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Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter49 Troubleshooting
Recovering from a Command Switch Failure
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 you must install a new
command switch. 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. These sections describe two solutions for replacing a failed command switch:
Replacing a Failed Command Switch with a Cluster Member, page49-9
Replacing a Failed Command Switch with Another Switch, page49-11
These recovery procedures require that you have physical access to the switch.
For information on command-capable switches, see the release notes.
Replacing a Failed Command Switch with a Cluster Member
To replace a failed command switch with a command-capable member in the same cluster, follow these
steps:
Step1 Disconnect the command switch from the member switches, and physically remove it from the cluster.
Step2 Insert the member switch in place of the failed command switch, and duplicate its connections to the
cluster members.
Step3 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, see the switch hardware installation guide.
Step4 At the switch prompt, enter privileged EXEC mode:
Switch> enable
Switch#
Step5 Enter the password of the failed command switch.
Step6 Enter global configuration mode.
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Step7 Remove the member switch from the cluster.
Switch(config)# no cluster commander-address
Step8 Return to privileged EXEC mode.
Switch(config)# end
Switch#
Step9 Use the setup program to configure the switch IP information. This program prompts you for IP address
information and passwords. From privileged EXEC mode, enter setup, and press Return.
Switch# setup
--- System Configuration Dialog ---
Continue with configuration dialog? [yes/no]: y
At any point you may enter a question mark '?' for help.