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Table of Contents

Configuration and Management

Configuration and Management

This chapter focuses on configuring and managing the switch out-of-band by connecting to the console port on the switch and using the management console locally from a terminal or remotely through a modem. This chapter provides the following topics:

You can also configure and manage the switch in-band by using Telnet to connect to the switch and using the management console or by using an SNMP-compatible network management application and the switch Management Interface Base (MIB) files. Accessing the MIB files and using SNMP are discussed at the end of this chapter in the "In-Band Management" section.

Overview

The management console of the switch is a menu-driven interface for configuring and monitoring the network conditions and statistics (see Figure 3-1). You can use the management console even when the network is down because the console communicates directly with the switch, bypassing the network.

To access the management console, you need to first connect the console port on the switch to the terminal or modem and then start up your terminal emulation program or Telnet session. When connected to a terminal or modem, the console port must be configured to the same baud rate and character format as the terminal or modem.

For complete information about connecting to and configuring the console port, see the "Connecting to the Console Port" section in the "Installation" chapter.


Figure 3-1: Management Console Menus and Displays

When you use the management console, keep the following in mind:

Using the Default Configuration Settings

The switch is shipped preconfigured with the default settings listed in Table 3-1. The table also includes the name of the menus you use if you want to change the settings.

You can operate the switch using the default configuration. Depending on how you plan to manage the switch, you need to assign some minimum information to the switch:

Assign the following information on the IP Configuration Menu (Figure 3-8):

  • IP address of the system

  • IP subnet mask

  • IP address of the default gateway


Table 3-1: Features, Default Settings, and Management Menus
Feature Default Setting Management Console Menu
Management

IP address, subnet mask, and
default gateway to the switch
0.0.0.0 IP Configuration Menu
Cisco Discovery Protocol Enabled CDP Configuration/Status Menu
Performance Tuning

Switching mode FragmentFree (cut-through) System Configuration Menu
Enhanced Congestion Control (ECC) for 10BaseT ports Disabled System Configuration Menu
Enhanced Congestion Control (ECC) for 100BaseT ports Disabled Port Configuration Menu for the 100BaseT Ports
Autonegotiation of duplex mode
for 100BaseTX ports
Enabled Port Configuration Menu for the 100BaseT Ports
Half-duplex mode with no flow control for 100BaseFX port Enabled Port Configuration Menu for the 100BaseT Ports
Half-duplex mode
for 10BaseT ports
Enabled Port Configuration Menu for the 10BaseT Ports
Half-duplex back pressure Disabled
Flooding/Traffic Control

Broadcast storm control Disabled System Configuration Menu
Store-and-forward on multicast Disabled System Configuration Menu
Network Port None System Configuration Menu
Flow control Disabled (100BaseT ports in full-duplex mode) Port Configuration Menu for the 100BaseT Ports
Flooding unknown unicast packets Enabled Port Addressing Menu
Flooding unregistered multicast packets Enabled Port Addressing Menu
Network Redundancy/Fault Tolerance

Spanning-Tree Protocol Enabled Spanning Tree Configuration Menu
Port Fast Spanning-Tree Protocol Enabled (10BaseT ports)


Disabled (100BaseT ports)

Diagnostics

Port monitoring Disabled Monitoring Configuration Menu
Usage reports -- Port Status Report
Port Addressing Report
Exception Statistics Report
Utilization Statistics Report
Bandwidth Usage Report
Security

Console password None Console Settings Menu
Action on address violation Suspend System Configuration Menu
Addressing security Disabled Port Addressing Menu
Port monitoring None Monitoring Configuration Menu
Define trap manager 0.0.0.0 Network Management (SNMP) Configuration Menu
Community strings -- Network Management (SNMP) Configuration Menu
Upgrading
Firmware -- Firmware Configuration Menu

Management Console Logon Screen

The Management Console Logon Screen (see Figure 3-2) is displayed after you connect the switch to a terminal or modem and start up your terminal emulation program or Telnet session. To log on to the management console and display the Management Console Main Menu, select Logon and press Return.

If a password for the switch has been defined, you are prompted for the password when you display the Management Console Logon Screen. Enter the password at the prompt, and press Return.

If you have forgotten the password, you can view the password from the Diagnostic Console - System Debug Interface Menu (see Figure 4-4).

You can use any Telnet TCP/IP package to use the management console. The switch supports up to seven simultaneous Telnet sessions. Changes made by one Telnet user are reflected in all other Telnet sessions.


Figure 3-2: Management Console Logon Screen
Catalyst 1900 Management Console
Copyright (c) Cisco Systems, Inc.  1993-1997
All rights reserved.
Ethernet address:      00-E0-1E-7E-B4-40
PCA Number: 73-2239-01
PCA Serial Number: SAD01200001
Model Number: WS-C1924-EN
System Serial Number: FAA01200001
-------------------------------------------------
Enter password:

Management Console Main Menu

The Management Console Main Menu (see Figure 3-3) is displayed after you successfully log on from the Management Console Logon Screen and press Return. Select an option from the Management Console Main Menu by entering the letter in brackets next to it. You do not need to press Return.


Figure 3-3: Management Console Main Menu
Catalyst 1900 - Main Menu
[C] Console Settings
[S] System
[N] Network Management
[P] Port Configuration
[A] Port Addressing
[D] Port Statistics Detail
[M] Monitoring
[R] Multicast Registration
[F] Firmware
[I] RS-232 Interface
[U] Usage Summaries
[H] Help
[X] Exit Management Console
Enter Selection:

Use the [H] option to display the online help and to change the expertise level for online prompts. The [X] option prompts you to confirm that you want to exit the management console. The rest of the options on the Management Console Main Menu are for configuring and managing the switch.

Console Settings Menu

The Console Settings Menu (see Figure 3-4) is displayed when you select the [C] option from the Management Console Main Menu. Use this menu to change the password, set the number of password intrusions allowed, set the default mode for the port status LEDs, and define how long the management console remains silent after an intrusion.


Figure 3-4: Console Settings Menu
Catalyst 1900 - Console Settings
--------------------Settings------------------
[P] Password intrusion threshold                3 attempt(s)
[S] Silent time upon intrusion detection        None
[T] Management Console inactivity timeout       None
[D] Default mode of status LED                  Port Status
--------------------Actions-------------------
[M] Modify password
[X] Exit to Main Menu
Enter Selection:

[P] Password intrusion threshold--Use this option to enter the allowed number of failed password attempts. After this number is reached, the management console becomes quiet for a user-defined length of time before allowing the next log-in attempt. To change the threshold value, enter the new setting. The default setting is 3.

[S] Silent time upon intrusion detection--Use this option to enter the number of minutes the management console is unavailable due to an excessive number of failed attempts to log in. You can specify from 0 to 65,500 minutes (where 0 is for no silent time). The default setting is No Silent Time.

[T] Management console inactivity time-out--Use this option to define the length of time the management console can remain idle before it times out. After a timeout, you need to re-enter the password to use the management console. The timeout period is set in seconds; a timeout of zero means the management console never times out. Enter 0 or a number between 30 and 65,500. The default setting is No Inactivity Timeout.

[D] Default mode of status LED--Use this option to select the default mode, which the switch automatically returns to 30 seconds after the you let go of the Mode button. You can select [1] Port Status, [2] Utilization, or [3] Duplex Status. The default setting is Port Status.

[M] Modify password--Use this option to enter a new password. The password must contain four to eight characters. You can use any character found on the keyboard, but case is not considered. (If you have a current password, you must enter it before it can be changed.) After you enter the new password, you enter the new password a second time to verify it. To erase a password, press the Backspace key and then press Return. The default setting is None.

[X] Exit--Use this option to display the Management Console Main Menu.

System Configuration Menu

The System Configuration Menu (see Figure 3-5) is displayed when you select the
[S] option from the Management Console Main Menu. Use this menu to reset the switch and to define the system-wide parameters of the switch.

Additional information about the following topics is provided in this section:

  • Switching modes

  • Broadcast storm control


Figure 3-5: System Configuration Menu
Catalyst 1900 - System Configuration
System Revision:  0   Address Capacity:  1024
System UpTime:    0day(s) 00hour(s) 11minute(s) 29second(s)
--------------------Settings------------------
[N] Name of system
[C] Contact name
[L] Location
[S] Switching mode                              FragmentFree
[U] Use of store-and-forward for multicast      Disabled
[A] Action upon address violation               Suspend
[G] Generate alert on address violation         Enabled
[I] Address aging time                          300 second(s)
[P] Network Port                                None
[E] Enhanced Congestion Control (10 Mbps Ports) Disabled
--------------------Actions-------------------
[R] Reset system                      [F] Reset to factory defaults
------------------Related Menus---------------
[B] Broadcast storm control           [X] Exit to Main Menu
Enter Selection:

[N] Name of system--Use this option to enter a name for the switch. Enter up to
255 characters.

[C] Contact name--Use this option to enter the name of the person or organization responsible for managing the switch. Enter up to 255 characters.

[L] Location--Use this option to enter the location of the switch. The location of the switch is an informal indication of where the switch is located. Enter up to 255 characters.

[S] Switching mode--Use this option to set the switching mode to one of the two settings: FragmentFree (cut-through) or store-and-forward. The default setting is FragmentFree. For additional information about this option, see "Switching Modes" later in this section.

[U] Use of store-and-forward for multicast--Enter E (enable) if you want to enable this option and force store-and-forward mode for multicast frames. The store-and-forward switching mode is always used for broadcast frames. Enter D (disable) if you want to disable this option and use the FragmentFree (cut-through) switching mode. The default setting is Disabled.

[A] Action upon address violation--Use this option to define how the switch responds to address violations. Address violations occur when a secured port receives a source address statically assigned to another port or when a secured port tries to learn an address that exceeds its defined maximum number of addresses. Enter one of the following values:

  • [S]uspend (default)--The port stops forwarding until a packet with a valid source address is received.

  • [D]isable--The port is disabled until its status is returned to enabled by an administrator.

  • [I]gnore--The port status remains unchanged.

[G] Generate alert on address violation--Whether or not the switch changes the port status when an address violation occurs, it can also send an SNMP alert to a management station. Enter E to enable or D to disable this feature. The default setting is Enabled.


Note Traps are sent to the IP addresses defined for the trap manager with the Network Management (SNMP) Configuration Menu.

[I] Address aging time--Use this option to define the time, in seconds, after which an unused dynamic address is automatically removed. During a topology change, ports are aged more quickly by using the forward-delay parameter. When the topology stabilizes, this value again takes effect.

The possible values you can enter range from 10 to 1,000,000 seconds (about 11 1/2 days). The default is 300 seconds (5 minutes). This value applies for all dynamic addresses in the switch address table.

[P] Network Port--Use this option to define a port as the destination port for all packets with unknown unicast addresses. The switch stops forwarding unknown unicast addresses to all other ports. This port is usually connected to a legacy network or backbone. A secured port cannot be the network port. The network port does not learn addresses. If you select a secure port to act as the network port, you are prompted to disable the security feature before continuing. The default setting is None.

A unicast address identifies one unique device on the network. However, if the switch has not received packets from the device for a while (longer than the aging period), the switch does not remember the location of the device on the network. The switch must flood (sent to all ports except the one the packet is received on) the unknown unicast address in order to ensure the device receives the packet. Once the switch learns the location of the device, this flooding stops and the address of the device is now a known unicast.

[E] Enhanced Congestion Control--Use this option to globally enable Enhanced Congestion Control (ECC) on the 10BaseT ports. The global implementation of ECC then provides the same level of congestion control for all the 10BaseT ports. The ECC option applies only when the ports are operating in half-duplex mode.

ECC helps reduce congestion in the switch and helps keep the switch from dropping frames due to full transmit queues. An ECC-enabled port uses a modified backoff algorithm to accelerate transmission of frames and empty its queue more quickly.

There are four settings for the ECC option:

  • [1] Adaptive--If the transmit queue of the port is not full, the port operates under the ECC Disabled setting. If the transmit queue of the port is full, the port uses the ECC Aggressive setting. To use this setting, enter 1.

  • [2] Disabled (Default)--This is the default setting for the ECC option. The port uses the standard IEEE 802.3 backoff algorithm for retransmitting frames. To use this setting, enter 2.

  • [3] Moderately Aggressive--The port uses a modified backoff algorithm to more aggressively retransmit frames and empty its queue than a port set at ECC Disabled. To use this setting, enter 3.

  • [4] Aggressive--This is the highest acceleration rate configurable for the ECC option. The port uses a modified backoff algorithm to more aggressively retransmit frames and empty its queue than a port set at ECC Moderately Aggressive or ECC Disabled. To use this setting, enter 4.

For Enhanced Congestion Control on 100BaseT Ports--You can enable ECC on a port-by-port basis for the 100BaseT ports, but not from the same screen you use to specify ECC for the 10BaseT ports. To enable ECC on the 100BaseT ports operating in half-duplex mode, follow these steps:


  1. Select the [P] option from the Management Console Main Menu, and then select either Port A or B at the prompt to display the Port Configuration Menu for the 100BaseT Ports.

  2. Select the [F] Performance option from the Port Configuration Menu for the 100BaseT Ports, and then select the [E] Enhanced congestion control option from the Port A (or Port B) Performance Configuration Menu:
Catalyst 1900 - Port A Performance Configuration
Auto-negotiation status: Auto-negotiate
--------------------Settings------------------
[F] Full duplex / Flow control                  Auto-negotiate
[B] Half duplex back pressure                   Disabled
[E] Enhanced congestion control                 Disabled

  1. At the prompt, select one of the settings: [1] Adaptive, [2] Disabled (Default),
    [3] Moderately Aggressive, or [4] Aggressive.

[R] Reset system--Use this option to reset the switch. All configured system parameters and static addresses are retained; all dynamic addresses are removed. Enter Y (yes) or
N (no).

[F] Reset with factory defaults--Use this option to reset the switch and return it to its factory settings. All static and dynamic addresses are removed, as are the IP address and all other configuration parameters. Enter Y (yes) or N (no).

[B] Broadcast storm control--Use this option to display the Broadcast Storm Control Menu. You can use this menu to inhibit the forwarding of broadcast packets when large numbers or storms of broadcast packets are received by a port.

[X] Exit--Use this option to display the Management Console Main Menu.

Switching Modes

This section provides additional information about the [S] Switching mode option on the System Configuration Menu.

The switching mode determines how quickly the switch can forward a packet and, therefore, how much latency the packet experiences. Latency is the delay between the time a port begins to receive a packet and the time the port begins to transmit the packet to a destination port. Selecting a switching mode is often a choice between enhanced error checking and lower latency. The switch offers the following switching modes:

  • The default switching mode, FragmentFree, is a form of cut-through switching. The FragmentFree switching mode filters out collision fragments (the majority of packet errors) before forwarding begins. In a properly functioning network, collision fragments are packets with less than 64 bytes. Packets greater than 64 bytes are considered valid and without errors. In FragmentFree mode, the switch waits until
    64 bytes are received (that is, the received packet has been determined not to be a collision fragment) before forwarding the packet. In FragmentFree mode, latency is measured as first-bit-received to first-bit-transmitted or "First-In, First-Out" (FIFO).

If latency is an issue, use FragmentFree switching.

  • The store-and-forward switching mode stores complete packets and checks for errors prior to transmission. In store-and-forward mode, latency is measured as last-bit-received to first-bit-transmitted or "Last-In, First-Out" (LIFO). This does not include the time it takes to receive the entire packet, which can vary, according to packet size. The time required to receive a packet at 100 Mbps varies between 51.2 microseconds and 1.2 milliseconds. At 10 Mbps, the time required to receive a packet varies between 5.12 microseconds to 120 microseconds. The store-and-forward mode is always used for broadcast packets and transfers from 10-Mbps to 100-Mbps ports.

When selecting a forwarding mode, consider that the store-and-forward is the most error-free form of switching, but the forwarding latency is higher than FragmentFree (cut-through) switching (see Table 3-2). If you have frame check sequence (FCS) or alignment errors, use the store-and-forward mode to ensure that packets with errors are filtered and not propagated to the rest of the network.

Table  3-2: Switching Latencies
Switching Mode 10 Mbps to
10 Mbps
10 Mbps to
100 Mbps
100 Mbps to
100 Mbps
100 Mbps to
10 Mbps
FragmentFree (cut-through) 70 microsec - 9 microsec 10 microsec
Store-and-forward1 7 microsec 7 microsec 3 microsec 3 microsec
  1. 1Although this table shows store-and-forward experiencing the lowest latency, the figures do not include the time it takes to receive the packet, which varies according to the packet size.

Broadcast Storm Control Menu

The Broadcast Storm Control Menu (see Figure 3-6) is displayed when you select the
[B] option from the System Configuration Menu. Use this menu to generate SNMP alerts and inhibit the forwarding of broadcast packets when an excessive number of them arrive from a given port.

A broadcast storm occurs when a large number of broadcast packets are received from a given port. Forwarding these packets can cause the network to slow down or time out. To avoid this, you can use broadcast storm control to set a threshold for the number of broadcast packets that can be received from a port before forwarding is blocked. You can set a second threshold to define when to re-enable the normal forwarding of broadcast packets.

Although it operates on a per-port basis, broadcast storm control is configured for the switch as a whole. By default, broadcast storm control does not monitor broadcast traffic and thus does not block traffic or send alerts based on broadcast storms.


Figure 3-6: Broadcast Storm Control Menu
Catalyst 1900 - Broadcast Storm Control
--------------------Settings------------------
[A] Action upon exceeding broadcast threshold   Ignore
[G] Generate alert when threshold exceeded      Disabled
[T] Broadcast threshold (BC's received / sec)   500
[R] Broadcast re-enable threshold               250
[X] Exit to previous menu
Enter Selection:

[A] Action upon exceeding broadcast threshold--Use this option to define the action to take when the number of broadcast packets reaches the broadcast threshold. The switch can block the broadcast storm, or it can ignore it. If you choose the block option, the switch drops all broadcast packets received from a port when the rate of broadcast packets exceeds the broadcast threshold. The switch begins forwarding again when the rate of broadcast packets received drops below the re-enable threshold. Enter B (block) or I (ignore). The default setting is Ignore.

[G] Generate alert when threshold exceeded--Use this option to generate SNMP alerts when the broadcast threshold is exceeded. The alert generated is the trap broadcastStorm. A maximum of 1 trap is generated every 30 seconds. Enter E (enable) or D (disable). The default setting is Disabled.

[T] Broadcast threshold (BCs received / sec)--Use this option to set the broadcast threshold. This measurement is the number of packets per second arriving on a port. When this threshold is exceeded, the switch blocks the forwarding of packets on the port and generates an SNMP alert, if configured to do so. The default is 500 packets per second. Enter a number between 10 and 14,400.

[R] Broadcast re-enabled threshold--Use this option to define when broadcast storm control is automatically disabled. Once a port has been blocked, the number of broadcast packets received from the port must drop below this re-enable threshold before packet forwarding is re-enabled. The default is 250 packets per second. Enter a number between 10 and 14,400.

[X] Exit--Use this option to display the System Configuration Menu.


Note Only broadcast packets are filtered. Multicast and unicast packets are still forwarded normally.

Network Management Menu

The Network Management Menu (see Figure 3-7) is displayed when you select the
[N] option from the Management Console Main Menu. Use this menu to display the following menus:

  • IP Configuration

  • SNMP Management

  • Bridge and Spanning-Tree Protocol configuration

  • Cisco Discovery Protocol


Figure 3-7: Network Management Menu
Catalyst 1900 - Network Management
[I] IP Configuration
[S] SNMP Management
[B] Bridge - Spanning Tree
[C] Cisco Discovery Protocol
[X] Exit to Main Menu
Enter Selection:

[I] IP Configuration--Use this option to display the IP Configuration Menu.

[S] SNMP Management--Use this option to display the Network Management (SNMP) Configuration Menu.

[B] Bridge-Spanning-Tree--Use this option to display the Spanning Tree Configuration Menu.

[C] Cisco Discovery Protocol--Use this option to display the CDP Configuration/Status Menu.

[X] Exit--Use this option to display the Management Console Main Menu.

IP Configuration Menu

The IP Configuration Menu (see Figure 3-8) is displayed when you select the [I] option from the Network Management Menu. Before the switch can be managed in-band, it must be configured with an IP address. Use the IP Configuration Menu to assign an IP address, or use BOOTP to assign one. You can also use this menu to assign subnet masks and define a default gateway for the switch.


Note The first time you assign an IP address to the switch, the address takes effect immediately. However, when you change the IP address, you need to reset the switch for the new IP address to take effect. To reset the switch, see the "System Configuration Menu" section in this chapter.

Figure 3-8: IP Configuration Menu
Catalyst 1900 - IP Configuration
Ethernet Address:  00-E0-1E-7E-B4-40
--------------------Settings------------------
[I] IP address                              0.0.0.0
[S] Subnet mask                             0.0.0.0
[G] Default gateway                         0.0.0.0
[X] Exit to previous menu
Enter Selection:

[I] IP address--Use this option to assign an IP address to the switch. The first time you assign an IP address, it takes effect immediately, and in-band management is available. If you change the IP address, you must reset the switch before the new IP address takes effect.

[S] Subnet mask--If IP subnetting is used, use this option to enter a subnet mask
(IP address) for the switch. The new value takes effect immediately. If subnetting is not used, the subnet mask is the same as the network mask.

[G] Default gateway--Use this option to assign a default gateway address for SNMP management. The default gateway IP address is used when the switch is trying to reach a non-local IP host.

[X] Exit--Use this option to display the Network Management Menu.

Network Management (SNMP) Configuration Menu

The Network Management (SNMP) Configuration Menu (see Figure 3-9) is displayed when you select the [S] option from the Network Management Menu. Use the Network Management (SNMP) Configuration Menu to specify the following:

  • Management stations that can set the switch MIB objects

  • READ and WRITE community strings

  • SNMP traps that are enabled and which stations receive them

  • Community strings that accompany traps sent by the switch

You can use SNMP management, based on the Catalyst 1900 MIB, to specify management stations authorized to set configuration parameters and receive certain traps. Up to four management stations can be specified to set MIB objects, and up to three stations can receive traps. If no management station is explicitly specified, any SNMP station can perform sets if the correct WRITE community string accompanies the request. However, once a WRITE-manager IP address is defined, only an explicitly specified management station can issue set operations on the switch. Once a management station has been assigned, it receives all traps issued by the switch.


Figure 3-9: Network Management (SNMP) Configuration Menu
Catalyst 1900 - Network Management (SNMP) Configuration
--------------------Settings------------------
[R] READ  community string
[W] WRITE community string
[1] 1st WRITE manager IP address                0.0.0.0
[2] 2nd WRITE manager IP address                0.0.0.0
[3] 3rd WRITE manager IP address                0.0.0.0
[4] 4th WRITE manager IP address                0.0.0.0
[F] First  TRAP community string
[A] First  TRAP manager IP address              0.0.0.0
[S] Second TRAP community string
[B] Second TRAP manager IP address              0.0.0.0
[T] Third  TRAP community string
[C] Third  TRAP manager IP address              0.0.0.0
[U] Authentication trap generation              Enabled
[L] LinkUp/LinkDown trap generation             Enabled
--------------------Actions-------------------
[X] Exit to previous menu
Enter Selection:

[R] READ community string--Use this option to define the SNMP agent Get community string. Enter a string of up to 32 characters. The default is Public.

[W] WRITE community string--Use this option to define a WRITE community string for the switch. Enter a string of up to 32 characters. The default is Private.

[1-4] WRITE manager IP address--Use the WRITE manager IP address [1-4] options to enter the IP addresses of stations authorized to issue WRITE requests to the switch. To remove an entry, enter 0. 0. 0. 0.

[F, S, T] TRAP community string and [A, B, C] TRAP Manager IP address--Use the TRAP community string [F, S, T] options and TRAP manager IP address [A, B, C] options to define up to three trap clients and their accompanying community strings.

A trap manager, or trap client, is a management workstation configured to receive and process traps. You can specify up to three trap managers with separate community strings. At least one trap manager must be defined before any traps are sent.

Enter a trap manager community string of up to 32 characters. You can specify the IP address for the trap manager in dotted quad format (nnn.nnn.nnn.nnn).

Continue with further definitions for the second and third traps, as needed.

For more information about traps, see the "Using FTP to Access the MIB Files" section later in this chapter.

[U] Authentication trap generation--Use this option to enable [E] or disable [D] authentication traps that alert a management station of SNMP requests not accompanied by a valid community string. Even if this parameter is set, no trap can be generated if no trap manager addresses have been specified. The default setting is Enabled.

[L] LinkUp/LinkDown trap generation--Use this option to enable [E] or disable [D] the linkUp/linkDown trap. The default setting is Enabled. The switch generates the linkDown trap whenever a port changes to a suspended or disabled state due to any of the following:

  • Spanning-Tree Protocol action

  • Secure address violation (address mismatch or duplication)

  • Network connection error (loss of linkbeat or jabber error)

  • Management intervention

The linkUp trap is generated whenever a port changes to the enabled state due to the following:

  • Presence of linkbeat

  • Spanning-Tree Protocol action

  • Management intervention


Note No more than one trap of each type is sent every 5 seconds per port. The last trap in the 5-second interval is the one sent.

After you have specified the management workstation(s) to receive traps, the switch generates, by default, the traps in the following list:

  • warmStart

  • coldStart

  • linkDown

  • linkUp

  • authenticationFailure

  • newRoot

  • topologyChange

  • logonIntruder

  • switchDiagnostic

  • addressViolation

  • broadcastStormControl

  • rpsFailed

[X] Exit--Use this option to display the Network Management Menu.

Spanning-Tree Configuration Menu

The Spanning Tree Configuration Menu (see Figure 3-10) is displayed when you select the [B] option from the Network Management Menu. Use the Spanning Tree Configuration Menu to display and configure the Spanning-Tree Protocol parameters defined for the switch.

The menu consists of an Information section that represents parameters controlled by Spanning-Tree Protocol operation as influenced by other bridges on the network and a Settings section that defines Spanning-Tree Protocol parameters that are global to this bridge. For more information, read the "Spanning-Tree Protocol" section later in this section.


Note The Port Fast mode option, used for end-station attachments only, bypasses two of the Spanning-Tree Protocol states and brings a port from a blocking state directly to a forwarding state. However, there is a delay in enabling the forwarding state during system startup to allow the Spanning-Tree Protocol to discover the network topology to ensure no temporary loops are formed. Spanning-tree discovery takes approximately 30 seconds to complete, and no packet forwarding takes place during this time. After the initial discovery, ports with Port Fast mode enabled will transition directly from blocking to forwarding with no delay. See the "Port Configuration Menu" section in this chapter for configuration instructions.

Figure 3-10: Spanning Tree Configuration Menu
Catalyst 1900 - Spanning Tree Configuration
Bridge ID: 8000 00-E0-1E-81-1E-40
--------------------Information----------------
Designated root 8000 00-E0-1E-81-1E-40
Number of member ports    27   Root port                N/A
Max age (sec)             20   Root path cost             0
Forward Delay (sec)       15   Hello time (sec)           2
Topology changes           0   Last TopChange   0d00h00m00s
--------------------Settings------------------
[S] Spanning Tree Algorithm & Protocol          Enabled
[B] Bridge priority                             32768 (8000 hex)
[M] Max age when operating as root              20 second(s)
[H] Hello time when operating as root           2 second(s)
[F] Forward delay when operating as root        15 second(s)
--------------------Actions-------------------
[X] Exit to previous menu
Enter Selection:

To use this menu, you need to understand the following terms:

  • Bridge ID--A unique identifier assigned to this bridge. This hexadecimal number consists of a bridge priority and a unique MAC address. You can change the bridge priority from this menu.

  • Designated root--The ID of the bridge assumed to be the root by Spanning-Tree Protocol.

  • Root port--The port on this bridge with the lowest cost path to the root bridge. This option identifies the port through which the path to the root bridge is established. N/A is displayed when Spanning-Tree Protocol is disabled or when this bridge is the root bridge.

  • Max age--The maximum time in seconds a bridge waits without receiving Spanning-Tree Protocol configuration messages before attempting a reconfiguration. This parameter takes effect when a bridge is operating as the root bridge. Bridges not acting as the root use the root bridge Max age parameter.

  • Root path cost--The cost of the path from this bridge to the root bridge shown in Designated root. It equals the path cost parameters held for the root port. When this switch is the root, the root path cost is zero.

  • Forward delay--The time interval in seconds spent waiting before a port changes from its Spanning-Tree Protocol learning and listening states to a forwarding state. This is necessary because every bridge on the network ensures no loop is formed before allowing the port to forward packets.

  • Hello time--The time interval in seconds between the transmission of Spanning-Tree Protocol configuration messages. All bridges send configuration messages during reconfiguration to elect the designated root bridge. Bridges not acting as a root bridge use the root bridge hello-time value. After the topology is stabilized, only designated bridges send configuration messages.

  • Number of TopChanges--The number of bridge topology changes experienced by this bridge. A topology change occurs as ports on this bridge change from a nonforwarding to forwarding state. A topology change also occurs when a new root is selected.

  • Time since last TopChange--The time, measured in days (d), hours (h), minutes (m), and seconds (s), since the last topology change.

[S] Spanning-Tree Algorithm and Protocol--Use this option to enable [E] or disable [D] the Spanning-Tree Protocol, an IEEE 802.1D standard to ensure a loop-free configuration in the bridge topology. When Spanning-Tree Protocol is enabled, redundant ports are kept in standby (suspended) status and are automatically enabled when needed. For additional information about this option, see the "Spanning-Tree Protocol" section later in this section. The default setting is Enabled.

[B] Bridge priority--Use this option to force a bridge to be selected as the root bridge or as a designated bridge. The bridge priority is a value used in determining the identity of the root bridge. The bridge with the lowest value has the highest priority and is selected as the root. The default setting is 32768.

[M] Max age when operating as root--Use this option to define the time in seconds to be used as the Max age interval when this switch becomes the root bridge. After this period expires, other bridges recognize that the root has not sent a configuration message and a new root is selected. Valid values range from 6 to 40 seconds; the default value is
20 seconds.

[H] Hello time when operating as root--Use this option to define the hello-time interval when this switch becomes the root bridge. Valid values range from 1 to 10 seconds; the default value is 2 seconds.

[F] Forward delay when operating as root--Use this option to define the time in seconds to be used as the forward delay interval when this switch becomes the root bridge. Valid values range from 4 to 30 seconds; the default value is 15 seconds.


Note Spanning-Tree Protocol also uses this value to accelerate address aging when the spanning tree is reconfigured. See the following "Spanning-Tree Protocol" section for more information.

[X] Exit--Use this option to display the Network Management Menu.

Spanning-Tree Protocol

This section provides additional information about the [S] Spanning-Tree Algorithm and Protocol option on the Spanning Tree Configuration Menu.

Spanning-Tree Protocol is a standard for maintaining a network of multiple bridges or switches. As part of the IEEE 802.1d standard, Spanning-Tree Protocol interoperates with compliant bridges and switches from other vendors. It transparently reconfigures bridges when the topology changes to avoid the creation of loops and to establish redundant paths in the event of lost connections.

All ports on the switch support Spanning-Tree Protocol, and management of Spanning-Tree Protocol is through the standard Bridge MIB.

  • Using Spanning-Tree Protocol to Support Redundant Connectivity--You can create a redundant backbone with Spanning-Tree Protocol by connecting two of the ports on a switch to another device or to two different devices. Spanning-Tree Protocol automatically disables one port but enables it if the other port is lost. If one link is high-speed and the other low-speed, the low-speed link is always disabled. If the speed of the two links is the same, the port priority and port ID are added together, and the link with the lowest value is disabled.

  • Spanning-Tree Protocol and Accelerated Address Aging--Dynamic addresses are aged and dropped from the address table after a configurable period of time. The default for aging dynamic addresses is 5 minutes. However, a reconfiguration of the spanning tree can cause many station locations to change. Because this could mean that many stations were unreachable for 5 minutes or more, the address-aging time is accelerated so that station addresses can be dropped from the address table and then relearned. The accelerated aging is the same as the forward-delay parameter value when Spanning-Tree Protocol reconfigures. You can define the forward-delay parameter from the
    [F] Forward delay option on the Spanning Tree Configuration Menu.

CDP Configuration/Status Menu

The CDP Configuration/Status Menu (see Figure 3-11) is displayed when you select the [C] option from the Network Management Menu. Use the CDP Configuration/Status Menu to enable the Cisco Discovery Protocol (CDP) on some or all of the switch ports. You can also use this menu to set the timing for transmission of CDP messages.

CDP allows network managers to obtain an accurate picture of the network at any time. By gathering information about the types of devices in the network, the links between those devices, and the number of interfaces within each device, CDP enables network management applications to display a graphical topology map of the network. Detailed information about the connections between devices is also available.


Figure 3-11: CDP Configuration/Status Menu
Catalyst 1900 - CDP Configuration/Status
CDP enabled on: 1-24, AUI, A, B
--------------------Settings------------------
[H] Hold Time (secs)                           180
[T] Transmission Interval (secs)                60
--------------------Actions-------------------
[E] Enable CDP on Port(s)
[D] Disable CDP on Port(s)
[S] Show Neighbor
[X] Exit to previous menu
Enter Selection:

[H] Hold Time--Use this option to set the number of seconds that a neighboring device retains the CDP neighbor information received from this switch. If a neighboring device does not receive a CDP message before this hold time expires, the neighboring device drops this switch as a neighbor. Enter a number between 5 and 255. The default setting is 180.

[T] Transmission Interval--Use this option to set the number of seconds between transmissions of CDP messages. Enter a number between 5 and 900. The default setting
is 60.

[E] Enable CDP on Port(s)--Use this option to enable CDP on one or more ports. You can separate the port numbers with a hyphen to create a range or can use commas or spaces between port numbers. Enter the high-speed port A (left) or port B (right). The word ALL creates a list of ports with all the switch ports. Enter port numbers according to these conventions. The default settings for all ports is Enabled.

[D] Disable CDP on Port(s)--Use this option to disable CDP on one or more ports. Enter the port numbers according to the conventions described in the previous paragraph.

[S] Show Neighbor--Use this option to display the information available about neighboring devices (see Figure 3-12). The first two lines in the display define the abbreviations used.


Figure 3-12: Show Neighbor Display
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
                 S - Switch, P - Repeater, H - Host, I - IGMP
DeviceID      IP Addr     Local Port  Capability  Platform   Remote Port
00E01E871FC0 192.9.200.192     4         TS       cisco 1900    3
00C01D80727  192.9.200.221     6         TS       cisco 1900    10
Press any key to continue.

[X] Exit--Use this option to display the Network Management Menu.

Port Configuration Menu

When you select the [P] option from the Network Management Menu, the following prompt is displayed:

Identify Port:  1 to 24[1-24], [AUI], [A], [B]:
Select [1 - 24, AUI, A, B]:

At the prompt, select the specific port that you want to configure. If you select a 10BaseT port (ports 1x through 12x or 24x or AUI), the Port Configuration Menu for the 10BaseT Ports in Figure 3-13 is displayed. If you select a 100BaseT port (ports Ax or Bx), the Port Configuration Menu for the 100BaseT Ports in Figure 3-14 is displayed.

Use the Port Configuration Menu to display the status of a port, enter a port description, change the port status, and define various Spanning-Tree Protocol parameters.


Figure 3-13: Port Configuration Menu for the 10BaseT Ports
Catalyst 1900 - Port 1 Configuration
Built-in 10Base-T
802.1d STP State:  Blocking     Forward Transitions:  0
--------------------Settings------------------
[D] Description/name of port
[S] Status of port                              Suspended-no-linkbeat
[F] Full duplex                                 Disabled
[B] Half duplex back pressure                   Disabled
[I] Port priority (spanning tree)               128 (80 hex)
[C] Path cost (spanning tree)                   100
[H] Port fast mode (spanning tree)              Enabled
------------------Related Menus---------------
[A] Port addressing           [V] View port statistics
[N] Next port                 [G] Goto port
[P] Previous port             [X] Exit to Main Menu
Enter Selection:


Figure 3-14: Port Configuration Menu for the 100BaseT Ports
Catalyst 1900 - Port A Configuration
Built-in 100Base-TX
802.1d STP State:  Blocking     Forward Transitions:  0
--------------------Settings------------------
[D] Description/name of port
[S] Status of port                              Suspended-no-linkbeat
[I] Port priority (spanning tree)               128 (80 hex)
[C] Path cost (spanning tree)                   10
[H] Port fast mode (spanning tree)              Disabled
------------------Related Menus---------------
[F] Performance
[A] Port addressing           [V] View port statistics
[N] Next port                 [G] Goto port
[P] Previous port             [X] Exit to Main Menu
Enter Selection:

The Spanning-Tree Protocol state is displayed at the top of the Port Configuration Menu. The following is a list of the possible Spanning-Tree Protocol states for ports on the switch.

  • Blocking--Port is not participating in the frame-forwarding process and is not learning new addresses.

  • Listening--The same as blocking, but the switch is actively trying to bring the port into the forwarding state. The port is not learning addresses.

  • Learning--Port is not forwarding frames but is learning addresses. The switch is actively trying to bring the port into the forwarding state.

  • Forwarding--Port is forwarding frames and learning addresses.

  • Disabled--Port has been removed from operation. Administrative intervention is required to enable the port.

The Forward Transitions field displays the number of times the Spanning-Tree Protocol state for this port has changed from listening or learning to forwarding.

[D] Description/name of port--Use this option to assign a name or description to the port. Enter up to 60 characters.

[S] Status of port--Use this option to enable [E] or disable [D] a port. Port status is a system-wide indicator of the state of a port. The status of a port can change in response to security violations, by management intervention, or by actions of the Spanning-Tree Protocol. At any given time, each port on the switch is in one of the states listed in Table 3-3.

No packets are forwarded to or from a disabled or suspended port. However, suspended ports do monitor incoming packets to look for an activating condition. If a linkbeat returns, for example, a port suspended due to linkbeat failure returns to the enabled state.


Table 3-3: Port Status Definitions
Port Status Definition
Enabled Normal operation. Port can transmit and receive.
Disabled-mgmt Disabled by explicit management action.
Suspended-no-linkbeat Suspended due to the absence of a linkbeat. This is usually because the attached station is disconnected or powered-down. Port automatically returns to enabled state when the condition causing the suspension is removed.
Suspended-jabber Suspended because attached station is jabbering. Port automatically returns to enabled state when the condition causing the suspension is removed.
Suspended-violation Suspended due to address violation. Port automatically returns to enabled state when the condition causing the suspension is removed.
Suspended-Spanning-Tree Protocol Spanning-Tree Protocol not forwarding. Port automatically returns to enabled state when the condition causing the suspension is removed.
Disabled-self-test Disabled because port failed self-test. Port must be manually returned to enabled state.
Disabled-violation Disabled due to address violation. Port must be manually returned to enabled state.
Reset Port is currently in the reset state.

[F] Full duplex (10BaseT ports)--Use this option to enable [E] or disable [D] full-duplex transmission on 10BaseT ports. The default setting for the 10BaseT ports is half-duplex mode (full-duplex disabled). Autonegotiation and flow control are not supported on the 10BaseT ports.

Full-duplex operation is simultaneous transmission of data in both directions across a link. For example, 100BaseTX ports operating in full-duplex mode can provide up to 200 Mbps of bandwidth across the switched link.

You can use full-duplex connections (either 10 Mbps or 100 Mbps) to enhance transmission speeds between other switches or routers that support full-duplex operation. A likely full-duplex scenario would be to connect a 100BaseT port to a server with a 100BaseT adapter configured for full-duplex operation.


Note As both ends of the link must be configured for full-duplex operation, a full-duplex port cannot be connected to a repeater.

For full-duplex on the 100BaseT ports--On a port-by-port basis, you can enable full-and half-duplex operation on the 100BaseTX and 100BaseFX ports and duplex mode autonegotiation on the 100BaseTX, but not from the same screen you use to specify the duplex mode for the 10BaseT ports. To specify duplex operation on the 100BaseT ports, follow these steps:


  1. Select the [P] option from the Management Console Main Menu, and then select either Port A or B at the prompt to display the Port Configuration Menu for the 100BaseT Ports.

  2. Select the [F] Performance option from the Port Configuration Menu for the 100BaseT Ports, and then select the [F] Full duplex / Flow control option from the Port A (or Port B) Performance Configuration Menu:
Catalyst 1900 - Port A Performance Configuration
Auto-negotiation status: Auto-negotiate
--------------------Settings------------------
[F] Full duplex / Flow control                  Auto-negotiate
[B] Half duplex back pressure                   Disabled
[E] Enhanced congestion control                 Disabled

  1. At the prompt, select one of the settings: [1] Full duplex, [2] Half duplex, [3] Full duplex with flow control, or [4] Auto-negotiate. The [4] Auto-negotiate option is available on the 100BaseTX port(s) only.

The default setting of the 100BaseTX ports is autonegotiation for duplex mode (no flow control) (see the "IEEE 802.3x Flow Control" section for more information about this standard). If the device at the target end of the connection also supports full-duplex, the port automatically configures for full-duplex operation. If the device does not support full-duplex operation, the port automatically configures to half-duplex operation.

The default setting for the 100BaseFX ports is half-duplex mode with no flow control. This port can be configured for full-duplex operation. Autonegotiation of duplex mode is not available on the 100BaseFX port.

[B] Half Duplex Back Pressure--Use this option to enable [E] or disable [D] the half-duplex back pressure on the ports. Back pressure can be configured on a port-by-port basis for all ports on the switch operating in half-duplex mode. The default setting for back-pressure control on the 10BaseT and 100BaseT ports is Disabled.

To specify back pressure on the 10BaseT ports, use the Port Configuration Menu for the 10BaseT Ports; for the 100BaseT ports, use the Port Configuration Menu for the 100BaseT Ports.

Back pressure ensures the retransmission of incoming packets when a port configured for half-duplex operation is temporarily unable to receive incoming frames. When back pressure is enabled and no buffers are available to a port, the switch generates collision frames across the affected port and causes the transmitting station to resend the packets. The switch can then use this retransmission time to clear its receive buffer by transmitting packets already in the queue.

[E] Enhanced congestion control--Use this option, from the Port Configuration Menu for the 100BaseT Ports, to enable Enhanced Congestion Control (ECC) on a port-by-port basis for the 100BaseT ports. You can enable ECC on a global basis for the 10BaseT ports from the System Configuration Menu. The ECC option applies only when the ports are operating in half-duplex mode.

ECC helps reduce congestion in the switch and helps keep the switch from dropping frames due to full transmit queues. An ECC-enabled port uses a modified backoff algorithm to accelerate transmission of frames and empty its queue more quickly.

There are four settings for the ECC option:

  • [1] Adaptive--If the transmit queue of the port is not full, the port operates under the ECC Disabled setting. If the transmit queue of the port is full, the port uses the ECC Aggressive setting. To use this setting, enter 1.

  • [2] Disabled (Default)--This is the default setting for the ECC option. The port uses the standard IEEE 802.3 backoff algorithm for retransmitting frames. To use this setting, enter 2.

  • [3] Moderately Aggressive--The port uses a modified backoff algorithm to more aggressively retransmit frames and empty its queue than a port set at ECC Disabled. To use this setting, enter 3.

  • [4] Aggressive--This is the highest acceleration rate configurable for the ECC option. The port uses a modified backoff algorithm to more aggressively retransmit frames and empty its queue than a port set at ECC Moderately Aggressive or ECC Disabled. To use this setting, enter 4.

[I] Port priority--Use this option to define which port is to remain enabled by Spanning-Tree Protocol if two ports form a loop. Enter a number from 0 to 255. The default setting for the 10BaseT and 100BaseT ports is 128.

[C] Path cost--Use this option to define the Spanning-Tree Protocol path cost of the port. It is inversely proportional to the LAN speed of the network interface at the port. A high path cost means the port has low bandwidth and should not be used, if possible. The default is 1000/LAN-speed-in-Mbps. The path cost of 100-Mbps ports is thus 10, and the path cost of 10-Mbps ports is 100. This option also affects which port is to remain enabled by Spanning-Tree Protocol if another bridge device forms a loop with the switch. Enter a value between 1 and 65535. The default setting for the 10BaseT ports is 100. The default setting for the 100BaseT ports is 10.

[H] Port fast mode--Use this option to accelerate the time it takes for Spanning-Tree Protocol to bring a port into the forwarding state. The Port Fast option is a simplified version of the Spanning-Tree Protocol that bypasses the normal pre-forwarding Spanning-Tree states, more quickly bringing ports into the forwarding states. Port Fast is an option that you can enable on a per-port basis. Port Fast-enabled ports are used for end-station attachments only. Enter E (enable) or D (disable). The default setting for the 10BaseT ports is Enabled. The default setting for the 100BaseT ports is Disabled.


Note When the switch is powered up, the forwarding state, even if the Port Fast mode is enabled, is delayed to allow the Spanning-Tree Protocol to discover the topology of the network and ensure no temporary loops are formed. Spanning-tree discovery takes approximately 30 seconds to complete, and no packet forwarding takes place during this time. After the initial discovery, ports with Port Fast mode enabled will transition directly from blocking to forwarding with no delay.

[A] Port addressing--Use this option to display the Port Addressing Menu.

[V] View port statistics--Use this option to display the Detailed Port Statistics Report.

[N] Next port--Use this option to display the Port Configuration Menu for the next sequentially numbered port of the switch.

[G] Go to port--Use this option to display the Port Configuration Menu for a specified port. The following prompt is displayed:

Identify port: 1 to 24, AUI,[A],[B]
Select [1 - 24, AUI, A, B]:

[P] Previous port--Use this option to display the Port Configuration Menu for the port number that is one less than the current port. (That is, if you are currently viewing the menu for port 5 and you select this option, the menu for port 4 is displayed.)

[X] Exit--Use this option to display the Management Console Main Menu.

IEEE 802.3x Flow Control

This section provides information about the [F] Full duplex option on the Port A (or
Port B) Configuration Menu.

All 100BaseT ports operating in full-duplex mode support the IEEE 802.3x implementation of port-based flow control. (Catalyst 1900 switches do not support flow control on 10-Mbps ports.) When flow control is enabled, the switch responds to pause-control frames received from other connected devices. The switch automatically holds subsequent transmissions in the port queue for the time specified in the pause-control frame. When no more pause-control frames are received, or when the default time specified has passed, the switch resumes the transmission of frames through the affected port.


Note Although the Catalyst 1900 switches do not generate pause-control frames, the switches do respond appropriately to pause-control frames generated by other devices.

Port Addressing Menu

When you select the [A] option from the Network Management Menu, the following prompt is displayed:

Identify Port:  1 to 24[1-24], [AUI], [A], [B]:
Select [1 - 24, AUI, A, B]:

At the prompt, select the specific port that you want to configure. The Port Addressing Menu (see Figure 3-15) is then displayed. Use the Port Addressing Menu to configure address security of a port and to define static unicast and multicast addresses. You can also use this menu to specify how a port filters and forwards unmatched unicast addresses and nonregistered multicast addresses. Although multicast address registrations are configured elsewhere, you can use this menu to specify additional source-port filtering on the multicast addresses.

Additional information about address learning, flooding controls, and securing ports is provided later in this section.


Figure 3-15: Port Addressing Menu
Catalyst 1900 - Port 1 Addressing
Address  : Static     00-00-00-00-00-1B
--------------------Settings------------------
[T] Address table size                          Unrestricted
[S] Addressing security                         Disabled
[U] Flood unknown unicasts                      Enabled
[M] Flood unregistered multicasts               Enabled
--------------------Actions-------------------
[A] Add a static address
[D] Define restricted static address
[L] List addresses
[E] Erase an address
[R] Remove all addresses
[C] Configure port            [V] View port statistics
[N] Next port                 [G] Goto port
[P] Previous port             [X] Exit to Main Menu
Enter Selection:

The top of the menu displays the current addressing situation:

  • Dynamic addresses--The current number of unicast addresses that have been automatically learned on this port. If this is a secured port, the dynamic addresses field is set to zero.

  • Static addresses--The current number of unicast addresses that have been assigned to this port.

For more information about address learning, see the "Address Learning" section later in this section.

[T] Address Table Size--Use this option to define the size of the address table for a secured port. Enter a number between 1 and 132.


Note The size of the address table for an unsecured network port cannot be modified.

[S] Addressing security--Use this option to secure a port. Enter E (enable) or D (disable). The default setting is Disabled.

Alerts can be generated when a secured port attempts to learn new addresses and its address table is full. The port can be disabled or suspended due to such address violations. See the "Securing Ports" section later in this section for more information.

This option must be disabled for network ports.

[U] Flood unknown unicasts--Use this option to enable [E] or disable [D] the forwarding of unknown unicasts to this port. When a frame with an unrecognized unicast destination address is received on any port, the default action is to forward the packet to all enabled ports. For more information about flooding, see the "Flooding Controls" section later in this section. The default setting is Enabled.

[M] Flood unregistered multicasts--Use this option to enable [E] or disable [D] the forwarding of unregistered multicast addresses to this port. The default setting is Enabled. When a frame with an unregistered multicast destination address is received on any port, the default action is to forward the packet to all enabled ports. For more information about flooding, see the "Flooding Controls" section later in this section.

This option must be disabled for network ports.

[A] Add a static address--If there is room in the port address table, you can use this option to add a static unicast address to it. If the address table is already full, an error message is generated. You can change the size of the address table with the [T] Address table size option.


Note Only unicast addresses can be added. An attempt to add a multicast or broadcast address will not be accepted and will generate an error message.

[D] Define a restricted static address--Use this option to enter the restricted static unicast or multicast address. Packets with static addresses are usually accepted from any source port. However, a restricted static address, which corresponds to IEEE 802.1d source port filtering, is accompanied by a list of ports that are allowed to send frames to this address and port.

You are then prompted to enter the port numbers allowed to send to this address. If there are any typing errors, the prompt is redisplayed.

[L] List addresses--Use this option to list all dynamic and static addresses that belong to this port. The switch displays up to 15 addresses per display; static addresses are listed first.

[E] Erase an address--Use this option to remove a dynamic or static address assigned to the current port.

[R] Remove all addresses--Use this option to remove all dynamic and static addresses currently associated with the port. Enter Y (yes) or N (no) at the confirmation prompt.

[C] Configure port--Use this option to display the Port Configuration Menu.

[V] View port statistics--Use this option to display the Detailed Port Statistics Report.

[N] Next port--Use this option to display the Port Addressing Menu for the next sequentially numbered port of the switch.

[G] Go to port--Use this option to display the Port Addressing Menu for a specified port. The following prompt is displayed:

Identify port: 1 to 24, AUI,[A],[B]
Select [1 - 24, AUI, A, B]:

[P] Previous port--Use this option to display the Port Addressing Menu for the port number that is one less than the current port. (That is, if you are currently viewing the menu for port 5 and you select this option, the menu for port 4 is displayed.)

[X] Exit--Use this option to display the Management Console Main Menu.

Address Learning

This section provides additional information for understanding and using the options on the Port Addressing Menu.

With multiple Media Access Control (MAC) address support on all ports, you can connect any port on the switch to individual workstations, repeaters, switches, routers, or other network devices. The switch provides dynamic addressing by learning the source address of each packet it receives on each port and adding the address and its associated port number to the address table. As stations are added or removed from the network, the switch updates the address table, adding new entries and aging out those that are currently not in use.

You can manually enter addresses into the address table, including static addresses. Because static addresses do not age, you must manually remove them. Static addressing also allows for a measure of security in that access to a port can be restricted. See the "Securing Ports" section in this chapter for more information.

Flooding Controls

This section provides information about using the flooding and addressing options on the Port Addressing Menu.

Flooding is the forwarding of unicast and multicast packets with unknown destination addresses to all ports. In certain applications, flooding might be unnecessary and undesirable. To control flooding, the switch forwards, floods, and filters packets in accordance with the IEEE 802.1d specification.

The switch forwards each packet according to the source address stored in the switch address table that matches the destination address of the packet. If the port a packet is received on has both the packet source and destination addresses on it, the packet is filtered (not forwarded).

If the switch cannot match a destination address of a packet with a source address in its address table, the switch floods the packet with the unknown destination address to all ports. Broadcast packets are always flooded to all ports.

For example, when the switch receives a unicast packet with a destination address that it has not learned, the default is to flood it to all ports. On ports with only statically assigned addresses or single stations attached, there are no unknown destinations and flooding would serve no purpose. In this case, you can disable flooding on a per-port basis.

In another example, when the switch receives a multicast or broadcast packet, you can use the Multicast Registration Menu or SNMP to register multicast addresses and specify to which ports these packets are to be forwarded. You can also disable the normal flooding of unregistered multicast packets on a per-port basis. Besides reducing unnecessary traffic, these features open up the possibility of using multicast packets for dedicated groupcast applications such as broadcast video. For more information about using the Multicast Registration Menu, see the "Multicast Registration Menu" later in this chapter.

The switch also supports source-port filtering. This enhanced filtering capability only forwards packets to destinations when received on specified ports. Packets to these destinations received on other ports are filtered. These destinations are referred to as restricted static addresses.

Securing Ports

This section provides additional information for using the [S] Addressing security option on the Port Addressing Menu.

Secured ports restrict the use of a port to a user-defined group of stations. When you assign static addresses to a secure port, the switch does not forward any packets with source addresses outside the group. If you define the address table of a secure port to contain only one address, the workstation or server attached to that port is guaranteed the full bandwidth of the port.

The number of devices on a secured port can range from 1 to 132. The addresses for the devices on a secure port are statically assigned by an administrator or sticky-learned. Sticky-learning takes place when the address table for a port that is set as secured does not contain a full complement of static addresses. The port sticky-learns the source address of incoming packets and automatically assigns them as static addresses.

Secured ports generate address-security violations under the following conditions:

  • When the address table of a secured port is full and the address of an incoming packet is not found in the table

  • When an incoming packet has a source address statically assigned to another port

When a security violation occurs, the port can be suspended or disabled. You can also choose to ignore the violation and keep the port enabled. By using the MIB objects, you can define the action taken by the switch.

Port Statistics Report

When you select the [D] option from the Management Console Main Menu or the
[V] option from the Port Configuration Menu or Port Addressing Menu, the following prompt is displayed:

Identify Port:  1 to 24[1-24], [AUI], [A], [B]:
Select [1 - 24, AUI, A, B]:

At the prompt, select the specific port for which you want to display the statistics and errors. The Detailed Port Statistics Report (see Figure 3-16) is then displayed. This report displays the frame transmit and receive statistics captured by the switch. The statistics and errors can be displayed for all ports on a per-port basis.

If you are using VT100 terminal emulation, the statistics displays are refreshed every
5 seconds. If you are connected to the Management Console via a modem running at less than 2400 baud, the statistics displays are refreshed every 8 seconds.

Figure 3-16 is an example statistics report for a 10BaseT port.


Figure 3-16: Detailed Port Statistics Report

Catalyst 1900 - Port 1 Statistics Report
Receive Statistics                     Transmit Statistics
---------------------------------  -------------------------------------
Total good frames            0  Total frames                        0
Total octets                 0  Total octets                        0
Broadcast/multicast frames   0  Broadcast/multicast frames          0
Broadcast/multicast octets   0  Broadcast/multicast octets          0
Good frames forwarded        0  Deferrals                           0
Frames filtered              0  Single collisions                   0
Runt frames                  0  Multiple collisions                 0
No buffer discards           0  Excessive collisions                0
                                Queue full discards                 0
Errors:                         Errors:
  FCS errors                 0    Late collisions                   0
  Alignment errors           0    Excessive deferrals               0
  Giant frames               0    Jabber errors                     0
  Address violations         0    Other transmit errors             0
Select [A] Port addressing, [C] Configure port,
       [N] Next port, [P] Previous port, [G] Goto port,
       [R] Reset port statistics, or [X] Exit to Main Menu:

Performance or connectivity problems could be evident in the port statistics, particularly those under the heading errors (Table 3-4). For example, FCS and alignment errors could be the result of cabling problems such as the following:

  • Cabling distance exceeded

  • Split pairs

  • Defective patch-panel ports

  • Wrong cable type

  • Misconfigured full-duplex connection


Table 3-4: Heading Error Descriptions
Heading Error Description
FCS errors A count of frames received on a particular interface that are an integral number of octets in length but do not pass the Frame Check Sequence (FCS) test.
Alignment errors A count of frames received on a particular interface that are not an integral number of octets in length and do not pass the FCS check.
Giant frames A count of frames received on a particular interface that exceed the maximum permitted frame size.
Address violations The number of times a source address was seen on this secured port that duplicates a static address configured on another port plus the number of times a source address was seen on this port that does not match any addresses secured for the port.
Late collisions The number of times that a collision is detected on a particular interface later than 512 bit-times into the transmission of a packet.
Excessive deferrals A count of frames for which transmission is deferred for an excessive period of time.
Jabber errors The number of times the jabber function was invoked because a frame received from this port exceeded a certain time duration.

[A] Port addressing--Use this option to display the Port Addressing Menu.

[C] Configure port--Use this option to display the Port Configuration Menu.

[R] Reset port statistics--Use this option to clear the port statistics by entering Y (yes). To update the display, press the Spacebar.

[N] Next port--Use this option to display the Detailed Port Statistics Report for the next sequentially numbered port of the switch.

[G] Go to port--Use this option to display the Detailed Port Statistics Report for a specified port. The following prompt is displayed:

Identify port: 1 to 24, AUI,[A],[B]
Select [1 - 24, AUI, A, B]:

[P] Previous port--Use this option to display the Detailed Port Statistics Report for the port number that is one less than the current port. (That is, if you are currently viewing the menu for port 5 and you select this option, the menu for port 4 is displayed.)

[X] Exit--Use this option to display the Management Console Main Menu.

Monitoring Configuration Menu

The Monitoring Configuration Menu (see Figure 3-17) is displayed when you select the [M] option from the Management Console Main Menu. Use the Monitoring Configuration Menu to do the following:

  • Turn frame-capturing on and off.

  • Define those ports whose frames are to be captured.

  • Define the port the captured frames are to be sent to.

Frame capturing cannot take place until all three of these parameters have been set.

You can route a copy of incoming and outgoing port traffic to a monitor port for analysis and troubleshooting. When a port is selected as the monitor port, it sends out only traffic seen on the ports defined in the port capture list.


Note Spanning-Tree Protocol and BOOTP are disabled on the monitor port if monitoring is enabled. The flooding of unregistered multicast packets and unknown unicast packets is similarly inhibited.

Note Enable monitoring only for problem diagnosis. Disable monitoring during normal operation so that performance of the switch is not degraded.

Figure 3-17: Monitoring Configuration Menu
Catalyst 1900 - Monitoring Configuration
--------------------Settings------------------
[C] Capturing frames to the Monitor             Disabled
[M] Monitor port assignment                     None
Current capture list:  No ports in list
--------------------Actions-------------------
[A] Add ports to capture list
[D] Delete ports from capture list
[X] Exit to Main Menu
Enter Selection:

[C] Capturing frames to the Monitor--Use this option to enable [E] or disable [D] frame capturing. The default setting is Disabled.

[M] Monitor port assignment--Use this option to specify the number of the port where captured frames are to be sent. The port capture list can include any number of the ports, from none to all 15 or 27 ports.

[A] Add ports to capture list--Use this option to add ports to the capture list.

[D] Delete ports from capture list--Use this option to delete port numbers from the capture list. Enter the port numbers that you want to delete from the list.

[X] Exit--Use this option to display the Management Console Main Menu.

Multicast Registration Menu

The Multicast Registration Menu (see Figure 3-18) is displayed when you select the
[R] option from the Management Console Main Menu. By default, all multicast or broadcast packets are forwarded to all ports of the switch. However, you can use the Multicast Registration Menu to register multicast addresses and list the ports these packets are to be forwarded to. Because these packets are then not forwarded to other ports, this reduces the amount of flooding performed by the switch.

You can also disable the normal flooding of unregistered multicast packets on a per-port basis. Besides reducing unnecessary traffic, these features open up the possibility of using multicast packets for dedicated groupcast applications such as broadcast video.

The first line of the menu displays the number of registered multicast addresses.


Figure 3-18: Multicast Registration Menu
Catalyst 1900 - Multicast Registration
Registered multicast addresses:  0
--------------------Actions-------------------
[R] Register a multicast address
[L] List all multicast addresses
[U] Unregister a multicast address
[E] Erase all multicast addresses
[X] Exit to Main Menu
Enter Selection:

[R] Register a multicast address--Use this option to register a multicast address. You can enter both the address and the ports to which frames destined for this address are to be forwarded. If you enter an invalid multicast address, the prompt refreshes itself so that you can try again. Invalid addresses include nonmulticast addresses, the broadcast address, and reserved multicast addresses, such as those used for Spanning-Tree Protocol.

[L] List all registered multicast addresses--Use this option to list all registered multicast addresses that exist in the switch. Addresses are listed with the port or ports to which they are assigned. Addresses with an asterisk are subject to source port filtering.

See the "Flooding Controls" section in the "Port Configuration Menu" section for more information.

[U] Unregister a multicast address--Use this option to delete registered multicast addresses. You cannot delete those multicast addresses that are not considered registered.

[E] Erase all registered multicast addresses--Use this option to remove all registered multicast addresses by pressing Y (yes).

[X] Exit--Use this option to display the Management Console Main Menu.

Firmware Configuration Menu

The Firmware Configuration Menu (see Figure 3-19) is displayed when you select the
[F] option from the Management Console Main Menu. Use the Firmware Configuration Menu to display the firmware version currently used by the switch and to perform firmware upgrades. The version number of the currently executing firmware and the size of the Flash memory of the switch is displayed in the System Information area in the menu. If there is a firmware upgrade in progress, its status is displayed in the Upgrade status field in the System Information area.


Figure 3-19: Firmware Configuration Menu
Catalyst 1900 - Firmware Configuration
-----------------System Information------------
FLASH:  1024K bytes
V6.00
Upgrade status:
No upgrade currently in progress.
--------------------Settings------------------
[S] Server:  IP address of TFTP server          0.0.0.0
[F] Filename for firmware upgrades
[A] Accept upgrade transfer from other hosts    Enabled
--------------------Actions-------------------
[U] System XMODEM upgrade        [D] Download test subsystem (XMODEM)
[T] System TFTP upgrade          [X] Exit to Main Menu
Enter Selection:

To upgrade Catalyst 1900 firmware, download the upgrade file into a temporary area. After it is validated by the existing firmware, the new image is transferred into Flash memory, the switch resets, and the new firmware begins executing immediately. If the upgrade file is invalid, the temporary image is discarded, the existing firmware continues to execute, and the firmware upgrade ends.

Caution  During the transfer of the upgrade file, the switch might not respond to commands for as long as 1 minute. This is normal and correct. If you interrupt the transfer by turning the switch off and on, the firmware could be corrupted. If this happens, follow the procedure described in the "Using the Diagnostic Console" section in the "Troubleshooting" chapter to restart the firmware.

How you upgrade the firmware depends on your installation. There are three possibilities:

  • From a TFTP server--You need to first enter the name of the TFTP server and the name of the file containing the upgrade. The upgrade can be initiated through the management console or with any SNMP-compatible management station. As a result, the switch retrieves the upgrade file from the server through TFTP.

  • From a TFTP client--The upgrade can be done via a TFTP client.

  • With the XMODEM protocol--The upgrade can be done via the XMODEM protocol after you attach a terminal to the console port on the switch.

[A] Accept upgrade transfer from other hosts--Use this option to enable [E] or
disable [D] the switch from accepting an upgrade the firmware from another host on the network. To prevent unauthorized upgrades from other TFTP clients, use the Disabled setting. The default setting is Enabled.

[D] Download test subsystem (XMODEM)--For Cisco personnel only.

[X] Exit to Main Menu--Use this option to display the Management Console Main Menu.

The following sections provide information on using the [S], [F], [U], and [T] options on the Firmware Configuration Menu.

Upgrading Catalyst 1900 Firmware from a TFTP Server

To upgrade the switch firmware from a TFTP server, follow these steps:

Step 1 Select the [S] option, and enter the IP address of the server where the upgrade file is located.

Step 2 Select the [F] option, and enter the name of the firmware-upgrade file.

Step 3 Make sure the switch can reach the TFTP server. Select the [T] option to initiate the TFTP transfer; the switch contacts the server to get the upgrade file.

Step 4 Verify the upgrade is in progress by checking the Upgrade status field in the System Information area on the menu.

At the end of the transfer, the switch does not respond to commands for about
1 minute.


When the transfer is complete, the switch resets and begins using the new firmware.



Note You can also initiate a TFTP transfer by setting the upgradeTFTPInitiate MIB object.

Upgrading Catalyst 1900 Firmware from a TFTP Client

To upgrade the switch firmware from a TFTP client, follow these steps:

Step 1 On the TFTP client workstation, establish a TFTP session with the IP address assigned to the switch.

Step 2 Ensure that the TFTP client is in binary transfer mode.

Step 3 At the command line, enter put and the filename.

Step 4 Verify the upgrade is in progress by checking the System Information section of the Firmware Configuration Menu.

At the end of the transfer, the switch does not respond to commands for about
1 minute.


When the transfer is complete, the switch resets and begins using the new firmware.


Upgrading Catalyst 1900 Firmware with the XMODEM Protocol

This procedure is largely dependent on the modem software you are using. ProComm and HyperTerminal are examples of applications that use the XMODEM protocol. To upgrade the switch firmware via XMODEM, follow these steps:

Step 1 Select the [U] option.

Step 2 When the first XMODEM request appears, use the appropriate command to start the transfer. After the transfer, the switch does not respond to commands for about 1 minute.

The switch resets after a successful transfer, the newly downloaded firmware begins to reset, and the Management Console Logon Screen is displayed.


RS-232 Interface Configuration Menu

The RS-232 Port Configuration Menu (see Figure 3-20) is displayed when you select the [I] option from the Management Console Main Menu. Use the RS-232 Port Configuration Menu to define the physical characteristics of the console port--baud rate, stop bits, and the like--and call features such as the time delay between outgoing calls.


Figure 3-20: RS-232 Port Configuration Menu
Catalyst 1900 - RS-232 Interface Configuration
------------------Group Settings--------------
[B] Baud rate                                   9600 baud
[D] Data bits                                   8 bit(s)
[S] Stop bits                                   1 bit(s)
[P] Parity setting                              None
--------------------Settings------------------
[M] Match remote baud rate (auto baud)          Enabled
[A] Auto answer                                 Enabled
[N] Number for dial-out connection
[T] Time delay between dial attempts            300
[I] Initialization string for modem
--------------------Actions-------------------
[C] Cancel and restore previous group settings
[G] Activate group settings
[X] Exit to Main Menu
Enter Selection:

[B] Baud rate--Use this option to enter the baud rate of the RS-232 serial port. The default setting is 9600.

[D] Data bits--Use this option to enter the data bits value for the serial port. Valid values are 7 and 8. The default setting is 8.

[S] Stop bits--Use this option to enter the stop bits value for the serial port. The default setting is 1.

[P] Parity settings--Use this option to change the parity settings for the serial port. The default setting is None.

[M] Match remote baud rate--Use this option to enable the RS-232 port to automatically match the baud rate of an incoming call. The switch only matches a baud rate lower than its configured baud rate. After the call, the switch reverts to its configured rate. Enter
E (enable) or D (disable). The default setting is Enabled.

[A] Auto answer--Use this option to enable the auto-answer feature. Enter E (enable) or D (disable). The default setting is Enabled.

[N] Number for dial-out connection--Use this option to enter the phone number the switch is configured to use when dialing out. This number is dialed when the switch is configured to communicate with a remote terminal upon power-up or reset. If the dial-out is unsuccessful and auto-answer is enabled, the switch ceases dialing and awaits incoming calls.

Enter up to 48 characters. To delete the number, press the Backspace key followed by Return. Using the format required by your modem when you enter the number.

[T] Time delay between attempts--Use this option to enter the amount of time in seconds between dial-out attempts. Zero (0) disables retry. The default setting is 300 seconds.

[I] Initialization string for modem--Use this option to change the initialization string to match your modem requirements. Enter up to 48 characters.


Note Do not specify an AT prefix or end-of-line suffix.

[C] Cancel and restore previous group settings--Use this option to undo any new values entered for the baud rate, data bits, stop bits, and parity setting. Values are restored to those last saved. Enter Y (yes) or N (no).

[G] Activate group settings--Use this option to activate the setting you have entered for baud rate, data bits, stops bits, and parity settings. After selecting this option, configure the attached terminal to match the new settings. Enter Y (yes) or N (no).


Note Note that the changes you make to parameters under the heading Group Settings are not invoked until you press G. Press C to cancel the session and return to the previous settings.

[X] Exit--Use this option to display the Management Console Main Menu.

Usage Summary Menu

The Usage Summary Menu (see Figure 3-21) is displayed when you select the [U] option from the Management Console Main Menu. Use the Usage Summary Menu to display summaries of network statistics for all ports. These reports are read-only.

If you are using VT100 terminal emulation, the statistics displays are refreshed every
5 seconds. If you are connected to the Management Console via a modem running at less than 2400 baud, the statistics displays are refreshed every 8 seconds. Press Return or the Spacebar to refresh these reports at any time.


Figure 3-21: Usage Summary Menu
Catalyst 1900 - Usage Summaries
[P] Port Status Report
[A] Port Addressing Report
[E] Exception Statistics Report
[U] Utilization Statistics Report
[B] Bandwidth Usage Report
[X] Exit to Main Menu
Enter Selection:

[X] Exit--Use this option to display the Management Console Main Menu.

Port Status Report

The Port Status Report (see Figure 3-22) is displayed when you select the [P] option from the Usage Summary Menu. Use the Port Status Report to display a summary of the status of all ports as defined on the Port Configuration Menu. Definitions of these terms can be found in the "Port Configuration Menu" section in this chapter.


Figure 3-22: Port Status Report
Catalyst 1900 - Port Status Report
1  : Suspended-no-linkbeat             13 : Suspended-no-linkbeat
2  : Suspended-no-linkbeat             14 : Enabled
3  : Suspended-no-linkbeat             15 : Enabled
4  : Enabled                           16 : Enabled
5  : Enabled                           17 : Enabled
6  : Enabled                           18 : Enabled
7  : Enabled                           19 : Suspended-no-linkbeat
8  : Suspended-no-linkbeat             20 : Suspended-no-linkbeat
9  : Enabled                           21 : Enabled
10 : Enabled                           22 : Enabled
11 : Enabled                           23 : Suspended-no-linkbeat
12 : Enabled                           24 : Suspended-no-linkbeat
                                       AUI : Enabled
A  : Enabled
B  : Enabled
Select [X] Exit to previous menu:

[X] Exit--Use this option to display the Usage Summary Menu.

Port Addressing Report

The Port Addressing Report (see Figure 3-23) is displayed when you select the [A] option from the Usage Summary Menu. Use the Port Addressing Report to display the address mode (dynamic or static) of the port and how many addresses have been assigned to the port.


Figure 3-23: Port Addressing Report
Catalyst 1900 - Port Addressing Report
1  :               Unaddressed          13 :               Unaddressed
2  :               Unaddressed          14 :               Unaddressed
3  :               Unaddressed          15 :               Unaddressed
4  :Dynamic 100       Static 0          16 :               Unaddressed
5  :Dynamic 900       Static 0          17 :               Unaddressed
6  :               Unaddressed          18 :               Unaddressed
7  :Dynamic 0         Static 3          19 :               Unaddressed
8  :               Unaddressed          20 :               Unaddressed
9  :               Unaddressed          21 :               Unaddressed
10 :               Unaddressed          22 :               Unaddressed
11 :               Unaddressed          23 :               Unaddressed
12 :               Unaddressed          24 :               Unaddressed
                                        AUI:               Unaddressed
A  :               Unaddressed
B  :               Unaddressed
Select [X] Exit to previous menu:

The two columns on this report have the following values:

  • Port--Whether the port is enabled for dynamic learning or secured.

  • Addresses--If it is a single station, this field contains its address; if it is not a single station, this field shows the number of static and dynamic addresses associated with the port.

[X] Exit--Use this option to display the Usage Summary Menu.

Exception Statistics Report

The Exception Statistics Report (see Figure 3-24) is displayed when you select the
[E] option from the Usage Summary Menu. Use the Exception Statistics Report to display the number of receive errors, transmit errors, and security violations for each port.


Figure 3-24: Exception Statistics Report
Catalyst 1900 - Exception Statistics Report (Frame counts)
     Receive   Transmit   Security        Receive   Transmit   Security
     Errors    Errors   Violations        Errors    Errors   Violations
     ------------------------------       ------------------------------
1  :     0         0          0       13 :   0        0          0
2  :     0         0          0       14 :   0        0          0
3  :     0         0          0       15 :   0        0          0
4  :     0         0          0       16 :   0        0          0
5  :     0         0          0       17 :   0        0          0
6  :     0         0          0       18 :   0        0          0
7  :     0         0          0       19 :   0        0          0
8  :     0         0          0       20 :   0        0          0
9  :     0         0          0       21 :   0        0          0
10 :     0         0          0       22 :   0        0          0
11 :     0         0          0       23 :   0        0          0
12 :     0         0          0       24 :   0        0          0
                                      AUI:   0        0          0
A  :     0         0          0
B  :     0         0          0
Select [R] Reset all statistics, or [X] Exit to previous menu:

The figures displayed are actually totals of various kinds of errors:

  • Receive errors--The combined number of giants, FCS, and alignment errors

  • Transmit errors--The combined number of excessive deferrals, late collisions, jabber errors and other transmit errors

  • Security violations--The combined number of secure address violations caused by address mismatches or duplications

[R] Reset all statistics--Use this option to reset all statistics to zero.

[X] Exit--Use this option to display the Usage Summary Menu.

Utilization Statistics Report

The Utilization Statistics Report (see Figure 3-25) is displayed when you select the
[U] option from the Usage Summary Menu. Use the Utilization Statistics Report to display the frame-count statistics generated by the switch.


Figure 3-25: Utilization Statistics Report
Catalyst 1900 - Utilization Statistics Report (Frame counts)
     Receive    Forward   Transmit          Receive    Forward   Transmit
     ------------------------------         ------------------------------
1  : 436908     126344   10         13 : 0          0          0
2  : 0          0        0          14 : 0          0          0
3  : 0          0        0          15 : 8          5          685226
4  : 50438      50438    1          16 : 0          0          0
5  : 0          0        0          17 : 685241   161764       8
6  : 685176     161750   8          18 : 169017   104935       0
7  : 0          0        0          19 : 0          0          0
8  : 126599     124963   3          20 : 0          0          0
9  : 0          0        0          21 : 0          0          0
10 : 0          0        0          22 : 86103    86103        4
11 : 0          0        0          23 : 0          0          0
12 : 353676     353676   7          24 : 0          0          685281
                                    AUI: 0          0          0
A  : 0          0        80
B  : 0          0        80
Select [R] Reset all statistics, or [X] Exit to previous menu:

Column headings have the following meanings:

  • Receive--The number of received good unicast frames, good multicast frames, and good broadcast frames

  • Forward--The number of good frames forwarded

  • Transmit--The combined number of transmitted unicast frames, multicast frames, and broadcast frames

[R] Reset all statistics--Use this option to reset all statistics to zero.

[X] Exit--Use this option to display the Usage Summary Menu.

Bandwidth Usage Report

The Bandwidth Usage Report (see Figure 3-26) is displayed when you select the [B] option from the Usage Summary Menu. Use the Bandwidth Usage Report to display the peak bandwidth of the network during a given period of time.


Figure 3-26: Bandwidth Usage Report
Catalyst 1900 - Bandwidth Usage Report
--------------------Information----------------
Current bandwidth usage                    0 Mbps
Peak Bandwidth Usage during this interval  0 Mbps
Peak Time recorded since start up          0d 00h 00m 32s
--------------------Settings------------------
[T] Capture time interval                  24 hour(s)
[R] Reset capture
[X] Exit to previous menu
Enter Selection:

[T] Capture time interval--Use this option to define the time period during which data is collected to calculate bandwidth usage. The tables in the "Port Mode and Port Status LEDs" section in the chapter "Introduction" chapter shows the bandwidth associated with each LED. Enter a number between 1 and 24. The default setting is 24 hours.

[R] Reset capture--Use this option to clear the entire peak bandwidth capture table and restart capturing at the current interval. Enter Y (yes) or N (no).

[X] Exit--Use this option to display the Usage Summary Menu.

In-Band Management

You can configure and manage the switch by accessing the MIB objects through in-band management. This section focuses on in-band management through SNMP and provides the following information:

  • Accessing the files containing the MIBs and traps supported by the switch

  • Accessing MIB variables using SNMP

Parameter changes take effect immediately. However, changed parameters might not be written to permanent storage for up to 30 seconds. If you turn off the switch before the new parameters are written to permanent storage, the change does not take effect.

Accessing MIB and Trap Information

The MIB files contain variables that can be set or read to provide information on the switch. Also contained in the MIB files is information about the traps generated by the switch.

The following MIB files contain the MIB and trap information for the switch:

  • RFC1213-MIB.my contains the MIB II (RFC 1213)

  • BRIDGE-MIB.my contains the Bridge MIB (RFC 1493)

  • ESSWITCH-MIB.my contains the Catalyst 1900 device-specific MIB

  • CISCO-CDP-MIB-V1SMI.my contains the Cisco Discovery Protocol (CDP) MIB

  • RS232-MIB-V1SMI.my contains the RS-232 MIB (RFC 1317)

The switch is shipped with one DOS diskette, containing the switch firmware and device-specific MIBs. You can also obtain a copy of the MIB files in the following ways:

  • Using File Transfer Protocol (FTP) to access the ftp.cisco.com server.

  • Using Cisco Connection Online (CCO) to access the cisco.com server.

Using FTP to Access the MIB Files

You can obtain each MIB file with the following procedure:

Step 1 Use FTP to access the server ftp.cisco.com.

Step 2 Log in with the username anonymous.

Step 3 Enter your e-mail name when prompted for the password.

Step 4 At the ftp> prompt, change directories to /pub/MIBs.

Step 5 Use the get README command to display the readme file containing a list of available files.

Step 6 Use the get MIB_filename command to obtain a copy of the MIB file.

Using CCO to Access the MIB Files

CCO serves a wide variety of users through two interfaces that are updated and enhanced simultaneously: a character-based version and a multimedia version that resides on the World Wide Web (WWW). The character-based CCO supports Zmodem, Kermit, Xmodem, FTP, and Internet e-mail, and it is excellent for quick access to information over lower bandwidths. The WWW version of CCO provides richly formatted documents with photographs, figures, graphics, and video, as well as hyperlinks to related information.

You can access CCO in the following ways:

  • WWW:  http://www.cisco.com

  • WWW:  http://www-europe.cisco.com

  • WWW:  http://www-china.cisco.com

  • Telnet:  cco.cisco.com

  • Modem:  From North America, 408 526-8070; from Europe, 33 1 64 46 40 82. Use the following terminal settings: VT100 emulation; databits: 8; parity: none; stop bits: 1; and connection rates up to 28.8 kbps.

For a copy of CCO's Frequently Asked Questions (FAQ), contact cco-help@cisco.com. For additional information, contact cco-team@cisco.com.

From the main menu, select Software Library. Then select MIBs and Public Files. The supportlists directory contains descriptions of the MIBs supported by the switch. Refer to the wsc1900 directory for switch products, including the Catalyst 1900 switches.

Accessing MIB Variables Using SNMP

The switch MIB variables are accessible through SNMP. SNMP is an application-layer protocol designed to facilitate the exchange of management information between network devices. The SNMP system consists of three parts: SNMP manager, SNMP agent, and MIB.

Instead of defining a large set of commands, SNMP places all operations in a get-request, get-next-request, and set-request format. For example, an SNMP manager can get a value from an SNMP agent or store a value into that SNMP agent. The SNMP manager can be part of a network management system (NMS), and the SNMP agent can reside on a networking device such as a switch. You can compile the switch MIB files with your network management software. The SNMP agent can respond to MIB-related queries being sent by the NMS.

An example of an NMS is the CiscoWorks network management software. CiscoWorks uses the switch MIB variables to set device variables and to poll devices on the network for specific information. The results of a poll can be displayed as a graph and analyzed in order to troubleshoot internetworking problems, increase network performance, verify the configuration of devices, monitor traffic loads, and more.

As shown in Figure 3-27, the SNMP agent gathers data from the MIB, which is the repository for information about device parameters and network data. The agent can send traps, or notification of certain events, to the manager.


Figure 3-27: SNMP Network

The SNMP manager uses information in the MIB to perform the operations described in Table 3-5.


Table 3-5: SNMP Manager Operations
Operation Description
get-request Retrieve a value from a specific variable.
get-next-request Retrieve a value from a variable within a table.1
get-response The reply to a get-request, get-next-request, and set-request sent by an NMS.
set-request Store a value in a specific variable.
trap An unsolicited message sent by an SNMP agent to an SNMP manager indicating that some event has occurred.
  1. 1 With this operation, an SNMP manager does not need to know the exact variable name. A sequential search is performed to find the needed variable from within a table.

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