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This chapter describes how to identify and resolve software problems related to the IOS software. Depending on the nature of the problem, you can use the command-line interface (CLI) or Cluster Manager Suite (CMS) to identify and solve problems.
This chapter describes how to perform the following tasks:
The IEEE 802.3u autonegotiation protocol manages the switch settings for speed (10 Mbps or 100 Mbps) and duplex (half or full). There are situations when this protocol can incorrectly align these settings, reducing performance. A mismatch occurs under these circumstances:
To maximize switch performance and ensure a link, follow one of these guidelines when changing the settings for duplex and speed:
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Note If a remote Fast Ethernet device does not autonegotiate, configure the duplex settings on the two ports to match. The speed parameter can adjust itself even if the connected port does not autonegotiate. To connect to a remote Gigabit Ethernet device that does not autonegotiate, disable autonegotiation on the local device, and set the duplex and flow control parameters to be compatible with the remote device. |
The recovery procedures in this section require that you have physical access to the switch. Recovery procedures include the following topics:
Switch software can be corrupted during an upgrade, by downloading the wrong file to the switch, and by deleting the image file. In all these cases, the switch does not pass the power-on self-test (POST), and there is no connectivity.
The following procedure uses the XMODEM Protocol to recover from a corrupt or wrong image file. There are many software packages that support the XMODEM protocol, and this procedure is largely dependent on the emulation software you are using.
Step 2 Set the line speed on the emulation software to 9600 baud.
Step 3 Unplug the switch power cord.
Step 4 Reconnect the power cord to the switch.
The software image does not load. The switch starts in boot loader mode, which is indicated by the switch: prompt
Step 5 Use the boot loader to enter commands, and start the transfer.
switch: copy xmodem: flash:image_filename.bin
Step 6 When the XMODEM request appears, use the appropriate command on the terminal-emulation software to start the transfer and to copy the software image into Flash memory.
Follow the steps in this procedure if you have forgotten or lost the switch password.
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Note You can configure your switch for Telnet by following the procedure in "Configuring the Switch for Telnet" section. |
Step 2 Set the line speed on the emulation software to 9600 baud.
Step 3 Unplug the switch power cord.
Step 4 Press in the Mode button, and at the same time reconnect the power cord to the switch.
You can release the Mode button a second or two after the LED above port 1X goes off. Several lines of information about the software appear, as do instructions:
The system has been interrupted prior to initializing the flash file system. The following commands will initialize the flash file system, and finish loading the operating system software: flash_init load_helper boot
Step 5 Initialize the Flash file system:
switch: flash_init
Step 6 If you had set the console port speed to anything other than 9600, it has been reset to that particular speed. Change the emulation software line speed to match that of the switch console port.
Step 7 Load any helper files:
switch: load_helper
Step 8 Display the contents of Flash memory:
switch: dir flash:
The switch file system is displayed:
Directory of flash: 2 -rwx 843947 Mar 01 1993 00:02:18 C2900XL-h-mz-112.8-SA 4 drwx 3776 Mar 01 1993 01:23:24 html 66 -rwx 130 Jan 01 1970 00:01:19 env_vars 68 -rwx 1296 Mar 01 1993 06:55:51 config.text 1728000 bytes total (456704 bytes free)
Step 9 Rename the configuration file to config.text.old.
This file contains the password definition.
switch: rename flash:config.text flash:config.text.old
Step 10 Boot the system:
switch: boot
You are prompted to start the setup program. Enter N at the prompt:
Continue with the configuration dialog? [yes/no]: N
Step 11 At the switch prompt, change to privileged EXEC mode:
switch> enable
Step 12 Rename the configuration file to its original name:
switch# rename flash:config.text.old flash:config.text
Step 13 Copy the configuration file into memory:
switch# copy flash:config.text system:running-configSource filename [config.text]?
Destination filename [running-config]?
Press Return in response to the confirmation prompts.
The configuration file is now reloaded, and you can use the following normal commands to change the password.
Step 14 Enter global configuration mode:
switch# config terminal
Step 15 Change the password:
switch(config)# enable secret <password>
or
switch(config)# enable password <password>
Step 16 Return to privileged EXEC mode:
switch(config)# exitswitch#
Step 17 Write the running configuration to the startup configuration file:
switch# copy running-config startup-config
The new password is now included in the startup configuration.
This section describes how to recover from a failed command switch. If you are running IOS Release 12.0(5)XU, you can configure a redundant command switch group by using the Hot Standby Router Protocol (HSRP). For more information, see the "Building a Redundant Cluster" section.
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Note HSRP is the preferred method for supplying redundancy to a cluster. |
If you have not configured a standby command switch, and your command switch loses power or fails in some other way, management contact with the member switches is lost, and a new command switch must be installed. However, connectivity between switches that are still connected is not affected, and the member switches forward packets as usual. You can manage the members as standalone switches through the console port or, if they have IP addresses, through the other management interfaces.
You can prepare for a command switch failure by assigning an IP address to a member switch or another switch that is command-capable, making a note of the command-switch password, and cabling your cluster to provide redundant connectivity between the member switches and the replacement command switch. This section describes two solutions for replacing a failed command switch:
For information on command-capable switches, see the "Supported Hardware" section.
Follow these steps to replace a failed command switch with a command-capable member of the same cluster:
Step 2 Insert the member switch in place of the failed command switch, and duplicate its connections to the cluster members.
Step 3 Start a CLI session on the new command switch.
You can access the CLI by using the console port or, if an IP address has been assigned to the switch, by using Telnet. For details about using the console port, refer to the switch installation guide.
Step 4 At the switch prompt, change to privileged EXEC mode:
Switch> enableSwitch#
Step 5 Enter the password of the failed command switch.
Step 6 From privileged EXEC mode, enter global configuration mode.
Switch# config terminalEnter configuration commands, one per line. End with CNTL/Z.
Step 7 From global configuration mode, remove the member switch from the cluster.
Switch(config)# no cluster commander-address
Step 8 Return to privileged EXEC mode.
Switch(config)# exitSwitch#
Step 9 Use the setup program to configure the switch IP information.
This program prompts you for an IP address, subnet mask, default gateway, and password. From privileged EXEC mode, enter setup, and press Return.
Switch# setup
--- System Configuration Dialog ---
At any point you may enter a question mark '?' for help.
Use Ctrl-c to abort configuration dialog at any prompt.
Default settings are in square brackets '[]'.
Continue with configuration dialog? [yes/no]:
Step 10 Enter Y at the first prompt:
Continue with configuration dialog? [yes/no]: y
If this prompt does not appear, enter enable, and press Return. Enter setup, and press Return to start the setup program.
Step 11 Enter the switch IP address, and press Return:
Enter IP address: ip_address
Step 12 Enter the subnet mask (IP netmask) address, and press Return:
Enter IP netmask: ip_netmask
Step 13 Enter Y to enter a default gateway (router) address:
Would you like to enter a default gateway address? [yes]: y
Step 14 Enter the IP address of the default gateway (router), and press Return:
Enter router IP address: IP_address
Step 15 Enter a host name, and press Return:
Enter host name: host_name
Step 16 Enter the password of the failed command switch again, and press Return:
Enter enable secret password: secret_password
Step 17 Enter a Telnet password, and press Return:
Would you like to configure a telnet password? [yes]: yEnter telnet password: password
The initial configuration displays:
The following configuration command script was created:
ip subnet-zero
interface VLAN1
ip address IP_address IP_netmask
ip default-gateway IP_address
hostname host_name
enable secret 5 $1$yDsa$/YLihJcV8e/HODagkW1Ff0
line vty 0 15
password password
snmp community private rw
snmp community public ro
!
end
Use this configuration? [yes/no]:
Step 18 Verify that the addresses are correct.
Step 19 Enter Y, and press Return if the displayed information is correct.
If this information is not correct, enter N, press Return, and begin again at Step 9.
Step 20 Start your browser, and enter the IP address you just entered for the switch.
Step 21 Display the VSM Home page for the switch, and select Enabled from the Command Switch drop-down list.
Step 22 Click Cluster Management, and display Cluster Builder.
CMS prompts you to add candidate switches. The password of the failed command switch is still valid for the cluster, and you should enter it when candidate switches are proposed for cluster membership.
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Note You can also add switches to the cluster by using the CLI. For the complete instructions, see the "Adding and Removing Member Switches" section. |
Follow these steps when you are replacing a failed command switch with a switch that is command capable but not part of the cluster:
Step 2 Start a CLI session on the new command switch.
You can access the CLI by using the console port or, if an IP address has been assigned to the switch, by using Telnet. For details about using the console port, refer to the switch installation guide.
Step 3 At the switch prompt, change to privileged EXEC mode:
Switch> enableSwitch#
Step 4 Enter the password of the failed command switch.
Step 5 Use the setup program to configure the switch IP information.
This program prompts you for an IP address, subnet mask, default gateway, and password. From privileged EXEC mode, enter setup, and press Return.
Switch# setup
--- System Configuration Dialog ---
At any point you may enter a question mark '?' for help.
Use ctrl-c to abort configuration dialog at any prompt.
Default settings are in square brackets '[]'.
Continue with configuration dialog? [yes/no]:
Step 6 Enter Y at the first prompt:
Continue with configuration dialog? [yes/no]: y
If this prompt does not appear, enter enable, and press Return. Enter setup, and press Return to start the setup program.
Step 7 Enter the switch IP address, and press Return:
Enter IP address: ip_address
Step 8 Enter the subnet mask (IP netmask) address, and press Return:
Enter IP netmask: ip_netmask
Step 9 Enter Y to enter a default gateway (router) address:
Would you like to enter a default gateway address? [yes]: y
Step 10 Enter the IP address of the default gateway (router), and press Return:
Enter router IP address: IP_address
Step 11 Enter a host name, and press Return:
Enter host name: host_name
Step 12 Enter the password of the failed command switch again, and press Return:
Enter enable secret password: secret_password
Step 13 Enter a Telnet password, and press Return:
Would you like to configure a telnet password? [yes]: yEnter telnet password: password
The initial configuration displays:
The following configuration command script was created:
ip subnet-zero
interface VLAN1
ip address IP_address IP_netmask
ip default-gateway IP_address
hostname host_name
enable secret 5 $1$yDsa$/YLihJcV8e/HODagkW1Ff0
line vty 0 15
password password
snmp community private rw
snmp community public ro
!
end
Use this configuration? [yes/no]:
Step 14 Verify that the addresses are correct.
Step 15 Enter Y, and press Return if the displayed information is correct.
If this information is not correct, enter N, press Return, and begin again at Step 5.
Step 16 Start your browser, and enter the IP address you just entered for the switch.
Step 17 Click Cluster Manager Suite or Visual Switch Manager, and display Cluster Builder.
It prompts you to add the candidate switches. The password of the failed command switch is still valid for the cluster. Enter it when candidate switches are proposed for cluster membership, and click OK.
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Note You can also add switches to the cluster by using the CLI. For the complete instructions, see the "Adding and Removing Member Switches" section. |
Some configurations can prevent the command switch from maintaining contact with member switches. If you are unable to maintain management contact with a member, and the member switch is forwarding packets normally, check for the following port-configuration conflicts:
Posted: Wed May 3 17:16:32 PDT 2000
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