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This chapter describes the commands used to troubleshoot your router. To troubleshoot, you need to discover, isolate, and fix the problems. You can discover problems with the system's monitoring commands, isolate problems with the system's test commands, and resolve problems with other commands, including debug.
This chapter describes general fault management commands. For detailed troubleshooting procedures and a variety of scenarios, see the Internetwork Troubleshooting Guide publication. For complete details on all debug commands, see the Debug Command Reference.
For troubleshooting tasks and examples, refer to the chapter entitled "Troubleshooting the Router" in the Configuration Fundamentals Configuration Guide.
To clear messages from the logging buffer, use the clear logging privileged EXEC command.
clear loggingThis command has no arguments or keywords.
Privileged EXEC
This command first appeared in Cisco IOS Release 11.2.
In the following example, the logging buffer is cleared:
Router# clear logging
Clear logging buffer [confirm]
Router#
You can use the master indexes or search online to find documentation of related commands.
To specify the name of the core dump file, use the exception core-file global configuration command. To return to the default core filename, use the no form of this command.
exception core-file name| name | Name of the core dump file saved on the server. |
The core file is named hostname-core, where hostname is the name of the router.
Global configuration
This command first appeared in Cisco IOS Release 10.3.
 | Caution Use the exception commands only under the direction of a technical support representative. Creating a core dump while the router is functioning in a network can disrupt network operation. The resulting binary file, which is very large, must be transferred to a TFTP, FTP, or rcp server and subsequently interpreted by technical personnel who have access to source code and detailed memory maps. |
If you use TFTP to dump the core file to a server, the router will only dump the first 16 MB of the core file. If the router's memory is larger than 16 MB, the whole core file will not be copied to the server. Therefore, use rcp or FTP to dump the core file.
The following example configures a router to use FTP to dump a core file named dumpfile to the FTP server at 172.17.92.2 when it crashes:
ip ftp username red ip ftp password blue exception protocol ftp exception dump 172.17.92.2 exception core-file dumpfile
You can use the master indexes or search online to find documentation of related commands.
exception dump
exception memory
exception protocol
ip ftp password
ip ftp username
To configure the router to dump a core file to a particular server when the router crashes, use the exception dump global configuration command. To disable core dumps, use the no form of this command.
exception dump ip-address| ip-address | IP address of the server that stores the core dump file. |
Disabled
Global configuration
This command first appeared in Cisco IOS Release 10.3.
| Caution Use the exception commands only under the direction of a technical support representative. Creating a core dump while the router is functioning in a network can disrupt network operation. The resulting binary file, which is very large, must be transferred to a TFTP, FTP, or rcp server and subsequently interpreted by technical personnel who have access to source code and detailed memory maps. |
If you use TFTP to dump the core file to a server, the router will only dump the first 16 MB of the core file. If the router's memory is larger than 16 MB, the whole core file will not be copied to the server. Therefore, use rcp or FTP to dump the core file.
The core dump is written to a file named hostname-core on your server, where hostname is the name of the router. You can change the name of the core file by configuring the exception core-file command.
This procedure can fail for certain types of system crashes. However, if successful, the core dump file will be the size of the memory available on the processor (for example, 16 MB for a CSC/4).
The following example configures a router to use FTP to dump a core file to the FTP server at 172.17.92.2 when it crashes:
ip ftp username red ip ftp password blue exception protocol ftp exception dump 172.17.92.2
You can use the master indexes or search online to find documentation of related commands.
exception core-file
exception memory
exception protocol
ip ftp password
ip ftp username
ip rcmd remote-username
To cause the router to create a core dump and reboot when certain memory size parameters are violated, use the exception memory global configuration command. To disable the rebooting and core dump, use the no form of this command.
exception memory {fragment size | minimum size}| fragment size | The minimum contiguous block of memory in the free pool, in bytes. |
| minimum size | The minimum size of the free memory pool, in bytes. |
Disabled
Global configuration
This command first appeared in Cisco IOS Release 10.3.
| Caution Use the exception commands only under the direction of a technical support representative. Creating a core dump while the router is functioning in a network can disrupt network operation. The resulting binary file, which is very large, must be transferred to a TFTP, FTP, or rcp server and subsequently interpreted by technical personnel who have access to source code and detailed memory maps. |
This command is useful to troubleshoot memory leaks.
The size is checked every 60 seconds. If you enter a size that is greater than the free memory, a core dump and router reload is generated after 60 seconds.
The exception dump command must be configured in order to generate a core file. If the exception dump command is not configured, the router reloads without generating a core dump.
The following example configures the router to monitor the free memory. If the amount of free memory falls below 250,000 bytes,the router will dump the core file and reload.
exception dump 131.108.92.2 exception core-file memory.overrun exception memory minimum 250000
You can use the master indexes or search online to find documentation of related commands.
exception core-file
exception dump
exception protocol
ip ftp password
ip ftp username
To configure the protocol used for core dumps, use the exception protocol global configuration command. To configure the router to use the default protocol, use the no form of this command.
exception protocol {ftp | rcp | tftp}| ftp | Use FTP for core dumps. |
| rcp | Use rcp for core dumps. |
| tftp | Use TFTP for core dumps. This is the default. |
TFTP
Global configuration
This command first appeared in Cisco IOS Release 10.3.
| Caution Use the exception commands only under the direction of a technical support representative. Creating a core dump while the router is functioning in a network can disrupt network operation. The resulting binary file, which is very large, must be transferred to a TFTP, FTP, or rcp server and subsequently interpreted by technical personnel who have access to source code and detailed memory maps. |
If you use TFTP to dump the core file to a server, the router will only dump the first 16 MB of the core file. If the router's memory is larger than 16 MB, the whole core file will not be copied to the server. Therefore, use rcp or FTP to dump the core file.
The following example configures a router to use FTP to dump a core file to the FTP server at 172.17.92.2 when it crashes:
ip ftp username red ip ftp password blue exception protocol ftp exception dump 172.17.92.2
You can use the master indexes or search online to find documentation of related commands.
exception core-file
exception dump
exception memory
ip ftp password
ip ftp username
To configure the router to use only passive FTP connections, use the ip ftp passive global configuration command. To allow all types of FTP connections, use the no form of this command.
ip ftp passiveThis command has no arguments or keywords.
All types of FTP connections are allowed.
Global configuration
This command first appeared in Cisco IOS Release 10.3.
The following example configures the router to use only passive FTP connections:
ip ftp passive
You can use the master indexes or search online to find documentation of related commands.
ip ftp password
ip ftp source-interface
ip ftp username
To specify the password to be used for FTP connections, use the ip ftp password global configuration command. Use the no form of this command to return the password to its default.
ip ftp password [type] password| type | (Optional) Type of encryption to use on the password. A value of 0 disables encryption. A value of 7 indicates proprietary encryption. |
| password | Password to use for FTP connections. |
The router forms a password username@routername.domain. The variable username is the username associated with the current session, routername is the configured host name, and domain is the domain of the router.
Global configuration
This command first appeared in Cisco IOS Release 10.3.
The following example configures the router to use the username red and the password blue for FTP connections:
ip ftp username red ip ftp password blue
You can use the master indexes or search online to find documentation of related commands.
ip ftp passive
ip ftp source-interface
ip ftp username
To specify the source IP address for FTP connections, use the ip ftp source-interface global configuration command. Use the no form of this command to use the address of the interface where the connection is made.
ip ftp source-interface interface| interface | The interface type and number to use to obtain the source address for FTP connections. |
The FTP source address is the the IP address of the interface the FTP packets use to leave the router.
Global configuration
This command first appeared in Cisco IOS Release 10.3.
Use this command to set the same source address for all FTP connections.
The following example configures the router to use the IP address associated with the Ethernet 0 interface as the source address on all FTP packets, regardless of which interface is actually used to transmit the packet:
ip ftp source-interface ethernet 0
You can use the master indexes or search online to find documentation of related commands.
ip ftp passive
ip ftp password
ip ftp username
To configure the username for FTP connections, use the ip ftp username global configuration command. To configure the router to attempt anonymous FTP, use the no form of this command.
ip ftp username username| username | Username for FTP connections. |
The Cisco IOS software attempts an anonymous FTP.
Global configuration
This command first appeared in Cisco IOS Release 10.3.
The remote username must be associated with an account on the destination server.
The following example configures the router to use the username red and the password blue for FTP connections:
ip ftp username red ip ftp password blue
You can use the master indexes or search online to find documentation of related commands.
ip ftp passive
ip ftp password
ip ftp source-interface
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 first appeared in Cisco IOS Release 10.0.
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
You can use the master indexes or search online to find documentation of related commands.
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. The default form of this command returns the buffer size to the default size.
logging buffered [size]| size | (Optional) Size of the buffer from 4096 to 4294967295 bytes. The default size varies by platform. |
For most platforms, the Cisco IOS software logs messages to the internal buffer.
Global configuration
This command first appeared in Cisco IOS Release 10.0.
This command copies logging messages to an internal buffer. 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 command default logging buffered resets the buffer size to the default for the platform.
The following example enables logging to an internal buffer:
logging buffered
You can use the master indexes or search online to find documentation of related commands.
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 86 for a list of the level keywords. |
debugging
Global configuration
This command first appeared in Cisco IOS Release 10.0.
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
You can use the master indexes or search online to find documentation of related commands.
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 87 for the facility-type keywords. |
local7
Global configuration
This command first appeared in Cisco IOS Release 10.0.
Table 87 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 the kernel facility type.
logging facility kern
You can use the master indexes or search online to find documentation of related commands.
To limit syslog messages sent to the router's history table and the SNMP network management station based on severity, use the logging history global configuration command. The no form of this command returns the logging of syslog messages to the default level.
logging history level| level | Limits the messages saved in the history table and sent to the SNMP network management station to the specified set of levels. See Table 88 for a list of the level keywords. |
warnings, errors, critical, alerts, and emergencies messages
Global configuration
This command first appeared in Cisco IOS Release 11.2.
Sending syslog messages to the SNMP network management station occurs when you enable syslog traps with the snmp-server enable trap global configuration command. Because SNMP traps are inherently unreliable and much too important to lose, at least one syslog message, the most recent message, is stored in a history table on the router. The number of messages stored in the table is governed by the logging history size command.
Specifying a level causes messages at that severity level and numerically lower levels to be stored in the router's history table and sent to the SNMP network management station. Severity levels are numbered 1 to 8 with 1 being the most important message and 8 being the least important message (that is, the lower the number, the more critical the message). For example, specifying the level critical causes critical (3), alerts (2), and emergencies (1) messages to be stored to the history table and sent to the SNMP network management station. See Table 88 for a list of severity levels.
| Level Keyword | Severity Level | Description | Syslog Definition |
|---|---|---|---|
| emergencies | 1 | System unusable | LOG_EMERG |
| alerts | 2 | Immediate action needed | LOG_ALERT |
| critical | 3 | Critical conditions | LOG_CRIT |
| errors | 4 | Error conditions | LOG_ERR |
| warnings | 5 | Warning conditions | LOG_WARNING |
| notifications | 6 | Normal but significant condition | LOG_NOTICE |
| informational | 7 | Informational messages only | LOG_INFO |
| debugging | 8 | Debugging messages | LOG_DEBUG |
The following example changes the level of messages sent to the history table and to the SNMP server to alerts, which means alerts (2) and emergencies (1) are sent:
logging history alerts
You can use the master indexes or search online to find documentation of related commands.
logging history size
show logging
snmp-server enable traps
To change the number of syslog messages stored in the router's history table, use the logging history size global configuration command. The no form of this command returns the number of messages to the default value.
logging history size number| number | Number from 1 to 500 that indicates the maximum number of messages stored in the history table. |
1 message
Global configuration
This command first appeared in Cisco IOS Release 11.2.
When the history table is full (that is, it contains the maximum number of message entries specified with the logging history size command), the oldest message entry is deleted from the table to allow the new message entry to be stored.
The following example sets the number of messages stored in the history table to 20:
logging history size 20
You can use the master indexes or search online to find documentation of related commands.
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 86. |
debugging
Global configuration
This command first appeared in Cisco IOS Release 10.0.
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
You can use the master indexes or search online to find documentation of related commands.
terminal monitor
To control logging of error messages, use the logging on global configuration command. This command sends debug or error messages to a logging process, which logs messages to designated locations asynchronously to the processes that generated the messages. The no form of this command disables the logging process.
logging onThis command has no arguments or keywords.
The Cisco IOS software sends messages to the asynchronous logging process.
Global configuration
This command first appeared in Cisco IOS Release 10.0.
The logging process controls the distribution of logging messages to the various destinations, such as the logging buffer, terminal lines, or syslog server. You can turn logging on and off for these destinations individually using the logging buffered, logging monitor, and logging commands. However, if the logging on command is disabled, no messages will be sent to these destinations. Only the console will receive messages.
Additionally, the logging process logs messages to the console and the various destinations after the processes that generated them have completed. When the logging process is disabled, messages are displayed on the console as soon as they are produced, often appearing in the middle of command output.
| Caution Disabling the logging on command will significantly slow down the router. Any process generating debug or error messages will wait until the messages have been displayed on the console before continuing. |
The logging synchronous command also affects the displaying of messages to the console. When the logging synchronous command is enabled, messages will only appear after the user types a carriage return.
The following example shows command output and message output when logging is enabled. The ping process finishes before any of the logging information is printed to the console (or any other destination).
Router(config)#logging onRouter(config)#endRouter# %SYS-5-CONFIG_I: Configured from console by console Router#ping dirtType escape sequence to abort. Sending 5, 100-byte ICMP Echos to 172.16.1.129, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 4/5/8 ms Router# IP: s=172.21.96.41 (local), d=172.16.1.129 (Ethernet1/0), len 100, sending IP: s=171.69.1.129 (Ethernet1/0), d=172.21.96.41, len 114, rcvd 1 IP: s=172.21.96.41 (local), d=172.16.1.129 (Ethernet1/0), len 100, sending IP: s=171.69.1.129 (Ethernet1/0), d=172.21.96.41, len 114, rcvd 1 IP: s=172.21.96.41 (local), d=172.16.1.129 (Ethernet1/0), len 100, sending IP: s=171.69.1.129 (Ethernet1/0), d=172.21.96.41, len 114, rcvd 1 IP: s=172.21.96.41 (local), d=172.16.1.129 (Ethernet1/0), len 100, sending IP: s=171.69.1.129 (Ethernet1/0), d=172.21.96.41, len 114, rcvd 1 IP: s=172.21.96.41 (local), d=172.16.1.129 (Ethernet1/0), len 100, sending IP: s=171.69.1.129 (Ethernet1/0), d=172.21.96.41, len 114, rcvd 1
In the next example, logging is disabled. The message output is displayed as messages are generated, causing the debug messages to be interspersed with the message "Type escape sequence to abort."
Router(config)#no logging onRouter(config)#end%SYS-5-CONFIG_I: Configured from console by console Router# Router#ping dirtIP: s=172.21.96.41 (local), d=172.16.1.129 (Ethernet1/0), len 100, sendingTyp IP: s=171.69.1.129 (Ethernet1/0), d=172.21.96.41, len 114, rcvd 1e IP: s=172.21.96.41 (local), d=172.16.1.129 (Ethernet1/0), len 100, sending esc IP: s=171.69.1.129 (Ethernet1/0), d=172.21.96.41, len 114, rcvd 1 IP: s=172.21.96.41 (local), d=172.16.1.129 (Ethernet1/0), len 100, sendingape IP: s=171.69.1.129 (Ethernet1/0), d=172.21.96.41, len 114, rcvd 1 IP: s=172.21.96.41 (local), d=172.16.1.129 (Ethernet1/0), len 100, sendingse IP: s=171.69.1.129 (Ethernet1/0), d=172.21.96.41, len 114, rcvd 1 IP: s=172.21.96.41 (local), d=172.16.1.129 (Ethernet1/0), len 100, sendingquen IP: s=171.69.1.129 (Ethernet1/0), d=172.21.96.41, len 114, rcvd 1ce to abort. Sending 5, 100-byte ICMP Echos to 172.16.1.129, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 152/152/156 ms Router#
You can use the master indexes or search online to find documentation of related commands.
logging
logging buffered
logging monitor
logging synchronous
To specify the source IP address of syslog packets, use the logging source-interface global configuration command. Use the no form of this command to remove the source designation.
logging source-interface type number| type | Interface type. |
| number | Interface number. |
No interface is specified.
Global configuration
This command first appeared in Cisco IOS Release 11.2.
Normally, a syslog message contains the IP address of the interface it uses to leave the router. The logging source-interface command specifies that syslog packets contain the IP address of a particular interface, regardless of which interface the packet uses to exit the router.
The following example specifies that the IP address for Ethernet interface 0 is the source IP address for all syslog messages:
logging source-interface ethernet 0
The following example specifies that the IP address for Ethernet interface 2/1 on a Cisco 7000 series router is the source IP address for all syslog messages:
logging source-interface ethernet 2/1
You can use the master indexes or search online to find documentation of related commands.
To synchronize unsolicited messages and debug output with solicited Cisco IOS software output and prompts for a specific console port line, auxiliary port line, or virtual terminal line, use the logging synchronous line configuration command. Use the no form of this command to disable synchronization of unsolicited messages and debug output.
logging synchronous [level severity-level | all] [limit number-of-buffers]| level severity-level | (Optional) Specifies the message severity level. Messages with a severity level equal to or higher than this value are printed asynchronously. 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
This command first appeared in Cisco IOS Release 10.0.
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
You can use the master indexes or search online to find documentation of related commands.
line
logging on
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 86. |
Informational
Global configuration
This command first appeared in Cisco IOS Release 10.0.
The EXEC command show logging displays the addresses and levels associated with the current logging setup. The command output also includes ancillary statistics.
Table 86 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
You can use the master indexes or search online to find documentation of related commands.
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
This command first appeared in Cisco IOS Release 10.0.
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 89 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:192.168.7.27Repeat 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 192.168.7.27, timeout is 2 seconds: !!!!! Success rate is 100 percent, round-trip min/avg/max = 1/2/4 ms
Table 90 describes the default ping fields shown in the display.
| Field | Description |
|---|---|
| Protocol [ip]: | Prompts for a supported protocol. Enter appletalk, clns, ip, novell, apollo, vines, decnet, or xns. Default: ip. |
| Target IP address: | Prompts for the IP address or host name of the destination node you plan to ping. If you have specified a supported protocol other than IP, enter an appropriate address for that protocol here. Default: none. |
| Repeat count [5]: | Number of ping packets that will be sent to the destination address. Default: 5. |
| Datagram size [100]: | Size of the ping packet (in bytes). Default: 100 bytes. |
| Timeout in seconds [2]: | Timeout interval. Default: 2 (seconds). |
| Extended commands [n]: | Specifies whether or not a series of additional commands appears. Many of the following displays and tables show and describe these commands. |
| Sweep range of sizes [n]: | Allows you to vary the sizes of the echo packets being sent. This capability is useful for determining the minimum sizes of the MTUs configured on the nodes along the path to the destination address. Packet fragmentation contributing to performance problems can then be reduced. |
| !!!!! | Each exclamation point (!) indicates receipt of a reply. A period (.) indicates the network server timed out while waiting for a reply. Other characters may appear in the ping output display, depending on the protocol type. |
| Success rate is 100 percent | Percentage of packets successfully echoed back to the router. Anything less than 80 percent is usually considered problematic. |
| round-trip min/avg/max = 1/2/4 ms | Round-trip travel time intervals for the protocol echo packets, including minimum/average/maximum (in milliseconds). |
You can use the master indexes or search online to find documentation of related commands.
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
This command first appeared in Cisco IOS Release 10.0.
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 terse 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 91 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 192.168.7.27, timeout is 2 seconds:
!!!!!
Success rate is 100 percent, round-trip min/avg/max = 1/3/4 ms
You can use the master indexes or search online to find documentation of related commands.
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 first appeared in Cisco IOS Release 11.1.
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.
This command has no arguments or keywords.
Disabled
Global configuration
This command first appeared in Cisco IOS Release 10.0.
The following example generates keepalives on incoming TCP connections:
service tcp-keepalives-in
You can use the master indexes or search online to find documentation of related commands.
To generate keepalive packets on idle outgoing network connections (initiated by a user), use the service tcp-keepalives-out global configuration command. The no form of this command with the appropriate keyword disables the keepalives.
service tcp-keepalives-outThis command has no arguments or keywords.
Disabled
Global configuration
This command first appeared in Cisco IOS Release 10.0.
The following example generates keepalives on outgoing TCP connections:
service tcp-keepalives-out
You can use the master indexes or search online to find documentation of related commands.
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
This command first appeared in Cisco IOS Release 10.0.
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
You can use the master indexes or search online to find documentation of related commands.
clock set
debug
ntp
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
This command first appeared in Cisco IOS Release 11.2.
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
This command has no arguments or keywords.
EXEC
This command first appeared in Cisco IOS Release 10.3.
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
You can use the master indexes or search online to find documentation of related commands.
To display information about the types of debugging that are enabled for your router, use the show debugging privileged EXEC command.
show debuggingThis command has no arguments or keywords.
Privileged EXEC
This command first appeared in Cisco IOS Release 11.1.
The following is sample output from the show debugging command. In this example, three types of CDP debugging are enabled.
Router# show debugging
CDP:
CDP packet info debugging is on
CDP events debugging is on
CDP neighbor info debugging is on
You can use the master indexes or search online to find documentation of related commands.
debug
| 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
This command first appeared in Cisco IOS Release 10.0.
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 92 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 93 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 94 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 95 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 96 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 97 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 98 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 99 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 6 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 100 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 environment 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 101 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 first appeared in Cisco IOS Release 11.2.
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)
...
Use the show logging EXEC command to display the state of logging (syslog).
show logging [history]| history | (Optional) Display information in the syslog history table only. |
EXEC
This command first appeared in Cisco IOS Release 10.0.
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 192.180.2.238
SNMP logging: disabled, retransmission after 30 seconds
0 messages logged
Table 102 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. |
The following is sample output from the show logging history command:
Router# show logging history
Syslog History Table: 1 maximum table entry, saving level notifications or higher
0 messages ignored, 0 dropped, 15 table entries flushed,
SNMP notifications not enabled
entry number 16: SYS-5-CONFIG_I
Configured from console by console
timestamp: 1110
Table 103 describes the significant fields shown in the display.
| Field | Description |
|---|---|
| maximum table entry | Number of messages that can be stored in the history table. Set with the logging history size command. |
| saving level notifications or higher | Level of messages that are stored in the history table and sent to the SNMP server (if SNMP notification is enabled). Set with the logging history command. |
| messages ignored | Number of messages not stored in the history table because the severity level is greater than that specified with the logging history command. |
| dropped | Number of messages that could not be processed due to lack of system resources. Dropped messages do not appear in the history table and are not sent to the SNMP server. |
| table entries flushed | Number of messages that have been removed from the history table to make room for newer messages. |
| SNMP notifications | Whether syslog traps of the appropriate level are sent to the SNMP server. Syslog traps are either enabled or not enabled through the snmp-server enable command. |
| entry number | Number of the message entry in the history table. |
| SYS-5-CONFIG_I Configured from console by console | Cisco IOS syslog message consisting of the facility name (SYS) which indicates where the message came from, the severity level (5), the message name (CONFIG_I), and the message text. |
| timestamp | Time, based on the router's up time, that the message was generated. |
You can use the master indexes or search online to find documentation of related commands.
Use the show memory EXEC command to show statistics about memory, including memory-free pool statistics.
show memory [memory-type] [free] [summary]| memory-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
This command first appeared in Cisco IOS Release 10.0.
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 104 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 105 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 I/O memory blocks. On the Cisco 4000, this command quickly shows how much unused I/O 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 I/O 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
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 104 and Table 105.
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)
You can use the master indexes or search online to find documentation of related commands.
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
This command first appeared in Cisco IOS Release 11.2.
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
...
Use the show processes EXEC command to display information about the active processes.
show processes [cpu]| cpu | (Optional) Displays detailed CPU utilization statistics. |
EXEC
This command first appeared in Cisco IOS Release 10.0.
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 106 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 the last 5 seconds. |
| 1Min | CPU utilization by task in the last minute. |
| 5Min | CPU utilization by task in the last 5 minutes. |
You can use the master indexes or search online to find documentation of related commands.
Use the show processes memory EXEC command to show memory used.
show processes memoryThis command has no arguments or keywords.
EXEC
This command first appeared in Cisco IOS Release 10.0.
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 107 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. |
| Getbufs | Number of times the process has requested a packet buffer. |
| Retbufs | Number of times the process has relinquished 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. |
You can use the master indexes or search online to find documentation of related commands.
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
This command first appeared in Cisco IOS Release 10.0.
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 192.168.1.1, 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 192.168.7.49, subnet mask is 255.255.255.240
Ethernet 1 is up, line protocol is up
Internet address is 192.168.2.1, 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 192.168.7.177, 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, Network Protocols Configuration Guide, Part 2, and Network Protocols Configuration Guide, Part 3.
Use the show stacks EXEC command to monitor the stack usage of processes and interrupt routines.
show stacksThis command has no arguments or keywords.
EXEC
This command first appeared in Cisco IOS Release 10.0.
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
You can use the master indexes or search online to find documentation of related commands.
To display the subsystem information, use the show subsys privileged EXEC command.
show subsys [class class | name name]| class class | (Optional) Shows the subsystems of the specified class. Valid classes are driver, kernel, library, management, protocol, and registry. |
| name name | (Optional) Shows the specified subsystem. Use the asterisk character (*) as a wildcard at the end of the name to list all subsystems starting with the specified characters. |
Privileged EXEC
This command first appeared in Cisco IOS Release 11.1.
Use the show subsys command to confirm that all required features are in the running image.
The following example shows partial sample output from the show subsys command:
Router# show subsys
Class Version
static_map Kernel 1.000.001
arp Kernel 1.000.001
ether Kernel 1.000.001
compress Kernel 1.000.001
alignment Kernel 1.000.002
monvar Kernel 1.000.001
slot Kernel 1.000.001
oir Kernel 1.000.001
atm Kernel 1.000.001
ip_addrpool_sys Library 1.000.001
chat Library 1.000.001
dialer Library 1.000.001
flash_services Library 1.000.001
ip_localpool_sys Library 1.000.001
nvram_common Driver 1.000.001
ASP Driver 1.000.001
sonict Driver 1.000.001
oc3suni Driver 1.000.001
oc12suni Driver 1.000.001
ds3suni Driver 1.000.001
...
Table 108 describes the fields shown in this display.
| Field | Description |
|---|---|
| static_map | Name of the subsystem. |
| Class | Class of the subsystem. Possible classes include Kernel, Library, Driver, Protocol, Management, Registry, and SystemInit. |
| Version | Version of the subsystem. |
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
This command first appeared in Cisco IOS Release 10.0.
The following is sample output from the show tcp command:
Router# show tcp
tty0, connection 1 to host cider
Connection state is ESTAB, I/O status: 1, unread input bytes: 0
Local host: 172.31.232.17, Local port: 11184
Foreign host: 172.31.1.137, Foreign port: 23
Enqueued packets for retransmit: 0, input: 0, saved: 0
Event Timers (current time is 67341276):
Timer: Retrans TimeWait AckHold SendWnd KeepAlive
Starts: 30 0 32 0 0
Wakeups: 1 0 14 0 0
Next: 0 0 0 0 0
iss: 67317172 snduna: 67317228 sndnxt: 67317228 sndwnd: 4096
irs: 1064896000 rcvnxt: 1064897597 rcvwnd: 2144 delrcvwnd: 0
SRTT: 317 ms, RTTO: 900 ms, RTV: 133 ms, KRTT: 0 ms
minRTT: 4 ms, maxRTT: 300 ms, ACK hold: 300 ms
Flags: higher precedence, idle user, retransmission timeout
Datagrams (max data segment is 536 bytes):
Rcvd: 41 (out of order: 0), with data: 34, total data bytes: 1596
Sent: 57 (retransmit: 1), with data: 35, total data bytes: 55
Table 109 describes the first five lines of output shown in the display:
| Field | Description |
|---|---|
| tty0 | Identifying number of the line. |
| connection 1 | Number identifying the TCP connection. |
| to host xxx | 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: | Number describing the current internal status of the connection. |
| unread input bytes: | Number of bytes that the lower-level TCP processes have read, but the higher level TCP processes have not yet processed. |
| Local host: | IP address of the network server. |
| Local port: | 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: | IP address of the remote host to which the TCP connection has been made. |
| Foreign port: | Destination port for the remote host. |
| Enqueued packets for retransmit: | 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: | Number of packets that are waiting on the input queue to be read by the user. |
| saved: | 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 67341276):
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 30 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: 30 0 32 0 0 Wakeups: 1 0 14 0 0 Next: 0 0 0 0 0
Table 110 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 111 describes the specific fields in these lines of output:
iss: 67317172 snduna: 67317228 sndnxt: 67317228 sndwnd: 4096 irs: 1064896000 rcvnxt: 1064897597 rcvwnd: 2144 delrcvwnd: 0
| Field | Description |
|---|---|
| iss: | Initial send sequence number. |
| snduna: | Last send sequence number the local host sent but has not received an acknowledgment for. |
| sndnxt: | Sequence number the local host will send next. |
| sndwnd: | TCP window size of the remote host. |
| irs: | Initial receive sequence number. |
| rcvnxt: | Last receive sequence number the local host has acknowledged. |
| rcvwnd: | Local host's TCP window size. |
| delrcvwnd: | 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 112 describes the fields in the following line of output:
SRTT: 317 ms, RTTO: 900 ms, RTV: 133 ms, KRTT: 0 ms minRTT: 4 ms, maxRTT: 300 ms, ACK hold: 300 ms Flags: higher precedence, idle user, retransmission timeout
| Field | Description |
|---|---|
| SRTT: | A calculated smoothed round-trip timeout. |
| RTTO: | Round-trip timeout. |
| RTV: | Variance of the round-trip time. |
| KRTT: | New round-trip timeout (using the Karn algorithm). This field separately tracks the round-trip time of packets that have been retransmitted. |
| minRTT: | Smallest recorded round-trip timeout (hard wire value used for calculation). |
| maxRTT: | Largest recorded round-trip timeout. |
| ACK hold: | Time the local host will delay an acknowledgment in order to piggyback data on it. |
| Flags: | Properties of the connection. |
For more information on these fields, refer to "Round Trip Time Estimation," P. Karn & C. Partridge, ACM SIGCOMM-87, August 1987.
Table 113 describes the fields in the following lines of output:
Datagrams (max data segment is 536 bytes): Rcvd: 41 (out of order: 0), with data: 34, total data bytes: 1596 Sent: 57 (retransmit: 1), with data: 35, total data bytes: 55
| Field | Description |
|---|---|
| Rcvd: | Number of datagrams the local host has received during this connection (and the number of these datagrams that were out of order). |
| with data: | Number of these datagrams that contained data. |
| total data bytes: | Total number of bytes of data in these datagrams. |
| Sent: | Number of datagrams the local host sent during this connection (and the number of these datagrams that had to be retransmitted). |
| with data: | Number of these datagrams that contained data. |
| total data bytes: | Total number of bytes of data in these datagrams. |
You can use the master indexes or search online to find documentation of related commands.
To display a concise description of TCP connection endpoints, use the show tcp brief EXEC command.
show tcp brief [all]| all | (Optional) Displays status for all endpoints. Without this keyword, endpoints in the LISTEN state are not shown. |
EXEC
This command first appeared in Cisco IOS Release 11.2.
The following is sample output from the show tcp brief command while a user has connected into the system via Telnet:
Router> show tcp brief
TCB Local Address Foreign Address (state)
609789AC Router.cisco.com.23 cider.cisco.com.3733 ESTAB
Table 114 describes the fields shown in the display.
| Field | Description |
|---|---|
| TCB | An internal identifier for the endpoint. |
| Local Address | The local IP address and port. |
| Foreign Address | The foreign IP address and port (at the opposite end of the connection). |
| (state) | The state of the connection. States are described in syntax description of the show tcp command. |
You can use the master indexes or search online to find documentation of related commands.
To display a snapshot of the time-division multiplexing (TDM) bus connection memory in a Cisco AS5200 access server, use the show tdm connections EXEC command.
show tdm connections [motherboard | slot number]| motherboard | (Optional) Motherboard in the Cisco AS5200 access server. |
| slot number | (Optional) Slot number. |
EXEC
This command first appeared in Cisco IOS Release 11.2.
The show tdm connections command shows the connection memory for all TDM bus connections in the access server if you do not limit the display to the motherboard or a slot.
The following example shows source stream 3 (ST3) channel 2 switched out of stream 6 (ST6) channel 2:
AS5200# show tdm connections motherboard
MT8980 motherboard unit 0, Control Register = 0x1F, ODE Register = 0x06
Connection Memory for ST6:
Ch0: 0x62, Ch1: 0x00, Ch2: 0x00, Ch3: 0x00
Ch4: 0x00, Ch5: 0x00, Ch6: 0x00, Ch7: 0x00
Ch8: 0x00, Ch9: 0x00, Ch10: 0x00, Ch11: 0x00
Ch12: 0x00, Ch13: 0x00, Ch14: 0x00, Ch15: 0x00
Ch16: 0x00, Ch17: 0x00, Ch18: 0x00, Ch19: 0x00
Ch20: 0x00, Ch21: 0x00, Ch22: 0x00, Ch23: 0x00
Ch24: 0x00, Ch25: 0x00, Ch26: 0x00, Ch27: 0x00
Ch28: 0x00, Ch29: 0x00, Ch30: 0x00, Ch31: 0x00
To interpret the hexadecimal number 0x62 into meaningful information, you must translate it into binary code. These two hexadecimal numbers represent a connection from any stream and a channel on any stream. The number 6 translates into the binary code 0110, which represents the third-source stream. The number 2 translates into the binary code 0010, which represents the second-source channel.
Stream 6 (ST6) channel 0 is the destination for source stream 3 (ST3) channel 2 in this example.
You can use the master indexes or search online to find documentation of related commands.
To display a snapshot of the time-division multiplexing (TDM) bus data memory in a Cisco AS5200 access server, use the show tdm data EXEC command.
show tdm data [motherboard | slot number]| motherboard | (Optional) Motherboard in the Cisco AS5200 access server. |
| slot number | (Optional) Slot number. |
EXEC
This command first appeared in Cisco IOS Release 11.2.
The data memory for all TDM bus connections in the access server is displayed if you do not specify a motherboard or slot.
The following example shows a snapshot of TDM memory where the normal ISDN idle pattern (0x7E) is present on all channels of the TDM device resident on the motherboard:
AS5200# show tdm data motherboard
MT8980 motherboard unit 0, Control Register = 0x1F, ODE Register = 0x06
Data Memory for ST0:
Ch0: 0x7E, Ch1: 0x7E, Ch2: 0x7E, Ch3: 0x7E
Ch4: 0x7E, Ch5: 0x7E, Ch6: 0x7E, Ch7: 0x7E
Ch8: 0x7E, Ch9: 0x7E, Ch10: 0x7E, Ch11: 0x7E
Ch12: 0x7E, Ch13: 0x7E, Ch14: 0x7E, Ch15: 0x7E
Ch16: 0x7E, Ch17: 0x7E, Ch18: 0x7E, Ch19: 0x7E
Ch20: 0x7E, Ch21: 0x7E, Ch22: 0x7E, Ch23: 0x7E
Ch24: 0x7E, Ch25: 0x7E, Ch26: 0x7E, Ch27: 0x7E
Ch28: 0x7E, Ch29: 0x7E, Ch30: 0x7E, Ch31: 0x7E
Data Memory for ST1:
Ch0: 0x7E, Ch1: 0x7E, Ch2: 0x7E, Ch3: 0x7E
Ch4: 0x7E, Ch5: 0x7E, Ch6: 0x7E, Ch7: 0x7E
Ch8: 0x7E, Ch9: 0x7E, Ch10: 0x7E, Ch11: 0x7E
Ch12: 0x7E, Ch13: 0x7E, Ch14: 0x7E, Ch15: 0x7E
Ch16: 0x7E, Ch17: 0x7E, Ch18: 0x7E, Ch19: 0x7E
Ch20: 0x7E, Ch21: 0x7E, Ch22: 0x7E, Ch23: 0x7E
Ch24: 0x7E, Ch25: 0x7E, Ch26: 0x7E, Ch27: 0x7E
Ch28: 0x7E, Ch29: 0x7E, Ch30: 0x7E, Ch31: 0x7E
You can use the master indexes or search online to find documentation of related commands.
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 label " |
Display output without page breaks and remove passwords and other security information.
Privileged EXEC
This command first appeared in Cisco IOS Release 11.2.
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.
You can use the master indexes or search online to find documentation of related commands.
show buffers
show controllers
show interfaces
show processes cpu
show processes memory
show running-config
show stacks
show version
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
This command first appeared in Cisco IOS Release 10.0.
The following example tests the Flash memory:
test flash
You can use the master indexes or search online to find documentation of related commands.
To test the system interfaces on the modular router, use the test interfaces EXEC command.
test interfacesThis command has no arguments or keywords.
EXEC
This command first appeared in Cisco IOS Release 10.0.
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 tests the system interfaces:
test interfaces
You can use the master indexes or search online to find documentation of related commands.
To perform a test of Multibus memory (including nonvolatile memory) on the modular router, use the test memory EXEC command. The memory test overwrites memory.
test memoryThis command has no arguments or keywords.
EXEC
This command first appeared in Cisco IOS Release 10.0.
| 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. |
The following example tests memory:
test memory
You can use the master indexes or search online to find documentation of related commands.
Use the trace privileged 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
This command first appeared in Cisco IOS Release 10.0.
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 (*).
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 (192.180.1.6) 1000 msec 8 msec 4 msec
2 BARRNET-GW.CISCO.COM (192.180.16.2) 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 (192.200.254.6) 8 msec 8 msec 8 msec
5 SU.ARC.BARRNET.NET (192.200.3.8) 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 115 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. |
| 192.180.1.6 | 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 116 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 117 describes the characters that can appear in trace command 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. |
You can use the master indexes or search online to find documentation of related commands.
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
This command first appeared in Cisco IOS Release 10.0.
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 (*).
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 (192.180.1.6) 1000 msec 8 msec 4 msec
2 BARRNET-GW.CISCO.COM (192.180.16.2) 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 (192.200.254.6) 8 msec 8 msec 8 msec
5 SU.ARC.BARRNET.NET (192.200.3.8) 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 118 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. |
| 192.180.1.61 | Internet address of this router. |
| 1000 msec 8 msec 4 msec | Round-trip time for each of the three probes that are sent. |
Table 119 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. |
You can use the master indexes or search online to find documentation of related commands.
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