uses the enable password for authentication. |
| krb5 | Uses Kerberos 5 for authentication. |
| line | Uses the line password for authentication. |
| local | Uses the local username database for authentication. |
| none | Uses no authentication. |
| radius | Uses Radius authentication. |
| tacacs+ | Uses TACACS+ authentication. |
The following example creates an AAA authentication list called MIS-access. This authentication first tries to contact a TACACS+ server. If no server is found, TACACS+ returns an error and AAA tries to use the enable password. If this attempt also returns an error (because no enable password is configured on the server), the user is allowed access with no authentication.
aaa authentication login MIS-access tacacs+ enable none
The following example creates the same list, but sets it as the default list that is used for all login authentications if no other list is specified:
aaa authentication login default tacacs+ enable none
aaa authentication local-override
aaa new-model
login authentication
To specify TACACS+ authentication for Netware Asynchronous Services Interface (NASI) clients connecting through the access server, use the aaa authentication nasi global configuration command. Use the no form of this command to disable authentication for NASI clients.
aaa authentication nasi {list-name | default} {methods list}| list-name | A character string used to name the following list of authentication methods activated when a user logs in. |
| default | Makes the listed authentication methods that follow this argument the default list of methods used when a user logs in. |
| methods | At least one and up to four of the methods described in Table 64. |
If the default list is not set, only the local user database is selected. This setting has the same effect as the following command:
aaa authentication nasi default local
Global configuration
The default and optional list names that you create with the aaa authentication nasi command are used with the nasi authentication command.
Create a list by entering the aaa authentication nasi command, where list-name is any character string that names this list, such as MIS-access. The method argument identifies the list of methods the authentication algorithm tries in the given sequence. Method keywords are described in Table 63.
To create a default list that is used if no list is assigned to a line with the nasi authentication command, use the default argument followed by the methods that you want in default situations.
The remaining methods of authentication are used only if the previous method returns an error, not if it fails. To ensure that the authentication succeeds even if all methods return an error, specify none as the final method in the command line.
If authentication is not specifically set for a line, the default is to deny access--no authentication is performed. Use the show running-config command to view currently configured lists of authentication methods.
| Keyword | Description |
|---|---|
| enable | Uses the enable password for authentication. |
| line | Uses the line password for authentication. |
| local | Uses the local username database for authentication. |
| none | Uses no authentication. |
| tacacs+ | Uses TACACS+ authentication. |
The following example creates an AAA authentication list called list1. This authentication first tries to contact a TACACS+ server. If no server is found, TACACS+ returns an error and AAA tries to use the enable password. If this attempt also returns an error (because no enable password is configured on the server), the user is allowed access with no authentication.
aaa authentication nasi list1 tacacs+ enable none
The following example creates the same list, but sets it as the default list that is used for all login authentications if no other list is specified:
aaa authentication nasi default tacacs+ enable none
A dagger (+) indicates the command is documented outside this chapter.
aaa authentication nasi
ipx nasi-server enable +
nasi authentication
show ipx nasi connections +
show ipx spx-protocol +
To change the text displayed when users are prompted for a password, use the aaa authentication password-prompt global configuration command. Use the no form of this command to return to the default password prompt text.
aaa authentication password-prompt {text-string}| text-string | String of text that will be displayed when the user is prompted to enter a password. If this text-string contains spaces or unusual characters, it must be enclosed in double-quotes (for example, "Enter your password:"). |
This command is disabled by default.
Global configuration
This command first appeared in Cisco IOS Release 11.0.
Use the aaa authentication password-prompt command to change the default text that the Cisco IOS software displays when prompting a user to enter a password. This command changes the password prompt for the enable password as well as for login passwords that are not supplied by remote security servers. The no form of this command returns the password prompt to the default value:
Password:
The aaa authentication password-prompt command does not change any dialog that is supplied by a remote TACACS+ or RADIUS server.
The following example changes the text for the password prompt:
aaa authentication password-prompt "Enter your password now:"
A dagger (+) indicates that the command is documented outside this chapter.
aaa authentication username prompt
aaa new-model
enable password +
To specify one or more AAA authentication methods for use on serial interfaces running Point-to-Point (PPP) when using TACACS+, use the aaa authentication ppp global configuration command. Use the no form of this command to disable authentication.
aaa authentication ppp {default | list-name} method1 [...[method4]]| default | Uses the listed authentication methods that follow this argument as the default list of methods when a user logs in. |
| list-name | Character string used to name the following list of authentication methods tried when a user logs in. |
| method | At least one and up to four of the keywords described in Table 4. |
If the default list is not set, only the local user database is checked. This version has the same effect as the following command:
aaa authentication ppp default local
Global configuration
The lists that you create with the aaa authentication ppp command are used with the ppp authentication command. These lists contain up to four authentication methods that are used when a user tries to log in to the serial interface.
Create a list by entering the aaa authentication ppp list-name method command, where list-name is any character string used to name this list, such as MIS-access. The method argument identifies the list of methods that the authentication algorithm tries in the given sequence. You can enter up to four methods. Method keywords are described in Table 65.
The additional methods of authentication are only used if the previous method returns an error, not if it fails. Specify none as the final method in the command line to have authentication succeed even if all methods return an error.
If authentication is not specifically set for a function, the default is none and no authentication is performed. Use the show running-config command to view lists of authentication methods.
The following example creates an AAA authentication list called MIS-access for serial lines that use PPP. This authentication first tries to contact a TACACS+ server. If this action returns an error, the user is allowed access with no authentication.
aaa authentication MIS-access ppp tacacs+ none
aaa authentication local-override
aaa new-model
ppp authentication
To change the text displayed when users are prompted to enter a username, use the aaa authentication username-prompt global configuration command. Use the no form of this command to return to the default username prompt text.
aaa authentication username-prompt {text-string}| text-string | String of text that will be displayed when the user is prompted to enter a username. If this text-string contains spaces or unusual characters, it must be enclosed in double-quotes (for example, "Enter your name:"). |
This command is disabled by default.
Global configuration
This command first appeared in Cisco IOS Release 11.0.
Use the aaa authentication username-prompt command to change the default text that the Cisco IOS software displays when prompting a user to enter a username. The no form of this command returns the username prompt to the default value:
Username:
Some protocols (for example, TACACS+) have the ability to override the use of local username prompt information. Using the aaa authentication username-prompt command will not change the username prompt text in these instances.
The following example changes the text for the username prompt:
aaa authentication username-prompt "Enter your name here:"
A dagger (+) indicates that the command is documented outside this chapter.
aaa authentication password-prompt
aaa new-model
enable password +
To set parameters that restrict a user's network access based on TACACS+ authorization, use the aaa authorization global configuration command. To disable authorization for a function, use the no form of this command.
aaa authorization {network | connection | exec | command level} methods| network | Performs authorization for all network-related service requests, including SLIP, PPP, PPP NCPs, and ARA protocol. |
| connection | Runs authorization for outbound Telnet and rlogin. |
| exec | Runs authorization to determine if the user is allowed to run an EXEC shell. This keyword might return user profile information such as autocommand information. |
| command | Runs authorization for all commands at the specified privilege level. |
| level | Specific command level that should be authorized. Valid entries are 0 through 15. |
| methods | Table 61 lists the methods keywords. |
Authorization is disabled for all actions (equivalent to the keyword none).
Global configuration
This command first appeared in Cisco IOS Release 10.0.
Use the aaa authorization command to create a list of one and up to four authorization methods that can be used when a user accesses the specified function.
The additional methods of authorization are only used if the previous method returns an error, not if it fails. Specify none as the final method in the command line to have authorization succeed even if all methods return an error.
| Keyword | Description |
|---|---|
| tacacs+ | Requests authorization information from the TACACS+ server. |
| if-authenticated | Allows the user to access the requested function if the user is authenticated. |
| none | No authorization is performed. |
| local | Uses the local database for authorization. |
| radius | Uses Radius authentication. |
If authorization is not specifically set for a function, the default is none and no authorization is performed.
The authorization command causes a request packet containing a series of attribute value pairs to be sent to the TACACS daemon as part of the authorization process. The daemon can:
Table 67 describes attribute value (AV) pairs associated with the aaa authorization command. Registered users can find more information about TACACS+ and attribute pairs on Cisco Connection Online (CCO).
| Attribute | Description | Cisco IOS Release 11.0 | Cisco IOS Release11.1 | Cisco IOS Release11.2 |
|---|---|---|---|---|
| service=x | The primary service. Specifying a service attribute indicates that this is a request for authorization or accounting of that service. Current values are slip, ppp, arap, shell, tty-daemon, connection, and system. This attribute must always be included. | yes | yes | yes |
| protocol=x | A protocol that is a subset of a service. An example would be any PPP NCP. Currently known values are lcp, ip, ipx, atalk, vines, lat, xremote, tn3270, telnet, rlogin, pad, vpdn, http, and unknown. | yes | yes | yes |
| cmd=x | A shell (EXEC) command. This indicates the command name for a shell command that is to be run. This attribute must be specified if service equals "shell." A NULL value indicates that the shell itself is being referred to. | yes | yes | yes |
| cmd-arg=x | An argument to a shell (EXEC) command. This indicates an argument for the shell command that is to be run. Multiple cmd-arg attributes may be specified, and they are order dependent. | yes | yes | yes |
| acl=x | ASCII number representing a connection access list. Used only when service=shell. | yes | yes | yes |
| inacl=x | ASCII identifier for an interface input access list. Used with service=ppp and protocol=ip. | yes | yes | yes |
| inacl#<n> | ASCII access list identifier for an input access list to be installed and applied to an interface for the duration of the current connect ion. Used with service=ppp and protocol=ip, and service service=ppp and protocol =ipx. | no | no | 11.2(4)F |
| outacl=x | ASCII identifier for an interface output access list. Used with service=ppp and protocol=ip, and service service=ppp and protocol=ipx. Contains an IP output access list for SLIP or PPP/IP (for example, outacl=4). The access list itself must be preconfigured on the router. Per-user access lists do not currently work with ISDN interfaces. | yes (PPP/IP only) | yes | yes |
| outacl#<n> | ACSII access list identifier for an interface output access list to be installed and applied to an interface for the duration of the current condition. Used with service=ppp and protocol=ip, and service service=ppp and protocol=ipx. | no | no | 11.2(4)F |
| zonelist=x | A numeric zonelist value. Used with service=arap. Specifies an AppleTalk zonelist for ARA (for example, zonelist=5). | yes | yes | yes |
| addr=x | A network address. Used with service=slip, service=ppp, and protocol=ip. Contains the IP address that the remote host should use when connecting via SLIP or PPP/IP. For example, addr=1.2.3.4. | yes | yes | yes |
| addr-pool=x | Specifies the name of a local pool from which to get the address of the remote host. Used with service=ppp and protocol=ip.
Note that addr-pool works in conjunction with local pooling. It specifies the name of a local pool (which must be preconfigured on the network access server). Use the ip-local pool command to declare local pools. For example: You can then use TACACS+ to return addr-pool=boo or addr-pool=moo to indicate the address pool from which you want to get this remote node's address. | yes | yes | yes |
| routing=x | Specifies whether routing information is to be propagated to, and accepted from this interface. Used with service=slip, service=ppp, and protocol=ip. Equivalent in function to the /routing flag in SLIP and PPP commands. Can either be true or false (for example, routing=true). | yes | yes | yes |
| route | Specifies a route to be applied to an interface. Used with service=slip, service=ppp, and protocol=ip.
During network authorization, the route attribute can be used to specify a per-user static route, to be installed by TACACS+ as follows: This indicates a temporary static route that is to be applied. dst_address, mask, and gateway are expected to be in the usual dotted-decimal notation, with the same meanings as in the familiar ip route configuration command on a network access server. If gateway is omitted, the peer's address is the gateway. The route is expunged when the connection terminates. | no | yes | yes |
| route#<n> | Like the route AV pair, this specifies a route to be applied to an interface, but these routes are numbered, allowing multiple routes to be applied. Used with service=ppp and protocol=ip, and service=ppp and protocol=ipx. | no | no | 11.2(4)F |
| timeout=x | The number of minutes before an ARA session disconnects (for example, timeout=60). A value of zero indicates no timeout. Used with service=arap. | yes | yes | yes |
| idletime=x | Sets a value, in minutes, after which an idle session is terminated. Does not work for PPP. A value of zero indicates no timeout. | no | yes | yes |
| autocmd=x | Specifies an autocommand to be executed at EXEC startup (for example, autocmd=telnet muruga.com). Used only with service=shell. | yes | yes | yes |
| noescape=x | Prevents user from using an escape character. Used with service=shell. Can be either true or false (for example, noescape=true). | yes | yes | yes |
| nohangup=x | Used with service=shell. Specifies the nohangup option. Can be either true or false (for example, nohangup=false). | yes | yes | yes |
| priv-lvl=x | Privilege level to be assigned for the EXEC. Used with service=shell. Privilege levels range from 0 to 15, with 15 being the highest. | yes | yes | yes |
| callback-dialstring | Sets the telephone number for a callback (for example: callback-dialstring=408-555-1212). Value is NULL, or a dial-string. A NULL value indicates that the service may choose to get the dialstring through other means. Used with service=arap, service=slip, service=ppp, service=shell. Not valid for ISDN. | no | yes | yes |
| callback-line | The number of a TTY line to use for callback (for example: callback-line=4). Used with service=arap, service=slip, service=ppp, service=shell. Not valid for ISDN. | no | yes | yes |
| callback-rotary | The number of a rotary group (between 0 and 100 inclusive) to use for callback (for example: callback-rotary=34). Used with service=arap, service=slip, service=ppp, service=shell. Not valid for ISDN. | no | yes | yes |
| nocallback-verify | Indicates that no callback verification is required. The only valid value for this parameter is 1 (for example, nocallback-verify=1). Used with service=arap, service=slip, service=ppp, service=shell. There is no authentication on callback. Not valid for ISDN. | no | yes | yes |
| tunnel-id | Specifies the username that will be used to authenticate the tunnel over which the individual user MID will be projected. This is analogous to the remote name in the vpdn outgoing command. Used with service=ppp and protocol=vpdn. | no | no | yes |
| ip-addresses | Space-separated list of possible IP addresses that can be used for the end-point of a tunnel. Used with service=ppp and protocol=vpdn. | no | no | yes |
| nas-password | Specifies the password for the network access server during the L2F tunnel authentication. Used with service=ppp and protocol=vpdn. | no | no | yes |
| gw-password | Specifies the password for the home gateway during the L2F tunnel authentication. Used with service=ppp and protocol=vpdn. | no | no | yes |
| rte-ftr-in#<n> | Specifies an input access list definition to be installed and applied to routing updates on the current interface for the duration of the current connection. Used with service=ppp and protocol=ip, and with service=ppp and protocol=ipx. | no | no | 11.2(4)F |
| rte-ftr-out#<n> | Specifies an output access list definition to be installed and applied to routing updates on the current interface for the duration of the current connection. Used with service=ppp and protocol=ip, and with service=ppp and protocol=ipx. | no | no | yes 11.2(4)F |
| sap#<n> | Specifies static Service Advertising Protocol (SAP) entries to be installed for the duration of a connection. Used with service=ppp and protocol=ipx. | no | no | yes 11.2(4)F |
| sap-fltr-in#<n> | Specifies an input SAP filter access list definition to be installed and applied on the current interface for the duration of the current connection. Used with service=ppp and protocol=ipx. | no | no | yes 11.2(4)F |
| sap-fltr-out#<n> | Specifies an output SAP filter access list definition to be installed and applied on the current interface for the duration of the current connection. Used with service=ppp and protocol=ipx. | no | no | 11.2(4)F |
| pool-def#<n> | Used to define IP address pools on the network access server. Used with service=ppp and protocol=ip. | no | no | 11.2(4)F |
| source-ip=x | Used as the source IP address of all VPDN packets generated as part of a VPDN tunnel. This is equivalent to the Cisco vpdn outgoing global configuration command. | no | no | yes |
The following example specifies that TACACS+-style of authorization is used for all network-related requests. If this authorization method returns an error (if the TACACS+ server cannot be contacted), no authorization is performed and the request is successful.
aaa authorization network tacacs+ none
The following example specifies that TACACS+-style of authorization is run for level 15 commands. If this authorization method returns an error (if the TACACS+ server cannot be contacted), no authorization is performed and the request succeeds.
aaa authorization command 15 tacacs+ none
To enable the AAA access control model that includes TACACS+, issue the aaa new-model global configuration command. Use the no form of this command to disable this functionality.
aaa new-modelThis command has no arguments or keywords.
AAA/TACACS+ is not enabled.
Global configuration
This command enables the AAA access control system and TACACS+. If you initialize this functionality and later decide to use TACACS or extended TACACS, issue the no version of this command before you enable the version of TACACS that you want to use.
After enabling AAA/TACACS+ with the aaa new-model command, you must use the tacacs-server key command to set the authentication key used in all TACACS+ communications with the TACACS+ daemon.
The following example initializes AAA and TACACS+:
aaa new-model
aaa accounting
aaa authentication arap
aaa authentication enable default
aaa authentication local-override
aaa authentication login
aaa authentication password-prompt
aaa authentication username-prompt
tacacs-server key
To enable the router to create a temporary access list entry in a dynamic access list, use the access-enable EXEC command.
access-enable [host] [timeout minutes]EXEC
This command enables the lock-and-key access feature.
You should always define either an idle timeout (with the timeout keyword in this command) or an absolute timeout (with the timeout keyword in the access-list command). Otherwise, the temporary access list entry will remain, even after the user has terminated his session.
The following example causes the software to create a temporary access list entry and tells the software to enable access only for the host from which the Telnet session originated. If the access list entry is not accessed within 2 minutes, it is deleted.
autocommand access-enable host timeout 2
A dagger (+) indicates that the command is documented outside this chapter.
autocommand +
access-list (extended) +
To manually place a temporary access list entry on a router to which you are connected, use the access-template EXEC command.
access-template [access-list-number] [dynamic-name] [source] [destination] [timeout minutes]| access-list-number | Number of the dynamic access list. |
| dynamic-name | (Optional) Name of a dynamic access list. |
| source | (Optional) Source address in a dynamic access list. The keywords host and any are allowed. All other attributes are inherited from the original access-list entry. |
| destination | (Optional) Destination address in a dynamic access list. The keywords host and any are allowed. All other attributes are inherited from the original access-list entry. |
| timeout minutes | (Optional) Specifies a maximum time limit for each entry within this dynamic list. This is an absolute time, from creation, that an entry can reside in the list. The default is an infinite time limit and allows an entry to remain permanently. |
EXEC
This command provides a way to enable the lock-and-key access feature.
You should always define either an idle timeout (with the timeout keyword in this command) or an absolute timeout (with the timeout keyword in the access-list command). Otherwise, the dynamic access list will remain, even after the user has terminated the session.
In the following example, the software enables IP access on incoming packets in which the source address is 171.69.1.129 and the destination address is 172.21.52.12. All other source and destination pairs are discarded.
access-template 101 payroll host 171.69.1.129 host 172.21.52.12 timeout 2
A dagger (+) indicates that the command is documented outside this chapter.
autocommand +
access-list (extended) +
clear access-template
To create a command alias, use the alias global configuration command. Use the no alias command to delete all aliases in a command mode or to delete a specific alias, and to revert to the original command syntax.
alias mode alias-name alias-command-line| mode | Command mode of the original and alias commands. See Table 68 for a list of options for this argument. |
| alias-name | Command alias. |
| alias-command-line | Original command syntax. |
Default aliases are in EXEC mode as follows:
| Command Alias | Original Command |
|---|---|
| h | help |
| lo | logout |
| p | ping |
| r | resume |
| s | show |
| w | where |
Global configuration
You can use simple words or abbreviations as aliases. The aliases in the Default section are predefined. They can be turned off using the no alias command.
Table 68 shows the acceptable options for the mode argument in the alias global configuration command.
See the summary of command modes in the "User Interface" chapter in the Configuration Fundamentals Configuration Guide for more information about command modes.
When you use online help, command aliases are indicated by an asterisk (*), as follows:
Router#lo?
*lo=logout lock login logout
When you use online help, aliases that contain spaces (for example, telnet device.cisco.com 25) are displayed as follows:
Router#configure terminalEnter configuration commands, one per line. End with CNTL/Z. Router(config)#alias exec device-mail telnet device.cisco.com 25Router(config)#endRouter#device-mail?*device-mail="telnet device.cisco.com 25"
When you use online help, the alias is expanded and replaced with the original command, as shown in the following example with the td alias:
Router(config)#alias exec td trace deviceRouter(config)#^ZRouter#t?*td="trace device" telnet terminal test tn3270 trace
To list only commands and omit aliases, begin your input line with a space. In the following example, the alias td is not shown, because there is a space before the t? command line.
Router# t?
telnet terminal test tn3270 trace
As with commands, you can use online help to display the arguments and keywords that can follow a command alias. In the following example, the alias td is created to represent the command telet device. The /debug and /line switches can be added to telnet device to modify the command:
Router(config)#alias exec td telnet deviceRouter(config)#^ZRouter#td ?/debug Enable telnet debugging mode /line Enable telnet line mode ... whois Whois port <cr> Router#telnet device
You must enter the complete syntax for the alias command. Partial syntax for aliases are not accepted. In the following example, the parser does not recognize the command t as indicating the alias td.
bones# t
% Ambiguous command: "t"
In the following example, the alias fixmyrt is created for the ip route198.92.116.16.
alias exec fixmyrt clear ip route 198.92.116.16
To enable TACACS+ authentication for ARA on a line, use the arap authentication line configuration command. Use the no form of the command to disable authentication for an ARA line.
arap authentication {default | list-name}![]() | Caution If you use a list-name value that was not configured with the aaa authentication arap command, ARA protocol will be disabled on this line. |
| default | Default list created with the aaa authentication arap command. |
| list-name | Indicated list created with the aaa authentication arap command. |
ARA protocol authentication uses the default set with aaa authentication arap command. If no default has been set, the local user database is checked.
Line configuration
This command is a per-line command that specifies the name of a list of AAA authentication methods to try at login. If no list is specified, the default list is used (whether or not it is specified in the command line). You create defaults and lists with the aaa authentication arap command. Entering the no version of arap authentication has the same effect as entering the command with the default argument.
Before issuing this command, create a list of authentication processes by using the aaa authentication arap global configuration command.
The following example specifies that the TACACS+ authentication list called MIS-access is used on ARA line 7:
line 7 arap authentication MIS-access
Use the buffers global configuration command to make adjustments to initial buffer pool settings and to the limits at which temporary buffers are created and destroyed. Use the no form of this command to return the buffers to their default size.
buffers {small | middle | big | verybig | large | huge | type number} {permanent | max-free| small | Buffer size of this public buffer pool is 104 bytes. |
| middle | Buffer size of this public buffer pool is 600 bytes. |
| big | Buffer size of this public buffer pool is 1524 bytes. |
| verybig | Buffer size of this public buffer pool is 4520 bytes. |
| large | Buffer size of this public buffer pool is 5024 bytes. |
| huge | Default buffer size of this public buffer pool is 18024 bytes. This value can be configured with the buffers huge size command. |
| type number | Interface type and interface number of the interface buffer pool. The type value cannot be fddi. |
| permanent | Number of permanent buffers that the system tries to create and keep. Permanent buffers are normally not trimmed by the system. |
| max-free | Maximum number of free or unallocated buffers in a buffer pool. A maximum of 20,480 small buffers can be constructed in the pool. |
| min-free | Minimum number of free or unallocated buffers in a buffer pool. |
| initial | Number of additional temporary buffers that are to be allocated when the system is reloaded. This keyword can be used to ensure that the system has necessary buffers immediately after reloading in a high-traffic environment. |
| number | Number of buffers to be allocated. |
The default number of buffers in a pool is determined by the hardware configuration and can be displayed with the EXEC show buffers command.
Global configuration
Normally you need not adjust these parameters; do so only after consulting with technical support personnel. Improper settings can adversely impact system performance.
You cannot configure FDDI buffers.
In the following example, the system will try to keep at least 50 small buffers free:
buffers small min-free 50
In the following example, the permanent buffer pool allocation for big buffers is increased to 200:
buffers big permanent 200
A general guideline is to display buffers with the show buffers command, observe which buffer pool is depleted, and increase that one.
In the following example, the permanent Ethernet 0 interface buffer pool on a Cisco 4000 is increased to 96 because the Ethernet 0 buffer pool is depleted:
buffers ethernet 0 permanent 96
Use the buffers huge size global configuration command to dynamically resize all huge buffers to the value you specify. Use the no form of this command to restore the default buffer values.
buffers huge size number| number | Size of huge buffers, in bytes. |
18024 bytes
Global configuration
Use only after consulting with technical support personnel. The buffer size cannot be lowered below the default.
In the following example, the system will resize huge buffers to 20000 bytes:
buffers huge size 20000
To set the system calendar for a Cisco 7000 system or a Cisco 4500 system, use the calendar set EXEC command.
calendar set hh:mm:ss day month year| hh:mm:ss | Current time in hours (military format), minutes, and seconds. |
| day | Current day (by date) in the month. |
| month | Current month (by name). |
| year | Current year (no abbreviation). |
EXEC
Once you set the Cisco 7000 calendar or the Cisco 4500 calendar, the system clock will be automatically set when the system is restarted or when the clock read-calendar EXEC command is issued. The calendar maintains its accuracy, even after a power failure or system reboot has occurred. The time specified in this command is relative to the configured time zone.
In the following example, the system calendar is manually set to 1:32 p.m. on July 23, 1993:
calendar set 13:32:00 23 July 1993
clock read-calendar
clock set
clock summer-time
clock timezone
clock update-calendar
To enable Cisco Discovery Protocol (CDP) on an interface, use the cdp enable interface configuration command. Use the no form of this command to disable CDP on an interface.
cdp enableThis command has no arguments or keywords.
Enabled at the global level and on all supported interfaces.
Interface configuration
CDP is enabled by default at the global level and on each interface in order to send or receive CDP information.
In the following example, CDP is enabled on Ethernet interface 0:
interface ethernet 0 cdp enable
To specify the amount of time the receiving device should hold a CDP packet from your router before discarding it, use the cdp holdtime global configuration command. Use the no form of this command to revert to the default setting.
cdp holdtime seconds| seconds | Specifies the hold time to be sent in the CDP update packets. |
180 seconds
Global configuration
CDP packets are sent with time-to-live, or hold time, that is nonzero after an interface is enabled and a hold time of 0 immediately before an interface is idled down.
The CDP hold time must be set to a higher number of seconds than the time between CDP transmissions, which is set using the cdp timer command.
In the following example, the CDP packets being sent from your router should be held by the receiving device for 60 seconds before being discarded. You might want to set the hold time lower than the default setting of 180 seconds if information about your router changes often and you want the receiving devices to purge this information more quickly.
cdp holdtime 60
To enable CDP, use the cdp run global configuration command. Use the no form of this command to disable CDP.
cdp runThis command has no arguments or keywords.
Enabled
Global configuration
CDP is enabled on your router by default, which means the Cisco IOS software will receive CDP information. CDP also is enabled on supported interfaces by default. To disable CDP on an interface, use the cdp enable interface configuration command.
In the following example, CDP is disabled:
no cdp run
To specify how often the Cisco IOS software sends CDP updates, use the cdp timer global configuration command. Use the no form of this command to revert to the default setting.
cdp timer seconds| seconds | Specifies how often the Cisco IOS software sends CDP updates. |
60 seconds
Global configuration
The trade-off with sending more frequent transmissions is providing up-to-date information versus using bandwidth more often.
In the following example, CDP updates are sent every 80 seconds, less frequently than the default setting of 60 seconds. You might want to make this change if you are concerned about preserving bandwidth.
cdp timer 80
To manually clear a temporary access list entry from a dynamic access list, use the clear access-template EXEC command.
clear access-template [access-list-number] [dynamic-name] [source] [destination]| access-list-number | (Optional) Number of the dynamic access list from which the entry is to be deleted. |
| dynamic-name | (Optional) Name of the dynamic access list from which the entry is to be deleted. |
| source | (Optional) Source address in a temporary access list entry to be deleted. |
| destination | (Optional) Destination address in a temporary access list entry to be deleted. |
EXEC
This command is related to the lock-and-key access feature. It clears any temporary access list entries that match the parameters you define.
The following example clears any temporary access list entries with a source of 133.20.1.12 from the dynamic access list named vendor:
clear access-template vendor 133.20.1.12
A dagger (+) indicates that the command is documented outside this chapter.
access-list (extended) +
access-template
To reset CDP traffic counters to zero (0), use the clear cdp counters privileged EXEC command.
clear cdp countersThis command has no arguments or keywords.
Privileged EXEC
In the following example, the CDP counters have been cleared. The show cdp traffic output shows that all of the traffic counters have been reset to zero (0).
Router#clear cdp countersRouter#show cdp trafficCDP counters: Packets output: 0, Input: 0 Hdr syntax: 0, Chksum error: 0, Encaps failed: 0 No memory: 0, Invalid packet: 0, Fragmented: 0
clear cdp table
show cdp traffic
To clear the table that contains CDP information about neighbors, use the clear cdp table privileged EXEC command.
clear cdp tableThis command has no arguments or keywords.
Privileged EXEC
In the following example, the CDP table is cleared. The output of the show cdp neighbors command shows that all information has been deleted from the table.
Router#clear cdp tableCDP-AD: Deleted table entry for neon.cisco.com, interface Ethernet0 CDP-AD: Deleted table entry for neon.cisco.com, interface Serial0 Router#show cdp neighborsCapability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge S - Switch, H - Host, I - IGMP Device ID Local Intrfce Holdtme Capability Platform Port ID
clear cdp counters
show cdp neighbors
Use the clear kerberos creds command to delete the contents of your credentials cache.
clear kerberos credsThis command has no keywords or arguments.
EXEC
Creds are cleared when the user logs out.
Cisco supports Kerberos version 5.0
The following example illustrates the clear kerberos creds command:
cisco-2500>show kerberos credsDefault Principal: Valid Starting Expires Service Principal 18-Dec-1995 16:21:07 19-Dec-1995 00:22:24 krbtgt/CISCO.COM@CISCO.COM cisco-2500>clear kerberos credscisco-2500>show kerberos credsNo Kerberos credentials. cisco-2500>
show kerberos creds
To configure the Cisco 7000 series or the Cisco 4500 as a time source for a network based on its calendar, use the clock calendar-valid global configuration command. Use the no form of this command to set the Cisco IOS software so that the calendar is not an authoritative time source.
clock calendar-validThis command has no arguments or keywords.
Neither the Cisco 7000 nor the Cisco 4500 are not configured as a time source.
Global configuration
Use this command if no outside time source is available.
In the following example, the Cisco 7000 is configured as the time source for a network based on its calendar:
clock calendar-valid
A dagger (+) indicates that the command is documented outside this chapter.
ntp master
vines time use-system +
To manually read the calendar into either the Cisco 7000 or the Cisco 4500 system clock, use the clock read-calendar EXEC command.
clock read-calendarThis command has no arguments or keywords.
EXEC
When either the Cisco 7000 series or the Cisco 4500 calendar is rebooted, the calendar is automatically read into the system clock. However, you may use this command to manually read the calendar setting into the system clock. This command is useful if the calendar set command has been used to change the setting of the calendar.
In the following example, the system clock is configured to set its date and time by the calendar setting:
clock read-calendar
calendar set
clock set
clock update-calendar
ntp update-calendar
To manually set the system clock, use the clock set EXEC command.
clock set hh:mm:ss day month year| hh:mm:ss | Current time in hours (military format), minutes, and seconds. |
| day | Current day (by date) in the month. |
| month | Current month (by name). |
| year | Current year (no abbreviation). |
EXEC
Generally, if the system is synchronized by a valid outside timing mechanism, such as an NTP or VINES clock source, or if you have a Cisco 7000 with calendar capability, you do not need to set the system clock. Use this command if no other time sources are available. The time specified in this command is relative to the configured time zone.
In the following example, the system clock is manually set to 1:32 p.m. on July 23, 1993:
clock set 13:32:00 23 July 1993
calendar set
clock read-calendar
clock summer-time
clock timezone
To configure the system to automatically switch to summer time (daylight savings time), use one of the formats of the clock summer-time configuration command. Use the no form of this command to configure the Cisco IOS software not to automatically switch to summer time.
clock summer-time zone recurring [week day month hh:mm week day month hh:mm [offset]]| zone | Name of the time zone (PDT,...) to be displayed when summer time is in effect. |
| week | Week of the month (1 to 5 or last). |
| day | Day of the week (Sunday, Monday,...). |
| date | Date of the month (1 to 31). |
| month | Month (January, February,...). |
| year | Year (1993 to 2035). |
| hh:mm | Time (military format) in hours and minutes. |
| offset | (Optional) Number of minutes to add during summer time (default is 60). |
Summer time is disabled. If clock summer-time zone recurring is specified without parameters, the summer time rules default to United States rules. Default of offset is 60.
Global configuration
Use this command if you want to automatically switch to summer time (for display purposes only). Use the recurring form of the command if the local summer time rules are of this form. Use the date form to specify a start and end date for summer time if you cannot use the first form.
In both forms of the command, the first part of the command specifies when summer time begins, and the second part specifies when it ends. All times are relative to the local time zone. The start time is relative to standard time. The end time is relative to summer time. If the starting month is after the ending month, the system assumes that you are in the Southern Hemisphere.
In the following example, summer time starts on the first Sunday in April at 02:00 and ends on the last Sunday in October at 02:00:
clock summer-time PDT recurring 1 Sunday April 2:00 last Sunday October 2:00
If you live in a place where summer time does not follow the pattern in the first example, you could set it to start on October 12, 1993 at 02:00, and end on April 28, 1994 at 02:00, with the following example:
clock summer-time date 12 October 1993 2:00 28 April 1994 2:00
To set the time zone for display purposes, use the clock timezone global configuration command. To set the time to Coordinated Universal Time (UTC), use the no form of this command.
clock timezone zone hours [minutes]| zone | Name of the time zone to be displayed when standard time is in effect. |
| hours | Hours offset from UTC. |
| minutes | (Optional) Minutes offset from UTC. |
UTC
Global configuration
The system internally keeps time in UTC, so this command is used only for display purposes and when the time is manually set.
In the following example, the timezone is set to Pacific Standard Time and is offset 8 hours behind UTC:
clock timezone PST -8
calendar set
clock set
clock summer-time
show clock
To set the Cisco 7000 or Cisco 4500 calendar from the system clock, use the clock update-calendar EXEC command.
clock update-calendarThis command has no arguments or keywords.
EXEC
If the system clock and calendar are not synchronized, and the system clock is more accurate, use this command to update the Cisco 7000 series or Cisco 4500 calendar to the correct date and time.
In the following example, the current time is copied from the system clock to the Cisco 7000 calendar:
clock update-calendar
clock read-calendar
ntp update-calendar
To assign a custom queue list to an interface, use the custom-queue-list interface configuration command. To remove a specific list or all list assignments, use the no form of the command.
custom-queue-list list| list | Number of the custom queue list you want to assign to the interface. An integer from 1 to 16. |
No custom queue list is assigned.
Interface configuration
Only one queue list can be assigned per interface. Use this command in place of the priority-list command (not in addition to it). Custom queuing allows a fairness not provided with priority queuing. With custom queuing, you can control the interfaces' available bandwidth when it is unable to accommodate the aggregate traffic enqueued. Associated with each output queue is a configurable byte count, which specifies how many bytes of data should be delivered from the current queue by the system before the system moves on to the next queue. When a particular queue is being processed, packets are sent until the number of bytes sent exceeds the queue byte count or until the queue is empty.
Use the show queuing custom and show interface commands to display the current status of the custom output queues.
In the following example, custom queue list number 3 is assigned to serial interface 0:
interface serial 0 custom-queue-list 3
queue-list default
queue-list interface
queue-list protocol
queue-list queue byte-count
queue-list queue limit
To generate a configuration that is compatible with an earlier Cisco IOS release, use the downward-compatible-config global configuration command. To remove this feature, use the no form of this command.
downward-compatible-config version| version | Cisco IOS Release number, not earlier than 10.2. |
Disabled
Global configuration
In Cisco IOS Release 10.3, IP access lists changed format. Use this command to regenerate a configuration in a format prior to Release 10.3 if you are going to downgrade from a Release 10.3 or later to an earlier release. The earliest release this command accepts is 10.2.
When this command is configured, the router attempts to generate a configuration that is compatible with the specified version. Currently, this command affects only IP access lists.
Under some circumstances, the software might not be able to generate a fully backward-compatible configuration. In such a case, the software issues a warning message.
In the following example, the router attempts to generate a configuration file compatible with Cisco IOS Release 10.2:
downward-compatible-config 10.2
A dagger (+) indicates that the command is documented outside this chapter.
access-list (extended) +
access-list (standard) +
To log onto the router at a specified level, use the enable EXEC command.
enable [level]| level | (Optional) Privilege level to log in to on the router. |
Level 15
EXEC
The enable command is a privilege level 0 command. If you configure AAA authorization for a privilege level greater than 0, the enable command will not be included in the command set for the privilege level.
In the following example, the user is logging on to privilege level 5 on a router:
enable 5
A dagger (+) indicates that the command is documented outside this chapter.
privilege level (global)
privilege level (line)
disable +
To specify what happens if the TACACS and extended TACACS servers used by the enable command do not respond, use the enable last-resort global configuration command. The no form of this command restores the default.
enable last-resort {password | succeed}| password | Allows you to enable by entering the privileged command level password. |
| succeed | Allows you to enable without further question. |
Default action is to fail.
Global configuration
The secondary authentication is used only if the first attempt fails. The secondary authentication does not occur if the first authentication is only unsuccessful.
In the following example, if the TACACS servers do not respond to the enable command, the user can enable by entering the privileged level password:
enable last-resort password
A dagger (+) indicates that the command is documented outside this chapter.
enable +
Use the enable password global configuration command to set a local password to control access to various privilege levels. Use the no form of this command to remove the password requirement.
enable password [level level] {password | encryption-type encrypted-password} no enable password [level level]| level level | (Optional) level for which the password applies. You can specify up to 16 privilege levels, using numbers 0 through 15. Level 1 is normal EXEC mode user privileges. If this argument is not specified in the command or the no form of the command, the privilege level defaults to 15 (traditional enable privileges). |
| password | Password as users will type it when entering enable mode. If service password-encryption is set, the encrypted form of the password you create here is displayed when a show startup-config command is entered. |
| encryption-type | (Optional) Cisco-proprietary algorithm used to encrypt the password. Currently the only encryption type available is 7. If you specify encryption-type, the next argument you supply must be an encrypted password (a password already encrypted by a Cisco router). |
| encrypted-password | Encrypted password you enter, copied from another router configuration. |
No password is defined. The default is 15.
Global configuration
You will not ordinarily enter an encryption type. Typically you enter an encryption type only if you copy and paste back into this command a password that has already been encrypted by a Cisco router.
![]() | Caution If you specify an encryption type and then enter a clear-text password, you will not be able to re-enter enable mode. You cannot recover a lost password that has been encrypted by any method. |
Use this command with the level option to define a password for a specific privilege level. Once the level and the password are specified, give the password to the users you want to have access at this level. Use the privilege level (global) configuration command to specify commands accessible at various levels.
Enable or disable password encryption with the service password-encryption command.
An enable password is defined as follows:
When the system prompts you to enter the enable password, you need not precede the question mark with the Ctrl-V; you can simply enter abc?123 at the password prompt.
In the following example, the password pswd2 is enabled for privilege level 2:
enable password level 2 pswd2
In the following example the encrypted password Xyti5Rkls3LoyxzS8t9, which has been copied from a router configuration file, is set for privilege level 2 using encryption type 7:
enable password level 2 7 Xyti5Rkls3LoyxzS8t9
A dagger (+) indicates that the command is documented outside this chapter.
disable +
enable +
privilege level (global)
service password-encryption
show privilege
show startup-config +
enable secret
Use the enable secret global configuration command to specify an additional layer of security over the enable password command. Use the no form of the command to turn off the enable secret function.
enable secret [level level] {password | encryption-type encrypted-password} no enable secret [level level]| level level | (Optional) level for which the password applies. You can specify up to sixteen privilege levels, using numbers 0 through 15. Level 1 is normal EXEC-mode user privileges. If this argument is not specified, the privilege level defaults to 15 (traditional enable privileges). The same holds true for the no form of the command. |
| password | Password as users will type it when entering enable mode. This password should be different from the password created with the enable password command. If service password-encryption is set, the encrypted form of the password you create here is displayed when a show startup-config command is entered |
| encryption-type | (Optional) Cisco-proprietary algorithm used to encrypt the password. Current the only encryption type available for this command is 5 . If you specify encryption-type, the next argument you supply must be an encrypted password (a password encrypted by a Cisco router). |
| encrypted password | An encrypted password you enter, copied from another router configuration. |
No password is defined. The default is 15.
Global configuration
You will not ordinarily enter an encryption type. Typically you enter an encryption type only if you paste back into this command an encrypted password that you copied from a router configuration file.
![]() | Caution If you specify encryption-type and then enter a clear-text password, you will not be able to re-enter enable mode. You cannot recover a lost password that has been encrypted by any method. |
The enable secret command is used in conjunction with the enable password command to provide an additional layer of security over the enable password. This scheme provides better security by storing the enable secret using a non-reversible cryptographic function.
This added layer of security is useful in environments where the password crosses the network or is stored on a TFTP server.
If you use the same password for enable password and enable secret, you receive an error message warning that this practice is not recommended but the password will be accepted. By using the same password, however, you undermine the additional security the enable secret command provides.
The following example specifies the enable secret password of gobbledegook:
enable secret gobbledegook
After specifying an enable secret password, users must enter this password to gain access. Any passwords set through enable password will no longer work.
Password: gobbledegook
In the following example the encrypted password $1$FaD0$Xyti5Rkls3LoyxzS8t98j2, which has been copied from a router configuration file, is enabled for privilege level 2 using encryption type 5:
enable password level 2 5 $1$FaD0$Xyti5Rkls3LoyxzS8t98j2
A dagger (+) indicates that the command is documented outside this chapter.
enable +
enable password
To enable use of the TACACS to determine whether a user can access the privileged command level, use the enable use-tacacs global configuration command. Use the no form of this command to disable TACACS verification.
enable use-tacacs![]() | Caution If you use the enable use-tacacs command, you must also use the tacacs-server authenticate enable command, or else you will be locked out. |
This command has no arguments or keywords.
Disabled
Global configuration
When you add this command to the configuration file, the EXEC enable command prompts for a new username and password pair. This pair is then passed to the TACACS server for authentication. If you are using extended TACACS, it also will pass any existing UNIX user identification code to the server.
The following example sets TACACS verification on the privileged EXEC-level login sequence:
enable use-tacacs tacacs-server authenticate enable
tacacs-server authenticate enable
To enable weighted fair queueing for an interface and to set the congestion threshold after which messages for high-bandwidth conversations are dropped, use the fair-queue interface configuration command. To disable weighted fair queueing for an interface, use the no form of this command.
fair-queue congestive-discard-threshold-number| congestive-discard-threshold-number | Number of messages creating a congestion threshold after which new messages for high-bandwidth conversations are no longer enqueued. Valid values are 1 to 4096 inclusive. The congestive-discard threshold default is 64 messages. |
Fair queueing is enabled by default for physical interfaces whose bandwidth is less than or equal to 2.048 megabits per second (Mbps) and that do not use Link Access Procedure, Balanced (LAPB), X.25, PPP, or Synchronous Data Link Control (SDLC) encapsulations. (Fair queuing is not an option for these protocols.) However, if custom queueing or priority queueing is enabled for a qualifying link, it overrides fair queueing, effectively disabling it. Additionally, fair queuing is automatically disabled if you enable autonomous or SSE switching.
Fair queueing is disabled automatically on interfaces configured with the ppp multlilink command. If the no ppp multilink command is configured, you must enable fair queuing manually on the interface.
The congestive-discard threshold is 64 messages.
Interface configuration
When enabled for an interface, weighted fair queueing provides traffic priority management that automatically sorts among individual traffic streams without requiring that you first define access lists. Enabling weighted fair queueing requires use of this command only.
Weighted fair queuing can manage duplex data streams, such as those between pairs of applications, and simplex data streams such as voice or video. From the perspective of weighted fair queueing, there are two categories of sessions: high-bandwidth sessions and low-bandwidth sessions. Low-bandwidth traffic has effective priority over high-bandwidth traffic, and high-bandwidth traffic shares the transmission service proportionally according to assigned weights.
When weighted fair queuing is enabled for an interface, new messages for high-bandwidth traffic streams are discarded after the configured or default congestive-messages threshold has been met. However, low-bandwidth conversations, which include control-message conversations, continue to enqueue data. As a result, the fair queue may occasionally contain more messages than its configured threshold number specifies.
Weighted fair queuing uses a traffic data stream discrimination registry service to determine which traffic stream a message belongs to. For each forwarding protocol, Table 69 shows the attributes of a message that are used to classify traffic into data streams.
| Forwarder | Fields Used |
|---|---|
| AppleTalk |
|
|
CLNS |
|
|
DECnet |
|
|
Frame Relay switching |
|
|
DDN IP |
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Transparent bridging |
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Source-route bridging |
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VINES |
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Apollo |
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XNS |
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Novell NetWare |
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| All others (default) | Value of pak -> linktype |
It is important to note that IP precedence, congestion in Frame Relay switching, and discard eligibility flags affect the weights used for queuing.
IP precedence, which is set by the host, is a number in the range of 0 to 7. Data streams of precedence number are weighted so that they are given an effective bit rate of number+1 times as fast as a data stream of precedence 0, which is normal.
In Frame Relay switching, message flags for congestion (FECN and BECN) and discard eligible (DE) message flags cause the algorithm to select weights that effectively impose reduced queue priority, providing the application with "slow down" feedback and sorting traffic, giving the best service to applications within their Committed Information Rate.
Fair queueing is supported for all LAN and line (WAN) protocols except those that use LAPB, which are listed in "Default." Because tunnels are software interfaces that are themselves routed over physical interfaces, fair queueing is not supported for tunnels. If fair queueing is configured for an interface, the default of no fair-queue is applied for these links and tunnels on the interface and appears in the configuration script for them.
The following example enables use of weighted fair queuing on Serial 0, with a congestive discard threshold of 300. This means that messages will be discarded from the queuing system only when 300 or more messages have been queued and the message is in a data stream that has more than one message in the queue. The transmit queue limit is set to 1, based on the 384-kilobit (kb) line set by the bandwidth command:
interface serial 0 bandwidth 384 fair-queue 300
To specify or modify the host name for the network server, use the hostname global configuration command. The host name is used in prompts and default configuration filenames. The setup command facility also prompts for a host name at startup.
hostname name| name | New host name for the network server. |
The factory-assigned default host name is router.
Global configuration
The order of display at startup is banner message-of-the-day (MOTD), then login and password prompts, then EXEC banner.
Do not expect case to be preserved. Upper- and lowercase characters look the same to many internet software applications (often under the assumption that the application is doing you a favor). It may seem appropriate to capitalize a name the same way you might do in English, but conventions dictate that computer names appear all lowercase. For more information, refer to RFC 1178, Choosing a Name for Your Computer.
The name must also follow the rules for ARPANET host names. They must start with a letter, end with a letter or digit, and have as interior characters only letters, digits, and hyphens. Names must be 63 characters or fewer. For more information, refer to RFC 1035, Domain Names--Implementation and Specification.
The following example changes the host name to sandbox:
hostname sandbox
To access the BOOTP service available from hosts on the network, use the ip bootp server global configuration command. Use the no form of the command to disable these services.
ip bootp serverThis command has no arguments or keywords.
Enabled
Global configuration
By default, the BOOTP server is enabled.
When you disable the BOOTP server, access to the BOOTP ports cause the Cisco IOS software to send an "ICMP port unreachable" message to the sender and discard the original incoming packet.
The following example disables the BOOTP service on the router:
no ip bootp server
To enable identification support, use the ip identd global configuration command. Use the no form of this command to disable this feature.
ip identdThis command has no arguments or keywords.
Identification support is not enabled.
Global configuration
The ip identd command returns accurate information about the host TCP port; however, no attempt is made to protect against unauthorized queries.
In the following example, identification support is enabled:
ip identd
In the following example, ip identd is disabled:
ip identd off
Use the ip radius source-interface global configuration command to force RADIUS to use the IP address of a specified interface for all outgoing radius packets. This address is used as long as the interface is in the up/up state.
ip radius source-interface subinterface-name| subinterface-name | The name of the interface that Radius uses for all of its outgoing packets. |
This command has no factory-assigned default.
Global configuration
Use this command to set a subinterface's IP address to be used as the source address for all outgoing radius packets. In this way the radius server can use one Ip address entry associated with the NAS client instead of maintaining a list of all IP addresses on the NAS client.
This command is especially useful in cases where the router has many interfaces, and you want to ensure that all radius packets from a particular router have the same IP address.
The specified interface must have an Ip address associated with it. If the specified subinterface does not have an IP address or is in a down state, then radius reverts to the default. To avoid this, add an IP address to the subinterface or bring the interface to the up state.
The following example makes Radius use the IP address of s2 for all outgoing radius packets:
ip radius source-interface s2
ip tftp source-interface
ip telnet source-interface
ip tacacs source-interface
Use the ip tacacs source-interface global configuration command to force tacacs to use the IP address of a specified interface for all outgoing tacacs packets. This address is used as long as the interface is in the up/up state.
ip tacacs source-interface subinterface-name| subinterface-name | The name of the interface that TACACS uses for all of its outgoing packets. |
This command has no factory-assigned default.
Global configuration
Use this command to set a subinterface's IP address for all outgoing tacacs packets. In this way the tacacs server can use one IP address entry associated with the NAS client instead of maintaining a list of all IP addresses on the NAS client.
This command is especially useful in cases where the router has many interfaces and you want to ensure that all tacacs packets from a particular router have the same IP address.
The specified interface must have an IP address associated with it. If the specified subinterface does not have an IP address or is in a down state, then tacacs reverts to the default. To avoid this, add an IP address to the subinterface or bring the interface to the up state.
The following example makes TACACS use the IP address of s2 for all outgoing TACACS (TACACS, Extended TACACS, or TACACS Plus) packets:
ip tacacs source-interface s2
ip tftp source-interface
ip telnet source-interface
ip radius source-interface
Use the ip telnet source-interface global configuration command to allow a user to select an address of an interface as the source address for telnet connections.
ip telnet source-interface interface| interface | The interface whose address is to be used as the source for telnet connections. |
The address of the closest interface to the destination as the source address. If the selected interface is not "up," the Cisco IOS software selects the address of the closest interface to the destination as the source address.
Global configuration
Use this command to set an interface's IP address as the source for all telnet connections.
The following example makes the IP address for interface Ethernet 1 as the source address for telnet connections:
ip telnet source-interface e 1
ip tacacs source-interface
ip tftp source-interface
ip radus source-interface
Use the ip tftp source-interface global configuration command to allow a user to select the interface whose address will be used as the source address for TFTP connections.
ip tftp source-interface interface| interface | The interface whose address is to be used as the source for TFTP connections. |
The address of the closest interface to the destination as the source address. If the selected interface is not "up," the Cisco IOS software selects the address of the closest interface to the destination as the source address.
Global configuration
Use this command to set an interface's IP address as the source for all tftp connections.
The following example makes the IP address for interface Ethernet 1 as the source address for TFTP connections:
ip tftp source-interface e 1
ip radius source-interface
ip tacacs source-interface
ip telnet source-interface
Use the kerberos local-realm global configuration command to define the name of the Kerberos realm in which the router is located.
kerberos local-realm {kerberos-realm}Disabled
Global Configuration
The router can be located in more than one realm at a time. However, there can only be one instance of Kerberos local-realm. This is the default realm. Note that in Cisco IOS Release 11.1, you can only get tickets during user authentication, a process that defaults to the Kerberos local-realm.
The following example illustrates the kerberos local realm command:
kerberos local-realm MURUGA.COM
kerberos realm
kerberos server
Use the kerberos preauth global configuration command to specify a preauthentication method to use to communicate with the KDC. Use the no form of this command to disable Kerberos preauthentication.
kerberos preauth [encrypted-unix-timestamp | none]| encrypted-unix-timestamp | Use an encrypted UNIX timestamp as a quick authentication method when communicating with the KDC. |
| none | Do not use Kerberos preauthentication. |
Disabled
Global configuration
This command first appeared in Cisco IOS Release 11.2.
It is more secure to use a preauthentication for communications with the KDC. However, communication with the KDC will fail if the KDC does not support this particular version of kerberos preauth. If that happens, turn off the preauthentication with the none option.
The no form of this command is equivalent to using the none option.
The following example illustrates how to enable and disable Kerberos preauthentication:
kerberos preauth encrypted-unix-timestamp kerberos preauth none
kerberos local-realm
kerberos server
kerberos srvtab entry
kerberos srvtab remote
Use the kerberos realm global configuration command to to map a hostname or Domain Name System (DNS) domain to a Kerberos realm. The router can be located in more than one realm at a time. To disable this feature, use the no form of this command.
kerberos realm {dns-domain | host} {kerberos-realm}| dns-domain | The name of a DNS domain or host. A domain begins with a full-stop. |
| host | The name of a DNS host. A host name does not begin with a full-stop. |
| kerberos-realm | The name of the default Kerberos realm. A Kerberos realm consists of users, hosts, and network services that are registered to a Kerberos server. The Kerberos realm must be in uppercase letters. |
Disabled
Global configuration
In Cisco IOS Release 11.1, all hosts and DNS domains default to the default Kerberos realm.
The following example illustrates the kerberos realm command:
kerberos realm .muruga.com MURUGA.COM kerberos realm muruga.com MURUGA.COM
kerberos local-realm
kerberos server
Use the kerberos server global configuration command to specify the location of the Kerberos server for a given Kerberos realm.
kerberos server {kerberos-realm} {hostname | ip-address} [port-number]| kerberos-realm | The name of the default Kerberos realm. A Kerberos realm consists of users, hosts, and network services that are registered to a Kerberos server. The Kerberos realm must be in uppercase letters. |
| hostname | Name of the host functioning as a Kerberos server for the specified Kerberos realm. |
| ip-address | IP address of the host functioning as a Kerberos server for the specified Kerberos realm. |
| port-number | (Optional) Defines the port that the KDS is monitoring. |
Disabled
Global configuration
The following example illustrates the kerberos server command:
kerberos server MURUGA.COM 126.38.47.66
kerberos local-realm
kerberos realm
To change the length of time for which data is used to compute load statistics, use the load-interval interface configuration command. Use the no form of this command to revert to the default setting.
load-interval seconds| seconds | Length of time for which data is used to compute load statistics. A value that is a multiple of thirty, between 30 and 600 (30, 60, 90, 120, and so forth). |
300 seconds (or 5 minutes)
Interface configuration
If you want load computations to be more reactive to short bursts of traffic, rather than averaged over five-minute periods, you can shorten the length of time over which load averages are computed.
If the load interval is set to thirty seconds, new data is used for load calculations over a thirty-second period. This data is used to compute load statistics, including input rate in bits and packets per second, output rate in bits and packets per second, load, and reliability.
Load data is gathered every five seconds. This data is used for a weighted average calculation in which more-recent load data has more weight in the computation than older load data. If the load interval is set to thirty seconds, the average is computed for the last thirty seconds of load data.
The load-interval command allows you to change the default interval of five minutes to a shorter or longer period of time. If you change it to a shorter period of time, the input and output statistics that are displayed when you use the show interface command will be more current, and based on more instantaneous data, rather than reflecting a more average load over a longer period of time.
This command is often used for dial backup purposes, to increase or decrease the likelihood of a backup interface being implemented, but it can be used on any interface.
In the following example, the default five-minute average is set it to a thirty-second average. A burst in traffic that would not trigger a dial backup for an interface configured with the default five-minute interval might trigger a dial backup for this interface that is set for a shorter, thirty-second interval.
interface serial 0 load-interval 30
A dagger (+) indicates that the command is documented outside this chapter.
show interfaces +
To log messages to a syslog server host, use the logging global configuration command. The no form of this command deletes the syslog server with the specified address from the list of syslogs.
logging host| host | Name or IP address of the host to be used as a syslog server. |
No messages are logged to a syslog server host.
Global configuration
This command identifies a syslog server host to receive logging messages. By issuing this command more than once, you build a list of syslog servers that receive logging messages.
The following example logs messages to a host named johnson:
logging johnson
logging trap
service timestamps
To log messages to an internal buffer, use the logging buffered global configuration command. The no form of this command cancels the use of the buffer and writes messages to the console terminal, which is the default.
logging buffered [size]| size | (Optional) Size of the buffer from 4096 to 4294967295 bytes. The default is 4096 bytes (4K). |
The Cisco IOS software displays all messages to the console terminal.
Global configuration
This command copies logging messages to an internal buffer instead of writing them to the console terminal. The buffer is circular in nature, so newer messages overwrite older messages after the buffer is filled.
To display the messages that are logged in the buffer, use the EXEC command show logging. The first message displayed is the oldest message in the buffer.
Do not make the buffer size too large because the router could run out of memory for other tasks. You can use the show memory EXEC command to view the free processor memory on the router; however, this is the maximum available and should not be approached.
The following example illustrates how to enable logging to an internal buffer:
logging buffered
To limit messages logged to the console based on severity, use the logging console global configuration command. The no form of this command disables logging to the console terminal.
logging console level| level | Limits the logging of messages displayed on the console terminal to a specified level. See Table 70 for a list of the level keywords. |
debugging
Global configuration
Specifying a level causes messages at that level and numerically lower levels to be displayed at the console terminal.
The EXEC command show logging displays the addresses and levels associated with the current logging setup, as well as any other logging statistics.
| Level Name | Level | Description | Syslog Definition |
|---|---|---|---|
| emergencies | 0 | System unusable | LOG_EMERG |
| alerts | 1 | Immediate action needed | LOG_ALERT |
| critical | 2 | Critical conditions | LOG_CRIT |
| errors | 3 | Error conditions | LOG_ERR |
| warnings | 4 | Warning conditions | LOG_WARNING |
| notifications | 5 | Normal but significant condition | LOG_NOTICE |
| informational | 6 | Informational messages only | LOG_INFO |
| debugging | 7 | Debugging messages | LOG_DEBUG |
The effect of the log keyword with the IP access list (extended) command depends on the setting of the logging console command. The log keyword takes effect only if the logging console level is set to 6 or 7. If you change the default to a level lower than 6 and specify the log keyword with the IP access list (extended) command, no information is logged or displayed.
The following example changes the level of messages displayed to the console terminal to alerts, which means alerts and emergencies are displayed:
logging console alerts
Related Commands
A dagger (+) indicates that the command is documented outside this chapter.
logging facility
access-list (extended) +
To configure the syslog facility in which error messages are sent, use the logging facility global configuration command. To revert to the default of local7, use the no form of this command.
logging facility facility-type| facility-type | Syslog facility. See Table 71 for the facility-type keywords. |
local7
Global configuration
Table 71 describes the acceptable options for the facility-type keyword.
| Keyword | Description |
|---|---|
| auth | Authorization system |
| cron | Cron facility |
| daemon | System daemon |
| kern | Kernel |
| local0-7 | Reserved for locally defined messages |
| lpr | Line printer system |
| Mail system | |
| news | USENET news |
| sys9 | System use |
| sys10 | System use |
| sys11 | System use |
| sys12 | System use |
| sys13 | System use |
| sys14 | System use |
| syslog | System log |
| user | User process |
| uucp | UNIX-to-UNIX copy system |
The following example configures the syslog facility to kernel:
logging facility kern
To limit messages logged to the terminal lines (monitors) based on severity, use the logging monitor global configuration command. This command limits the logging messages displayed on terminal lines other than the console line to messages with a level at or above level. The no form of this command disables logging to terminal lines other than the console line.
logging monitor level| level | One of the level keywords listed in Table 70. |
debugging
Global configuration
Specifying a level causes messages at that level and numerically lower levels to be displayed to the monitor.
The following example specifies that only messages of the levels errors, critical, alerts, and emergencies be displayed on terminals:
logging monitor errors
A dagger (+) indicates that the command is documented in the Cisco Access Connection Guide.
terminal monitor +
To control logging of error messages, use the logging on global configuration command. This command enables or disables message logging to all destinations except the console terminal. The no form of this command enables logging to the console terminal only.
logging onThis command has no arguments or keywords.
The Cisco IOS software logs messages to the console terminal.
Global configuration
The following example shows how to direct error messages to the console terminal only:
no logging on
| level severity-level | (Optional) Specifies the message severity level. Messages with a severity level equal to or higher than this value are printed asynchronously. When specifying a severity level number, consider that for the logging system, low numbers indicate greater severity and high numbers indicate lesser severity. The default value is 2. |
| all | (Optional) Specifies that all messages are printed asynchronously, regardless of the severity level. |
| limit number-of-buffers | (Optional) Specifies the number of buffers to be queued for the terminal after which new messages are dropped. The default value is 20. |
This feature is turned off by default.
If you do not specify a severity level, the default value of 2 is assumed.
If you do not specify the maximum number of buffers to be queued, the default value of 20 is assumed.
Line configuration
When synchronous logging of unsolicited messages and debug output is turned on, unsolicited Cisco IOS software output is displayed on the console or printed after solicited Cisco IOS software output is displayed or printed. Unsolicited messages and debug output is displayed on the console after the prompt for user input is returned. This is to keep unsolicited messages and debug output from being interspersed with solicited software output and prompts. After the unsolicited messages are displayed, the console displays the user prompt again.
When specifying a severity level number, consider that for the logging system, low numbers indicate greater severity and high numbers indicate lesser severity.
When a terminal line's message-queue limit is reached, new messages are dropped from the line, although these messages might be displayed on other lines. If messages are dropped, the notice "%SYS-3-MSGLOST number-of-messages due to overflow" follows any messages that are displayed. This notice is displayed only on the terminal that lost the messages. It is not sent to any other lines, any logging servers, or the logging buffer.
![]() | Caution By configuring abnormally large message-queue limits and setting the terminal to "terminal monitor" on a terminal that is accessible to intruders, you expose yourself to "denial of service" attacks. An intruder could carry out the attack by putting the terminal in synchronous output mode, making a Telnet connection to a remote host, and leaving the connection idle. This could cause large numbers of messages to be generated and queued, and these messages would consume all available RAM. Although unlikely to occur, you should guard against this type of attack through proper configuration. |
The following example identifies line 4 and enables synchronous logging for line 4 with a severity level of 6. Then the example identifies another line, line 2, and enables synchronous logging for line 2 with a severity level of 7 and specifies a maximum number of buffers to be 70000:
line 4 logging synchronous level 6 line 2 logging synchronous level 7 limit 70000
A dagger (+) indicates that the command is documented outside this chapter.
line+
To limit messages logged to the syslog servers based on severity, use the logging trap global configuration command. The command limits the logging of error messages sent to syslog servers to only those messages at the specified level. Use the no form of this command to disable logging to syslog servers.
logging trap level| level | One of the level keywords listed in Table 70. |
Informational
Global configuration
The EXEC command show logging displays the addresses and levels associated with the current logging setup. The command output also includes ancillary statistics.
Table 70 lists the syslog definitions that correspond to the debugging message levels. Additionally, there are four categories of messages generated by the software, as follows:
Use the logging and logging trap commands to send messages to a UNIX syslog server.
The following example logs messages to a host named johnson:
logging johnson logging trap notifications
To enable TACACS+ authentication for logins, use the login authentication line configuration command. Use the no form of this command to return to the default.
login authentication {default | list-name}![]() | Caution If you use a list-name value that was not configured with the aaa authentication login command, you will disable login on this line. |
| default | Uses the default list created with the aaa authentication login command. |
| list-name | Uses the indicated list created with the aaa authentication login command. |
Uses the default set with aaa authentication login.
Line configuration
This command is a per-line command used with AAA that specifies the name of a list of TACACS+ authentication methods to try at login. If no list is specified, the default list is used (whether or not it is specified in the command line). You create defaults and lists with the aaa authentication login command. Entering the no version of login authentication has the same effect as entering the command with the default argument.
Before issuing this command, create a list of authentication processes by using the global configuration aaa authentication login command.
The following example specifies that the default AAA authentication is to be used on line 4:
line 4 login authentication default
The following example specifies that the AAA authentication list called list1 is to be used on line 7:
line 7 login authentication list1
To configure your router to use TACACS user authentication, use the login tacacs line configuration command. Use the no form of this command to disable TACACS user authentication for a line.
login tacacsThis command has no arguments or keywords.
Disabled
Line configuration
You can use TACACS security if you have configured a TACACS server and you have a CCL script that allows you to use TACACS security. For information about using files provided by Cisco to modify CCL scripts to support TACACS user authentication, refer to the "Configuring AppleTalk Remote Access" chapter in the Access Services Configuration Guide.
In the following example, lines 1 through 16 are configured for TACACS user authentication:
line 1 16 login tacacs
To enable TACACS+ authentication for NetWare Asynchronous Services Interface (NASI) clients connecting to a router, use the nasi authentication line configuration command. To return to the default, as specified by the aaa authentication nasi command, use the no form of the command.
nasi authentication {default | list-name}| default | Uses the default list created with the aaa authentication nasi command. |
| list-name | Uses the list created with the aaa authentication nasi command. |
Uses the default set with the aaa authentication nasi command.
Line configuration
This command is a per-line command used with AAA that specifies the name of a list of TACACS+ authentication methods to try at login. If no list is specified, the default list is used, even if it is specified in the command line. (You create defaults and lists with the aaa authentication nasi command.) Entering the no form of this command has the same effect as entering the command with the default argument.
![]() | Caution If you use a list-name value that was not configured with the aaa authentication nasi command, you will disable login on this line. |
Before issuing this command, create a list of authentication processes by using the global configuration aaa authentication nasi command.
The following example specifies that the default AAA authentication is to be used on line 4:
line 4 nasi authentication default
The following example specifies that the AAA authentication list called list1 is to be used on line 7:
line 7 nasi authentication list1
A dagger (+) indicates that the command is documented outside this chapter.
aaa authentication nasi
ipx nasi-server enable +
show ipx nasi connections +
show ipx spx-protocol +
To control access to the system's Network Time Protocol (NTP) services, use the ntp access-group global configuration command. To remove access control to the system's NTP services, use the no form of this command.
ntp access-group {query-only | serve-only | serve | peer} access-list-number| query-only | Allows only NTP control queries. See RFC 1305 (NTP version 3). |
| serve-only | Allows only time requests. |
| serve | Allows time requests and NTP control queries, but does not allow the system to synchronize to the remote system. |
| peer | Allows time requests and NTP control queries and allows the system to synchronize to the remote system. |
| access-list-number | Number (1 to 99) of a standard IP access list. |
No access control (full access granted to all systems)
Global configuration
The access group options are scanned in the following order from least restrictive to most restrictive:
Access is granted for the first match that is found. If no access groups are specified, all access is granted to all sources. If any access groups are specified, only the specified access is granted. This facility provides minimal security for the time services of the system. However, it can be circumvented by a determined programmer. If tighter security is desired, use the NTP authentication facility.
In the following example, the system is configured to allow itself to be synchronized by a peer from access list 99. However, the system restricts access to allow only time requests from access list 42.
ntp access-group peer 99 ntp access-group serve-only 42
A dagger (+) indicates that the command is documented outside this chapter.
access-list +
To enable Network Time Protocol (NTP) authentication, use the ntp authenticate global configuration command. Use the no form of this command to disable the feature.
ntp authenticateThis command has no keywords or arguments.
No authentication
Global configuration
Use this command if you want authentication. If this command is specified, the system will not synchronize to a system unless it carries one of the authentication keys specified in the ntp trusted-key command.
The following example enables NTP authentication:
ntp authenticate
ntp authentication-key
ntp trusted-key
To define an authentication key for Network Time Protocol (NTP), use the ntp authentication-key global configuration command. Use the no form of this command to remove the authentication key for NTP.
ntp authentication-key number md5 value| number | Key number (1 to 4294967295). |
| md5 | Authentication key. Message authentication support is provided using the Message Digest (MD5) algorithm. The key type md5 is currently the only key type supported. |
| value | Key value (an arbitrary string of up to eight characters). |
No authentication key is defined for NTP.
Global configuration
Use this command to define authentication keys for use with other NTP commands in order to provide a higher degree of security.
The following example sets authentication key 10 to aNiceKey:
ntp authentication-key 10 md5 aNiceKey
ntp authenticate
ntp peer
ntp server
ntp trusted-key
To specify that a specific interface should send Network Time Protocol (NTP) broadcast packets, use the ntp broadcast interface configuration command. Use the no form of this command to disable this capability.
ntp broadcast [version number]| version number | (Optional) Number from 1 to 3 indicating the NTP version. |
Disabled
Interface configuration
In the following example, Ethernet interface 0 is configured to send NTP version 2 packets:
interface ethernet 0 ntp broadcast version 2
ntp broadcast client
ntp broadcastdelay
To allow the system to receive NTP broadcast packets on an interface, use the ntp broadcast client command. Use the no form of this command to disable this capability.
ntp broadcast clientThis command has no arguments or keywords.
Disabled
Interface configuration
Use this command to allow the system to listen to broadcast packets on an interface-by-interface basis.
In the following example, the Cisco IOS software synchronizes to NTP packets broadcasted on Ethernet
interface 1:
interface ethernet 1ntp broadcast client
ntp broadcast
ntp broadcastdelay
To set the estimated round-trip delay between the Cisco IOS software and a Network Time Protocol (NTP) broadcast server, use the ntp broadcastdelay global configuration command. Use the no form of this command to revert to the default value.
ntp broadcastdelay microseconds| microseconds | Estimated round-trip time (in microseconds) for NTP broadcasts. The range is from 1 to 999999. |
3000 microseconds
Global configuration
Use this command when the router is configured as a broadcast client and the round-trip delay on the network is other than 3000 microseconds.
In the following example, the estimated round-trip delay between a router and the broadcast client is set to 5000 microseconds:
ntp broadcastdelay 5000
ntp broadcast
ntp broadcast client
![]() | Caution Do not enter this command; it is documented for informational purposes only. The system automatically generates this command as Network Time Protocol (NTP) determines the clock error and compensates. |
As NTP compensates for the error in the system clock, it keeps track of the correction factor for this error. The system automatically saves this value into the system configuration using the ntp clock-period global configuration command. The system uses the no form of this command to revert to the default.
ntp clock-period value| value | Amount to add to the system clock for each clock hardware tick (in units of 2-32 seconds). |
17179869 (4 milliseconds)
Global configuration
If a copy running-config startup-config command is entered to save the configuration to NVRAM, this command will automatically be added to the configuration. It is a good idea to perform this task after NTP has been running for a week or so; this will help NTP synchronize more quickly if the system is restarted.
To prevent an interface from receiving Network Time Protocol (NTP) packets, use the ntp disable interface configuration command. To enable receipt of NTP packets on an interface, use the no form of this command.
ntp disableThis command has no arguments or keywords.
Enabled
Interface configuration
This command provides a simple method of access control.
In the following example, Ethernet interface 0 is prevented from receiving NTP packets:
interface ethernet 0 ntp disable
To configure the Cisco IOS software as a Network Time Protocol (NTP) master clock to which peers synchronize themselves when an external NTP source is not available, use the ntp master global configuration command. To disable the master clock function, use the no form of this command.
ntp master [stratum]![]() | Caution Use this command with extreme caution. It is very easy to override valid time sources using this command, especially if a low stratum number is configured. Configuring multiple machines in the same network with the ntp master command can cause instability in timekeeping if the machines do not agree on the time. |
| stratum | (Optional) Number from 1 to 15. Indicates the NTP stratum number that the system will claim. |
By default, the master clock function is disabled. When enabled, the default stratum is 8.
Global configuration
Because Cisco's implementation of NTP does not support directly attached radio or atomic clocks, the router is normally synchronized, directly or indirectly, to an external system that has such a clock. In a network without Internet connectivity, such a time source may not be available. The ntp master command is used in such cases.
If the system has ntp master configured, and it cannot reach any clock with a lower stratum number, the system will claim to be synchronized at the configured stratum number, and other systems will be willing to synchronize to it via NTP.
In the following example, a router is configured as an NTP master clock to which peers may synchronize:
ntp master 10
To configure the system clock to synchronize a peer or to be synchronized by a peer, use the
ntp peer global configuration command. To disable this capability, use the no form of this command.
| ip-address | IP address of the peer providing, or being provided, the clock synchronization. |
| version | (Optional) Defines the Network Time Protocol (NTP) version number. |
| number | (Optional) NTP version number (1 to 3). |
| key | (Optional) Defines the authentication key. |
| keyid | (Optional) Authentication key to use when sending packets to this peer. |
| source | (Optional) Names the interface. |
| interface | (Optional) Name of the interface from which to pick the IP source address. |
| prefer | (Optional) Makes this peer the preferred peer that provides synchronization. |
No peers are configured by default. If a peer is configured, the default NTP version number is 3, no authentication key is used, and the source IP address is taken from the outgoing interface.
Global configuration
Use this command if you want to allow this machine to synchronize with the peer, or vice versa. Using the prefer keyword reduces switching back and forth between peers.
If you are using the default version of 3 and NTP synchronization does not occur, try using NTP version number 2. Many NTP servers on the Internet run version 2.
In the following example, a router is configured to allow its system clock to be synchronized with the clock of the peer (or vice versa) at IP address 131.108.22.33 using NTP version 2. The source IP address is the address of Ethernet 0.
ntp peer 131.108.22.33 version 2 source ethernet 0
ntp authentication-key
ntp server
ntp source
To allow the system clock to be synchronized by a time server, use the ntp server global configuration command. To disable this capability, use the no form of this command.
ntp server ip-address [version number] [key keyid] [source interface] [prefer]| ip-address | IP address of the time server providing the clock synchronization. |
| version | (Optional) Defines the Network Time Protocol (NTP) version number. |
| number | (Optional) NTP version number (1 to 3). |
| key | (Optional) Defines the authentication key. |
| keyid | (Optional) Authentication key to use when sending packets to this peer. |
| source | (Optional) Identifies the interface from which to pick the IP source address. |
| interface | (Optional) Name of the interface from which to pick the IP source address. |
| prefer | (Optional) Makes this server the preferred server that provides synchronization. |
No peers are configured by default. If a peer is configured, the default NTP version number is 3, no authentication key is used, and the source IP address is taken from the outgoing interface.
Global configuration
Use this command if you want to allow this machine to synchronize with the specified server. The server will not synchronize to this machine.
Using the prefer keyword reduces switching back and forth between servers.
If you are using the default version of 3 and NTP synchronization does not occur, try using NTP version number 2. Many NTP servers on the Internet run version 2.
In the following example, a router is configured to allow its system clock to be synchronized with the clock of the peer at IP address 128.108.22.44 using NTP version 2:
ntp server 128.108.22.44 version 2
ntp authentication-key
ntp peer
ntp source
To use a particular source address in Network Time Protocol (NTP) packets, use the ntp source global configuration command. Use the no form of this command to remove the specified source address.
ntp source interface| interface | Any valid system interface name. |
Source address is determined by the outgoing interface.
Global configuration
Use this command when you want to use a particular source IP address for all NTP packets. The address is taken from the named interface. This command is useful if the address on an interface cannot be used as the destination for reply packets. If the source keyword is present on an ntp server or ntp peer command, that value overrides the global value.
In the following example, a router is configured to use the IP address of Ethernet 0 as the source address of all outgoing NTP packets:
ntp source ethernet 0
If you want to authenticate the identity of a system to which Network Time Protocol (NTP) will synchronize, use the ntp trusted-key global configuration command. Use the no form of this command to disable authentication of the identity of the system.
ntp trusted-key key-number| key-number | Key number of authentication key to be trusted. |
Disabled
Global configuration
If authentication is enabled, use this command to define one or more key numbers (corresponding to the keys defined with thentp authentication-key command) that a peer NTP system must provide in its NTP packets, in order for this system to synchronize to it. This provides protection against accidentally synchronizing the system to a system that is not trusted, since the other system must know the correct authentication key.
In the following example, the system is configured to synchronize only to systems providing authentication key 42 in its NTP packets:
ntp authenticate ntp authentication-key 42 md5 aNiceKey ntp trusted-key 42
ntp authenticate
ntp authentication-key
To periodically update the Cisco 7000 calendar from Network Time Protocol (NTP), use the ntp update-calendar global configuration command. Use the no form of this command to disable this feature.
ntp update-calendarThis command has no arguments or keywords.
The Cisco 7000 calendar is not updated.
Global configuration
If a Cisco 7000 is synchronized to an outside time source via NTP, it is a good idea to periodically update the calendar with the time learned from NTP. Otherwise, the calendar will tend to gradually lose or gain time. The calendar will be updated only if NTP has synchronized to an authoritative time server.
In the following example, the system is configured to periodically update the calendar from the system clock:
ntp update-calendar
clock read-calendar
clock update-calendar
Use the ping (packet internet groper) privileged EXEC command to diagnose basic network connectivity on Apollo, AppleTalk, Connectionless Network Service (CLNS), DECnet, IP, Novell IPX, VINES, or XNS networks.
ping [protocol] {host | address}| protocol | (Optional) Protocol keyword, one of apollo, appletalk, clns, decnet, ip, ipx, vines, or xns. |
| host | Host name of system to ping. |
| address | Address of system to ping. |
Privileged EXEC
The ping program sends an echo request packet to an address, then awaits a reply. Ping output can help you evaluate path-to-host reliability, delays over the path, and whether the host can be reached or is functioning.
To abnormally terminate a ping session, type the escape sequence--by default, Ctrl-^ X. You type the default by simultaneously pressing and releasing the Ctrl, Shift, and 6 keys, and then pressing the X key.
Table 72 describes the test characters that the ping facility sends.
| Char | Meaning |
|---|---|
| ! | Each exclamation point indicates receipt of a reply. |
| . | Each period indicates the network server timed out while waiting for a reply. |
| U | A destination unreachable error PDU was received. |
| C | A congestion experienced packet was received. |
| I | User interrupted test. |
| ? | Unknown packet type. |
| & | Packet lifetime exceeded. |
After you enter the ping command in privileged mode, the system prompts for one of the following keywords: appletalk, clns, ip, novell, apollo, vines, decnet, or xns. The default protocol is IP.
If you enter a host name or address on the same line as the ping command, the default action is taken as appropriate for the protocol type of that name or address.
While the precise dialog varies somewhat from protocol to protocol, all are similar to the ping session using default values shown in the following display.
Router#pingProtocol [ip]: Target IP address:192.31.7.27Repeat count [5]: Datagram size [100]: Timeout in seconds [2]: Extended commands [n]: Sweep range of sizes [n]: Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 192.31.7.27, timeout is 2 seconds: !!!!! Success rate is 100 percent, round-trip min/avg/max = 1/2/4 ms
Table 73 describes the default ping fields shown in the display.
Use the ping (packet internet groper) user EXEC command to diagnose basic network connectivity on AppleTalk, CLNS, IP, Novell, Apollo, VINES, DECnet, or XNS networks.
ping [protocol] {host | address}| protocol | (Optional) Protocol keyword, one of apollo, appletalk, clns, decnet, ip, ipx, vines, or xns. |
| host | Host name of system to ping. |
| address | Address of system to ping. |
EXEC
The user-level ping feature provides a basic ping facility for users who do not have system privileges. This feature allows the Cisco IOS software to perform the simple default ping functionality for a number of protocols. Only the nonverbose form of the ping command is supported for user-level pings.
If the system cannot map an address for a host name, it returns an "%Unrecognized host or address" error message.
To abnormally terminate a ping session, type the escape sequence--by default, Ctrl-^ X. You type the default by simultaneously pressing and releasing the Ctrl, Shift, and 6 keys and then pressing the X key.
Table 74 describes the test characters that the ping facility sends.
| Char | Meaning |
|---|---|
| ! | Each exclamation point indicates receipt of a reply. |
| . | Each period indicates the network server timed out while waiting for a reply. |
| U | A destination unreachable error PDU was received. |
| C | A congestion experienced packet was received. |
| I | User interrupted test. |
| ? | Unknown packet type. |
| & | Packet lifetime exceeded. |
The following display shows sample ping output when you ping the IP host named donald:
Router> ping donald
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.31.7.27, timeout is 2 seconds:
!!!!!
Success rate is 100 percent, round-trip min/avg/max = 1/3/4 ms
To enable Challenge Handshake Authentication Protocol (CHAP) or Password Authentication Protocol (PAP) and to enable an AAA authentication method on an interface, use the ppp authentication interface configuration command. Use the no form of this command to disable this authentication.
ppp authentication {chap | pap} [if-needed] [list-name]![]() | Caution If you use a list-name value that was not configured with the aaa authentication ppp command, you will disable PPP on this interface. |
| chap | Enables CHAP on a serial interface. |
| pap | Enables PAP on a serial interface. |
| if-needed | (Optional) Used with TACACS and extended TACACS. Does not perform CHAP or PAP authentication if the user has already provided authentication. This option is available only on asynchronous interfaces. |
| list-name | (Optional) Used with AAA/TACACS+. Specifies the name of a list of AAA methods of authentication to use. If no listname is specified, the system uses the default. Lists and default are created with the aaa authentication ppp command. |
PPP authentication is not enabled.
Interface configuration
Once you have enabled CHAP or PAP, the local router requires a password from remote devices. If the remote device does not support CHAP or PAP, no traffic is passed to that device.
If you are using autoselect on a TTY line, you will probably want to use the ppp authentication command to turn on PPP authentication for the corresponding interface.
If you specify the if-needed option, PPP authentication is not required when the user has already provided authentication. This option is useful if you are using the autoselect command, but it cannot be used with AAA/TACACS+.
The list-name argument can be used only when AAA/TACACS+ is initialized and cannot be used with the if-needed argument.
The following example enables CHAP on asynchronous interface 4, and uses the authentication list MIS-access:
interface async 4 encapsulation ppp ppp authentication chap MIS-access
A dagger (+) indicates that the command is documented outside this chapter.
aaa authentication password-prompt
aaa new-model
autoselect +
encapsulation ppp +
ppp use-tacacs
username
Use the ppp chap password interface configuration command to enable a router calling a collection of routers that do not support this command (such as routers running older Cisco IOS software images) to configure a common CHAP secret password to use in response to challenges from an unknown peer. To disable this function, use the no form of this command.
ppp chap password secret| secret | The secret used to compute the response value for any CHAP challenge from an unknown peer. |
Disabled.
Interface configuration.
This command first appeared in Cisco IOS Release 11.2.
This command allows you to replace several username and password configuration commands with a single copy of this command on any dialer interface or asynchronous group interface.
This command is used for remote CHAP authentication only (when routers authenticate to the peer) and does not affect local CHAP authentication.
The commands in the following example specify Integrated Services Digital Network (ISDN) Basic Rate Interface (BRI) number 0. The method of encapsulation on the interface is PPP. If a CHAP challenge is received from a peer whose name is not found in the global list of usernames, the encrypted secret 7 1267234591 is decrypted and used to create a CHAP response value.
interface bri 0 encapsulation ppp ppp chap password 7 1234567891
aaa authentication ppp
ppp authentication
ppp chap hostname
ppp pap
To enable TACACS for PPP authentication, use the ppp use-tacacs interface configuration command. Use the no form of the command to disable TACACS for PPP authentication.
ppp use-tacacs [single-line]| single-line | (Optional) Accept the username and password in the username field. This option applies only when using CHAP authentication. |
TACACS is not used for PPP authentication.
Interface configuration
This is a per-interface command. Use this command only when you have set up an extended TACACS server. This command requires the new extended TACACS server.
When CHAP authentication is being used, the ppp use-tacacs command with the single-line option specifies that if a username and password are specified in the username, separated by an asterisk (*), then a standard tacacs login query is performed using that username and password. If the username does not contain an asterisk, then normal CHAP authentication is performed using TACACS.
This feature is useful when integrating TACACS with other authentication systems that require a clear-text version of the user's password. Such systems include one-time password systems, token card systems, Kerberos, and others.
![]() | Caution Normal CHAP authentications prevent the clear-text password from being transmitted over the link. When you use the single-line option, passwords will cross the link in the clear. |
If the username and password are contained in the CHAP password, the CHAP secret is not used by the Cisco system. Because most PPP clients will require that a secret be specified, you can use any arbitrary string; the Cisco system will ignore it.
In the following example, asynchronous serial interface 1 is configured to use TACACS for CHAP authentication.
interface async 1 ppp authentication chap ppp use-tacacs
In the following example, asynchronous serial interface 1 is configured to use TACACS for PAP authentication.
interface async 1 ppp authentication pap ppp use-tacacs
ppp authentication
tacacs-server extended
tacacs-server host
To assign the specified priority list to an interface, use the priority-group interface configuration command. Use the no form of this command to remove the specified priority group assignment.
priority-group list| list | Priority list number assigned to the interface. An integer from 1 to 16. |
None
Interface configuration
Only one list can be assigned per interface. Priority output queueing provides a mechanism to prioritize packets transmitted on an interface.
Use the show queuing priority and show interface commands to display the current status of the output queues.
The following example causes packets on interface serial 0 to be classified by priority list 1:
interface serial 0 priority-group 1
priority-list default
priority-list interface
priority-list queue-limit
prompt
To assign a priority queue for those packets that do not match any other rule in the priority list, use the priority-list default global configuration command. Use the no form of this command to return to the default or assign normal as the default.
priority-list list-number default {high | medium | normal | low}| list-number | Arbitrary integer between 1 and 16 that identifies the priority list selected by the user. |
| high | medium | normal | low | Priority queue level. |
The normal queue, if you use the no form of the command.
Global configuration
When using multiple rules, remember that the system reads the priority settings in order of appearance. When classifying a packet, the system searches the list of rules specified by priority-list commands for a matching protocol or interface type. When a match is found, the packet is assigned to the appropriate queue. The list is searched in the order it is specified, and the first matching rule terminates the search.
The following example sets the priority queue for those packets that do not match any other rule in the priority list to a low priority:
priority-list 1 default low
To establish queuing priorities on packets entering from a given interface, use the priority-list interface global configuration command. Use the no form of this command with the appropriate arguments to remove an entry from the list.
priority-list list-number interface interface-type interface-number {high | medium || list-number | Arbitrary integer between 1 and 16 that identifies the priority list selected by the user. |
| interface-type | Specifies the name of the interface. |
| interface-number | Number of the specified interface. |
| high | medium | normal | low | Priority queue level. |
No queuing priorities are established.
Global configuration
When using multiple rules, remember that the system reads the priority settings in order of appearance. When classifying a packet, the system searches the list of rules specified by priority-list commands for a matching protocol or interface type. When a match is found, the packet is assigned to the appropriate queue. The list is searched in the order it is specified, and the first matching rule terminates the search.
The following example sets any packet type entering on Ethernet interface 0 to a medium priority:
priority-list 3 interface ethernet 0 medium
To establish queuing priorities based upon the protocol type, use the priority-list protocol global configuration command. Use the no form of this command with the appropriate list number to remove an entry from the list.
priority-list list -number protocol protocol-name {high | medium | normal | low}| list-number | Arbitrary integer between 1 and 16 that identifies the priority list selected by the user. |
| protocol-name | Specifies the protocol type: aarp, arp, apollo, appletalk, bridge (transparent), clns, clns_es, clns_is, compressedtcp, cmns, decnet, decnet_node, decnet_router-l1, decnet_router-l2, ip, ipx, pad, rsrb, stun, vines, xns, and x25. |
| high | medium | normal | low | Priority queue level. |
| queue-keyword keyword-value | Possible keywords are fragments, gt, lt, list, tcp, and udp. See Table 75. |
No queuing priorities are established.
Global configuration
When using multiple rules for a single protocol, remember that the system reads the priority settings in order of appearance. When classifying a packet, the system searches the list of rules specified by priority-list commands for a matching protocol type. When a match is found, the packet is assigned to the appropriate queue. The list is searched in the order it is specified, and the first matching rule terminates the search.
The decnet_router-l1 keyword refers to the multicast address for all level-1 routers, which are intra-area routers, and the decnet_router-l2 keyword refers to all level 2 routers, which are interarea routers.
Use Table 75, Table 76, and Table 77 to configure the queuing priorities for your system.
| Option | Description |
|---|---|
| fragments | Assigns the priority level defined to fragmented IP packets (for use with IP protocol only). More specifically, IP packets whose fragment offset field is nonzero are matched by this command. The initial fragment of a fragmented IP packet has a fragment offset of zero, so such packets are not matched by this command.
Note: Packets with a nonzero fragment offset do not contain TCP or UDP headers, so other instances of this command that use the tcp or udp keyword will always fail to match such packets. |
| gt byte-count | Specifies a greater-than count. The priority level assigned goes into effect when a packet exceeds the value entered for the argument byte-count. The size of the packet must also include additional bytes due to MAC encapsulation on the outgoing interface. |
| lt byte-count | Specifies a less-than count. The priority level assigned goes into effect when a packet size is less than the value entered for byte-count. The size of the packet must also include additional bytes due to MAC encapsulation on the outgoing interface. |
| list list-number | Assigns traffic priorities according to a specified list when used with Appletalk, bridging, IP, IPX, VINES, or XNS. The list-number argument is the access list number as specified by the access-list global configuration command for the specified protocol-name. For example, if the protocol is AppleTalk, list-number should be a valid AppleTalk access list number. |
| tcp port | Assigns the priority level defined to TCP segments originating from or destined to a specified port (for use with the IP protocol only). Table 76 lists common TCP services and their port numbers. |
| udp port | Assigns the priority level defined to UDP packets originating from or destined to the specified port (for use with the IP protocol only). Table 77 lists common UDP services and their port numbers. |
| Service | Port |
|---|---|
| Telnet | 23 |
| SMTP | 25 |
| Service | Port |
|---|---|
| TFTP | 69 |
| NFS | 2049 |
| SNMP | 161 |
| RPC | 111 |
| DNS | 53 |
Use the no priority-list global configuration command followed by the appropriate list-number argument and the protocol keyword to remove a priority list entry assigned by protocol type.
The following example assigns 1 as the arbitrary priority list number, specifies DECnet as the protocol type, and assigns a high-priority level to the DECnet packets transmitted on this interface:
priority-list 1 protocol decnet high
The following example assigns a medium-priority level to every DECnet packet with a size greater than 200 bytes:
priority-list 2 protocol decnet medium gt 200
The following example assigns a medium-priority level to every DECnet packet with a size less than 200 bytes:
priority-list 4 protocol decnet medium lt 200
The following example assigns a high-priority level to traffic that matches IP access list 10:
priority-list 1 protocol ip high list 10
The following example assigns a medium-priority level to Telnet packets:
priority-list 4 protocol ip medium tcp 23
The following example assigns a medium-priority level to UDP Domain Name service packets:
priority-list 4 protocol ip medium udp 53
The following example assigns a high-priority level to traffic that matches Ethernet type code access list 201:
priority-list 1 protocol bridge high list 201
To specify the maximum number of packets that can be waiting in each of the priority queues, use the priority-list queue-limit global configuration command.The no form of this command selects the normal queue.
priority-list list-number queue-limit high-limit medium-limit normal-limit low-limit| list-number | Arbitrary integer between 1 and 16 that identifies the priority list selected by the user. |
| high-limit medium-limit normal-limit low-limit | Priority queue maximum length. A value of 0 for any of the four arguments means that the queue can be of unlimited size for that particular queue. |
The default queue limit arguments are listed in Table 78.
| Priority Queue Argument | Packet Limits |
|---|---|
| high-limit | 20 |
| medium-limit | 40 |
| normal-limit | 60 |
| low-limit | 80 |
Global configuration
If a priority queue overflows, excess packets are discarded and quench messages can be sent, if appropriate, for the protocol.
The following example sets the maximum packets in the priority queue to 10:
priority-list 2 queue-limit 10 40 60 80
To set the privilege level for a command, use the privilege level global configuration command. Use the no form of this command to revert to default privileges for a given command.
privilege mode level level command| mode | Configuration mode. See Table 68 in the description of the alias command for a list of acceptable options. |
| level | Privilege level to be associated with the specified command. You can specify up to sixteen privilege levels, using numbers 0 through 15. |
| command | Command to which privilege level is associated. |
Level 15 is the level of access permitted by the enable password.
Level 1 is normal EXEC-mode user privileges.
Global configuration
Table 68 in the description of the alias command shows the acceptable options for the mode argument in the privilege level global configuration command.
The password for the privilege level defined using the privilege level global configuration mode is configured using the enable passwordcommand.
There are five commands associated with privilege level 0: disable, enable, exit, help, and logout. If you configure AAA authorization for a privilege level greater than 0, these five commands will not be included. Level 0 can be used to specify a more-limited subset of commands for specific users or lines. For example, you can allow user "guest" to only use the show users and exit commands.
If you set a command to a privilege level, all commands that have a syntax that is a subset of the syntax of that command will also be set to that level. For example, if you set the command show ip route to level 15, if you do not set show commands and show ip commands to a different level, they will also be at privilege level 15.
In the following example, the configure command in global configuration mode is assigned a privilege level of 14. Only users who know the level 14 password will be able to use the configure command.
privilege exec level 14 configure enable password level 14 pswd14
enable password
privilege level (line)
To set the default privilege level for a line, use the privilege level line configuration command. Use the no form of this command to restore the default user privilege level to the line.
privilege level level| level | Privilege level to be associated with the specified line. |
Level 15 is the level of access permitted by the enable password.
Level 1 is normal EXEC-mode user privileges.
Line configuration
The privilege level that is set using this command can be overridden by a user logging in to the line and enabling a different privilege level. The user can lower the privilege level by using the disable command. If they know the password to a higher privilege level, they can use that password to enable the higher privilege level.
Level 0 can be used to specify a more limited subset of commands for specific users or lines. For example, you can allow user "guest" to only use the show users and exit commands.
You might specify a high level of privilege for your console line if you are able to restrict who uses that line.
In the following example, the auxiliary line is configured for privilege level 5. Anyone who is using the auxiliary line will have privilege level 5 by default.
line aux 0 privilege level 5
If you configure:
privilege exec level 7 show ip route
then you have set the privilege level for *ALL* "show ip" commands and indeed, for all "show" commands to 7. This is equivalent to having typed:
privilege exec level 7 show
If you configure:
privilege exec level 7 show ip route privilege exec level 1 show ip
then "show ip route" becomes a level 7 command, while "show" and "show ip" become level 1 commands.
enable password
privilege level (line)
To customize the prompt, use the prompt global configuration command. To revert to the default prompt, use the no form of this command.
prompt string| string | Prompt. It can consist of all printing characters and the escape sequences listed in Table 79 in the "Usage Guidelines" section. |
The default prompt is either Router or the name defined with the hostname global configuration command, followed by an angle bracket (>) for EXEC mode or a pound sign (#) for privileged EXEC mode.
Global configuration
You can include escape sequences when specifying the prompt. All escape sequences are preceded by a percent sign (%). Table 79 lists the valid escape sequences.
| Escape Sequence | Interpretation |
|---|---|
| %h | Host name. This is either Router or the name defined with the hostname global configuration command. |
| %n | Physical terminal line (TTY) number of the EXEC user. |
| %p | Prompt character itself. It is either an angle bracket (>) for EXEC mode or a pound sign (#) for privileged EXEC mode. |
| %s | Space. |
| %t | Tab. |
| %% | Percent sign (%) |
Issuing the prompt%h command has the same effect as issuing the no prompt command.
The following example changes the EXEC prompt to include the TTY number, followed by the name and a space:
prompt TTY%n@%h%s%p
The following are examples of user and privileged EXEC prompts that result from the previous command:
TTY17@Router1 > TTY17SRouter1 #
To assign a priority queue for those packets that do not match any other rule in the queue list, use the queue-list default global configuration command. To restore the default value, use the
no form of this command.
| list-number | Number of the queue list. An integer from 1 to 16. |
| queue-number | Number of the queue. An integer from 1 to 16. |
Queue number 1
Global configuration
Queue number 0 is a system queue. It is emptied before any of the other queues are processed. The system enqueues high-priority packets, such as keepalives, to this queue.
When using multiple rules, remember that the system reads the queue-list commands in order of appearance. When classifying a packet, the system searches the list of rules specified by queue-list commands for a matching protocol or interface type. When a match is found, the packet is assigned to the appropriate queue. The list is searched in the order it is specified, and the first matching rule terminates the search.
In the following example, the default queue for list 10 is set to queue number 2:
queue-list 10 default 2
custom-queue-list
show queueing
To establish queuing priorities on packets entering on an interface, use the queue-list interface global configuration command. To remove an entry from the list, use the no form of the command.
queue-list list-number interface interface-type interface-number queue-number| list-number | Number of the queue list. An integer from 1 to 16. |
| interface-type | Required argument that specifies the name of the interface. |
| interface-number | Number of the specified interface. |
| queue-number | Number of the queue. An integer from 1 to 16. |
No queuing priorities are established.
Global configuration
When using multiple rules, remember that the system reads the queue-list commands in order of appearance. When classifying a packet, the system searches the list of rules specified by queue-list commands for a matching protocol or interface type. When a match is found, the packet is assigned to the appropriate queue. The list is searched in the order it is specified, and the first matching rule terminates the search.
In the following example, queue list 4 established queuing priorities for packets entering on interface tunnel 3. The queue number assigned is 10.
queue-list 4 interface tunnel 3 10
custom-queue-list
show queueing
To establish queuing priority based upon the protocol type, use the queue-list protocol global configuration command. Use the no form of this command with the appropriate list number to remove an entry from the list.
queue-list list-number protocol protocol-name queue-number queue-keyword keyword-value| list-number | Number of the queue list. An integer from 1 to 16. |
| protocol-name | Required argument that specifies the protocol type: aarp, arp, apollo, appletalk, bridge (transparent), clns, clns_es, clns_is, compressedtcp, cmns, decnet, decnet_node, decnet_routerl1, dlsw, decnet_routerl2, ip, ipx, pad, rsrb, stun, vines, xns, and x25. |
| queue-number | Number of the queue. An integer from 1 to 16. |
| queue-keyword keyword-value | Possible keywords are gt, lt, list, tcp, and udp. See Table 75. |
No queuing priorities are established.
Global configuration
When using multiple rules, remember that the system reads the queue-list commands in order of appearance. When classifying a packet, the system searches the list of rules specified by queue-list commands for a matching protocol or interface type. When a match is found, the packet is assigned to the appropriate queue. The list is searched in the order it is specified, and the first matching rule terminates the search.
The decnet_router-l1 keyword refers to the multicast address for all level-1 routers, which are intra-area routers, and the decnet_router-l2 keyword refers to all level 2 routers, which are interarea routers.
The rsrb keyword refers only to RSRB direct encapsulation.
Use Table 75, Table 76, and Table 77 from the priority-list protocol command to configure custom queuing for your system.
The following example assigns 1 as the custom queue list, specifies DECnet as the protocol type, and assigns 3 as a queue number to the packets transmitted on this interface:
queue-list 1 protocol decnet 3
The following example assigns DECnet packets with a size greater than 200 bytes to queue number 2:
queue-list 2 protocol decnet 2 gt 200
The following example assigns DECnet packets with a size less than 200 bytes to queue number 2:
queue-list 4 protocol decnet 2 lt 200
The following example assigns traffic that matches IP access list 10 to queue number 1:
queue-list 1 protocol ip 1 list 10
The following example assigns Telnet packets to queue number 2:
queue-list 4 protocol ip 2 tcp 23
The following example assigns UDP Domain Name service packets to queue number 2:
queue-list 4 protocol ip 2 udp 53
The following example assigns traffic that matches Ethernet type code access list 201 to queue number 1:
queue-list 1 protocol bridge 1 list 201
custom-queue-list
show queueing
To designate the byte size allowed per queue, use the queue-list queue byte-count global configuration command. To return the byte size to the default value, use the no form of the command.
queue-list list-number queue queue-number byte-count byte-count-number| list-number | Number of the queue list. An integer from 1 to 16. |
| queue-number | Number of the queue. An integer from 1 to 16. |
| byte-count-number | Specifies the lower boundary on how many bytes the system allows to be delivered from a given queue during a particular cycle. |
1500 bytes
Global configuration
In the following example, queue list 9 establishes the byte-count as 1400 for queue number 10:
queue-list 9 queue 10 byte-count 1400
custom-queue-list
show queueing
To designate the queue length limit for a queue, use the queue-list queue limit global configuration command. To return the queue length to the default value, use the no form of the command.
queue-list list-number queue queue-number limit limit-number| list-number | Number of the queue list. An integer from 1 to 16. |
| queue-number | Number of the queue. An integer from 1 to 16. |
| limit-number | Maximum number of packets which can be enqueued at any time. Range is 0 to 32767 queue entries. A value of 0 means that the queue can be of unlimited size. |
20 entries
Global configuration
In the following example, the queue length of queue 10 is increased to 40:
queue-list 5 queue 10 limit 40
custom-queue-list
show queueing
To improve RADIUS response times when some servers might be unavailable, use the radius-server dead-time global configuration command to cause the unavailable servers to be skipped immediately. Use the no form of this command to set dead-time to 0.
radius-server dead-time minutes| minutes | Length of time a RADIUS server is skipped over by transaction requests, up to a maximum of 1440 minutes (24 hours). |
Dead time is set to 0.
Global configuration
To cause RADIUS servers that fail to respond to authentication requests to be skipped by additional requests, you can mark it as "dead," thus avoiding the wait for the request to time out before trying the next configured server. A RADIUS server marked as "dead" is skipped by additional requests for the duration of minutes or unless there are no servers not marked "dead."
The following example specifies 5 minutes dead-time for RADIUS servers that fail to respond to authentication requests.
radius-server dead-time 5
radius-server host
radius-server retransmit
radius-server timeout
To specify a RADIUS server host, use the radius-server host global configuration command. Use the no form of this command to delete the specified RADIUS host.
radius-server host {hostname | ip-address} [auth-port port-number] [acct-port port-number]| hostname | DNS name of the RADIUS server host. |
| ip-address | IP address of the RADIUS server host. |
| auth-port | Specifies the UDP destination port for authentication requests. |
| port-number | Port number for authentication requests; the host is not used for authentication if set to 0. |
| acct-port | Specifies the UDP destination port for accounting requests. |
| port-number | Port number for accounting requests; the host is not used for accounting if set to 0. |
No RADIUS host is specified.
Global configuration
You can use multiple radius-server host commands to specify multiple hosts. The software searches for hosts in the order you specify them.
The following example specifies host1 as the RADIUS server and uses default ports for both accounting and authentication.
radius-server host host1.company.com
The following example specifies port 12 as the destination port for authentication requests and port 16 as the destination port for accounting requests on a RADIUS host named host1:
radius-server host host1.company.com auth-port 12 acct-port 16
Note that because entering a line resets all the port numbers, you must specify a host and configure accounting and authentication ports on a single line.
To use separate servers for accounting and authentication, use the zero port value as appropriate. The following example specifies that RADIUS server host1 be used for accounting but not for authentication, and that RADIUS server host2 be used for authentication but not for accounting:
radius-server host host1.company.com auth-port 0
radius-server host host2.company.com acct-port 0
A dagger (+) indicates that the command is documented outside this chapter.
aaa accounting +
aaa authentication
aaa authorization
login authentication +
login tacacs
ppp+
ppp authentication
slip +
tacacs-server
username +
Use the radius-server key command to set the authentication and encryption key for all Radius communications between the router and the Radius daemon. To disable the key, use the no form of the command.
radius-server key {string}| string | (Optional) The key used to set authentication and encryption. This key must match the encryption used on the Radius daemon. |
Disabled
Global Configuration
After enabling AAA with the aaa new-model command, you must set the authentication and encryption key using the radius-server key command.
The key entered must match the key used on the Radius daemon. All leading spaces are ignored, but spaces within and at the end of the key are used. If you use spaces in your key, do not enclose the key in double quotes, unless the quotes themselves are part of the key.
The following example illustrates how to set the authentication and encryption key to "dare to go":
radius-server key dare to go
A dagger (+) indicates that the command is documented in the Access Services Command Reference. Two daggers (++) indicate that the command is documented in the Cisco Access Connection Guide.
login tacacs +
ppp ++
slip ++
tacacs-server
kerberos
login authentication
ppp authentication
username
To specify the number of times the Cisco IOS software will search the list of Radius server hosts before giving up, use the radius-server retransmit global configuration command.
radius-server retransmitr retries| retries | Maximum number of retransmission attempts. |
Three retries
Global configuration
The Cisco IOS software tries all servers, allowing each one to time out before increasing the retransmit count.
The following example specifies a retransmit counter value of five times:
radius-server retransmit 5
To set the interval that the router waits for a server host to reply, use the radius-server timeout global configuration command. Use the no form of this command to restore the default.
radius-server timeout seconds| seconds | Integer that specifies the timeout interval in seconds. |
5 seconds
Global configuration
The following example changes the interval timer to 10 seconds:
radius-server timeout 10
A dagger (+) indicates that the command is documented in the Access Services Command Reference. Two daggers (++) indicate that the command is documented in the Cisco Access Connection Guide.
login tacacs +
ppp ++
slip ++
tacacs-server
kerberos
login authentication
ppp authentication
username
To enable Remote Network Monitoring (RMON) on an Ethernet interface, use the rmon interface configuration command. Use the no form of this command to disable RMON on the interface.
rmon {native | promiscuous}| native | Enables RMON on the Ethernet interface. In native mode, the router processes only packets destined for this interface. |
| promiscuous | Enables RMON on the Ethernet interface. In promiscuous mode, the router examines every packet. |
RMON is disabled on the interface.
Interface configuration
This command enables RMON on Ethernet interfaces of Cisco 2500 series routers only. A generic RMON console application such as Frontier NETscout ManagerTM or Traffic DirectorTM is required in order to use the RMON network management capabilities. SNMP must also be configured. RMON provides visibility of individual nodal activity and allows you to monitor all nodes and their interaction on a LAN segment. When the rmon command is issued, the router automatically installs an Ethernet statistics study for the associated interface.
All Cisco IOS software Release 11.1 feature sets support RMON alarm and event groups. Additional RMON groups are supported in certain feature sets. Refer to the Cisco IOS Release 11.1 Release Notes for feature set descriptions. As a security precaution, support for the packet capture group allows capture of packet header information only; data payloads are not captured.
The RMON MIB is described in RFC 1757.
The following example enables RMON on Ethernet interface 0 and allows the router to examine only packets destined for the interface:
interface ethernet 0 rmon native
rmon alarm
rmon event
rmon queuesize
show rmon
To set an alarm on any MIB object, use the rmon alarm configuration command. Use the no form of this command to disable the alarm.
rmon alarm number variable interval {delta | absolute} rising-threshold value [event-number] falling-threshold value [event-number] [owner string]| number | Alarm number, which is identical to the alarmIndex in the alarmTable in the Remote Monitoring (RMON) MIB. |
| variable | MIB object to monitor, which translates into the alarmVariable used in the alarmTable of the RMON MIB. |
| interval | Time in seconds the alarm monitors the MIB variable, which is identical to the alarmValue used in the alarmTable of the RMON MIB. |
| delta | Tests the change between MIB variables, which affects the alarmSampleType in the alarmTable of the RMON MIB. |
| absolute | Tests each MIB variable directly, which affects the alarmSampleType in the alarmTable of the RMON MIB. |
| rising-threshold value | Value at which the alarm is triggered. |
| event-number | (Optional) Event number to trigger when the rising or falling threshold exceeds its limit. This value is identical to the alarmRisingEventIndex or the alarmFallingEventIndex in the alarmTable of the RMON MIB. |
| falling-threshold value | Value at which the alarm is reset. |
| owner string | (Optional) Specifies an owner for the alarm, which is identical to the alarm owner in the alarmTable of the RMON MIB. |
No alarms configured
Global configuration
To disable the RMON alarms, you must use the no form of the command on each configured alarm. For example, enter no rmon alarm 1, where the 1 identifies which alarm is to be removed.
See RFC 1757 for more information about the RMON alarm group.
The following example configures an RMON alarm using the rmon alarm command:
rmon alarm 10 ifEntry.20.1 20 delta rising-threshold 15 1 falling-threshold 0 owner jjohnson
This example configures RMON alarm number 10. The alarm monitors the MIB variable ifEntry.20.1 once every 20 seconds until the alarm is disabled, and checks the change in the variable's rise or fall. If the ifEntry.20.1 value shows a MIB counter increase of 15 or more, such as from 100000 to 100015, the alarm is triggered. The alarm in turn triggers event number 1, which is configured with the rmon event command. Possible events include a log entry or a SNMP trap. If the ifEntry.20.1 value changes by 0 (falling-threshold 0), the alarm is reset and can be triggered again.
To add or remove an event in the RMON event table that is associated with an RMON event number, use the rmon event global configuration command. Use the no form of this command to disable RMON on the interface.
rmon event number [log] [trap community] [description string] [owner string]| number | Assigned event number, which is identical to the eventIndex in the eventTable in the RMON MIB. |
| log | (Optional) Generates an RMON log entry when the event is triggered and sets the eventType in the RMON MIB to log or log-and-trap. |
| trap community | (Optional) SNMP community string used for this trap. Configures the setting of the eventType in the RMON MIB for this row as either snmp-trap or log-and-trap. This value is identical to the eventCommunityValue in the eventTable in the RMON MIB. |
| description string | (Optional) Specifies a description of the event, which is identical to the event description in the eventTable of the RMON MIB. |
| owner string | (Optional) Owner of this event, which is identical to the eventDescription in the eventTable of the RMON MIB. |
No events configured
Global configuration
This command applies only to the AS5200 access server.
See RFC 1757 for more information about the RMON MIB.
The following example enables the rmon event command:
rmon event 1 log trap eventtrap description "High ifOutErrors" owner sdurham
This example configuration creates RMON event number 1, which is defined as High ifOutErrors, and generates a log entry when the event is triggered by an alarm. The user sdurham owns the row that is created in the event table by this command. This configuration also generates a Simple Network Management Protocol (SNMP) trap when the event is triggered.
To change the size of the queue that holds packets for analysis by the Remote Network Monitoring (RMON) process, use the rmon queuesize global configuration command. Use the no form of this command to restore the default value.
rmon queuesize size| size | Number of packets allowed in the queue awaiting RMON analysis. Default queue size is 64 packets. |
64 packets
Global configuration
This command applies to the RMON function, which is available on Ethernet interfaces of Cisco 2500 series routers only.
You might want to increase the queue size if the RMON function indicates it is dropping packets. You can determine this from the output of the show rmon command or from the etherStatsDropEvents object in the etherStats table. A feasible maximum queue size depends on the amount of memory available in the router and the configuration of the buffer pool.
The following example configures the RMON queue size to be 128 packets:
rmon queuesize 128
To guarantee CPU time for processes, use the scheduler allocate global configuration command on the Cisco 7200 series and Cisco 7500 series. The no form of this command restores the default.
scheduler allocate interrupt-time process-time| interrupt-time | Integer (in microseconds) that limits the maximum number of microseconds to spend on fast switching within any one network interrupt context. The range is 400 to 60000 microseconds. The default is 4000 microseconds. |
| process-time | Integer (in microseconds) that guarantees the minimum number of microseconds to spend at the process level when network interrupts are disabled. The range is 100 to 4000. The default is 200 microseconds. |
Approximately 5 percent of the CPU is available for process tasks.
Global configuration
This command applies to the Cisco 7200 series and Cisco 7500 series.
![]() | Caution Cisco recommends that you do not change the default values. |
The following example makes 20 percent of the CPU available for process tasks:
scheduler allocate 2000 500
To control the maximum amount of time that can elapse without running system processes, use the scheduler interval global configuration command. The no form of this command restores the default.
scheduler interval milliseconds| milliseconds | Integer that specifies the interval, in milliseconds. The minimum interval that you can specify is 500 milliseconds; there is no maximum value. |
High-priority operations are allowed to use as much of the central processor as needed.
Global configuration
The normal operation of the network server allows the switching operations to use as much of the central processor as is required. If the network is running unusually heavy loads that do not allow the processor the time to handle the routing protocols, give priority to the system process scheduler. High-priority operations are allowed to use as much of the central processor as needed.
On the Cisco 7200 series and Cisco 7500 series, use the scheduler allocate global configuration command.
The following example changes the low-priority process schedule to an interval of 750 milliseconds:
scheduler interval 750
To specify that line numbers be displayed and interpreted as decimal numbers rather than octal numbers, use the service decimal-tty global configuration command. Use the no form of this command to restore the default.
service decimal-ttyThis command has no arguments or keywords.
Decimal numbers on the 500-CS and Cisco 2500 Series.
Global configuration
The following example shows how to display decimal rather than octal line numbers:
service decimal-tty
To delay the startup of the EXEC on noisy lines, use the service exec-wait global configuration command. Use the no form of this command to disable this feature.
service exec-waitThis command has no arguments or keywords.
Disabled
Global configuration
This command delays startup of the EXEC until the line has been idle (no traffic seen) for 3 seconds. The default is to enable the line immediately on modem activation.
This command is useful on noisy modem lines or when a modem attached to the line is configured to ignore MNP or V.42 negotiations, and MNP or V.42 modems may be dialing in. In these cases, noise or MNP/V.42 packets may be interpreted as usernames and passwords, causing authentication failure before the user gets a chance to type a username/password. The command is not useful on non-modem lines or lines without some kind of login configured.
The following example delays the startup of the EXEC:
service exec-wait
To allow Finger protocol requests (defined in RFC 742) to be made of the network server, use the service finger global configuration command. This service is equivalent to issuing a remote show users command. Use the no form of this command to remove this service.
service fingerThis command has no arguments or keywords.
Enabled
Global configuration
The following is an example of how to disable the Finger protocol:
no service finger
To hide addresses while trying to establish a Telnet session, use the service hide-telnet-address global configuration command. Use the no form of this command to remove this service.
service hide-telnet-addressThis command has no arguments or keywords.
Addresses are displayed.
Global configuration
When you attempt to connect to a device, the router displays addresses and other messages (for example, Trying router1 (171.69.1.154, 2008)...). With the hide feature, the router suppresses the display of the address (for example, Trying router1 address #1...). The router continues to display all other messages that would normally display during a connection attempt, such as detailed error messages if the connection was not successful.
The hide feature improves the functionality of the busy-message feature. When you configure only the busy-message command, the normal messages generated during a connection attempt are not displayed; only the busy-message is displayed. When you use the hide and busy features together you can customize the information displayed during Telnet connection attempts. When you configure the service hide-telnet-address command and the busy-message command, the router suppresses the address and displays the message specified with the busy-message command if the connection attempt is not successful.
The following example shows how to hide Telnet addresses:
service hide-telnet-address
A dagger (+) indicates that the command is documented outside this chapter.
busy-message +
To enable the Nagle congestion control algorithm, use the service nagle global configuration command. Use the no form of this command to disable this feature.
service nagleThis command has no arguments or keywords.
Disabled
Global configuration
When using a standard TCP implementation to send keystrokes between machines, TCP tends to send one packet for each keystroke typed. On larger networks, many small packets use up bandwidth and contribute to congestion.
John Nagle's algorithm (RFC 896) helps alleviate the small-packet problem in TCP. In general, it works this way: The first character typed after connection establishment is sent in a single packet, but TCP holds any additional characters typed until the receiver acknowledges the previous packet. Then the second, larger packet is sent, and additional typed characters are saved until the acknowledgment comes back. The effect is to accumulate characters into larger chunks, and pace them out to the network at a rate matching the round-trip time of the given connection. This method is usually a good for all TCP-based traffic. However, do not use the service nagle command if you have XRemote users on X Window sessions.
The following example enables the Nagle algorithm:
service nagle
To encrypt passwords, use the service password-encryption global configuration command. Use the no form of this command to disable this service.
service password-encryptionThis command has no arguments or keywords.
No encryption
Global configuration
The actual encryption process occurs when the current configuration is written or when a password is configured. Password encryption is applied to all passwords, including authentication key passwords, the privileged command password, console and virtual terminal line access passwords, and BGP neighbor passwords. This command is primarily useful for keeping unauthorized individuals from viewing your password in your configuration file.
When password encryption is enabled, the encrypted form of the passwords is displayed when a show startup-config command is entered.
| **before**This command does not provide a high level of network security. If you use this command, you should also take additional network security measures.@@before@@ | Caution **after**This command does not provide a high level of network security. If you use this command, you should also take additional network security measures.@@after@@ |
The following example causes password encryption to take place:
service password-encryption
A dagger (+) indicates that the command is documented outside this chapter.
enable password
key-string +
neighbor password +
To display the configuration prompt (config), use the service prompt config global configuration command. Use the no form of this command to remove the configuration prompt.
service prompt configThis command has no arguments or keywords.
Router(config)#
Global configuration
In the following example, notice how the configuration prompt varies, depending on what sub division of configuration mode you are using.
Router#config terminalEnter configuration commands, one per line. End with CNTL/Z. Router(config)#interface ethernet 0Router(config-if)#line config 0Router(config-line)#router ripRouter(config-router)#map-list murugaRouter(config-map-list)#map-class atm barRouter(config-map-class)#exitRouter(config)#exitRouter#
To allow slave Versatile Interface Processor (VIP) cards to log important error messages to the console, use the service slave-log global configuration command. Use the no form of this command to disable slave logging.
service slave-logThis command has no arguments or keywords.
This command is enabled by default.
Global configuration
This command allows slave slots to log error messages of level 2 or higher (critical, alerts, and emergencies).
The following example logs important messages from the slave cards to the console:
service slave-log
The following example illustrates sample output when this command is enabled:
%IPC-5-SLAVELOG: VIP-SLOT2: IPC-2-NOMEM: No memory available for IPC system initialization
The first line indicates which slot sent the message. The second line contains the error message.
To generate keepalive packets on idle network connections, use the service tcp-keepalives global configuration command. The no form of this command with the appropriate keyword disables the keepalives.
service tcp-keepalives-in | tcp-keepalives-out| in | Generates keepalives on incoming connections (initiated by remote host). |
| out | Generates keepalives on outgoing connections (initiated by a user). |
Disabled
Global configuration
The following example generates keepalives on incoming TCP connections:
service tcp-keepalives in
To access minor TCP/IP services available from hosts on the network, use the service tcp-small-servers command. Use the no form of the command to disable these services.
service tcp-small-serversThis command has no arguments or keywords.
Enabled
Global configuration
By default, the TCP servers for Echo, Discard, Chargen, and Daytime services are enabled.
When you disable the minor TCP/IP servers, access to the Echo, Discard, Chargen, and Daytime ports cause the Cisco IOS software to send a TCP RESET packet to the sender and discard the original incoming packet.
The following example enables minor TCP/IP services available from the network:
service tcp-small-servers
To set the TCP window to zero (0) when the Telnet connection is idle, use the service telnet-zero-idle global configuration command. Use the no form of this command to disable this feature.
service telnet-zero-idleThis command has no arguments or keywords.
Disabled
Global configuration
Normally, data sent to noncurrent Telnet connections is accepted and discarded. When service telnet-zero-idle is enabled, if a session is suspended (that is, some other connection is made active or the EXEC is sitting in command mode), the TCP window is set to zero. This action prevents the remote host from sending any more data until the connection is resumed. Use this command when it is important that all messages sent by the host be seen by the users and the users are likely to use multiple sessions.
Do not use this command if your host will eventually time out and log out a TCP user whose window is zero.
The following example sets the TCP window to zero when the Telnet connection is idle:
service telnet-zero-idle
A daggers (+) indicates that the command is documented in the Cisco Access Connection Guide.
resume +
To configure the system to timestamp debugging or logging messages, use one of the service timestamps global configuration commands. Use the no form of this command to disable this service.
service timestamps type [uptime]type | Type of message to timestamp: debug or log. |
|---|---|
| uptime | (Optional) Timestamp with time since the system was rebooted. |
| datetime | Timestamp with the date and time. |
| msec | (Optional) Include milliseconds in the date and timestamp. |
| localtime | (Optional) Timestamp relative to the local time zone. |
| show-timezone | (Optional) Include the time zone name in the timestamp. |
No timestamping.
If service timestamps is specified with no arguments or keywords, default is service timestamps debug uptime.
The default for service timestamps type datetime is to format the time in UTC, with no milliseconds and no time zone name.
The command no service timestamps by itself disables timestamps for both debug and log messages.
Global configuration
Timestamps can be added to either debugging or logging messages independently. The uptime form of the command adds timestamps in the format HHHH:MM:SS, indicating the time since the system was rebooted. The datetime form of the command adds timestamps in the format MMM DD HH:MM:SS, indicating the date and time according to the system clock. If the system clock has not been set, the date and time are preceded by an asterisk (*) to indicate that the date and time are probably not correct.
The following example enables timestamps on debugging messages, showing the time since reboot:
service timestamps debug uptime
The following example enables timestamps on logging messages, showing the current time and date relative to the local time zone, with the time zone name included:
service timestamps log datetime localtime show-timezone
A dagger (+) indicates that the command is documented in the Debug Command Reference.
clock set
debug +
ntp
To access minor User Datagram Protocol (UDP) services available from hosts on the network, use the service udp-small-servers command. Use the no form of the command to disable these services.
service udp-small-serversThis command has no arguments or keywords.
Enabled
Global configuration
By default the UPD servers for Echo, Discard, and Chargen services are enabled.
When you disable the servers, access to Echo, Discard, and Chargen ports causes the Cisco IOS software to send an "ICMP port unreachable" message to the sender and discard the original incoming packet.
The following example disables minor UDP services on the router:
no service udp-small-servers
Use the show accounting command to step through all active sessions and to print all the accounting records for actively accounted functions. To disable this function, use the no form of the command.
show accounting {system | network | connection | exec | command level} {start-stop || system | Performs accounting for all system-level events not associated with users, such as reloads. |
| network | Performs accounting for all network-related service requests, including SLIP, PPP, PPP NCPs, and ARAP. |
| connection | Performs accounting for outbound Telnet and rlogin. |
| exec | Performs accounting for EXECs (user shells). This keyword might return user profile information such as autocommand information. |
| command | Performs accounting for all commands at the specified privilege level. |
| level | Specifies the command level that needs to be accounted. Valid entries are 0 through 15. |
| start-stop | Sends a start record accounting notice at the beginning of a process and a stop record at the end of a process. The start accounting record is sent in the background. The requested user process begins regardless of whether or not the start accounting record was received by the accounting server. |
| wait-start | Sends both a start and a stop accounting record to the accounting server. However, if you use the wait-start keyword, the requested user service does not begin until the start accounting record is acknowledged. A stop accounting record is also sent. |
| stop-only | Sends a stop record accounting notice at the end of the requested user process. |
| tacacs+ | Enables the TACACS-style accounting. |
Disabled.
EXEC
The following is sample output from the show accounting command:
router#show accountingActive Accounted actions on tty0, User chard Priv 1 Task ID 4425, EXEC Accounting record, 0:04:53 Elapsed task_id=4425 service=exec port=0 Task ID 3759, Connection Accounting record, 0:01:06 Elapsed task_id=3759 service=exec port=0 protocol=telnet address=171.19.3.78 cmd=grill Active Accounted actions on tty10, User chard Priv 1 Task ID 5115, EXEC Accounting record, 0:04:07 Elapsed task_id=5115 service=exec port=10 Task ID 2593, Connection Accounting record, 0:00:56 Elapsed task_id=2593 service=exec port=10 protocol=tn3270 address=172.21.14.90 cmd=tn snap Active Accounted actions on tty11, User mary Priv 1 Task ID 7390, EXEC Accounting record, 0:00:25 Elapsed task_id=7390 service=exec port=11 Task ID 931, Connection Accounting record, 0:00:20 Elapsed task_id=931 service=exec port=11 protocol=telnet address=171.19.6.129 cmd=coal
The show accounting command allows you to display the active "accountable events" on the system. It provides systems administrators with a quick look at what is going on, and it also can help collect information in the event of a data loss on the accounting server.
The show accounting command displays additional data on the internal state of AAA if debug aaa accounting is turned on as well.
show users
show line
debug aaa accounting
To display all alias commands, or the alias commands in a specified mode, use the show aliases EXEC command.
show aliases [mode]| mode | (Optional) Command mode. See Table 68 in the description of the alias command for acceptable options for the mode argument. |
EXEC
All of the modes listed in Table 68 have their own prompts, except for the null interface mode. For example, the prompt for interface configuration mode is Router(config-if).
The following is sample output from the show aliases exec commands. The aliases configured for commands in EXEC mode are displayed.
Router# show aliases exec
Exec mode aliases:
h help
lo logout
p ping
r resume
s show
w where
Use the show buffers EXEC command to display statistics for the buffer pools on the network server.
show buffers [type number | alloc [dump]]| type number | (Optional) Displays interface pool information. If the specified interface type and number has its own buffer pool, displays information for that pool. Value of type can be ethernet, serial, tokenring, fddi, bri, atm, e1, t1. |
| alloc | (Optional) Displays a brief listing of all allocated buffers. |
| dump | (Optional) Dumps all allocated buffers. This keyword must be used with the alloc keyword, not by itself. |
EXEC
The following is sample output from the show buffers command with no arguments, showing all buffer pool information:
Router# show buffers
Buffer elements:
398 in free list (500 max allowed)
1266 hits, 0 misses, 0 created
Public buffer pools:
Small buffers, 104 bytes (total 50, permanent 50):
50 in free list (20 min, 150 max allowed)
551 hits, 0 misses, 0 trims, 0 created
Middle buffers, 600 bytes (total 25, permanent 25):
25 in free list (10 min, 150 max allowed)
39 hits, 0 misses, 0 trims, 0 created
Big buffers, 1524 bytes (total 50, permanent 50):
49 in free list (5 min, 150 max allowed)
27 hits, 0 misses, 0 trims, 0 created
VeryBig buffers, 4520 bytes (total 10, permanent 10):
10 in free list (0 min, 100 max allowed)
0 hits, 0 misses, 0 trims, 0 created
Large buffers, 5024 bytes (total 0, permanent 0):
0 in free list (0 min, 10 max allowed)
0 hits, 0 misses, 0 trims, 0 created
Huge buffers, 18024 bytes (total 0, permanent 0):
0 in free list (0 min, 4 max allowed)
0 hits, 0 misses, 0 trims, 0 created
Interface buffer pools:
Ethernet0 buffers, 1524 bytes (total 64, permanent 64):
16 in free list (0 min, 64 max allowed)
48 hits, 0 fallbacks
16 max cache size, 16 in cache
Ethernet1 buffers, 1524 bytes (total 64, permanent 64):
16 in free list (0 min, 64 max allowed)
48 hits, 0 fallbacks
16 max cache size, 16 in cache
Serial0 buffers, 1524 bytes (total 64, permanent 64):
16 in free list (0 min, 64 max allowed)
48 hits, 0 fallbacks
16 max cache size, 16 in cache
Serial1 buffers, 1524 bytes (total 64, permanent 64):
16 in free list (0 min, 64 max allowed)
48 hits, 0 fallbacks
16 max cache size, 16 in cache
TokenRing0 buffers, 4516 bytes (total 48, permanent 48):
0 in free list (0 min, 48 max allowed)
48 hits, 0 fallbacks
16 max cache size, 16 in cache
TokenRing1 buffers, 4516 bytes (total 32, permanent 32):
32 in free list (0 min, 48 max allowed)
16 hits, 0 fallbacks
0 failures (0 no memory)
Table 80 describes significant fields shown in the display.
| Field | Description |
|---|---|
| Buffer elements | Buffer elements are small structures used as placeholders for buffers in internal operating system queues. Buffer elements are used when a buffer may need to be on more than one queue. |
| Free list | Total number of the currently unallocated buffer elements. |
| Max allowed | Maximum number of buffers that are available for allocation. |
| Hits | Count of successful attempts to allocate a buffer when needed. |
| Misses | Count of buffer allocation attempts that resulted in growing the buffer pool to allocate a buffer. |
| Created | Count of new buffers created to satisfy buffer allocation attempts when the available buffers in the pool have already been allocated. |
| Public buffer pools | |
| Small buffers | Buffers that are 104 bytes long. |
| Middle buffers | Buffers that are 600 bytes long. |
| Big buffers | Buffers that are 1524 bytes long. |
| VeryBig buffers | Buffers that are 4520 bytes long. |
| Large buffers | Buffers that are 5024 bytes long. |
| Huge buffers | Buffers that are 18024 bytes long. |
| Total | Total number of this type of buffer. |
| Permanent | Number of these buffers that are permanent. |
| Free list | Number of available or unallocated buffers in that pool. |
| Min | Minimum number of free or unallocated buffers in the buffer pool |
| Max allowed | Maximum number of free or unallocated buffers in the buffer pool |
| Hits | Count of successful attempts to allocate a buffer when needed. |
| Misses | Count of buffer allocation attempts that resulted in growing the buffer pool in order to allocate a buffer. |
| Trims | Count of buffers released to the system because they were not being used. This field is displayed only for dynamic buffer pools, not interface buffer pools, which are static. |
| Created | Count of new buffers created in response to misses. This field is displayed only for dynamic buffer pools, not interface buffer pools, which are static. |
| Interface buffer pools | |
| Total | Total number of this type of buffer. |
| Permanent | Number of these buffers that are permanent. |
| Free list | Number of available or unallocated buffers in that pool. |
| Min | Minimum number of free or unallocated buffers in the buffer pool. |
| Max allowed | Maximum number of free or unallocated buffers in the buffer pool. |
| Hits | Count of successful attempts to allocate a buffer when needed. |
| Fall backs | Count of buffer allocation attempts that resulted in falling back to the public buffer pool that is the smallest pool at least as big as the interface buffer pool. |
| Max Cache Size | Maximum number of buffers from that interface's pool that can be in that interface buffer pool's cache. Each interface buffer pool has its own cache. These are not additional to the permanent buffers; they come from the interface's buffer pools. Some interfaces place all of their buffers from the interface pool into the cache. In this case, it is normal for the free list to display 0. |
| Failures | Total number of allocation requests that have failed because no buffer was available for allocation; the datagram was lost. Such failures normally occur at interrupt level. |
| (no memory) | Number of failures that occurred because no memory was available to create a new buffer. |
The following is sample output from the show buffers command with an interface type and number:
Router# show buffers Ethernet 0
Ethernet0 buffers, 1524 bytes (total 64, permanent 64):
16 in free list (0 min, 64 max allowed)
48 hits, 0 fallbacks
16 max cache size, 16 in cache
The following is sample output from the show buffers command when alloc is specified:
Router# show buffers alloc
Buffer elements:
398 in free list (500 max allowed)
1266 hits, 0 misses, 0 created
Public buffer pools:
Small buffers, 104 bytes (total 50, permanent 50):
50 in free list (20 min, 150 max allowed)
551 hits, 0 misses, 0 trims, 0 created
Middle buffers, 600 bytes (total 25, permanent 25):
25 in free list (10 min, 150 max allowed)
39 hits, 0 misses, 0 trims, 0 created
Big buffers, 1524 bytes (total 50, permanent 50):
49 in free list (5 min, 150 max allowed)
27 hits, 0 misses, 0 trims, 0 created
VeryBig buffers, 4520 bytes (total 10, permanent 10):
10 in free list (0 min, 100 max allowed)
0 hits, 0 misses, 0 trims, 0 created
Large buffers, 5024 bytes (total 0, permanent 0):
0 in free list (0 min, 10 max allowed)
0 hits, 0 misses, 0 trims, 0 created
Huge buffers, 18024 bytes (total 0, permanent 0):
0 in free list (0 min, 4 max allowed)
0 hits, 0 misses, 0 trims, 0 created
Interface buffer pools:
Ethernet0 buffers, 1524 bytes (total 64, permanent 64):
16 in free list (0 min, 64 max allowed)
48 hits, 0 fallbacks
16 max cache size, 16 in cache
Ethernet1 buffers, 1524 bytes (total 64, permanent 64):
16 in free list (0 min, 64 max allowed)
48 hits, 0 fallbacks
16 max cache size, 16 in cache
Serial0 buffers, 1524 bytes (total 64, permanent 64):
16 in free list (0 min, 64 max allowed)
48 hits, 0 fallbacks
16 max cache size, 16 in cache
Serial1 buffers, 1524 bytes (total 64, permanent 64):
16 in free list (0 min, 64 max allowed)
48 hits, 0 fallbacks
16 max cache size, 16 in cache
TokenRing0 buffers, 4516 bytes (total 48, permanent 48):
0 in free list (0 min, 48 max allowed)
48 hits, 0 fallbacks
16 max cache size, 16 in cache
TokenRing1 buffers, 4516 bytes (total 32, permanent 32):
32 in free list (0 min, 48 max allowed)
16 hits, 0 fallbacks
0 failures (0 no memory)
Address PakAddr Data Off Data Pool Ref Link Enc Flags Output Input
Area set Size Cnt Type Type (Hex) Idb Idb
--------------------------------------------------------------------------------
604B37A0 604B37C0 40004A38 62 60 Big 1 65 3 0 Et0
604C6DA0 604C6DC0 40007038 84 0 Ether 1 0 0 0
604C6F60 604C6F80 400076E4 84 0 Ether 1 0 0 0
604C7120 604C7140 40007D90 84 0 Ether 1 0 0 0
604C72E0 604C7300 4000843C 84 0 Ether 1 0 0 0
604C74A0 604C74C0 40008AE8 84 0 Ether 1 0 0 0
604C7660 604C7680 40009194 84 0 Ether 1 0 0 0
604C7820 604C7840 40009840 84 0 Ether 1 0 0 0
.
.
.
Use the show c7200 EXEC command to display information about the CPU and midplane for Cisco 7200 series routers.
show c7200This command has no arguments or keywords.
EXEC
You can use the output of this command to determine whether the hardware version level and upgrade is current. The information is generally useful for diagnostic tasks performed by technical support only.
The following is sample output from the show c7200 command:
router# show c7200
C7200 Network IO Interrupt Throttling:
throttle count=0, timer count=0
active=0, configured=0
netint usec=3999, netint mask usec=200
C7200 Midplane EEPROM:
Hardware revision 1.2 Board revision A0
Serial number 2863311530 Part number 170-43690-170
Test history 0xAA RMA number 170-170-170
MAC=0060.3e28.ee00, MAC Size=1024
EEPROM format version 1, Model=0x6
EEPROM contents (hex):
0x20: 01 06 01 02 AA AA AA AA AA AA AA AA 00 60 3E 28
0x30: EE 00 04 00 AA AA AA AA AA AA AA 50 AA AA AA AA
C7200 CPU EEPROM:
Hardware revision 2.0 Board revision A0
Serial number 3509953 Part number 73-1536-02
Test history 0x0 RMA number 00-00-00
EEPROM format version 1
EEPROM contents (hex):
0x20: 01 15 02 00 00 35 8E C1 49 06 00 02 00 00 00 00
0x30: 50 00 00 00 FF FF FF FF FF FF FF FF FF FF FF FF
To display the calendar hardware setting for the Cisco 7000 or Cisco 4500, use the show calendar EXEC command:
show calendarThis command has no arguments or keywords.
EXEC
You can compare the time and date shown with this command with the time and date listed via the show clock command to verify that the calendar and system clock are in sync with each other. The time displayed is relative to the configured time zone.
In the following sample display, the hardware calendar indicates the timestamp of 12:13:44 p.m. on Friday, January 1, 1993:
Router# show calendar
12:13:44 PST Fri Jan 1 1993
To display global CDP information, including timer and hold-time information, use the show cdp privileged EXEC command.
show cdpThis command has no arguments or keywords.
Privileged EXEC
The following is sample output from the show cdp command. Global CDP timer and hold-time parameters are set to the defaults of 60 and 180 seconds, respectively.
Router# show cdp
Global CDP information:
Sending CDP packets every 60 seconds
Sending a holdtime value of 180 seconds
cdp holdtime
cdp timer
show cdp entry
show cdp neighbors
To display information about a neighbor device listed in the CDP table, use the show cdp entry privileged EXEC command.
show cdp entry {* | entry-name [protocol | version]}| * | Shows all of the CDP neighbors. |
| entry-name | Name of neighbor about which you want information.
You can enter an aserisk (*) at the end of an entry-name, such as |
| protocol | (Optional) Limits the display to information about the protocols enabled on a router. |
| version | (Optional) Limits the display to information about the version of software running on the router. |
Privileged EXEC
The following is sample output from the show cdp entry command with no limits. Information about the neighbor device.cisco.com is displayed, including device ID, address and protocol, platform, interface, hold time, and version.
Router# show cdp entry device.cisco.com
Device ID: device.cisco.com
Entry address(es):
IP address: 198.92.68.18
CLNS address: 490001.1111.1111.1111.00
DECnet address: 10.1
Interface: Ethernet0, Port ID (outgoing port): Ethernet0
Holdtime: 155 sec
Version:
GS Software (GS3), Experimental Version 10.2(10302) [asmith 161]
Copyright (c) 1986-1994 by cisco Systems, Inc.
Compiled Mon 07-Nov-94 14:34
The following is sample output from the show cdp entry privilege command. Only information about the protocols enabled on neon-cisco.com is displayed.
Router# show cdp entry device.cisco.com protocol
Protocol information for device.cisco.com:
IP address: 198.92.68.18
CLNS address: 490001.1111.1111.1111.00
DECnet address: 10.1
The following is sample output from the show cdp entry version command. Only information about the version of software running on device.cisco.com is displayed.
Router# show cdp entry device.cisco.com version
Version information for device.cisco.com:
GS Software (GS3), Experimental Version 10.2(10302) [asmith 161]
Copyright (c) 1986-1994 by cisco Systems, Inc.
Compiled Mon 07-Nov-94 14:34
To display information about the interfaces on which CDP is enabled, use the show cdp interface command.
show cdp interface [type number]| type | (Optional) Type of interface about which you want information. |
| number | (Optional) Number of the interface about which you want information. |
Privileged EXEC
The following sample output form the show cdp interface command. Status information and information about CDP timer and hold time settings is displayed for all interfaces on which CDP is enabled.
Router# show cdp interface
Serial0 is up, line protocol is up, encapsulation is SMDS
Sending CDP packets every 60 seconds
Holdtime is 180 seconds
Ethernet0 is up, line protocol is up, encapsulation is ARPA
Sending CDP packets every 60 seconds
Holdtime is 180 seconds
The following is sample output from the show cdp interface command with an interface specified. Status information and information about CDP timer and holdtime settings is displayed for Ethernet interface 0 only.
Router# show cdp interface ethernet 0
Ethernet0 is up, line protocol is up, encapsulation is ARPA
Sending CDP packets every 60 seconds
Holdtime is 180 seconds
To display information about neighbors, use the show cdp neighbors privileged EXEC command.
show cdp neighbors [interface-type interface-number] [detail]| interface-type | (Optional) Type of the interface connected to the neighbors about which you want information. |
| interface-number | (Optional) Number of the interface connected to the neighbors about which you want information. |
| detail | (Optional) Displays detailed information about a neighbor (or neighbors) including network address, enabled protocols, hold time, and software version. |
Privileged EXEC
The following is sample output from the show cdp neighbors command. Device ID, interface type and number, holdtime settings, capabilities, platform, and port ID information about neighbors is displayed.
Router# show cdp neighbors
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
S - Switch, H - Host, I - IGMP
Device ID Local Intrfce Holdtme Capability Platform Port ID
device.cisco.com Eth 0 151 R T AGS Eth 0
device.cisco.com Ser 0 165 R T AGS Ser 3
The following is sample output from the show cdp neighbors detail command. Additional detail is shown about neighbors, including network address, enabled protocols, and software version:
Router# show cdp neighbors detail
Device ID: device.cisco.com
Entry address(es):
IP address: 198.92.68.18
CLNS address: 490001.1111.1111.1111.00
DECnet address: 10.1
Platform: AGS, Capabilities: Router Trans-Bridge
Interface: Ethernet0, Port ID (outgoing port): Ethernet0
Holdtime: 143 sec
Version:
GS Software (GS3), Experimental Version 10.2(10302) [asmith 161]
Copyright (c) 1986-1994 by cisco Systems, Inc.
Compiled Mon 07-Nov-94 14:34
To display traffic information from the CDP table, use the show cdp traffic privileged EXEC command.
show cdp trafficThis command has no arguments or keywords.
Privileged EXEC
The following is sample output from the show cdp traffic command.
Router# show cdp traffic
CDP counters:
Packets output: 94, Input: 75
Hdr syntax: 0, Chksum error: 0, Encaps failed: 0
No memory: 0, Invalid packet: 0, Fragmented: 0
In this example, traffic information is displayed including the numbers of packets sent, the number of packets received, header syntax, checksum errors, failed encapsulations, memory problems, and invalid and fragmented packets is displayed. Header syntax indicates the number of packets CDP receives with that have an invalid header format.
To display the system clock, use the show clock EXEC command:
show clock [detail]| detail | (Optional) Indicates the clock source (NTP, VINES, 7000 calendar, and so forth) and the current summer-time setting (if any). |
EXEC
The system clock keeps an "authoritative" flag that indicates whether or not the time is authoritative (believed to be accurate). If system clock has been set by a timing source (Cisco 7000 calendar, NTP, VINES, and so forth), the flag is set. If the time is not authoritative, it will be used only for display purposes. Until the clock is authoritative and the "authoritative" flag is set, the flag prevents peers from synchronizing to it when the its time is invalid.
The symbol that precedes the show clock display indicates the following:
| Symbol | Description |
|---|---|
| * | Time is not authoritative. |
| (blank) | Time is authoritative. |
| . | Time is authoritative, but NTP is not synchronized. |
The following sample output shows that the current clock is authoritative and that the time source is NTP:
Router# show clock detail
15:29:03.158 PST Mon Mar 1 1993
Time source is NTP
Router#
Use the show context EXEC command to display information stored in NVRAM when the router crashes. This command only works on the Cisco 7000 series, Cisco 7200 series, and Cisco 7500 series platforms.
show contextThis command has no arguments or keywords.
EXEC
The display from the show context command includes the following information:
This information is of use only to your technical support representative in analyzing crashes in the field. It is included here in case you need to read the displayed statistics to an engineer over the phone.
The following is sample output from the show context command following a system failure:
Router> show context
System was restarted by error - a Software forced crash, PC 0x60189354
GS Software (RSP-PV-M), Experimental Version 11.1(2033) [ganesh 111]
Compiled Mon 31-Mar-97 13:21 by ganesh
Image text-base: 0x60010900, data-base: 0x6073E000
Stack trace from system failure:
FP: 0x60AEA798, RA: 0x60189354
FP: 0x60AEA798, RA: 0x601853CC
FP: 0x60AEA7C0, RA: 0x6015E98C
FP: 0x60AEA7F8, RA: 0x6011AB3C
FP: 0x60AEA828, RA: 0x601706CC
FP: 0x60AEA878, RA: 0x60116340
FP: 0x60AEA890, RA: 0x6011632C
Fault History Buffer:
GS Software (RSP-PV-M), Experimental Version 11.1(2033) [ganesh 111]
Compiled Mon 31-Mar-97 13:21 by ganesh
Signal = 23, Code = 0x24, Uptime 00:04:19
$0 : 00000000, AT : 60930120, v0 : 00000032, v1 : 00000120
a0 : 60170110, a1 : 6097F22C, a2 : 00000000, a3 : 00000000
t0 : 60AE02A0, t1 : 8000FD80, t2 : 34008F00, t3 : FFFF00FF
t4 : 00000083, t5 : 3E840024, t6 : 00000000, t7 : 11010132
s0 : 00000006, s1 : 607A25F8, s2 : 00000001, s3 : 00000000
s4 : 00000000, s5 : 00000000, s6 : 00000000, s7 : 6097F755
t8 : 600FABBC, t9 : 00000000, k0 : 30408401, k1 : 30410000
gp : 608B9860, sp : 60AEA798, s8 : 00000000, ra : 601853CC
EPC : 60189354, SREG : 3400EF03, Cause : 00000024
To display information about the types of CDP debugging that are enabled for your router, use the show debugging privileged EXEC command.
show debuggingThis command has no arguments or keywords.
Privileged EXEC
The following is sample output from the show debug command:
Router# show debugging
CDP:
CDP packet info debugging is on
CDP events debugging is on
CDP neighbor info debugging is on
CDP-PA: Packet received from neon.cisco.com on interface Ethernet0
CDP-EV: Encapsulation on interface Serial0 failed
CDP-AD: Aging entry for neon.cisco.com, on interface Ethernet0
In this example, all three types of CDP debugging are enabled.
A dagger (+) indicates that the command is documented in the Debug Command Reference.
debug cdp packets +
debug cdp adjacency +
debug cdp events +
To display diagnostic information about the controller, interface processor, and port adapters associated with a specified slot of a Cisco 7000 series, Cisco 7200 series, or Cisco 7500 series router, use the show diag privileged EXEC command.
show diag [slot]| slot | (Optional) Number of a specific slot. If not specified, this command displays information about all slots. |
EXEC
The following is sample output for the Cisco 7513 with a VIP2 interface processor board in slot 8. This card has two 4-port Token Ring port adapters located in port adapter bays 0 and 1.
Router# show diag 8
Slot 8:
Physical slot 8, ~physical slot 0x7, logical slot 8, CBus 0
Microcode Status 0x4
Master Enable, LED, WCS Loaded
Board is analyzed
Pending I/O Status: None
EEPROM format version 1
VIP2 controller, HW rev 2.2, board revision UNKNOWN
Serial number: 03341418 Part number: 73-1684-02
Test history: 0x00 RMA number: 00-00-00
Flags: cisco 7000 board; 7500 compatible
EEPROM contents (hex):
0x20: 01 15 02 02 00 32 FC 6A 49 06 94 02 00 00 00 00
0x30: 07 2B 00 2A 1A 00 00 00 00 00 00 00 00 00 00 00
Slot database information:
Flags: 0x4 Insertion time: 0x3188 (01:20:53 ago)
Controller Memory Size: 8 MBytes
PA Bay 0 Information:
Token Ring PA, 4 ports
EEPROM format version 1
HW rev 1.1, Board revision 0
Serial number: 02827613 Part number: 73-1390-04
PA Bay 1 Information:
Token Ring PA, 4 ports
EEPROM format version 1
HW rev 1.1, Board revision 88
Serial number: 02023786 Part number: 73-1390-04
| Field | Description |
|---|---|
| Slot | Slot in which the interface processor board is installed. |
| VIP2 controller | Information about the controller on the VIP2 board. |
| PA Bay | Number of the port adapter bay; this section provides information the hardware in this bay. For example, the type and the number of ports. |
The following is sample output from the show diag command for the Ethernet interface in slot 2 on a Cisco 7200 series router.
Router# show diag 0
Slot 2:
Ethernet port adapter, 8 ports
Port adapter is analyzed
Port adapter insertion time 1d18h ago
Hardware revision 1.0 Board revision K0
Serial number 2023387 Part number 73-1391-03
Test history 0x0 RMA number 00-00-00
EEPROM format version 1
EEPROM contents (hex):
0x20: 01 01 01 00 00 1E DF DB 49 05 6F 03 00 00 00 00
0x30: A0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Use the show environment EXEC command to display temperature and voltage information on the Cisco 7000 series, Cisco 7200 series, and Cisco 7500 series routers.
show environment [all | last | table]| all | (Optional) Displays a detailed listing of the power supplies, temperature readings, and voltage readings. |
| last | (Optional) Displays the reason for the last system shutdown that was related to voltage or temperature and the environmental status at that time. |
| table | (Optional) Displays the temperature and voltage thresholds and a table that lists the ranges of environmental measurements that are within specification. |
If no options are specified, the router displays the date and time that the environmental measurements were last checked and whether the environmental measurements were within specifications. For the Cisco 7500 series, the router displays only measurements that are out of normal range.
EXEC
Once a minute a routine is run that gets environmental measurements from sensors and stores the output into a buffer. This buffer is displayed on the console when show environment is invoked.
If a measurement exceeds desired margins, but has not exceeded fatal margins, a warning message is printed to the system console. The system software queries the sensors for measurements once a minute, but warnings for a given test point are printed at most once every hour for sensor readings in the warning range and once every 5 minutes for sensor readings in the critical range. If a measurement is out of line within these time segments, an automatic warning message appears on the console. As noted, you can query the environmental status with the show environment command at any time to determine whether a measurement is at the warning or critical tolerance.
If a shutdown occurs because of detection of fatal environmental margins, the last measured value from each sensor is stored in internal nonvolatile memory.
For environmental specifications, refer to the hardware installation and maintenance publication for your individual chassis.
The following example shows the typical show environment display when there are no warning conditions in the system for the Cisco 7000 series and Cisco 7200 series. This information may vary slightly depending on the platform you are using. The date and time of the query are displayed, along with the data refresh information and a message indicating that there are no warning conditions.
Router> show environment
Environmental Statistics
Environmental status as of 13:17:39 UTC Thu Jun 6 1996
Data is 7 second(s) old, refresh in 53 second(s)
All Environmental Measurements are within specifications
Table 1 describes the fields shown in the display.
| Field | Description |
|---|---|
| Environmental status as of... | Current date and time. |
| Data is..., refresh in... | Environmental measurements are output into a buffer every 60 seconds, unless other higher-priority processes are running. |
| Status message | If environmental measurements are not within specification, warning messages are displayed. |
The following are examples of messages that display on the system console when a measurement has exceeded an acceptable margin:
ENVIRONMENTAL WARNING: Air flow appears marginal. ENVIRONMENTAL WARNING: Internal temperature measured 41.3(C) ENVIRONMENTAL WARNING: +5 volt testpoint measured 5.310(V)
The system displays the following message if voltage or temperature exceed maximum margins:
SHUTDOWN: air flow problem
In the following example, there have been two intermittent power failures since a router was turned on, and the lower power supply is not functioning. The last intermittent power failure occurred on Monday, June 10, 1996, at 11:07 p.m.
7000# show environment all
Environmental Statistics
Environmental status as of 23:19:47 UTC Wed Jun 12 1996
Data is 6 second(s) old, refresh in 54 second(s)
WARNING: Lower Power Supply is NON-OPERATIONAL
Lower Power Supply:700W, OFF Upper Power Supply: 700W, ON
Intermittent Powerfail(s): 2 Last on 23:07:05 UTC Mon Jun 10 1996
+12 volts measured at 12.05(V)
+5 volts measured at 4.96(V)
-12 volts measured at -12.05(V)
+24 volts measured at 23.80(V)
Airflow temperature measured at 38(C)
Inlet temperature measured at 25(C)
Table 2 describes the fields shown in the display.
| Field | Description |
|---|---|
| Environmental status as of... | Date and time of last query. |
| Data is..., refresh in... | Environmental measurements are output into a buffer every 60 seconds, unless other higher-priority processes are running. |
| WARNING: | If environmental measurements are not within specification, warning messages are displayed. |
| Lower Power Supply | Type of power supply installed and its status (On or Off). |
| Upper Power Supply | Type of power supply installed and its status (On or Off). |
| Intermittent Powerfail(s) | Number of power hits (not resulting in shutdown) since the system was last booted. |
| Voltage Specifications | System voltage measurements. |
| Airflow and inlet temperature | Temperature of air coming in and going out. |
The following example is for the Cisco 7000 series router. The router retrieves the environmental statistics at the time of the last shutdown. In this example, the last shutdown was Friday, May 19, 1995, at 12:40 p.m., so the environmental statistics at that time are displayed:
Router# show environment last
Environmental Statistics
Environmental status as of 14:47:00 UTC Sun May 21 1995
Data is 6 second(s) old, refresh in 54 second(s)
WARNING: Upper Power Supply is NON-OPERATIONAL
LAST Environmental Statistics
Environmental status as of 12:40:00 UTC Fri May 19 1995
Lower Power Supply: 700W, ON Upper Power Supply: 700W, OFF
No Intermittent Powerfails
+12 volts measured at 12.05(V)
+5 volts measured at 4.98(V)
-12 volts measured at -12.00(V)
+24 volts measured at 23.80(V)
Airflow temperature measured at 30(C)
Inlet temperature measured at 23(C)
Table 3 describes the fields shown in the display.
| Field | Description |
|---|---|
| Environmental status as of... | Current date and time. |
| Data is..., refresh in... | Environmental measurements are output into a buffer every 60 seconds, unless other higher-priority processes are running. |
| WARNING: | If environmental measurements are not within specification, warning messages are displayed. |
| LAST Environmental Statistics | Displays test point values at time of the last environmental shutdown. |
| Lower Power Supply:
Upper Power Supply: | For the Cisco 7000, indicates the status of the two 700W power supplies.
For the Cisco 7010, indicates the status of the single 600W power supply. |
The following sample output shows the current environmental status in tables that list voltage and temperature parameters. There are three warning messages: one each about the lower power supply, the airflow temperature, and the inlet temperature. In this example, voltage parameters are shown to be in the normal range, airflow temperature is at a critical level, and inlet temperature is at the warning level:
Router> show environment table
Environmental Statistics
Environmental status as of Mon 11-2-1992 17:43:36
Data is 52 second(s) old, refresh in 8 second(s)
WARNING: Lower Power Supply is NON-OPERATIONAL
WARNING: Airflow temperature has reached CRITICAL level at 73(C)
WARNING: Inlet temperature has reached WARNING level at 41(C)
Voltage Parameters:
SENSE CRITICAL NORMAL CRITICAL
-------|--------------------|------------------------|--------------------
+12(V) 10.20 12.05(V) 13.80
+5(V) 4.74 4.98(V) 5.26
-12(V) -10.20 -12.05(V) -13.80
+24(V) 20.00 24.00(V) 28.00
Temperature Parameters:
SENSE WARNING NORMAL WARNING CRITICAL SHUTDOWN
-------|-------------|------------|-------------|--------------|-----------
Airflow 10 60 70 73(C) 88
Inlet 10 39 41(C) 46 64
Table 4 describes the fields shown in the display.
| Field | Description |
|---|---|
| SENSE (Voltage Parameters) | Voltage specification for DC line. |
| SENSE (Temperature Parameters) | Air being measured. Inlet measures the air coming in, and Airflow measures the temperature of the air inside the chassis. |
| WARNING | System is approaching an out-of-tolerance condition. |
| NORMAL | All monitored conditions meet normal requirements. |
| CRITICAL | Out-of-tolerance condition exists. |
| SHUTDOWN | Processor has detected condition that could cause physical damage to the system. |
The system displays the following message if the voltage or temperature enters the "Warning" range:
%ENVM-4-ENVWARN: Chassis outlet 3 measured at 55C/131F
The system displays the following message if the voltage or temperature enters the "Critical" range:
%ENVM-2-ENVCRIT: +3.45 V measured at +3.65 V
The system displays the following message if the voltage or temperature exceeds the maximum margins:
%ENVM-0-SHUTDOWN: Environmental Monitor initiated shutdown
The following message is sent to the console if a power supply has been inserted or removed from the system. This message relates only to systems that have two power supplies:
%ENVM-6-PSCHANGE: Power Supply 1 changed from Zytek AC Power Supply to removed
The following message is sent to the console if a power supply has been powered on or off. In the case of the power supply being shut off, this message can be due to the user shutting off the power supply or to a failed power supply. This message relates only to systems that have two power supplies:
%ENVM-6-PSLEV: Power Supply 1 state changed from normal to shutdown
The following is sample output from the show environment all command on the Cisco 7200 series router when there is a voltage warning condition in the system:
7200# show environment all
Power Supplies:
Power supply 1 is unknown. Unit is off.
Power supply 2 is Zytek AC Power Supply. Unit is on.
Temperature readings:
chassis inlet measured at 25C/77F
chassis outlet 1 measured at 29C/84F
chassis outlet 2 measured at 36C/96F
chassis outlet 3 measured at 44C/111F
Voltage readings:
+3.45 V measured at +3.83 V:Voltage in Warning range!
+5.15 V measured at +5.09 V
+12.15 measured at +12.42 V
-11.95 measured at -12.10 V
Table 5 describes the fields shown in the display.
| Field | Description |
|---|---|
| Power Supplies: | Current condition of the power supplies including the type and whether the power supply is on or off. |
| Temperature readings: | Current measurements of the chassis temperature at the inlet and outlet locations. |
| Voltage readings: | Current measurement of the power supply test points. |
The following example is for the Cisco 7200 series router. This example shows the measurements immediately before the last shutdown and the reason for the last shutdown (if appropriate).
7200# show environment last
chassis inlet previously measured at 27C/80F
chassis outlet 1 previously measured at 31C/87F
chassis outlet 2 previously measured at 37C/98F
chassis outlet 3 previously measured at 45C/113F
+3.3 V previously measured at 4.02
+5.0 V previously measured at 4.92
+12.0 V previously measured at 12.65
-12.0 V previously measured at 11.71
last shutdown reason - power supply shutdown
Table 6 describes the fields shown in the display.
| Field | Description |
|---|---|
| chassis inlet | Temperature measurements at the inlet area of the chassis. |
| chassis outlet | Temperature measurements at the outlet areas of the chassis. |
| voltages | Power supply test point measurements. |
| last shutdown reason | Possible shutdown reasons are power supply shutdown, critical temperature, and critical voltage. |
The following example is for the Cisco 7200 series router. This information lists the temperature and voltage shutdown thresholds for each sensor.
7200# show environment table
Sample Point LowCritical LowWarning HighWarning HighCritical
chassis inlet 40C/104F 50C/122F
chassis outlet 1 43C/109F 53C/127F
chassis outlet 2 75C/167F 75C/167F
chassis outlet 3 55C/131F 65C/149F
+3.45 V +2.76 +3.10 +3.80 +4.14
+5.15 V +4.10 +4.61 +5.67 +6.17
+12.15 V +9.72 +10.91 +13.37 +14.60
-11.95 V -8.37 -9.57 -14.34 -15.53
Shutdown system at 70C/158F
Table 7 describes the fields shown in the display.
| Field | Description |
|---|---|
| Sample Point | Area for which measurements are taken. |
| LowCritical | Level at which a critical message is issued for an out-of-tolerance voltage condition. The system continues to operate; however, the system is approaching shutdown. |
| LowWarning | Level at which a warning message is issued for an out-of-tolerance voltage condition. The system continues to operate, but operator action is recommended to bring the system back to a normal state. |
| HighWarning | Level at which a warning message is issued. The system continues to operate, but operator action is recommended to bring the system back to a normal state. |
| HighCritical | Level at which a critical message is issued. For the chassis, the router is shut down. For the power supply, the power supply is shut down. |
| Shutdown system at | The system is shut down if the specified temperature is met. |
The sample output for the Cisco 7500 series routers may vary depending on the specific model (for example, the Cisco 7513). The following is sample output from the show environment all command on the Cisco 7500 series router:
7500#showenvironmentallArbiter type 1, backplane type 7513 (id 2) Power supply #1 is 1200W AC (id 1), power supply #2 is removed (id 7) Active fault conditions: none Fan transfer point: 100% Active trip points: Restart_Inhibit 15 of 15 soft shutdowns remaining before hard shutdown 1 0123456789012 Dbus slots: X XX X card inlet hotpoint exhaust RSP(6) 35C/95F 47C/116F 40C/104F RSP(7) 35C/95F 43C/109F 39C/102F Shutdown temperature source is 'hotpoint' on RSP(6), requested RSP(6) +12V measured at 12.31 +5V measured at 5.21 -12V measured at -12.07 +24V measured at 22.08 +2.5 reference is 2.49 PS1 +5V Current measured at 59.61 A (capacity 200 A) PS1 +12V Current measured at 5.08 A (capacity 35 A) PS1 -12V Current measured at 0.42 A (capacity 3 A) PS1 output is 378 W
Table 8 describes the fields shown in the display.
| Field | Description |
|---|---|
| Arbiter type 1 | Numbers indicating the arbiter type and backplane type. |
| Power supply | Number and type of power supply installed in the chassis. |
| Active fault conditions: | If any fault conditions exist (such as power supply failure, fan failure, and temperature too high), they are listed here. |
| Fan transfer point: | Software controlled fan speed. If the router is operating below its automatic restart temperature, the transfer point is reduced by 10 percent of the full range each minute. If the router is at or above its automatic restart temperature, the transfer point is increased in the same way. |
| Active trip points: | Temperature sensor is compared against the values displayed at the bottom of the show environment table command output. |
| 15 of 15 soft shutdowns remaining | When the temperature increases above the "board shutdown" level, a soft shutdown occurs (that is, the cards are shut down, and the power supplies, fans, and CI continue to operate). When the system cools to the restart level, the system restarts. The system counts the number of times this occurs and keeps the up/down cycle from continuing forever. When the counter reaches zero, the system performs a hard shutdown, which requires a power cycle to recover. The soft shutdown counter is reset to its maximum value after the system has been up for 5 hours. |
| Dbus slots: | Indicates which chassis slots are occupied. |
| card, inlet, hotpoint, exhaust | Temperature measurements at the inlet, hotpoint, and exhaust areas of the card. The (6) and (7) indicate the slot numbers. Dual-RSP chassis can show two RSPs. |
| Shutdown temperature source | Indicates which of the three temperature sources is selected for comparison against the "shutdown" levels listed with the show environment table command. |
| Voltages (+12V, +5V, -12V, +24V,+2.5) | Voltages measured on the backplane. |
| Power supply current (PS1) | Current measured on the power supply. |
The following example is for the Cisco 7500 series router. This example shows the measurements immediately before the last shutdown.
7500#showenvironmentlastRSP(4) Inlet previously measured at 37C/98F RSP(4) Hotpoint previously measured at 46C/114F RSP(4) Exhaust previously measured at 52C/125F +12 Voltage previously measured at 12.26 +5 Voltage previously measured at 5.17 -12 Voltage previously measured at -12.03 +24 Voltage previously measured at 23.78
Table 9 describes the fields shown in the display
| Field | Description |
|---|---|
| RSP(4) Inlet, Hotpoint, Exhaust | Temperature measurements at the inlet, hotpoint, and exhaust areas of the card. |
| Voltages | Voltages measured on the backplane. |
The following example is for the Cisco 7500 series router. This information lists the temperature and voltage thresholds for each sensor. These thresholds indicate when error messages occur. There are two level of messages: warning and critical.
7500#show env table
Sample Point LowCritical LowWarning HighWarning HighCritical
RSP(4) Inlet 44C/111F 50C/122F
RSP(4) Hotpoint 54C/129F 60C/140F
RSP(4) Exhaust
+12 Voltage 10.90 11.61 12.82 13.38
+5 Voltage 4.61 4.94 5.46 5.70
-12 Voltage -10.15 -10.76 -13.25 -13.86
+24 Voltage 20.38 21.51 26.42 27.65
2.5 Reference 2.43 2.51
Shutdown boards at 70C/158F
Shutdown power supplies at 76C/168F
Restart after shutdown below 40C/104F
Table 10 describes the fields shown in the display.
| Field | Description |
|---|---|
| Sample Point | Area for which measurements are taken. |
| LowCritical | Level at which a critical message is issued for an out-of-tolerance voltage condition. The system continues to operate; however, the system is approaching shutdown. |
| LowWarning | Level at which a warning message is issued for an out-of-tolerance voltage condition. The system continues to operate, but operator action is recommended to bring the system back to a normal state. |
| HighWarning | Level at which a warning message is issued. The system continues to operate, but operator action is recommended to bring the system back to a normal state. |
| HighCritical | Level at which a critical message is issued. For the chassis, the router is shut down. For the power supply, the power supply is shut down. |
| Shutdown boards at | The card is shut down if the specified temperature is met. |
| Shutdown power supplies at | The system is shut down if the specified temperature is met. |
| Restart after shutdown | The system will restart when the specified temperature is met. |
Use the show gt64010 EXEC command to display all GT64010 internal registers and interrupt status on the Cisco 7200 series routers.
show gt64010This command has no arguments or keywords.
EXEC
This command displays information about the CPU interface, DRAM/device address space, device parameters, DMA channels, timers and counters, and PCI internal registers. The information is generally useful for diagnostic tasks performed by technical support only.
The following is a partial sample output for the show gt64010 command:
Router# show gt64010
GT64010 Channel 0 DMA:
dma_list=0x6088C3EC, dma_ring=0x4B018480, dma_entries=256
dma_free=0x6088CECC, dma_reqt=0x6088CECC, dma_done=0x6088CECC
thread=0x6088CEAC, thread_end=0x6088CEAC
backup_thread=0x0, backup_thread_end=0x0
dma_working=0, dma_complete=6231, post_coalesce_frames=6231
exhausted_dma_entries=0, post_coalesce_callback=6231
GT64010 Register Dump: Registers at 0xB4000000
CPU Interface:
cpu_interface_conf : 0x80030000 (b/s 0x00000380)
addr_decode_err : 0xFFFFFFFF (b/s 0xFFFFFFFF)
Processor Address Space :
ras10_low : 0x00000000 (b/s 0x00000000)
ras10_high : 0x07000000 (b/s 0x00000007)
ras32_low : 0x08000000 (b/s 0x00000008)
ras32_high : 0x0F000000 (b/s 0x0000000F)
cs20_low : 0xD0000000 (b/s 0x000000D0)
cs20_high : 0x74000000 (b/s 0x00000074)
cs3_boot_low : 0xF8000000 (b/s 0x000000F8)
cs3_boot_high : 0x7E000000 (b/s 0x0000007E)
pci_io_low : 0x00080000 (b/s 0x00000800)
pci_io_high : 0x00000000 (b/s 0x00000000)
pci_mem_low : 0x00020000 (b/s 0x00000200)
pci_mem_high : 0x7F000000 (b/s 0x0000007F)
internal_spc_decode : 0xA0000000 (b/s 0x000000A0)
bus_err_low : 0x00000000 (b/s 0x00000000)
bus_err_high : 0x00000000 (b/s 0x00000000)
...
To display the active accounting or checkpointed database or to display access-list violations, use the show ip accounting privileged EXEC command.
show ip accounting [checkpoint] [output-packets | access-violations]| checkpoint | (Optional) Indicates that the checkpointed database should be displayed. |
| output-packets | (Optional) Indicates that information pertaining to packets that passed access control and were successfully routed should be displayed. This is the default value if neither output-packets nor access-violations is specified. |
| access-violations | (Optional) Indicates that information pertaining to packets that failed access lists and were not routed should be displayed. |
If neither the output-packets nor access-violations keyword is specified, show ip accounting displays information pertaining to packets that passed access control and were successfully routed.
EXEC
To use this command, you must first enable IP accounting on a per-interface basis.
The following example displays information pertaining to packets that failed access lists and were not routed (see sample display for command).
show ip accounting access-violations
Following is sample output from the show ip accounting command:
Router# show ip accounting
Source Destination Packets Bytes
172.30.19.40 172.30.67.20 7 306
172.30.13.55 172.30.67.20 67 2749
172.30.2.50 172.30.33.51 17 1111
172.30.2.50 172.30.2.1 5 319
172.30.2.50 172.30.1.2 463 30991
172.30.19.40 172.30.2.1 4 262
172.30.19.40 172.30.1.2 28 2552
172.30.20.2 172.30.6.100 39 2184
172.30.13.55 172.30.1.2 35 3020
172.30.19.40 172.30.33.51 1986 95091
172.30.2.50 172.30.67.20 233 14908
172.30.13.28 172.30.67.53 390 24817
172.30.13.55 172.30.33.51 214669 9806659
172.30.13.111 172.30.6.23 27739 1126607
172.30.13.44 172.30.33.51 35412 1523980
172.30.7.21 172.30.1.2 11 824
172.30.13.28 172.30.33.2 21 1762
172.30.2.166 172.30.7.130 797 141054
172.30.3.11 172.30.67.53 4 246
172.30.7.21 172.30.33.51 15696 695635
172.30.7.24 172.30.67.20 21 916
172.30.13.111 172.30.10.1 16 1137
Table 82 describes significant fields shown in the display.
| Field | Description |
|---|---|
| Source | Source address of the packet |
| Destination | Destination address of the packet |
| Packets | Number of packets transmitted from the source address to the destination address |
| Bytes | Number of bytes transmitted from the source address to the destination address |
Following is sample output from the show ip accounting access-violations command:
Router# show ip accounting access-violations
Source Destination Packets Bytes ACL 172.30.19.40 172.30.67.20 7 306 77
172.30.13.55 172.30.67.20 67 2749 185
172.30.2.50 172.30.33.51 17 1111 140
172.30.2.50 172.30.2.1 5 319 140
172.30.19.40 172.30.2.1 4 262 77
Accounting data age is 41
Table 83 describes significant fields shown in the display.
| Field | Description |
|---|---|
| Source | Source address of the packet |
| Destination | Destination address of the packet |
| Packets | For accounting keyword, number of packets transmitted from the source address to the destination address
For access-violations keyword, number of packets transmitted from the source address to the destination address that violated the access control list |
| Bytes | For accounting keyword, number of bytes transmitted from the source address to the destination address
For access-violations keyword, number of bytes transmitted from the source address to the destination address that violated the access-control list |
| ACL | Number of the access list of the last packet transmitted from the source to the destination that failed an access list |
A dagger (+) indicates that the command is documented outside this chapter.
clear ip accounting +
ip accounting +
ip accounting-list +
ip accounting-threshold +
ip accounting-transits +
Use the show kerberos creds EXEC command to display the contents of your credentials cache. The show kerberos creds command is equivalent to the UNIX klist command.
show kerberos credsThis command has no keywords or arguments.
EXEC
When users authenticate themselves with Kerberos, they are issued an authentication ticket called a credential. The credential is stored in a credential cache.
In the following example, the entries in the credentials cache are displayed:
Router> show kerberos creds
Default Principal:
Valid Starting Expires Service Principal
18-Dec-1995 16:21:07 19-Dec-1995 00:22:24 krbtgt/CISCO.COM@CISCO.COM
In the following example, output is returned that acknowledges that credentials do not exist in the credentials cache:
Router> show kerberos creds
No Kerberos credentials
clear kerberos creds
Use the show logging EXEC command to display the state of logging (syslog).
show loggingThis command has no arguments or keywords.
EXEC
This command displays the state of syslog error and event logging, including host addresses, and whether console logging is enabled. This command also displays Simple Network Management Protocol (SNMP) configuration parameters and protocol activity.
The following is sample output from the show logging command:
Router# show logging
Syslog logging: enabled
Console logging: disabled
Monitor logging: level debugging, 266 messages logged.
Trap logging: level informational, 266 messages logged.
Logging to 131.108.2.238
SNMP logging: disabled, retransmission after 30 seconds
0 messages logged
Table 84 describes significant fields shown in the display.
| Field | Description |
|---|---|
| Syslog logging | When enabled, system logging messages are sent to a UNIX host that acts as a syslog server; that is, it captures and saves the messages. |
| Console logging | If enabled, states the level; otherwise, this field displays disabled. |
| Monitor logging | Minimum level of severity required for a log message to be sent to a monitor terminal (not the console). |
| Trap logging | Minimum level of severity required for a log message to be sent to a syslog server. |
| SNMP logging | Shows whether SNMP logging is enabled and the number of messages logged, and the retransmission interval. |
Use the show memory EXEC command to show statistics about memory, including memory free pool statistics.
show memory [type] [free] [summary]| type | (Optional) Memory type to display (processor, multibus, io, sram). If type is not specified, statistics for all memory types present are displayed. |
| free | (Optional) Displays free memory statistics. |
| summary | (Optional) Displays a summary of memory usage including the size and number of blocks allocated for each address of the system call that allocated the block. |
EXEC
The show memory command displays information about memory available after the system image decompresses and loads.
The following is sample output from the show memory command:
Router# show memory
Head Total(b) Used(b) Free(b) Lowest(b) Largest(b)
Processor B0EE38 5181896 2210036 2971860 2692456 2845368
Processor memory
Address Bytes Prev. Next Ref PrevF NextF Alloc PC What
B0EE38 1056 0 B0F280 1 18F132 List Elements
B0F280 2656 B0EE38 B0FD08 1 18F132 List Headers
B0FD08 2520 B0F280 B10708 1 141384 TTY data
B10708 2000 B0FD08 B10F00 1 14353C TTY Input Buf
B10F00 512 B10708 B11128 1 14356C TTY Output Buf
B11128 2000 B10F00 B11920 1 1A110E Interrupt Stack
B11920 44 B11128 B11974 1 970DE8 *Init*
B11974 1056 B11920 B11DBC 1 18F132 messages
B11DBC 84 B11974 B11E38 1 19ABCE Watched Boolean
B11E38 84 B11DBC B11EB4 1 19ABCE Watched Boolean
B11EB4 84 B11E38 B11F30 1 19ABCE Watched Boolean
B11F30 84 B11EB4 B11FAC 1 19ABCE Watched Boolean
Router#
The following is sample output from the show memory free command:
Router# show memory free
Head Total(b) Used(b) Free(b) Lowest(b) Largest(b)
Processor B0EE38 5181896 2210076 2971820 2692456 2845368
Processor memory
Address Bytes Prev. Next Ref PrevF NextF Alloc PC What
24 Free list 1
CEB844 32 CEB7A4 CEB88C 0 0 0 96B894 SSE Manager
52 Free list 2
72 Free list 3
76 Free list 4
80 Free list 5
D35ED4 80 D35E30 D35F4C 0 0 D27AE8 96B894 SSE Manager
D27AE8 80 D27A48 D27B60 0 D35ED4 0 22585E SSE Manager
88 Free list 6
100 Free list 7
D0A8F4 100 D0A8B0 D0A980 0 0 0 2258DA SSE Manager
104 Free list 8
B59EF0 108 B59E8C B59F84 0 0 0 2258DA (fragment)
The display of show memory free contains the same types of information as the show memory display, except that only free memory is displayed, and the information is displayed in order for each free list.
The first section of the display includes summary statistics about the activities of the system memory allocator. Table 85 describes significant fields shown in the first section of the display.
| Field | Description |
|---|---|
| Head | Hexadecimal address of the head of the memory allocation chain. |
| Total (b) | Sum of used bytes plus free bytes. |
| Used (b) | Amount of memory in use. |
| Free (b) | Amount of memory not in use. |
| Lowest(b) | Smallest amount of free memory since last boot. |
| Largest (b) | Size of largest available free block. |
The second section of the display is a block-by-block listing of memory use. Table 86 describes significant fields shown in the second section of the display.
| Field | Description |
|---|---|
| Address | Hexadecimal address of block. |
| Bytes | Size of block in bytes. |
| Prev. | Address of previous block (should match Address on previous line). |
| Next | Address of next block (should match address on next line). |
| Ref | Reference count for that memory block, indicating how many different processes are using that block of memory. |
| PrevF | Address of previous free block (if free). |
| NextF | Address of next free block (if free). |
| Alloc PC | Address of the system call that allocated the block. |
| What | Name of process that owns the block, or "(fragment)" if the block is a fragment, or "(coalesced)" if the block was coalesced from adjacent free blocks. |
The show memory io command displays the free IO memory blocks. On the Cisco 4000, this command quickly shows how much unused IO memory is available.
The following is sample output from the show memory io command:
Router# show memory io
Address Bytes Prev. Next Ref PrevF NextF Alloc PC What
6132DA0 59264 6132664 6141520 0 0 600DDEC 3FCF0 *Packet Buffer*
600DDEC 500 600DA4C 600DFE0 0 6132DA0 600FE68 0
600FE68 376 600FAC8 600FFE0 0 600DDEC 6011D54 0
6011D54 652 60119B4 6011FEO 0 600FE68 6013D54 0
614FCA0 832 614F564 614FFE0 0 601FD54 6177640 0
6177640 2657056 6172E90 0 0 614FCA0 0 0
Total: 2723244
The show memory sram command displays the free SRAM memory blocks. For the Cisco 4000, this command supports the high-speed static RAM memory pool to make it easier to debug or diagnose problems with allocation or freeing of such memory.
The following is sample output from the show memory sram command:
Router# show memory sram
Address Bytes Prev. Next Ref PrevF NextF Alloc PC What
7AE0 38178 72F0 0 0 0 0 0
Total 38178
The show memory command on the Cisco 4000 includes information about SRAM memory and IO memory, and appears as follows:
Router# show memory
Head Total(b) Used(b) Free(b) Lowest(b) Largest(b)
Processor 49C724 28719324 1510864 27208460 26511644 15513908
I/O 6000000 4194304 1297088 2897216 2869248 2896812
SRAM 1000 65536 63400 2136 2136 2136
Address Bytes Prev. Next Ref PrevF NextF Alloc PC What
1000 2032 0 17F0 1 3E73E *Init*
17F0 2032 1000 1FE0 1 3E73E *Init*
1FE0 544 17F0 2200 1 3276A *Init*
2200 52 1FE0 2234 1 31D68 *Init*
2234 52 2200 2268 1 31DAA *Init*
2268 52 2234 229C 1 31DF2 *Init*
72F0 2032 6E5C 7AE0 1 3E73E Init
7AE0 38178 72F0 0 0 0 0 0
Router#
The show memory summary command displays a summary of all memory pools as well as memory usage per Alloc PC (address of the system call that allocated the block).
The following is a partial sample output from the show memory summary command. This command shows the size, blocks, and bytes allocated. Bytes equal the size multiplied by the blocks. For a description of the other fields, see Table 85 and Table 86.
router# show memory summary
Head Total(b) Used(b) Free(b) Lowest(b) Largest(b)
Processor B0EE38 5181896 2210216 2971680 2692456 2845368
Processor memory
Alloc PC Size Blocks Bytes What
0x2AB2 192 1 192 IDB: Serial Info
0x70EC 92 2 184 Init
0xC916 128 50 6400 RIF Cache
0x76ADE 4500 1 4500 XDI data
0x76E84 4464 1 4464 XDI data
0x76EAC 692 1 692 XDI data
0x77764 408 1 408 Init
0x77776 116 1 116 Init
0x777A2 408 1 408 Init
0x777B2 116 1 116 Init
0xA4600 24 3 72 List
0xD9B5C 52 1 52 SSE Manager
.......................
0x0 0 3413 2072576 Pool Summary
0x0 0 28 2971680 Pool Summary (Free Blocks)
0x0 40 3441 137640 Pool Summary(All Block Headers)
0x0 0 3413 2072576 Memory Summary
0x0 0 28 2971680 Memory Summary (Free Blocks)
To show the status of Network Time Protocol (NTP) associations, use the show ntp associations EXEC command.
show ntp associations [detail]| detail | (Optional) Shows detailed information about each NTP association. |
EXEC
Detailed descriptions of the information displayed by this command can be found in the NTP specification (RFC 1305).
The following is sample output from the show ntp associations command:
Router# show ntp associations
address ref clock st when poll reach delay offset disp
~160.89.32.2 160.89.32.1 5 29 1024 377 4.2 -8.59 1.6
+~131.108.13.33 131.108.1.111 3 69 128 377 4.1 3.48 2.3
*~131.108.13.57 131.108.1.111 3 32 128 377 7.9 11.18 3.6
* master (synced), # master (unsynced), + selected, - candidate, ~ configured
Router#
Table 87 describes significant fields shown in the display.
| Field | Description |
|---|---|
| (leading characters in display lines) | The first characters in a display line can be one or more of the following characters:
* Synchronized to this peer |
| address | Address of peer. |
| ref clock | Address of peer's reference clock. |
| st | Peer's stratum. |
| when | Time since last NTP packet received from peer. |
| poll | Polling interval (seconds). |
| reach | Peer reachability (bit string, in octal). |
| delay | Round-trip delay to peer (milliseconds). |
| offset | Relative time of peer's clock to local clock (milliseconds). |
| disp | Dispersion |
The following is sample output of the show ntp associations detail command:
Router# show ntp associations detail 160.89.32.2 configured, insane, invalid, stratum 5 ref ID 160.89.32.1, time AFE252C1.6DBDDFF2 (00:12:01.428 PDT Mon Jul 5 1993) our mode active, peer mode active, our poll intvl 1024, peer poll intvl 64 root delay 137.77 msec, root disp 142.75, reach 376, sync dist 215.363 delay 4.23 msec, offset -8.587 msec, dispersion 1.62 precision 2**19, version 3 org time AFE252E2.3AC0E887 (00:12:34.229 PDT Mon Jul 5 1993) rcv time AFE252E2.3D7E464D (00:12:34.240 PDT Mon Jul 5 1993) xmt time AFE25301.6F83E753 (00:13:05.435 PDT Mon Jul 5 1993) filtdelay = 4.23 4.14 2.41 5.95 2.37 2.33 4.26 4.33 filtoffset = -8.59 -8.82 -9.91 -8.42 -10.51 -10.77 -10.13 -10.11 filterror = 0.50 1.48 2.46 3.43 4.41 5.39 6.36 7.34 131.108.13.33 configured, selected, sane, valid, stratum 3 ref ID 131.108.1.111, time AFE24F0E.14283000 (23:56:14.078 PDT Sun Jul 4 1993) our mode client, peer mode server, our poll intvl 128, peer poll intvl 128 root delay 83.72 msec, root disp 217.77, reach 377, sync dist 264.633 delay 4.07 msec, offset 3.483 msec, dispersion 2.33 precision 2**6, version 3 org time AFE252B9.713E9000 (00:11:53.442 PDT Mon Jul 5 1993) rcv time AFE252B9.7124E14A (00:11:53.441 PDT Mon Jul 5 1993) xmt time AFE252B9.6F625195 (00:11:53.435 PDT Mon Jul 5 1993) filtdelay = 6.47 4.07 3.94 3.86 7.31 7.20 9.52 8.71 filtoffset = 3.63 3.48 3.06 2.82 4.51 4.57 4.28 4.59 filterror = 0.00 1.95 3.91 4.88 5.84 6.82 7.80 8.77 131.108.13.57 configured, our_master, sane, valid, stratum 3 ref ID 131.108.1.111, time AFE252DC.1F2B3000 (00:12:28.121 PDT Mon Jul 5 1993) our mode client, peer mode server, our poll intvl 128, peer poll intvl 128 root delay 125.50 msec, root disp 115.80, reach 377, sync dist 186.157 delay 7.86 msec, offset 11.176 msec, dispersion 3.62 precision 2**6, version 2 org time AFE252DE.77C29000 (00:12:30.467 PDT Mon Jul 5 1993) rcv time AFE252DE.7B2AE40B (00:12:30.481 PDT Mon Jul 5 1993) xmt time AFE252DE.6E6D12E4 (00:12:30.431 PDT Mon Jul 5 1993) filtdelay = 49.21 7.86 8.18 8.80 4.30 4.24 7.58 6.42 filtoffset = 11.30 11.18 11.13 11.28 8.91 9.09 9.27 9.57 filterror = 0.00 1.95 3.91 4.88 5.78 6.76 7.74 8.71
Table 88 describes significant fields shown in the display.
| Field | Descriptions |
|---|---|
| configured | Peer was statically configured. |
| dynamic | Peer was dynamically discovered. |
| our_master | Local machine is synchronized to this peer. |
| selected | Peer is selected for possible synchronization. |
| candidate | Peer is a candidate for selection. |
| sane | Peer passes basic sanity checks. |
| insane | Peer fails basic sanity checks. |
| valid | Peer time is believed to be valid. |
| invalid | Peer time is believed to be invalid. |
| leap_add | Peer is signaling that a leap second will be added. |
| leap-sub | Peer is signaling that a leap second will be subtracted. |
| unsynced | Peer is not synchronized to any other machine. |
| ref ID | Address of machine peer is synchronized to. |
| time | Last timestamp peer received from its master. |
| our mode | Our mode relative to peer (active / passive / client / server / bdcast / bdcast client). |
| peer mode | Peer's mode relative to us. |
| our poll ivl | Our poll interval to peer. |
| peer poll ivl | Peer's poll interval to us. |
| root delay | Delay along path to root (ultimate stratum 1 time source). |
| root disp | Dispersion of path to root. |
| reach | Peer reachability (bit string in octal). |
| sync dist | Peer synchronization distance. |
| delay | Round trip delay to peer. |
| offset | Offset of peer clock relative to our clock. |
| dispersion | Dispersion of peer clock. |
| precision | Precision of peer clock in Hz. |
| version | NTP version number that peer is using. |
| org time | Originate time stamp. |
| rcv time | Receive time stamp. |
| xmt time | Transmit time stamp. |
| filtdelay | Round trip delay in milliseconds of each sample. |
| filtoffset | Clock offset in milliseconds of each sample. |
| filterror | Approximate error of each sample. |
To show the status of Network Time Protocol (NTP), use the show ntp status EXEC command.
show ntp statusThis command has no arguments or keywords.
EXEC
The following is sample output from the show ntp status command:
Router# show ntp status Clock is synchronized, stratum 4, reference is 131.108.13.57 nominal freq is 250.0000 Hz, actual freq is 249.9990 Hz, precision is 2**19 reference time is AFE2525E.70597B34 (00:10:22.438 PDT Mon Jul 5 1993) clock offset is 7.33 msec, root delay is 133.36 msec root dispersion is 126.28 msec, peer dispersion is 5.98 msec
Table 89 shows the significant fields in the display.
| Field | Description |
|---|---|
| synchronized | System is synchronized to an NTP peer. |
| unsynchronized | System is not synchronized to any NTP peer. |
| stratum | NTP stratum of this system. |
| reference | Address of peer we are synchronized to. |
| nominal freq | Nominal frequency of system hardware clock. |
| actual freq | Measured frequency of system hardware clock. |
| precision | Precision of this system's clock (in Hz). |
| reference time | Reference timestamp. |
| clock offset | Offset of our clock to synchronized peer. |
| root delay | Total delay along path to root clock. |
| root dispersion | Dispersion of root path. |
| peer dispersion | Dispersion of synchronized peer. |
Use the show pci EXEC command to display information about the peripheral component interconnect (PCI) hardware registers or bridge registers for the Cisco 7200 series routers.
show pci {hardware | bridge [register]}| hardware | Displays PCI hardware registers. |
| bridge | Displays PCI bridge registers. |
| register | (Optional) Number of a specific bridge register in the range 0 to 7. If not specified, this command displays information about all registers. |
EXEC
The output of this command is generally useful for diagnostic tasks performed by technical support only.
The following is sample output for the PCI bridge register 1 on a Cisco 7200 series router:
router# show pci bridge 1
Bridge 4, Port Adaptor 1, Handle=1
DEC21050 bridge chip, config=0x0
(0x00): cfid = 0x00011011
(0x04): cfcs = 0x02800147
(0x08): cfccid = 0x06040002
(0x0C): cfpmlt = 0x00010010
(0x18): cfsmlt = 0x18050504
(0x1C): cfsis = 0x22805050
(0x20): cfmla = 0x48F04880
(0x24): cfpmla = 0x00004880
(0x3C): cfbc = 0x00000000
(0x40): cfseed = 0x00100000
(0x44): cfstwt = 0x00008020
The following is partial sample output for the PCI hardware register, which also includes information on all the PCI bridge registers on a Cisco 7200 series router:
router# show pci hardware
GT64010 External PCI Configuration registers:
Vendor / Device ID : 0xAB114601 (b/s 0x014611AB)
Status / Command : 0x17018002 (b/s 0x02800117)
Class / Revision : 0x00000006 (b/s 0x06000000)
Latency : 0x0F000000 (b/s 0x0000000F)
RAS[1:0] Base : 0x00000000 (b/s 0x00000000)
RAS[3:2] Base : 0x00000001 (b/s 0x01000000)
CS[2:0] Base : 0x00000000 (b/s 0x00000000)
CS[3] Base : 0x00000000 (b/s 0x00000000)
Mem Map Base : 0x00000014 (b/s 0x14000000)
IO Map Base : 0x01000014 (b/s 0x14000001)
Int Pin / Line : 0x00010000 (b/s 0x00000100)
Bridge 0, Downstream MB0 to MB1, Handle=0
DEC21050 bridge chip, config=0x0
(0x00): cfid = 0x00011011
(0x04): cfcs = 0x02800143
(0x08): cfccid = 0x06040002
(0x0C): cfpmlt = 0x00011810
(0x18): cfsmlt = 0x18000100
(0x1C): cfsis = 0x02809050
(0x20): cfmla = 0x4AF04880
(0x24): cfpmla = 0x4BF04B00
(0x3C): cfbc = 0x00000000
(0x40): cfseed = 0x00100000
(0x44): cfstwt = 0x00008020
...
To display your current level of privilege, use the show privilege EXEC command.
show privilegeThis command has no arguments or keywords.
EXEC
The following is sample output from the show privilege command. The current privilege level is 15.
Router# show privilege
Current privilege level is 15
enable password level
Use the show processes EXEC command to display information about the active processes.
show processes [cpu]| cpu | (Optional) Displays detailed CPU utilization statistics. |
EXEC
The following is sample output from the show processes command:
Router# show processes
CPU utilization for five seconds: 21%/0%; one minute: 2%; five minutes: 2%
PID QTy PC Runtime (ms) Invoked uSecs Stacks TTY Process
1 Mwe 2FEA4E 1808 464 3896 1796/3000 0 IP-EIGRP Router
2 Lst 11682 10236 109 93908 1828/2000 0 Check heaps
3 Mst 3AE9C 0 280 0 1768/2000 0 Timers
4 Lwe 74AD2 0 12 0 1492/2000 0 ARP Input
5.ME 912E4 0 2 0 1892/2000 0 IPC Zone Manager
6.ME 91264 0 1 0 1936/2000 0 IPC Realm Manager
7.ME 91066 0 30 0 1784/2000 0 IPC Seat Manager
8.ME 133368 0 1 0 1928/2000 0 CXBus hot stall
9.ME 1462EE 0 1 0 1940/2000 0 Microcode load
10 Msi 127538 4 76 52 1608/2000 0 Env Mon
11.ME 160CF4 0 1 0 1932/2000 0 MIP Mailbox
12 Mwe 125D7C 4 280 14 1588/2000 0 SMT input
13 Lwe AFD0E 0 1 0 1772/2000 0 Probe Input
14 Mwe AF662 0 1 0 1784/2000 0 RARP Input
15 Hwe A1F9A 228 549 415 3240/4000 0 IP Input
16 Msa C86A0 0 114 0 1864/2000 0 TCP Timer
17 Lwe CA700 0 1 0 1756/2000 0 TCP Protocols
18.ME CCE7C 0 1 0 1940/2000 0 TCP Listener
19 Mwe AC49E 0 1 0 1592/2000 0 BOOTP Server
20 Mwe 10CD84 24 77 311 1652/2000 0 CDP Protocol
21 Mwe 27BF82 0 2 0 1776/2000 0 ATMSIG Input
The following is sample output from the show processes cpu command:
Router# show processes cpu
CPU utilization for five seconds: 5%/2%; one minute: 3%; five minutes: 2%
PID Runtime (ms) Invoked uSecs 5Sec 1Min 5Min TTY Process
1 1736 58 29931 0% 0% 0% Check heaps
2 68 585 116 1.00% 1.00% 0% IP Input
3 0 744 0 0% 0% 0% TCP Timer
4 0 2 0 0% 0% 0% TCP Protocols
5 0 1 0 0% 0% 0% BOOTP Server
6 16 130 123 0% 0% 0% ARP Input
7 0 1 0 0% 0% 0% Probe Input
8 0 7 0 0% 0% 0% MOP Protocols
9 0 2 0 0% 0% 0% Timers
10 692 64 10812 0% 0% 0% Net Background
11 0 5 0 0% 0% 0% Logger
12 0 38 0 0% 0% 0% BGP Open
13 0 1 0 0% 0% 0% Net Input
14 540 3466 155 0% 0% 0% TTY Background
15 0 1 0 0% 0% 0% BGP I/O
16 5100 1367 3730 0% 0% 0% IGRP Router
17 88 4232 20 0.20% 1.00% 0% BGP Router
18 152 14650 10 0% 0% 0% BGP Scanner
19 224 99 2262 0% 0% 1.00% Exec
Table 90 describes significant fields shown in the two displays.
| Field | Description |
|---|---|
| CPU utilization for five seconds | CPU utilization for the last 5 seconds. The second number indicates the percent of CPU time spent at the interrupt level. |
| one minute | CPU utilization for the last minute. |
| five minutes | CPU utilization for the last 5 minutes. |
| PID | Process ID. |
| Q | Process queue priority. Possible values: H (high), M (medium), L (low). |
| Ty | Scheduler test. Possible values: * (currently running), E (waiting for an event), S (ready to run, voluntarily relinquished processor), rd (ready to run, wakeup conditions have occurred), we (waiting for an event), sa (sleeping until an absolute time), si (sleeping for a time interval), sp (sleeping for a time interval (alternate call), st (sleeping until a timer expires), hg (hung; the process will never execute again), xx (dead. The process has terminated, but not yet been deleted.). |
| PC | Current program counter. |
| Runtime (ms) | CPU time the process has used, in milliseconds. |
| Invoked | Number of times the process has been invoked. |
| uSecs | Microseconds of CPU time for each process invocation. |
| Stacks | Low water mark/Total stack space available, shown in bytes. |
| TTY | Terminal that controls the process. |
| Process | Name of process. |
| 5Sec | CPU utilization by task, in last 5 seconds. |
| 1Min | CPU utilization by task in last minute. |
| 5Min | CPU utilization by task in last 5 minutes. |
Use the show processes memory EXEC command to show memory utilization.
show processes memoryThis command has no arguments or keywords.
EXEC
The following is sample output from the show processes memory command:
Router# show processes memory
Total: 5611448, Used: 2307548, Free: 3303900
PID TTY Allocated Freed Holding Getbufs Retbufs Process
0 0 199592 1236 1907220 0 0 *Init*
0 0 400 76928 400 0 0 *Sched*
0 0 5431176 3340052 140760 349780 0 *Dead*
1 0 256 256 1724 0 0 Load Meter
2 0 264 0 5032 0 0 Exec
3 0 0 0 2724 0 0 Check heaps
4 0 97932 0 2852 32760 0 Pool Manager
5 0 256 256 2724 0 0 Timers
6 0 92 0 2816 0 0 CXBus hot stall
7 0 0 0 2724 0 0 IPC Zone Manager
8 0 0 0 2724 0 0 IPC Realm Manager
9 0 0 0 2724 0 0 IPC Seat Manager
10 0 892 476 3256 0 0 ARP Input
11 0 92 0 2816 0 0 SERIAL A'detect
12 0 216 0 2940 0 0 Microcode Loader
13 0 0 0 2724 0 0 RFSS watchdog
14 0 15659136 15658584 3276 0 0 Env Mon
...
77 0 116 0 2844 0 0 IPX-EIGRP Hello
2307224 Total
Table 91 describes significant fields shown in the display.
| Field | Description |
|---|---|
| Total | Total amount of memory held. |
| Used | Total amount of used memory. |
| Free | Total amount of free memory. |
| PID | Process ID. |
| TTY | Terminal that controls the process. |
| Allocated | Bytes of memory allocated by the process. |
| Freed | Bytes of memory freed by the process, regardless of who originally allocated it. |
| Holding | Amount of memory currently allocated to the process. |
| Getbuffs | Number of times the process has requested a packet buffer. |
| Retbuffs | Number of times the process has relinguished a packet buffer. |
| Process | Process name. |
| *Init* | System initialization. |
| *Sched* | The scheduler. |
| *Dead* | Processes as a group that are now dead. |
| Total | Total amount of memory held by all processes. |
Use the show protocols EXEC command to display the configured protocols.
This command shows the global and interface-specific status of any configured Level 3 protocol; for example, IP, DECnet, IPX, AppleTalk, and so forth.
show protocolsThis command has no arguments or keywords.
EXEC
The following is sample output from the show protocols command:
Router# show protocols
Global values:
Internet Protocol routing is enabled
DECNET routing is enabled
XNS routing is enabled
Appletalk routing is enabled
X.25 routing is enabled
Ethernet 0 is up, line protocol is up
Internet address is 131.108.1.1, subnet mask is 255.255.255.0
Decnet cost is 5
XNS address is 2001.AA00.0400.06CC
AppleTalk address is 4.129, zone Twilight
Serial 0 is up, line protocol is up
Internet address is 192.31.7.49, subnet mask is 255.255.255.240
Ethernet 1 is up, line protocol is up
Internet address is 131.108.2.1, subnet mask is 255.255.255.0
Decnet cost is 5
XNS address is 2002.AA00.0400.06CC
AppleTalk address is 254.132, zone Twilight
Serial 1 is down, line protocol is down
Internet address is 192.31.7.177, subnet mask is 255.255.255.240
AppleTalk address is 999.1, zone Magnolia Estates
For more information on the parameters or protocols shown in this sample output, see the Network Protocols Configuration Guide, Part 1 and the Network Protocols Configuration Guide, Part 2.
To list the current state of the queue lists, use the show queueing privileged EXEC command.
show queueing [custom | priority]| custom | (Optional) Shows status of custom queue lists. |
| priority | (Optional) Shows status of priority lists. |
Privileged EXEC
If no keyword is entered, this command show the status of both custom and priority queue lists.
The following is sample output from the show queueing custom EXEC command:
Router# show queueing custom
Current custom queue configuration:
List Queue Args
3 10 default
3 3 interface Tunnel3
3 3 protocol ip
3 3 byte-count 444 limit 3
The following is sample output from the show queueing command. On interface Serial0, there are two active conversations. Weighted fair queueing ensures that both of these IP data streams--both using TCP--receive equal bandwidth on the interface while they have messages in the pipeline, even though there is more FTP data in the queue than rcp data.
Router# show queueing
Current fair queue configuration:
Interface Serial0
Input queue: 0/75/0 (size/max/drops); Total output drops: 0
Output queue: 18/64/30 (size/threshold/drops)
Conversations 2/8 (active/max active)
Reserved Conversations 0/0 (allocated/max allocated)
(depth/weight/discards) 3/4096/30
Conversation 117, linktype: ip, length: 556, flags: 0x280
source: 171.69.128.115, destination: 171.69.58.89, id: 0x1069, ttl: 59,
TOS: 0 prot: 6, source port 514, destination port 1022
(depth/weight/discards) 14/4096/0
Conversation 155, linktype: ip, length: 1504, flags: 0x280
source: 171.69.128.115, destination: 171.69.58.89, id: 0x104D, ttl: 59,
TOS: 0 prot: 6, source port 20, destination port 1554
custom-queue-list
priority-group
priority-list interface
priority-list queue-limit
queue-list default
queue-list interface
queue-list protocol
queue-list queue byte-count
queue-list queue limit
Use the show rmon EXEC command to display the current RMON agent status on the router.
show rmon [alarms | capture | events | filter | history | hosts | matrix | statistics | task | topn]| alarms | (Optional) Displays the RMON alarm table. |
| capture | (Optional) Displays the RMON buffer capture table. Available on Cisco 2500 series and Cisco AS5200 only. |
| events | (Optional) Displays the RMON event table. |
| filter | (Optional) Displays the RMON filter table. Available on Cisco 2500 series and Cisco AS5200 only. |
| history | (Optional) Displays the RMON history table. Available on Cisco 2500 series and Cisco AS5200 only. |
| hosts | (Optional) Displays the RMON hosts table. Available on Cisco 2500 series and Cisco AS5200 only. |
| matrix | (Optional) Displays the RMON matrix table. Available on Cisco 2500 series and Cisco AS5200 only. |
| statistics | (Optional) Displays the RMON statistics table. Available on Cisco 2500 series and Cisco AS5200 only. |
| task | (Optional) Displays general RMON statistics. |
| topn | (Optional) Displays the RMON top-n hosts table. Available on Cisco 2500 series and Cisco AS5200 only. |
If no option is specified, the task option is displayed.
EXEC
Refer to the specific show rmon command for an example and description of the fields.
For additional information, refer to the RMON MIB described in RFC 1757.
The following is sample output from the show rmon command. All counters are from the time the router was initialized.
Router#show rmon145678 packets input (34562 promiscuous), 0 drops 145678 packets processed, 0 on queue, queue utilization 15/64
Table 92 describes the fields shown in the display.
| Field | Description |
|---|---|
| x packets input | Number of packets received on RMON-enabled interfaces. |
| x promiscuous | Number of input packets that were seen by the router only because RMON placed the interface in promiscuous mode. |
| x drops | Number of input packets that could not be processed because the RMON queue overflowed. |
| x packets processed | Number of input packets actually processed by the RMON task. |
| x on queue | Number of input packets that are sitting on the RMON queue, waiting to be processed. |
| queue utilization x/y | y is the maximum size of the RMON queue; x is the largest number of packets that were ever on the queue at a particular time. |
rmon
rmon alarm
rmon event
rmon queuesize
show rmon alarms
show rmon capture
show rmon events
show rmon filter
show rmon history
show rmon hosts
show rmon matrix
show rmon statistics
show rmon topn
Use the show rmon alarms EXEC command to display the contents of the router's RMON alarm table.
show rmon alarmsThis command has no keywords or arguments.
EXEC
For additional information, refer to the RMON MIB described in RFC 1757.
You must have first enabled RMON on the interface, and configured RMON alarms to display alarm information with the show rmon alarms command.
The following is sample output from the show rmon alarms command:
router#show rmon alarms
Alarm 2 is active, owned by manager1
Monitors ifEntry.1.1 every 30 seconds
Taking delta samples, last value was 0
Rising threshold is 15, assigned to event 12
Falling threshold is 0, assigned to event 0
On startup enable rising or falling alarm
Table 93 describes the fields shown in the display.
| Field | Description |
|---|---|
| Alarm 2 is active, owned by manager1 | Unique index into the alarmTable, showing the alarm status is active, and the owner of this row, as defined in the alarmTable of RMON. |
| Monitors ifEntry.1.1 | Object identifier of the particular variable to be sampled. Equivalent to alarmVariable in RMON. |
| every 30 seconds | Interval in seconds over which the data is sampled and compared with the rising and falling thresholds. Equivalent to alarmInterval in RMON. |
| Taking delta samples | Method of sampling the selected variable and calculating the value to be compared against the thresholds. Equivalent to alarmSampleType in RMON. |
| last value was | Value of the statistic during the last sampling period. Equivalent to alarmValue in RMON. |
| Rising threshold is | Threshold for the sampled statistic. Equivalent to alarmRisingThreshold in RMON. |
| assigned to event | Index of the eventEntry that is used when a rising threshold is crossed. Equivalent to alarmRisingEventIndex in RMON. |
| Falling threshold is | Threshold for the sampled statistic. Equivalent to alarmFallingThreshold in RMON. |
| assigned to event | Index of the eventEntry that is used when a falling threshold is crossed. Equivalent to alarmFallingEventIndex in RMON. |
| On startup enable rising or falling alarm | Alarm that may be sent when this entry is first set to valid. Equivalent to alarmStartupAlarm in RMON. |
Use the show rmon capture EXEC command to display the contents of the router's RMON capture table.
show rmon captureThis command has no keywords or arguments.
EXEC
For additional information, refer to the RMON MIB described in RFC 1757.
You must have first enabled RMON on the interface, and configured RMON alarms and events to display alarm information with the show rmon capture command.
This command is available on the Cisco 2500 series and Cisco AS5200 only.
The following is sample output from the show rmon capture command:
router#show rmon capture
Buffer 4096 is active, owned by manager1
Captured data is from channel 4096
Slice size is 128, download size is 128
Download offset is 0
Full Status is spaceAvailable, full action is lockWhenFull
Granted 65536 octets out of 65536 requested
Buffer has been on since 00:01:16, and has captured 1 packets
Current capture buffer entries:
Packet 1 was captured 416 ms since buffer was turned on
Its length is 326 octets and has a status type of 0
Packet ID is 634, and contains the following data:
00 00 0c 03 12 ce 00 00 0c 08 9d 4e 08 00 45 00
01 34 01 42 00 00 1d 11 e3 01 ab 45 30 15 ac 15
31 06 05 98 00 a1 01 20 9f a8 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00
Table 94 describes the fields shown in the display.
| Field | Description |
|---|---|
| Buffer 4096 is active | Equates to bufferControlIndex in the bufferControlTable of RMON. Uniquely identifies a valid (active) row in this table. |
| owned by manager1 | Denotes the owner of this row. Equates to bufferControlOwner in the bufferControlTable of RMON. |
| Captured data is from channel | Equates to the bufferControlChannelIndex and identifies which RMON channel is the source of these packets. |
| Slice size is | Identifies the maximum number of octets of each packet that will be saved in this capture buffer. Equates to bufferControlCaptureSliceSize of RMON. |
| download size is | Identifies the maximum number of octets of each packet in this capture buffer that will be returned in an SNMP retrieval of that packet. Equates to bufferControlDownloadSliceSize in RMON. |
| Download offset is | Offset of the first octet of each packet in this capture buffer that will be returned in an SNMP retrieval of that packet. Equates to bufferControlDownloadOffset in RMON. |
| Full Status is spaceAvailable | Shows whether the buffer is full or has room to accept new packets. Equates to bufferControlFullStatus in RMON. |
| full action is lockWhenFull | Controls the action of the buffer when it reaches full status. Equates to bufferControlFullAction in RMON. |
| Granted 65536 octets | Actual maximum number of octets that can be saved in this capture buffer. Equates to bufferControlMaxOctetsGranted in RMON. |
| out of 65536 requested | Requested maximum number of octets to be saved in this capture buffer. Equates to bufferControlMaxOctetsRequested in RMON. |
| Buffer has been on since | Indicates how long the buffer has been available. |
| and has captured 1 packets | Number of packets captured since buffer was turned on. Equates to bufferControlCapturedPackets in RMON. |
| Current capture buffer entries: | Lists each packet captured. |
| Packet 1 was captured 416 ms since buffer was turned on
Its length is 326 octets and has a status type of 0 | Zero indicates the error status of this packet. Equates to captureBufferPacketStatus in RMON, where its value options are documented. |
| Packet ID is | Index that describes the order of packets received on a particular interface. Equates to captureBufferPacketID in RMON. |
| and contains the following data: | Data inside the packet, starting at the beginning of the packet. |
rmon
rmon alarm
rmon event
show rmon
Use the show rmon events EXEC command to display the contents of the router's RMON event table.
show rmon eventsThis command has no keywords or arguments.
EXEC
For additional information, refer to the RMON MIB described in RFC 1757.
You must have first enabled RMON on the interface, and configured RMON events to display alarm information with the show rmon events command.
The following is sample output from the show rmon events command:
router#show rmon events
Event 12 is active, owned by manager1
Description is interface-errors
Event firing causes log and trap to community rmonTrap, last fired 00:00:00
Table 95 describes the fields shown in the display.
| Field | Description |
|---|---|
| Event 12 is active, owned by manager1 | Unique index into the eventTable, showing the event status is active, and the owner of this row, as defined in the eventTable of RMON. |
| Description is interface-errors | Type of event, in this case an interface error. |
| Event firing causes log and trap | Type of notification that the router will make about this event. Equivalent to eventType in RMON. |
| community rmonTrap | If an SNMP trap is to be sent, it will be sent to the SNMP community specified by this octet string. Equivalent to eventCommunity in RMON. |
| last fired | Last time the event was generated. |
Use the show rmon filter EXEC command to display the contents of the router's RMON filter table.
show rmon filterThis command has no keywords or arguments.
EXEC
For additional information, refer to the RMON MIB described in RFC 1757.
You must have first enabled RMON on the interface, and configured RMON alarms and events to display alarm information with the show rmon filter command.
This command is available on the Cisco 2500 series and Cisco AS5200 only.
The following is sample output from the show rmon filter command:
router#show rmon filter
Filter 4096 is active, and owned by manager1
Data offset is 12, with
Data of 08 00 00 00 00 00 00 00 00 00 00 00 00 00 ab 45 30 15 ac 15 31 06
Data Mask is ff ff 00 00 00 00 00 00 00 00 00 00 00 00 ff ff ff ff ff ff ff ff
Data Not Mask is 0
Pkt status is 0, status mask is 0, not mask is 0
Associated channel 4096 is active, and owned by manager1
Type of channel is acceptFailed, data control is off
Generate event index 0
Event status is eventFired, # of matches is 1482
Turn on event index is 0, turn off event index is 0
Description:
Table 96 describes the fields shown in the display.
| Field | Description |
|---|---|
| Filter 4096 is active, and owned by manager1 | Unique index of the filter, its current state, and the owner, as defined in the filterTable of RMON. |
| Data offset is | Offset from the beginning of each packet where a match of packet data will be attempted. Equivalent to filterPktDataOffset in RMON. |
| Data of | Data that is to be matched with the input packet. Equivalent to filterPktData in RMON. |
| Data Mask is | Mask that is applied to the match process. Equivalent to filterPktDataMask in RMON. |
| Data Not Mask is | Inversion mask that is applied to the match process. Equivalent to filterPktDataNotMask in RMON. |
| Pkt status is | Status that is to be matched with the input packet. Equivalent to filterPktStatus in RMON. |
| status mask is | Mask that is applied to the status match process. Equivalent to filterPktStatusMask in RMON. |
| not mask is | Inversion mask that is applied to the status match process. Equivalent to filterPktStatusNotMask in RMON. |
| Associated channel 4096 is active, and owned by manager1 | Unique index of the channel, its current state, and the owner, as defined in the channelTable of RMON. |
| Type of channel is acceptMatched | This object controls the action of the filters associated with this channel. Equivalent to channelAcceptType of RMON. |
| data control is off | This object controls the flow of data through this channel. Equivalent to channelDataControl in RMON. |
| Generate event index 0 | Value of this object identifies the event that is configured to be generated when the associated channelDataControl is on and a packet is matched. Equivalent to channelEventIndex in RMON. |
| Event status is eventFired | When the channel is configured to generate events when packets are matched, this message indicates the means of controlling the flow of those events. Equivalent to channelEventStatus in RMON. |
| # of matches is | Number of times this channel has matched a packet. Equivalent to channelMatches in RMON. |
| Turn on event index is | Value of this object identifies the event that is configured to turn the associated channelDataControl from off to on when the event is generated. Equivalent to channelTurnOnEventIndex in RMON. |
| Turn off event index is | Value of this object identifies the event that is configured to turn the associated channelDataControl from on to off when the event is generated. Equivalent to channelTurnOffEventIndex in RMON. |
| Description: | Comment describing this channel. |
rmon
rmon alarm
rmon event
show rmon
Use the show rmon history EXEC command to display the contents of the router's RMON history table.
show rmon historyThis command has no keywords or arguments.
EXEC
For additional information, refer to the RMON MIB described in RFC 1757.
You must have first enabled RMON on the interface, and configured RMON alarms and events to display alarm information with the show rmon history command.
This command is available on the Cisco 2500 series and Cisco AS5200 only.
The following is sample output from the show rmon history command:
router#show rmon history
Entry 1 is active, and owned by manager1
Monitors ifEntry.1.1 every 30 seconds
Requested # of time intervals, ie buckets, is 5
Granted # of time intervals, ie buckets, is 5
Sample # 14 began measuring at 00:11:00
Received 38346 octets, 216 packets,
0 broadcast and 80 multicast packets,
0 undersized and 0 oversized packets,
0 fragments and 0 jabbers,
0 CRC alignment errors and 0 collisions.
# of dropped packet events is 0
Network utilization is estimated at 10
Table 97 describes the fields shown in the display.
| Field | Description |
|---|---|
| Entry 1 is active, and owned by manager1 | Unique index of the history entry, its current state, and the owner as defined in the historyControlTable of RMON. |
| Monitors ifEntry.1.1 | This object identifies the source of the data for which historical data was collected and placed in a media-specific table. Equivalent to historyControlDataSource in RMON. |
| every 30 seconds | Interval in seconds over which the data is sampled for each bucket in the part of the media-specific table associated with this historyControlEntry. Equivalent to historyControlInterval in RMON. |
| Requested # of time intervals, ie buckets, is | Requested number of discrete time intervals over which data is to be saved in the part of the media-specific table associated with this historyControlEntry. Equivalent to historyControlBucketsRequested in RMON. |
| Granted # of time intervals, ie buckets, is | Actual number of discrete time intervals over which data is to be saved in the part of the media-specific table associated with this historyControlEntry. Equivalent to historyControlBucketsGranted in RMON. |
| Sample # 14 began measuring at | Time at the start of the interval over which this sample was measured. |
| Received 38346 octets | Total number of octets of data (including those in bad packets) received on the network (excluding framing bits but including FCS octets). Equivalent to etherHistoryOctets in RMON. |
| x packets | Number of packets (including bad packets) received during this sampling interval. Equivalent to etherHistoryPkts in RMON. |
| x broadcast | Number of good packets received during this sampling interval that were directed to the broadcast address. Equivalent to etherHistoryBroadcastPkts in RMON. |
| x multicast packets | Number of good packets received during this sampling interval that were directed to a multicast address. Equivalent to etherHistoryMulticastPkts in RMON. |
| x undersized | Number of packets received during this sampling interval that were fewer than 64 octets long (excluding framing bits but including FCS octets) and were otherwise well formed. Equivalent to etherHistoryUndersizedPkts in RMON. |
| x oversized packets | Number of packets received during this sampling interval that were longer than 1518 octets (excluding framing bits but including FCS octets) but were otherwise well formed. Equivalent to etherHistoryOversizePkts in RMON. |
| x fragments | Total number of packets received during this sampling interval that were fewer than 64 octets in length (excluding framing bits but including FCS octets), and had either a bad Frame Check Sequence (FCS) with an integral number of octets (FCS Error) or a bad FCS with a nonintegral number of octets (Alignment Error). Equivalent to etherHistoryFragments in RMON. |
| x jabbers | Number of packets received during this sampling interval that were longer than 1518 octets (excluding framing bits but including FCS octets), and had either a bad Frame Check Sequence (FCS) with an integral number of octets (FCS Error) or a bad FCS with a nonintegral number of octets (Alignment Error). Note that this definition of jabber is different than the definition in IEEE-802.3 section 8.2.1.5 (10BASE5) and section 10.3.1.4 (10BASE2). Equivalent to etherHistoryJabbers in RMON. |
| x CRC alignment errors | Number of packets received during this sampling interval that had a length (excluding framing bits but including FCS octets) from 64 to 1518 octets, inclusive, but had either a bad Frame Check Sequence (FCS) with an integral number of octets (FCS Error) or a bad FCS with a nonintegral number of octets (Alignment Error). Equivalent to etherHistoryCRCAlignErrors in RMON. |
| x collisions | Best estimate of the total number of collisions on this Ethernet segment during this sampling interval. Equivalent to etherHistoryCollisions in RMON. |
| # of dropped packet events is | Total number of events in which packets were dropped by the probe because of resources during this sampling interval. Note that this number is not necessarily the number of packets dropped, it is just the number of times this condition has been detected. Equivalent to etherHistoryDropEvents in RMON. |
| Network utilization is estimated at | Best estimate of the mean physical-layer network usage on this interface during this sampling interval, in hundredths of a percent. Equivalent to etherHistoryUtilization in RMON. |
rmon
rmon alarm
rmon event
show rmon
Use the show rmon hosts EXEC command to display the contents of the router's RMON hosts table.
show rmon hostsThis command has no keywords or arguments.
EXEC
For additional information, refer to the RMON MIB described in RFC 1757.
You must have first enabled RMON on the interface, and configured RMON alarms and events to display alarm information with the show rmon hosts command.
This command is available on the Cisco 2500 series and Cisco AS5200 only.
The following is sample output from the show rmon hosts command:
router#show rmon hosts
Host Control Entry 1 is active, and owned by manager1
Monitors host ifEntry.1.1
Table size is 51, last time an entry was deleted was 00:00:00
Creation Order number is 1
Physical address is 0000.0c02.5808
Packets: rcvd 6963, transmitted 7041
Octets: rcvd 784062, transmitted 858530
# of packets transmitted: broadcast 28, multicast 48
# of bad packets transmitted is 0
Table 98 describes the fields shown in the display.
| Field | Description |
|---|---|
| Host Control Entry 1 is active, and owned by manager1 | Unique index of the host entry, its current state, and the owner as defined in the hostControlTable of RMON. |
| Monitors host ifEntry.1.1 | This object identifies the source of the data for this instance of the host function. Equivalent to hostControlDataSource in RMON. |
| Table size is | Number of hostEntries in the hostTable and the hostTimeTable associated with this hostControlEntry. Equivalent to hostControlTableSize in RMON. |
| last time an entry was deleted was | Time when the last entry was deleted from the hostTable. |
| Creation Order number is | Index that defines the relative ordering of the creation time of hosts captured for a particular hostControlEntry. Equivalent to hostCreationOrder in RMON. |
| Physical address is | Physical address of this host. Equivalent to hostAddress in RMON. |
| Packets: rcvd | Number of good packets transmitted to this address. Equivalent to hostInPkts in RMON. |
| transmitted | Number of packets, including bad packets transmitted by this address. Equivalent to hostOutPkts in RMON. |
| Octets: rcvd | Number of octets transmitted to this address since it was added to the hostTable (excluding framing bits but including FCS octets), except for those octets in bad packets. Equivalent to hostInOctets in RMON. |
| transmitted | Number of octets transmitted by this address since it was added to the hostTable (excluding framing bits but including FCS octets), including those octets in bad packets. Equivalent to hostOutOctets in RMON. |
| # of packets transmitted: | Number of good packets transmitted by this address that were broadcast or multicast. |
| # of bad packets transmitted is | Number of bad packets transmitted by this address. |
rmon
rmon alarm
rmon event
show rmon
Use the show rmon matrix EXEC command to display the contents of the router's RMON matrix table.
show rmon matrixThis command has no keywords or arguments.
EXEC
For additional information, refer to the RMON MIB described in RFC 1757.
You must have first enabled RMON on the interface, and configured RMON alarms and events to display alarm information with the show rmon matrix command.
This command is available on the Cisco 2500 series and Cisco AS5200 only.
The following is sample output from the show rmon matrix command:
router#show rmon matrix
Matrix 1 is active, and owned by manager1
Monitors ifEntry.1.1
Table size is 451, last time an entry was deleted was at 00:00:00
Table 99 describes the fields shown in the display.
| Field | Description |
|---|---|
| Matrix 1 is active, and owned by manager1 | Unique index of the matrix entry, its current state, and the owner as defined in the matrixControlTable of RMON. |
| Monitors ifEntry.1.1 | This object identifies the source of the data for this instance of the matrix function. Equivalent to matrixControlDataSource in RMON. |
| Table size is 451, last time an entry was deleted was at | Size of the matrix table and the time that the last entry was deleted. |
rmon
rmon alarm
rmon event
show rmon
Use the show rmon statistics EXEC command to display the contents of the router's RMON statistics table.
show rmon statisticsThis command has no keywords or arguments.
EXEC
For additional information, refer to the RMON MIB described in RFC 1757.
You must have first enabled RMON on the interface, and configured RMON alarms and events to display alarm information with the show rmon statistics command.
This command is available on the Cisco 2500 series and Cisco AS5200 only.
The following is sample output from the show rmon statistics command:
router#show rmon statistics
Interface 1 is active, and owned by config
Monitors ifEntry.1.1 which has
Received 60739740 octets, 201157 packets,
1721 broadcast and 9185 multicast packets,
0 undersized and 0 oversized packets,
0 fragments and 0 jabbers,
0 CRC alignment errors and 32 collisions.
# of dropped packet events (due to lack of resources): 511
# of packets received of length (in octets):
64: 92955, 65-127: 14204, 128-255: 1116,
256-511: 4479, 512-1023: 85856, 1024-1518:2547
Table 100 describes the fields shown in the display.
| Field | Description |
|---|---|
| Interface 1 is active, and owned by config | Unique index of the statistics entry, its current state, and the owner as defined in the etherStatsTable of RMON. |
| Monitors ifEntry.1.1 | This object identifies the source of the data that this etherStats entry is configured to analyze. Equivalent to etherStatsDataSource in RMON. |
| Received 60739740 octets | Total number of octets of data (including those in bad packets) received on the network (excluding framing bits but including FCS octets). Equivalent to etherStatsOctets in RMON. |
| x packets | Number of packets (including bad packets) received. Equivalent to etherStatsPkts in RMON. |
| x broadcast | Number of good packets received that were directed to the broadcast address. Equivalent to etherStatsBroadcastPkts in RMON. |
| x multicast packets | Number of good packets received that were directed to a multicast address. Equivalent to etherStatsMulticastPkts in RMON. |
| x undersized | Number of packets received that were fewer than 64 octets long (excluding framing bits but including FCS octets) and were otherwise well formed. Equivalent to etherStatsUndersizedPkts in RMON. |
| x oversized packets | Number of packets received that were longer than 1518 octets (excluding framing bits but including FCS octets) but were otherwise well formed. Equivalent to etherStatsOversizePkts in RMON. |
| x fragments | Total number of packets received that were fewer than 64 octets in length (excluding framing bits but including FCS octets), and had either a bad Frame Check Sequence (FCS) with an integral number of octets (FCS Error) or a bad FCS with a nonintegral number of octets (Alignment Error). Equivalent to etherStatsFragments in RMON. |
| x jabbers | Number of packets received that were longer than 1518 octets (excluding framing bits but including FCS octets), and had either a bad Frame Check Sequence (FCS) with an integral number of octets (FCS Error) or a bad FCS with a nonintegral number of octets (Alignment Error). Note that this definition of jabber is different than the definition in IEEE-802.3 section 8.2.1.5 (10BASE5) and section 10.3.1.4 (10BASE2). Equivalent to etherStatsJabbers in RMON. |
| x CRC alignment errors | Number of packets received that had a length (excluding framing bits but including FCS octets) from 64 to 1518 octets, inclusive, but had either a bad Frame Check Sequence (FCS) with an integral number of octets (FCS Error) or a bad FCS with a nonintegral number of octets (Alignment Error). Equivalent to etherStatsCRCAlignErrors in RMON. |
| x collisions | Best estimate of the total number of collisions on this Ethernet segment. Equivalent to etherHistoryCollisions in RMON. |
| # of dropped packet events (due to lack of resources): | Total number of events in which packets were dropped by the probe because of a lack of resources. Note that this number is not necessarily the number of packets dropped, it is just the number of times this condition has been detected. Equivalent to etherStatsDropEvents in RMON. |
| # of packets received of length (in octets): | Separates the received packets (good and bad) by packet size in the given ranges (64, 65 to 127,128 to 255, 256 to 511, 512 to 1023, 1024 to 1516). |
rmon
rmon alarm
rmon event
show rmon
Use the show rmon topn EXEC command to display the contents of the router's RMON Top-N host table.
show rmon topnThis command has no keywords or arguments.
EXEC
For additional information, refer to the RMON MIB described in RFC 1757.
You must have first enabled RMON on the interface, and configured RMON events to display alarm information with the show rmon events command.
This command is available on the Cisco 2500 series and Cisco AS5200 only.
The following is sample output from the show rmon topn command:
router#show rmon topn
Host Entry 1 of report 1 is active, owned by manager1
The rate of change is based on hostTopNInPkts
This report was last started at 00:00:00
Time remaining in this report is 0 out of 0
Hosts physical address is 00ad.beef.002b
Requested # of hosts: 10, # of hosts granted: 10
Report # 1 of Top N hosts entry 1 is recording
Host 0000.0c02.5808 at a rate of 12
Table 101 describes the fields shown in the display.
| Field | Description |
|---|---|
| Host Entry 1 of report 1 is active, owned by manager1 | Unique index of the hostTopN entry, its current state, and the owner as defined in the hostTopNControlTable of RMON. |
| The rate of change is based on hostTopNInPkts | Variable for each host that the hostTopNRate variable is based on. |
| This report was last started at | Time the report was started. |
| Time remaining in this report is | Number of seconds left in the report currently being collected. Equivalent to hostTopNTimeRemaining in RMON. |
| out of | Number of seconds that this report has collected during the last sampling interval, or if this report is currently being collected, the number of seconds that this report is being collected during this sampling interval. Equivalent to hostTopNDuration in RMON. |
| Hosts physical address is | Host address. |
| Requested # of hosts: | Maximum number of hosts requested for the Top-N table. Equivalent to hostTopNRequestedSize in RMON. |
| # of hosts granted: | Maximum number of hosts granted for the Top-N table.Eqivalent to hostTopNGrantedSiz in RMON. |
| Report # 1 of Top N hosts entry 1 is recording | Report number and entry. |
| Host 0000.0c02.5808 at a rate of | Physical address of the host, and the amount of change in the selected variable during this sampling interval. Equivalent to hostTopNAddress and hostTopNRate in RMON. |
rmon
rmon alarm
rmon event
show rmon
To check the status of communications between the SNMP agent and SNMP manager, use the
show snmp EXEC command.
This command has no arguments or keywords.
EXEC
This command provides counter information for RFC 1213 SNMP operations. It also displays the chassis ID string defined with the snmp-server chassis-id command.
The following is sample output from the show snmp command:
Router# show snmp
Chassis: SN#TS02K229
167 SNMP packets input
0 Bad SNMP version errors
0 Unknown community name
0 Illegal operation for community name supplied
0 Encoding errors
167 Number of requested variables
0 Number of altered variables
0 Get-request PDUs
167 Get-next PDUs
0 Set-request PDUs
167 SNMP packets output
0 Too big errors (Maximum packet size 484)
0 No such name errors
0 Bad values errors
0 General errors
167 Get-response PDUs
0 SNMP trap PDUs
Use the show stacks EXEC command to monitor the stack utilization of processes and interrupt routines.
show stacksThis command has no arguments or keywords.
EXEC
The display from this command includes the reason for the last system reboot. If the system was reloaded because of a system failure, a saved system stack trace is displayed. This information is of use only to your technical support representative in analyzing crashes in the field. It is included here in case you need to read the displayed statistics to an engineer over the phone.
The following is sample output from the show stacks command following a system failure:
Router# show stacks
Minimum process stacks:
Free/Size Name
652/1000 Router Init
726/1000 Init
744/1000 BGP Open
686/1200 Virtual Exec
Interrupt level stacks:
Level Called Free/Size Name
1 0 1000/1000 env-flash
3 738 900/1000 Multiport Communications Interfaces
5 178 970/1000 Console UART
System was restarted by bus error at PC 0xAD1F4, address 0xD0D0D1A
GS Software (GS3), Version 9.1(0.16), BETA TEST SOFTWARE
Compiled Tue 11-Aug-92 13:27 by jthomas
Stack trace from system failure:
FP: 0x29C158, RA: 0xACFD4
FP: 0x29C184, RA: 0xAD20C
FP: 0x29C1B0, RA: 0xACFD4
FP: 0x29C1DC, RA: 0xAD304
FP: 0x29C1F8, RA: 0xAF774
FP: 0x29C214, RA: 0xAF83E
FP: 0x29C228, RA: 0x3E0CA
FP: 0x29C244, RA: 0x3BD3C
To display general information about the router when reporting a problem, use the show tech-support privileged EXEC command.
show tech-support [page] [password]| page | (Optional) Causes the output to display a page of information at a time. Use the return key to display the next line of output or use the space bar to display the next page of information. If not used, the output scrolls (that is, does not stop for page breaks). |
| password | (Optional) Leaves passwords and other security information in the output. If not used, passwords and other security-sensitive information in the output are replaced with the word "<removed>" (this is the default). |
Display output without page breaks and remove passwords and other security information.
Privileged EXEC
Use this command to help collect general information about the router when you are reporting a problem. This command displays the equivalent of the following show commands:
For a sample display of the output of the show tech-support command, refer to these show commands.
A dagger (+) indicates that the command is documented outside this chapter.
show buffers
show controllers +
show interfaces +
show processes cpu
show processes memory
show running-config +
show stacks +
show version +
Use the show tcp EXEC command to display the status of TCP connections.
show tcp [line-number]| line-number | (Optional) Absolute line number of the line for which you want to display Telnet connection status |
EXEC
The following is sample output from the show tcp command:
Router# show tcp
con0 (console terminal), connection 1 to host MATHOM
Connection state is ESTAB, I/O status: 1, unread input bytes: 1
Local host: 172.30.7.18, 33537 Foreign host: 192.31.7.17, 23
Enqueued packets for retransmit: 0, input: 0, saved: 0
Event Timers (current time is 2043535532):
Timer: Retrans TimeWait AckHold SendWnd KeepAlive
Starts: 69 0 69 0 0
Wakeups: 5 0 1 0 0
Next: 2043536089 0 0 0 0
iss: 2043207208 snduna: 2043211083 sndnxt: 2043211483 sndwnd: 1344
irs: 3447586816 rcvnxt: 3447586900 rcvwnd: 2144 delrcvwnd: 83
RTTO: 565 ms, RTV: 233 ms, KRTT: 0 ms, minRTT: 68 ms, maxRTT: 1900 ms
ACK hold: 282 ms
Datagrams (max data segment is 536 bytes):
Rcvd: 106 (out of order: 0), with data: 71, total data bytes: 83
Sent: 96 (retransmit: 5), with data: 92, total data bytes: 4678
Table 102 describes the following lines of output shown in the display:
con0 (console terminal), connection 1 to host MATHOM Connection state is ESTAB, I/O status: 1, unread input bytes: 1 Local host: 172.30.7.18, 33537 Foreign host: 192.31.7.17, 23 Enqueued packets for retransmit: 0, input: 0, saved: 0
| Field | Description |
|---|---|
| con0 | Identifying number of the line. |
| (console terminal) | Location string. |
| connection 1 | Number identifying the TCP connection. |
| to host MATHOM | Name of the remote host to which the connection has been made. |
| Connection state is ESTAB | A connection progresses through a series of states during its lifetime. These states follow in the order in which a connection progresses through them.
For more information, see RFC 793, Transmission Control Protocol Functional Specification. |
| I/O status: 1 | Number describing the current internal status of the connection. |
| unread input bytes: 1 | Number of bytes that the lower-level TCP processes have read, but the higher level TCP processes have not yet processed. |
| Local host: 192.31.7.18 | IP address of the network server. |
| 33537 | Local port number, as derived from the following equation: line-number + (512 * random-number). (The line number uses the lower nine bits; the other bits are random.) |
| Foreign host: 192.31.7.17 | IP address of the remote host to which the TCP connection has been made. |
| 23 | Destination port for the remote host. |
| Enqueued packets for retransmit: 0 | Number of packets waiting on the retransmit queue. These are packets on this TCP connection that have been sent but have not yet been acknowledged by the remote TCP host. |
| input: 0 | Number of packets that are waiting on the input queue to be read by the user. |
| saved: 0 | Number of received out-of-order packets that are waiting for all packets comprising the message to be received before they enter the input queue. For example, if packets 1, 2, 4, 5, and 6 have been received, packets 1 and 2 would enter the input queue, and packets 4, 5, and 6 would enter the saved queue. |
The following line of output shows the current time according to the system clock of the local host:
Event Timers (current time is 2043535532):
The time shown is the number of milliseconds since the system started.
The following lines of output display the number of times that various local TCP timeout values were reached during this connection. In this example, the local host retransmitted 69 times because it received no response from the remote host, and it transmitted an acknowledgment many more times because there was no data on which to piggyback.
Timer: Retrans TimeWait AckHold SendWnd KeepAlive Starts: 69 0 69 0 0 Wakeups: 5 0 1 0 0 Next: 2043536089 0 0 0 0
Table 103 describes the fields in the preceding lines of output.
| Field | Description |
|---|---|
| Timer: | The names of the timers in the display. |
| Starts: | The number of times the timer has been started during this connection. |
| Wakeups: | Number of keepalives transmitted without receiving any response. (This field is reset to zero when a response is received.) |
| Next: | The system clock setting that will trigger the next time this timer will go off. |
| Retrans | The Retransmission timer is used to time TCP packets that have not been acknowledged and are waiting for retransmission. |
| TimeWait | The TimeWait timer is used to ensure that the remote system receive a request to disconnect a session. |
| AckHold | The Acknowledgment timer is used to delay the sending of acknowledgments to the remote TCP in an attempt to reduce network use. |
| SendWnd | The Send Window is used to ensure that there is no closed window due to a lost TCP acknowledgment. |
| KeepAlive | The KeepAlive timer is used to control the transmission of test messages to the remote TCP to ensure that the link has not been broken without the local TCP's knowledge. |
The following lines of output display the sequence numbers that TCP uses to ensure sequenced, reliable transport of data. The local host and remote host each use these sequence numbers for flow control and to acknowledge receipt of datagrams. Table 104 describes the specific fields in these lines of output:
iss: 2043207208 snduna: 2043211083 sndnxt: 2043211483 sndwnd: 1344 irs: 3447586816 rcvnxt: 3447586900 rcvwnd: 2144 delrcvwnd: 83
| Field | Description |
|---|---|
| iss: 2043207208 | Initial send sequence number. |
| snduna: 2043211083 | Last send sequence number the local host sent but has not received an acknowledgment for. |
| sndnxt: 2043211483 | Sequence number the local host will send next. |
| sndwnd: 1344 | TCP window size of the remote host. |
| irs: 3447586816 | Initial receive sequence number. |
| rcvnxt: 3447586900 | Last receive sequence number the local host has acknowledged. |
| rcvwnd: 2144 | Local host's TCP window size. |
| delrcvwnd: 83 | Delayed receive window--data the local host has read from the connection, but has not yet subtracted from the receive window the host has advertised to the remote host. The value in this field gradually increases until it is larger than a full-sized packet, at which point it is applied to the rcvwnd field. |
The following lines of output display values that the local host uses to keep track of transmission times so that TCP can adjust to the network it is using. Table 105 describes the fields in the following line of output:
RTTO: 565 ms, RTV: 233 ms, KRTT: 0 ms, minRTT: 68 ms, maxRTT: 1900 ms ACK hold: 282 ms
| Field | Description |
|---|---|
| RTTO: 565 ms | Round-trip timeout. |
| RTV: 233 ms | Variance of the round-trip time. |
| KRTT: 0 ms | New round-trip timeout (using the Karn algorithm). This field separately tracks the round-trip time of packets that have been retransmitted. |
| minRTT: 68 ms | Smallest recorded round-trip timeout (hard wire value used for calculation). |
| maxRTT: 1900 ms | Largest recorded round-trip timeout. |
| ACK hold: 282 ms | Time the local host will delay an acknowledgment in order to piggyback data on it. |
For more information on these fields, refer to "Round Trip Time Estimation," P. Karn & C. Partridge, ACM SIGCOMM-87, August 1987.
Table 106 describes the fields in the following lines of output:
Datagrams (max data segment is 536 bytes): Rcvd: 106 (out of order: 0), with data: 71, total data bytes: 83 Sent: 96 (retransmit: 5), with data: 92, total data bytes: 4678
| Field | Description |
|---|---|
| Rcvd: 106 (out of order: 0) | Number of datagrams the local host has received during this connection (and the number of these datagrams that were out of order). |
| with data: 71 | Number of these datagrams that contained data. |
| total data bytes: 83 | Total number of bytes of data in these datagrams. |
| Sent: 96 (retransmit: 5) | Number of datagrams the local host sent during this connection (and the number of these datagrams that had to be retransmitted). |
| with data: 92 | Number of these datagrams that contained data. |
| total data bytes: 4678 | Total number of bytes of data in these datagrams. |
To display general information about the router when reporting a problem, use the show tech-support privileged EXEC command.
show tech-support [page] [password]| page | (Optional) Causes the output to display a page of information at a time. Use the return key to display the next line of output or use the space bar to display the next page of information. If not used, the output scrolls (that is, does not stop for page breaks). |
| password | (Optional) Leaves passwords and other security information in the output. If not used, passwords and other security-sensitive information in the output are replaced with the word "<removed>" (this is the default). |
Display output without page breaks and remove passwords and other security information.
Privileged EXEC
Use this command to help collect general information about the router when you are reporting a problem. This command displays the equivalent of the following show commands:
For a sample display of the output of the show tech-support command, refer to these show commands.
A dagger (+) indicates that the command is documented outside this chapter.
show buffers
show controllers +
show interfaces +
show processes cpu
show processes memory
show running-config +
show stacks +
show version +
To create or update an access policy, use the snmp-server access-policy global configuration command. To remove the specified access policy, use the no form of this command.
snmp-server access-policy destination-party source-party context privileges| destination-party | Name of a previously defined party identified as the destination party or target for this access policy. This name serves as a label used to reference a record defined for this party through the snmp-server party command. |
| source-party | Name of a previously defined party identified as the source party or subject for this access policy. This name serves as a label used to reference a record defined for this party through the snmp-server party command. |
| context | Name of a previously defined context that defines the resources for the access policy. This name serves as a label used to reference a record defined for this context through the snmp-server context command. |
| privileges | Bit mask representing the access privileges that govern the management operations that the source party can ask the destination party to perform. |
Global configuration
An access policy defines the management operations the destination party can perform in relation to resources defined by the specified context when requested by the source party. A destination party performs management operations that are requested by a source party. A source party sends communications to a destination party requesting the destination party to perform management operations. A context identifies object resources accessible to a party.
Access policies are defined for communications from the manager to the agent; in this case, the agent is the destination party and the manager is the source party. Access policies can also be defined on for Response message and trap message communication from the agent to the manager; in this case, the manager is the destination party and the agent is the source party.
The privileges argument specifies the types of SNMP operations that are allowed between the two parties. There are seven types of SNMP operations.You specify the privileges as a bit mask representing the access privileges that govern the management operations that the source party can ask the destination party to perform. In other words, the bit mask identifies the commands that the source party can send to the destination party.
You use decimal or hexadecimal format to specify privileges as a sum of values in which each value specifies an SNMP PDU type that the source party can use to request an operation. The decimal values are defined as follows:
To remove an access-policy entry, all three arguments specified as command arguments must match exactly the values of the entry to be deleted. A difference of one value constitutes a different access policy.
The first snmp-server command that you enter enables both versions of SNMP.
The following example configures an access policy providing the manager with read-only access to the agent:
snmp-server access-policy agt1 mgr1 ctx1 0x23
The following example configures an access policy providing the manager with read-write access to the agent:
snmp-server access-policy agt2 mgr2 ctx2 43
The following example configures an access policy that allows responses and SNMP v.2 traps to be sent from the agent to a management station:
snmp-server access-policy mgr1 agt1 ctx1 132
The following example removes the access policy configured for the destination party named agt1, the source party named mgr1, and with a context named ctx1.
no snmp-server access-policy agt1 mgr1 ctx1
snmp-server context
snmp-server party
To provide a message line identifying the SNMP server serial number, use the snmp-server chassis-id global configuration command. Use the no form of this command to restore the default value, if any.
snmp-server chassis-id text| text | Message you want to enter to identify the chassis serial number. |
On hardware platforms where the serial number can be machine read, the default is the serial number. For example, a Cisco 7000 has a default value of its serial number.
Global configuration
The Cisco MIB provides a chassis MIB variable that enables the SNMP manager to gather data on system card descriptions, chassis type, chassis hardware version, chassis ID string, software version of ROM monitor, software version of system image in ROM, bytes of processor RAM installed, bytes of NVRAM installed, bytes of NVRAM in use, current configuration register setting, and the value of the configuration register at the next reload. The following installed card information is provided: type of card, serial number, hardware version, software version, and chassis slot number.
The chassis ID message can be seen with show snmp command.
In the following example, the chassis serial number specified is 1234456:
snmp-server chassis-id 1234456
To set up the community access string to permit access to the SNMPv1 protocol, use the snmp-server community global configuration command. The no form of this command removes the specified community string.
snmp-server community string [view view-name] [ro | rw] [number]| string | Community string that acts like a password and permits access to the SNMP protocol. |
| ro | (Optional) Specifies read-only access. Authorized management stations are only able to retrieve MIB objects. |
| rw | (Optional) Specifies read-write access. Authorized management stations are able to both retrieve and modify MIB objects. |
| view view-name | (Optional) Name of a previously defined view. The view defines the objects available to the community. |
| number | (Optional) Integer from 1 to 99 that specifies an access list of IP addresses that are allowed to use the community string to gain access to the SNMP v.1 agent. |
By default, an SNMP community string permits read-only access to all objects.
Global configuration
For the previous version of this command, the string argument was optional. The string argument is now required. However, to prevent errors and provide backward-compatibility, if the string option is omitted, a default value of public is assumed.
The no snmp-server command disables both versions of SNMP (SNMPv1 and SNMPv2).
The first snmp-server command that you enter enables both versions of SNMP.
The following example assigns the string comaccess to SNMPv1 allowing read-only access and specifies that IP access list 4 can use the community string:
snmp-server community comaccess ro 4
The following example disables both versions of SNMP:
no snmp-server
To set the system contact (syscontact) string, use the snmp-server contact global configuration command. Use the no form to remove the system contact information.
snmp-server contact text| text | String that describes the system contact information. |
No syscontact string is set.
Global configuration
The following is an example of a syscontact string:
snmp-server contact Dial System Operator at beeper # 27345
To create or update a context record, use the snmp-server context global configuration command. To remove a specific context entry, use the no form of this command.
snmp-server context context-name context-oid view-name [volatile]| context-name | Name of the context to be created or updated. This name serves as a label used to reference a record for this context. |
| context-oid | Object identifier to assign to the context. Specify this value in dotted decimal notation, with an optional text identifier; for example, 1.3.6.1.6.3.3.1.4.131.108.45.11.1(== initialContextId.131.108.45.11.1). |
| view-name | Name of a previously defined view. The view defines the objects available to the context. |
| volatile | (Optional) Indicates that the entry identified by context-name will not be written to nonvolatile memory when the copy running-config startup-config command is given, or to the terminal when the show running-config command is given. |
Global configuration
A context record identifies object resources accessible to a party. A context record is one of the components that make up an access policy. Therefore, you must configure a context record before you can create an access policy that includes the context. Context records and party records further codify MIB views.
To remove a context entry, specify only the name of the context. The name identifies the context to be deleted.
The first snmp-server command that you enter enables both versions of SNMP.
The following example shows how to create a context that includes all objects in the MIB-II subtree using a previously defined view named mib2:
snmp-server context mycontext initialContextid.131.108.24.56.3 mib2
A dagger (+) indicates that the command is documented outside this chapter.
snmp-server view
copy running-config startup-config +
show running-config +
To enable the router to send SNMP traps, use the snmp-server enable global configuration command. The no form of this command disables sending SNMP traps.
snmp-server enable traps [trap-type] [trap-option]No traps are enabled.
If you enter this command with no keywords, the default is to enable all trap types.
Global configuration
This command is useful for disabling traps which are generating a large amount of uninteresting or useless noise.
If you do not enter an snmp-server enable command, no traps are sent. In order to configure the router to send SNMP traps, you must enter at least one snmp-server enable command. If you enter the command with no keywords, all trap types are enabled. If you enter the command with a keyword, only the trap type related to that keyword is enabled. In order to enable multiple types of traps, you must issue a separate snmp-server enable command for each trap type and trap option.
The snmp-server enable command is used in conjuction with the snmp-server host command. Use the snmp-server host command to specify which host or hosts receive SNMP traps. In order to send traps, you must configure at least one snmp-server host command.
For a host to receive a trap, both the snmp-server enable command and the snmp-server host command for that host must be enabled.
The trap types used in this command all have an associated MIB object that allows them to be globally enabled or disabled. Not all of the traps types available in the snmp-server host command have notificationEnable MIB objects, so some of these cannot be controlled using the snmp-server enable command.
The following example enables the router to send all traps to all hosts
snmp-server enable traps snmp-server host
The following example enables the router to send Frame Relay and environmental monitor traps.
snmp-server enable trap frame-relay snmp-server enable trap envmon temperature snmp-server host
The following example will not send traps to any host. The BGP traps are enabled for all hosts, but the only traps enabled to be sent to a host are ISDN traps.
snmp-server enable traps bgp snmp-server host bob public isdn
A dagger (+) indicates that the command is documented outside this chapter.
snmp trap illegal-address +
snmp-server host
To specify the recipient of an SNMP trap operation, use the snmp-server host global configuration command. The no form of this command removes the specified host.
snmp-server host host community-string [trap-type]| host | Name or Internet address of the host. |
| community-string | Password-like community string to send with the trap operation. |
| trap-type | (Optional) Type of trap to be sent to the trap receiver host. If no type is specified, all traps are sent. It can be one or more of the following values:
· bgp--Send Border Gateway Protocol (BGP) state change traps. · config--Send configuration traps. · dspu--Send downstream physical unit (DSPU) traps. · envmon--Send Cisco enterprise-specific environmental monitor traps when an environmental threshold is exceeded. · frame-relay--Send Frame Relay traps. · isdn--Send ISDN traps. · llc2--Send Logical Link Control, type 2 (LLC2) traps. · rptr--Send standard repeater (hub) traps. · rsrb--Send remote source route bridging (RSRB) traps. · sdlc--Send Synchronous Data Link Control (SDLC) traps. · sdllc--Send SDLLC traps. · snmp--Send SNMP traps defined in RFC 1157. · stun--Send serial tunnel (STUN) traps. · tty--Send Cisco enterprise-specific traps when a TCP connection closes. · x25--Send X.25 event traps. |
No traps are sent.
If you enter this command with no keywords, the default is to send all trap types.
Global configuration
If you do not enter an snmp-server host command, no traps are sent. In order to configure the router to send SNMP traps, you must enter at least one snmp-server host command. If you enter the command with no keywords, all hosts are enabled for all traps types. If you enter the command for one host, only traps to that host are enabled. In order to enable multiple hosts, you must issue a separate snmp-server host command for each host. You can specify multiple traps types in the command for each host.
When multiple snmp-server host commands are given for the same host, the community string in the last command is used, and in general, the trap types set in the last command will be used to filter the SNMP trap messages sent to that host.
The snmp-server host command is used in conjuction with the snmp-server enable command. Use the snmp-server enable command to specify which SNMP traps are sent globally. In order to send traps, you must configure at least one snmp-server enable command.
For a host to receive a trap, both the snmp-server enable command and the snmp-server host command for that host must be enabled.
A trap-type option's availability depends on the router type and Cisco IOS software features supported on the router. For example, the envmon trap-type is available only if the environmental monitor is part of the system.
The following example sends the SNMP traps defined in RFC 1157 to the host specified by the name cisco.com. The community string is defined as comaccess.
snmp-server enable traps snmp-server host cisco.com comaccess snmp
The following example sends the SNMP and Cisco environmental monitor enterprise-specific traps to address 172.30.2.160:
snmp-server enable traps snmp-server host 172.30.2.160 snmp envmon
The following example enables the router to send all traps to all hosts:
snmp-server enable traps snmp-server host
The following example will not send traps to any host. The BGP traps are enabled for all hosts, but the only ISDN traps are enabled to be sent to a host.
snmp-server enable traps bgp snmp-server host bob public isdn
snmp-server enable
snmp-server trap-timeout
To set the system location string, use the snmp-server location global configuration command. Use the no form of this command to remove the location string.
snmp-server location text| text | String that describes the system location information. |
No system location string is set.
Global configuration
The following example illustrates a system location string:
snmp-server location Building 3/Room 214
To establish control over the largest SNMP packet size permitted when the SNMP server is receiving a request or generating a reply, use the snmp-server packetsize global configuration command. Use the no form of this command to restore the default value.
snmp-server packetsize byte-count| byte-count | Integer byte count from 484 to 8192. |
484 bytes
Global configuration
The following example establishes a packet filtering of a maximum size of 1024 bytes:
snmp-server packetsize 1024
To create or update a party record, use the snmp-server party global configuration command. To remove a specific party entry, use the no form of this command.
snmp-server party party-name party-oid [protocol-address] [packetsize size]| party-name | Name of the party characterized by the contents of the record. This name serves as a label used to reference the party record that you are creating or modifying. |
| party-oid | Object identifier to assign to the party. Specify this value in dotted decimal notation, with an optional text identifier; for example, 1.3.6.1.6.3.3.1.3.131.108.34.54.1 (= initialPartyId.131.108.34.54.1) |
| protocol-address | (Optional) Address of the protocol that the party record pertains to. Currently the only supported protocol is UDP, so this value specifies a UDP address in the format a.b.c.d port.
In future releases, additional protocols will be supported. This value is used to specify the destination of trap messages. |
| packetsize size | (Optional) Maximum size in bytes of a message that this party is able to receive. By default, the packet size set through the snmp-server packetsize command is used. |
| local | remote | (Optional) Indicates that the party is local or remote. If neither local nor remote is specified, a default value of local is assumed. |
| authentication | (Optional) Indicates that the party uses an authentication protocol. If specified, either md5 or snmpv1 is required. |
| md5 key | (Optional) Indicates that the party uses the Message Digest algorithm MD5 for message authentication. If md5 is specified, you must also specify a 16-byte hexadecimal ASCII string representing the MD5 authentication key for the party. All messages sent to this party will be authenticated using the SNMP v2 MD5 authentication method with the key specified by key. |
| clock clock | (Optional) Initial value of the authentication clock. |
| lifetime lifetime | (Optional) Lifetime, in seconds, that represents the upper bound on acceptable delivery delay for messages generated by the party. |
| snmpv1 string | (Optional) Community string. The keyword snmpv1 indicates that the party uses community-based authentication. All messages sent to this party will be authenticated using the SNMP v1community string specified by string instead of MD5. |
| volatile | (Optional) Indicates that the entry identified by party-name will not be written to nonvolatile memory when the copy running-config startup-config command is given, or to the terminal when the show running-config command is given. |
If neither local nor remote is specified to indicate the location of the party, the party is assumed to be local.
If you do not specify a packet size, the packet size set through the snmp-server packetsize command is used.
Global configuration
You define parties to identify managers and agents. An SNMP v2 party identity is unique; it includes the logical network location of the party, characterized by the transport protocol domain and transport addressing information, and, optionally, an authentication method and its arguments.The authentication protocol reliably identifies the origin of all messages sent by the party. The authentication protocol also ensures the integrity of the messages; in other words, it ensures that the message received is the message that was sent.
Specifying md5 as the authentication method implies that this party record pertains to an SNMPv2 party.
Specifying snmpv1 as the authentication method implies that this party record pertains to an SNMPv1 party. Instead of using the snmp-server community command, you can use the snmp-server party command with the snmpv1 keyword to define an SNMP v.1 party to be used to communicate with an SNMP v.1 management station.
If authentication is not specified, the party record pertains to an SNMPv2 party, and no authentication will be performed for messages sent to this party.
To remove a party record, specify only the name of the party. The name identifies the party to be deleted.
The first snmp-server command that you enter enables both versions of SNMP.
The following example configures a remote unauthenticated party:
snmp-server party mgr1 initialPartyId.131.108.45.32.3 udp 131.108.45.76 162
The following example configures a local MD5-authenticated party with a large maximum packet size. You enter this command as a single line:
snmp-server party agt1 initialPartyId.131.108.45.32.4 packetsize 1500 local authentication md5 23de457623900ac3ef568fcb236589 lifetime 400
The following example configures an SNMP v.1 proxy party for the community public:
snmp-server party proxyv1 initialPartyId.131.108.45.32.100 authentication snmpv1 public
The following example removes the party named mgr1:
no snmp-server party mgr1
A dagger (+) indicates that the command is documented outside this chapter.
snmp-server community
copy running-config startup-config +
show running-config +
To establish the message queue length for each trap host, use the snmp-server queue-length global configuration command.
snmp-server queue-length length| length | Integer that specifies the number of trap events that can be held before the queue must be emptied. |
10 events
Global configuration
This command defines the length of the message queue for each trap host. Once a trap message is successfully transmitted, software will continue to empty the queue, but never faster than at a rate of four trap messages per second.
The following example establishes a message queue that traps four events before it must be emptied:
snmp-server queue-length 4
To use the SNMP message reload feature, the router configuration must include the snmp-server system-shutdown global configuration command. The no form of this command prevents an SNMP system-shutdown request (from an SNMP manager) from resetting the Cisco agent.
snmp-server system-shutdownThis command has no arguments or keywords.
This command is not included in the configuration file.
Global configuration
The following example illustrates how to include the SNMP message reload feature in the router configuration:
snmp-server system-shutdown
To limit the TFTP servers used via SNMP-controlled TFTP operations (saving and loading configuration files) to the servers specified in an access list, use the snmp-server tftp-server-list global configuration command. To disable this feature, use the no form of this command.
snmp-server tftp-server-list number| number | Standard IP access list number from 1 to 99. |
Disabled
Global configuration
The following example limits the TFTP servers that can be used for configuration file copies via SNMP to the servers in access list 44.
snmp-server tftp-server-list 44
To establish trap message authentication, use the snmp-server trap-authentication global configuration command. To remove message authentication, use the no form of this command.
snmp-server trap-authentication [snmpv1 | snmpv2]| snmpv1 | (Optional) Indicates that SNMP authentication traps will be sent to SNMPv1 management stations only. |
| snmpv2 | (Optional) Indicates that SNMP authentication traps will be sent to SNMPv2 management stations only. |
Specifying the snmp-server trap-authentication command without a keyword turns on trap message authentication. In this case, messages are sent to the host that is specified though the snmp-server host command and to any SNMP stations configured through access policies to receive trap messages.
Global configuration
Specify the snmpv1 or snmpv2 keyword to indicate the type of management stations to send the trap messages to.
This command enables the router as an agent to send a trap message when it receives an SNMPv1 packet with an incorrect community string or an SNMPv2 packet with an incorrect MD5 authentication key.
The SNMP specification requires that a trap message be generated for each packet with an incorrect community string or authentication key; however, because this action can result in a security breach, the router (as an agent) by default does not send a trap message when it receives an incorrect community string or authentication key.
The community string or key is checked before any access list that may be set, so it is possible to get spurious trap messages. In other words, if you have issued an snmp-server community command with a specified access list, you might receive messages that come from someone that is not on the access list; in this case, an authentication trap is issued.The only workarounds are to disable trap authentication or to configure an access list on a router between the SNMP agent and the SNMP manager to prevent packets from getting to the SNMP agent.
To turn off all message authentication traps, use the no snmp-server trap-authentication without a keyword. To turn off message authentication traps only for SNMPv1 stations or only for SNMPv2 stations, give the negative form of the command with the appropriate keyword.
The first snmp-server command that you enter enables both versions of SNMP.
The following example illustrates how to enter the command that establishes trap message authentication:
snmp-server trap-authentication
To specify the interface (and hence the corresponding IP address) that an SNMP trap should originate from, use the snmp-server trap-source global configuration command. Use the no form of the command to remove the source designation.
snmp-server trap-source interface| interface | Interface from which the SNMP trap originates. The argument includes the interface type and number in platform-specific syntax. |
No interface is specified.
Global configuration
When an SNMP trap is sent from a Cisco SNMP server, it has a trap address of whatever interface it happened to go out of at that time. Use this command if you want to use the trap address to trace particular needs.
The following example specifies that the IP address for interface Ethernet 0 is the source for all traps:
snmp-server trap-source ethernet 0
The following example specifies that the IP address for interface Ethernet 2/1 on a Cisco 7000 is the source for all traps:
snmp-server trap-source ethernet 2/1
To define how often to try resending trap messages on the retransmission queue, use the snmp-server trap-timeout global configuration command.
snmp-server trap-timeout seconds| seconds | Integer that sets the interval, in seconds, for resending the messages |
30 seconds
Global configuration
Before the Cisco IOS software tries to send a trap, it looks for a route to the destination address. If there is no known route, the trap is saved in a retransmission queue. The server trap-timeout command determines the number of seconds between retransmission attempts.
The following example sets an interval of 20 seconds to try resending trap messages on the retransmission queue:
snmp-server trap-timeout 20
To create or update a view entry, use the snmp-server view global configuration command. To remove the specified SNMP server view entry, use the no form of this command.
snmp-server view view-name oid-tree {included | excluded} [volatile]| view-name | Label for the view record that you are updating or creating. The name is used to reference the record. |
| oid-tree | Object identifier of the ASN.1 subtree to be included or excluded from the view. To identify the subtree, specify a text string consisting of numbers, such as 1.3.6.2.4, or a word, such as system. Replace a single subidentifier with the asterisk (*) wildcard to specify a subtree family; for example 1.3.*.4. |
| included | excluded | Type of view. You must specify either included or excluded. |
| volatile | (Optional) Indicates that the entry identified by view-name will not be written to nonvolatile memory when the copy running-config startup-config command is given, or to the terminal when the show running-config command is issued. |
Global configuration
Other SNMPv2 commands require a view as an argument. You use this command to create a view to be used as arguments for other commands that create records including a view.
Two standard predefined views can be used when a view is required, instead of defining a view. One is everything, which indicates that the user can see all objects. The other is restricted, which indicates that the user can see three groups: system, snmpStats, and snmpParties. The predefined views are described in RFC 1447.
The first snmp-server command that you enter enables both versions of SNMP.
The following example creates a view that includes all objects in the MIB-II subtree:
snmp-server view mib2 mib-2 included
The following example creates a view that includes all objects in the MIB-II system group and all objects in the Cisco enterprise MIB:
snmp-server phred system included snmp-server view phred cisco included
The following example creates a view that includes all objects in the MIB-II system group except for sysServices (System 7) and all objects for interface 1 in the MIB-II interfaces group:
snmp-server view agon system included snmp-server view agon system.7 excluded snmp-server view agon ifEntry.*.1 included
A dagger (+) indicates that the command is documented outside this chapter.
snmp-server context
copy running-config startup-config +
show running-config +
To enable SNMP link trap generation, use the snmp trap link-status command. To disable SNMP link traps, use the no form of this command.
snmp trap link-statusThis command has no arguments or keywords.
SNMP link traps are sent when an interface goes up or down.
Interface Configuration
By default, SNMP link traps are sent when an interface goes up or down. For interfaces expected to go up and down during normal usage, such as ISDN interfaces, the output generated by these traps may not be useful. The no form of this command disables these traps.
This example disables the sending of SNMP link traps related to the ISDN BRI 0 interface. This will stop all SNMP %LINK-UPDOWN messages from being sent for this interface.
interface bri 0 no snmp trap link-status
To control the number of login attempts that can be made on a line set up for TACACS verification, use the tacacs-server attempts global configuration command. Use the no form of this command to remove this feature and restore the default.
tacacs-server attempts count| count | Integer that sets the number of attempts. |
Three attempts
Global configuration
The following example changes the login attempt to just one try:
tacacs-server attempts 1
To specify for TACACS and Extended TACACS that the network or Cisco IOS software must indicate whether the user may perform an action when the user attempts to perform the action, use the tacacs-server authenticate global configuration command.
tacacs-server authenticate {connection [always] | enable | slip [always] [access-lists]}| connection | Configures a required response when a user makes a TCP connection. |
| enable | Configures a required response when a user enters the enable command. |
| slip | Configures a required response when a user starts a SLIP or PPP session. |
| always | (Optional) Performs authentication even when a user is not logged in. This option only applies to the connection or slip keywords. |
| access-lists | (Optional) Requests and installs access lists. This option only applies to the slip keyword. |
Global configuration
Enter one of the keywords to specify the action (when a user makes a TCP connection, for example).
The following example configures TACACS logins that authenticate user TCP connections:
tacacs-server authenticate connect
enable secret
enable use-tacacs
To send only a username to a specified server when a direct request is issued, use the tacacs-server directed-request global configuration command. Use the no form of this command to disable the direct-request feature.
tacacs-server directed-requestThis command has no arguments or keywords.
Enabled
Global configuration
This command sends the portion of the username before the @ symbol to the host specified after the @ symbol. In other words, with the directed-request feature enabled, you can direct a request to any of the configured servers and only the username is sent to the specified server.
Disabling tacacs-server directed-request causes the whole string, both before and after the @ symbol to be sent to the default tacacs server. When directed-request is disabled, the router queries the list of servers, starting with the first one in the list, sending the whole string, and accepting the first response that it gets from the server. The tacacs-server directed-request command is useful for sites that have developed their own tacacs server software which parses the whole string and makes decisions based on it.
With tacacs-server directed-request enabled, only configured tacacs servers can be specified by the user after the @ symbol. If the hostname specified by the user does not match the IP address of a tacacs server configured by the administrator, the user input is rejected.
Use no tacacs-server directed-request to disable the ability of the user to choose between configured tacacs servers and to cause the entire string to be passed to the default server.
The following example enables tacacs-server directed-request such that the entire user input is passed to the default tacacs server:
no tacacs-server directed-request
To enable an extended TACACS mode, use the tacacs-server extended global configuration command. Use the no form of this command to disable the mode.
tacacs-server extendedThis command has no arguments or keywords.
Disabled
Global configuration
This command initializes extended TACACS. To initialize AAA/TACACS+, use the aaa new-model command.
The following example enables extended TACACS mode:
tacacs-server extended
To specify a TACACS host, use the tacacs-server host global configuration command. You can use multiple tacacs-server host commands to specify multiple hosts. The Cisco IOS software searches for the hosts in the order you specify them. The no form of this command deletes the specified name or address.
tacacs-server host name| name | Name or IP address of the host. |
No TACACS host is specified.
Global configuration
The following example specifies a TACACS host named SCACAT:
tacacs-server host SCACAT
A dagger (+) indicates that the command is documented outside this chapter.
login tacacs +
ppp +
slip +
Use the tacacs-server key command to set the authentication/encryption key used for all TACACS+ communications between the access server and the TACACS+ daemon. To disable the key, use the no form of the command.
tacacs-server key key| key | The key used to set authentication and encryption. This key must match the key used on the TACACS+ daemon. |
Global Configuration
After enabling AAA with the aaa new-model command, you must set the authentication and encryption key using the tacacs-server key command.
The key entered must match the key used on the TACACS+ daemon. All leading spaces are ignored, spaces within and at the end of the key are not. If you use spaces in your key, do not enclose the key in double quotes unless the quotes themselves are part of the key.
The following example illustrates how to set the authentication and encryption key to 'dare to go':
tacacs-server key dare to go
To cause the network server to request the privileged password as verification, or to force successful login without further input from the user, use the tacacs-server last-resort global configuration command. The no tacacs-server last-resort command restores the system to the default behavior.
tacacs-server last-resort {password | succeed}| password | Allows the user to access the EXEC command mode by entering the password set by the enable command. |
| succeed | Allows the user to access the EXEC command mode without further question. |
If, when running the TACACS server, the TACACS server does not respond, the default action is to deny the request.
Global configuration
Use the tacacs-server last-resort command to be sure that login can occur; for example, when a systems administrator needs to log in to troubleshoot TACACS servers that might be down.
The following example forces successful login:
tacacs-server last-resort succeed
A dagger (+) indicates that the command is documented outside this chapter.
enable password
login (EXEC) +
To specify how long the system will wait for login input (such as username and password) before timing out, use the tacacs-server login-timeout global configuration command. Use the no form of this command to restore the default value of 30 seconds.
tacacs-server login-timeout seconds| seconds | Integer that determines the number of seconds the system will wait for login input before timing out. Available settings are from 1 to 300 seconds. |
The default login timeout value is 30 seconds.
Global configuration
With aaa new-model enabled, the default login timeout value is 30 seconds. The tacacs-server login-timeout command lets you change this timeout value from 1 to 300 seconds. To restore the default login timeout value of 30 seconds, use the no tacacs-server login-timeout command.
The following example changes the login timeout value to 60 seconds:
tacacs login 60
Use the tacacs-server notify global configuration command to cause a message to be transmitted to the TACACS server, with retransmission being performed by a background process for up to 5 minutes.
tacacs-server notify {connection [always] | enable | logout [always] | slip [always]}| connection | Specifies that a message be transmitted when a user makes a TCP connection. |
| always | (Optional) Sends a message even when a user is not logged in. This option applies only to SLIP or PPP sessions and can be used with the connection, logout, or slip keywords. |
| enable | Specifies that a message be transmitted when a user enters the enable command. |
| logout | Specifies that a message be transmitted when a user logs out. |
| slip | Specifies that a message be transmitted when a user starts a SLIP or PPP session. |
No message is transmitted to the TACACS server.
Global configuration
The terminal user receives an immediate response allowing access to the feature specified. Enter one of the keywords to specify notification of the TACACS server upon the corresponding action (when user logs out, for example).
The following example sets up notification of the TACACS server when a user logs out:
tacacs-server notify logout
To specify that the first TACACS request to a TACACS server be made without password verification, use the tacacs-server optional-passwords global configuration command. Use the no form of this command to restore the default.
tacacs-server optional-passwordsThis command has no arguments or keywords.
Disabled
Global configuration
When the user types in the login name, the login request is transmitted with the name and a zero-length password. If accepted, the login procedure completes. If the TACACS server refuses this request, the server software prompts for a password and tries again when the user supplies a password. The TACACS server must support authentication for users without passwords to make use of this feature. This feature supports all TACACS requests--login, SLIP, enable, and so on.
The following example configures the first login to not require TACACS verification:
tacacs-server optional-passwords
To specify the number of times the Cisco IOS software searches the list of TACACS server hosts before giving up, use the tacacs-server retransmit global configuration command.
tacacs-server retransmit retries| retries | Integer that specifies the retransmit count. |
Two retries
Global configuration
The Cisco IOS software will try all servers, allowing each one to time out before increasing the retransmit count.
The following example specifies a retransmit counter value of five times:
tacacs-server retransmit 5
To set the interval that the server waits for a server host to reply, use the tacacs-server timeout global configuration command. The no form of this command restores the default.
tacacs-server timeout seconds| seconds | Integer that specifies the timeout interval in seconds. |
5 seconds
Global configuration
The following example changes the interval timer to 10 seconds:
tacacs-server timeout 10
To test Flash memory on MCI and envm Flash EPROM interfaces, use the test flash EXEC command.
test flashThis command has no arguments or keywords.
EXEC
The following example illustrates how to begin the interface test:
test flash
To test the system interfaces on the modular router, use the test interfaces EXEC command.
test interfacesThis command has no arguments or keywords.
EXEC
The test interfaces EXEC command is intended for the factory checkout of network interfaces. It is not intended for diagnosing problems with an operational router. The test interfaces output does not report correct results if the router is attached to a "live" network. For each network interface that has an IP address that can be tested in loopback (MCI and ciscoBus Ethernet and all serial interfaces), the test interfaces command sends a series of ICMP echoes. Error counters are examined to determine the operational status of the interface.
The following example illustrates how to begin the interface test:
test interfaces
To perform a test of Multibus memory (including nonvolatile memory) on the modular router, use the test memory EXEC command.
test memory![]() | Caution The memory test overwrites memory. If you use the test memory command, you will need to rewrite nonvolatile memory. For example, if you test Multibus memory, which is the memory used by the CSC-R 4-Mbps Token Ring interfaces, you will need to reload the system before the network interfaces will operate properly. The test memory command is intended primarily for use by Cisco personnel. |
This command has no arguments or keywords.
EXEC
The following example illustrates how to begin the memory test:
test memory
Use the trace EXEC command to discover the routes that packets will actually take when traveling to their destination.
trace [protocol] [destination]| protocol | (Optional) Protocols that can be used are appletalk, clns, ip and vines. |
| destination | (Optional) Destination address or host name on the command line. The default parameters for the appropriate protocol are assumed and the tracing action begins. |
The protocol argument is based on the Cisco IOS software's examination of the format of destination. For example, if the software finds a destination argument in IP format, the protocol value defaults to ip.
Privileged EXEC
The trace command works by taking advantage of the error messages generated by routers when a datagram exceeds its time-to-live (TTL) value.
The trace command starts by sending probe datagrams with a TTL value of one. This causes the first router to discard the probe datagram and send back an error message. The trace command sends several probes at each TTL level and displays the round-trip time for each.
The trace command sends out one probe at a time. Each outgoing packet may result in one or two error messages. A "time exceeded" error message indicates that an intermediate router has seen and discarded the probe. A "destination unreachable" error message indicates that the destination node has received the probe and discarded it because it could not deliver the packet. If the timer goes off before a response comes in, trace prints an asterisk (*).
The trace command terminates when the destination responds, when the maximum TTL is exceeded, or when the user interrupts the trace with the escape sequence. By default, to invoke the escape sequence, type Ctrl-^ X--by simultaneously pressing and releasing the Ctrl, Shift, and 6 keys, and then pressing the X key.
To use nondefault parameters and invoke an extended trace test, enter the command without a destination argument. You will be stepped through a dialog to select the desired parameters.
Due to bugs in the IP implementation of various hosts and routers, the IP trace command may behave in odd ways.
Not all destinations will respond correctly to a probe message by sending back an "ICMP port unreachable" message. A long sequence of TTL levels with only asterisks, terminating only when the maximum TTL has been reached, may indicate this problem.
There is a known problem with the way some hosts handle an "ICMP TTL exceeded" message. Some hosts generate an "ICMP" message but they reuse the TTL of the incoming packet. Since this is zero, the ICMP packets do not make it back. When you trace the path to such a host, you may see a set of TTL values with asterisks (*). Eventually the TTL gets high enough that the ICMP message can get back. For example, if the host is six hops away, trace will time out on responses 6 through 11.
The following display shows sample IP trace output when a destination host name has been specified:
Router# trace ABA.NYC.mil
Type escape sequence to abort.
Tracing the route to ABA.NYC.mil (26.0.0.73)
1 DEBRIS.CISCO.COM (131.108.1.6) 1000 msec 8 msec 4 msec
2 BARRNET-GW.CISCO.COM (131.108.16.2) 8 msec 8 msec 8 msec
3 EXTERNAL-A-GATEWAY.STANFORD.EDU (192.42.110.225) 8 msec 4 msec 4 msec
4 BB2.SU.BARRNET.NET (131.119.254.6) 8 msec 8 msec 8 msec
5 SU.ARC.BARRNET.NET (131.119.3.8) 12 msec 12 msec 8 msec
6 MOFFETT-FLD-MB.in.MIL (192.52.195.1) 216 msec 120 msec 132 msec
7 ABA.NYC.mil (26.0.0.73) 412 msec 628 msec 664 msec
Table 107 describes the fields shown in the display.
| Field | Description |
|---|---|
| 1 | Indicates the sequence number of the router in the path to the host. |
| DEBRIS.CISCO.COM | Host name of this router. |
| 131.108.1.6 | Internet address of this router. |
| 1000 msec 8 msec 4 msec | Round-trip time for each of the three probes that are sent. |
The following display shows a sample trace session involving the extended dialog of the trace command.
Router#traceProtocol [ip]: Target IP address:mit.eduSource address: Numeric display [n]: Timeout in seconds [3]: Probe count [3]: Minimum Time to Live [1]: Maximum Time to Live [30]: Port Number [33434]: Loose, Strict, Record, Timestamp, Verbose[none]: Type escape sequence to abort. Tracing the route to MIT.EDU (18.72.2.1) 1 ICM-DC-2-V1.ICP.NET (192.108.209.17) 72 msec 72 msec 88 msec 2 ICM-FIX-E-H0-T3.ICP.NET (192.157.65.122) 80 msec 128 msec 80 msec 3 192.203.229.246 540 msec 88 msec 84 msec 4 T3-2.WASHINGTON-DC-CNSS58.T3.ANS.NET (140.222.58.3) 84 msec 116 msec 88 msec 5 T3-3.WASHINGTON-DC-CNSS56.T3.ANS.NET (140.222.56.4) 80 msec 132 msec 88 msec 6 T3-0.NEW-YORK-CNSS32.T3.ANS.NET (140.222.32.1) 92 msec 132 msec 88 msec 7 T3-0.HARTFORD-CNSS48.T3.ANS.NET (140.222.48.1) 88 msec 88 msec 88 msec 8 T3-0.HARTFORD-CNSS49.T3.ANS.NET (140.222.49.1) 96 msec 104 msec 96 msec 9 T3-0.ENSS134.T3.ANS.NET (140.222.134.1) 92 msec 128 msec 92 msec 10 W91-CISCO-EXTERNAL-FDDI.MIT.EDU (192.233.33.1) 92 msec 92 msec 112 msec 11 E40-RTR-FDDI.MIT.EDU (18.168.0.2) 92 msec 120 msec 96 msec 12 MIT.EDU (18.72.2.1) 96 msec 92 msec 96 msec
Table 108 describes the fields that are unique to the extended trace sequence, as shown in the display.
| Field | Description |
|---|---|
| Target IP address | You must enter a host name or an IP address. There is no default. |
| Source address | One of the interface addresses of the router to use as a source address for the probes. The router will normally pick what it feels is the best source address to use. |
| Numeric display | The default is to have both a symbolic and numeric display; however, you can suppress the symbolic display. |
| Timeout in seconds | The number of seconds to wait for a response to a probe packet. The default is 3 seconds. |
| Probe count | The number of probes to be sent at each TTL level. The default count is 3. |
| Minimum Time to Live [1] | The TTL value for the first probes. The default is 1, but it can be set to a higher value to suppress the display of known hops. |
| Maximum Time to Live [30] | The largest TTL value that can be used. The default is 30. The trace command terminates when the destination is reached or when this value is reached. |
| Port Number | The destination port used by the UDP probe messages. The default is 33434. |
| Loose, Strict, Record, Timestamp, Verbose | IP header options. You can specify any combination. The trace command issues prompts for the required fields. Note that trace will place the requested options in each probe; however, there is no guarantee that all routers (or end nodes) will process the options. |
| Loose | Allows you to specify a list of nodes that must be traversed when going to the destination. |
| Strict | Allows you to specify a list of nodes that must be the only nodes traversed when going to the destination. |
| Record | Allows you to specify the number of hops to leave room for. |
| Timestamp | Allows you to specify the number of time stamps to leave room for. |
| Verbose | If you select any option, the verbose mode is automatically selected and trace prints the contents of the option field in any incoming packets. You can prevent verbose mode by selecting it again, toggling its current setting. |
Table 109 describes the characters that can appear in trace output.
| Char | Description |
|---|---|
| nn msec | For each node, the round-trip time in milliseconds for the specified number of probes. |
| * | The probe timed out. |
| ? | Unknown packet type. |
| A | Administratively unreachable. Usually, this output indicates that an access list is blocking traffic. |
| H | Host unreachable. |
| N | Network unreachable. |
| P | Protocol unreachable. |
| Q | Source quench. |
| U | Port unreachable. |
Use the trace EXEC command to discover the IP routes that packets will actually take when traveling to their destination.
trace [protocol] [destination]| protocol | (Optional) Protocols that can be used are appletalk, clns, ip and vines. |
| destination | (Optional) Destination address or host name on the command line. The default parameters for the appropriate protocol are assumed and the tracing action begins. |
The protocol argument is based on the Cisco IOS software examination of the format of the destination argument. For example, if the software finds a destination in IP format, the protocol defaults to ip.
EXEC
The trace command works by taking advantage of the error messages generated by routers when a datagram exceeds its time-to-live (TTL) value.
The trace command starts by sending probe datagrams with a TTL value of one. This causes the first router to discard the probe datagram and send back an error message. The trace command sends several probes at each TTL level and displays the round-trip time for each.
The trace command sends out one probe at a time. Each outgoing packet may result in one or two error messages. A "time exceeded" error message indicates that an intermediate router has seen and discarded the probe. A "destination unreachable" error message indicates that the destination node has received the probe and discarded it because it could not deliver the packet. If the timer goes off before a response comes in, trace prints an asterisk (*).
The trace command terminates when the destination responds, when the maximum TTL is exceeded, or when the user interrupts the trace with the escape sequence. By default, to invoke the escape sequence, type Ctrl-^ X by simultaneously pressing and releasing the Ctrl, Shift, and 6 keys, and then pressing the X key.
Due to bugs in the IP implementation of various hosts and routers, the IP trace command may behave in odd ways.
Not all destinations will respond correctly to a probe message by sending back an "ICMP port unreachable" message. A long sequence of TTL levels with only asterisks, terminating only when the maximum TTL has been reached, may indicate this problem.
There is a known problem with the way some hosts handle an "ICMP TTL exceeded" message. Some hosts generate an ICMP message but they reuse the TTL of the incoming packet. Since this is zero, the ICMP packets do not make it back. When you trace the path to such a host, you may see a set of TTL values with asterisks (*). Eventually the TTL gets high enough that the "ICMP" message can get back. For example, if the host is six hops away, trace will time out on responses 6 through 11.
The following display shows sample IP trace output when a destination host name has been specified:
Router# trace ip ABA.NYC.mil
Type escape sequence to abort.
Tracing the route to ABA.NYC.mil (26.0.0.73)
1 DEBRIS.CISCO.COM (131.108.1.6) 1000 msec 8 msec 4 msec
2 BARRNET-GW.CISCO.COM (131.108.16.2) 8 msec 8 msec 8 msec
3 EXTERNAL-A-GATEWAY.STANFORD.EDU (192.42.110.225) 8 msec 4 msec 4 msec
4 BB2.SU.BARRNET.NET (131.119.254.6) 8 msec 8 msec 8 msec
5 SU.ARC.BARRNET.NET (131.119.3.8) 12 msec 12 msec 8 msec
6 MOFFETT-FLD-MB.in.MIL (192.52.195.1) 216 msec 120 msec 132 msec
7 ABA.NYC.mil (26.0.0.73) 412 msec 628 msec 664 msec
Table 110 describes the fields shown in the display.
| Field | Description |
|---|---|
| 1 | Indicates the sequence number of the router in the path to the host. |
| DEBRIS.CISCO.COM | Host name of this router. |
| 131.108.1.61 | Internet address of this router. |
| 1000 msec 8 msec 4 msec | Round-trip time for each of the three probes that are sent. |
Table 111 describes the characters that can appear in trace output.
| Char | Description |
|---|---|
| nn msec | For each node, the round-trip time in milliseconds for the specified number of probes. |
| * | The probe timed out. |
| ? | Unknown packet type. |
| A | Administratively unreachable. Usually, this output indicates that an access list is blocking traffic. |
| H | Host unreachable. |
| N | Network unreachable. |
| P | Protocol unreachable. |
| Q | Source quench. |
| U | Port unreachable. |
To establish a username-based authentication system, enter the username global configuration command. The authentication enabled with this command takes precedence over any TACACS or TACACS+ authentication you might have established.
username name [nopassword | password encryption-type password]None
Global configuration
The username command provides username/password authentication for login purposes only. (Note that it does not provide username/password authentication for enable mode when the enable use-tacacs command is also used.)
Multiple username commands can be used to specify options for a single user.
Add a username entry for each remote system that the local router communicates with and requires authentication from. The remote device must have a username entry for the local router. This entry must have the same password as the local router's entry for that remote device.
This command can be useful for defining usernames that get special treatment, for example, an "info" username that does not require a password, but connects the user to a general purpose information service.
The username command is also required as part of the configuration for the Challenge Handshake Authentication Protocol (CHAP). For each remote system that the local router communicates with from which it requires authentication, add a username entry.
If there is no secret specified and debug serial-interface is enabled, an error is displayed when a link is established and the CHAP challenge is not implemented. Debugging information on CHAP is available using the debug serial-interface and debug serial-packet commands. For more information about debug commands, refer to the Debug Command Reference.
The keyword noescape prevents users from using escape characters on the hosts to which they are connected.
To implement a service similar to the UNIX who command, which can be entered at the login prompt and lists the current users of the router, the username command takes the following form:
username who nopassword nohangup autocommand show users
To implement an information service that does not require a password to be used, the command takes the following form:
username info nopassword noescape autocommand telnet nic.ddn.mil
To implement an ID that will work even if the TACACS servers all break, the command takes the following form:
username superuser password superpassword
The following example configuration enables CHAP on interface serial 0. It also defines a password for the local server, Adam, and a remote server, Eve.
hostname Adam interface serial 0 encapsulation ppp ppp authentication chap username Adam password oursystem username Eve password theirsystem
When you look at your configuration file, the passwords will be encrypted and the display will look similar to the following:
hostname Adam interface serial 0 encapsulation ppp ppp authentication chap username Adam password 7 1514040356 username Eve password 7 121F0A18
A dagger (+) indicates that the command is documented outside this chapter. Two daggers (++) indicate that the command is documented in the Debug Command Reference.
arap callback +
callback-forced-wait +
debug callback ++
ppp callback +
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