Cisco Systems 3750E manual Recovering from a Command Switch Failure, 45-9

Chapter 45 Troubleshooting

Recovering from a Command Switch Failure

the switch current-stack-member-number renumber new-stack-member-number global configuration command to manually assign a stack member number. For more information about stack member numbers, see the “Stack Member Numbers” section on page 5-6.

If you replace a stack member with an identical model, the new switch functions with the exact same configuration as the replaced switch. This is also assuming the new switch is using the same member number as the replaced switch.

Removing powered-on stack members causes the switch stack to divide (partition) into two or more switch stacks, each with the same configuration. If you want the switch stacks to remain separate, change the IP address or addresses of the newly created switch stacks. To recover from a partitioned switch stack:

1.Power off the newly created switch stacks.

2.Reconnect them to the original switch stack through their StackWise Plus ports.

3.Power on the switches.

For the commands that you can use to monitor the switch stack and its members, see the “Displaying Switch Stack Information” section on page 5-24.

Recovering from a Command Switch Failure

This section describes how to recover from a failed command switch. You can configure a redundant command switch group by using the Hot Standby Router Protocol (HSRP). For more information, see Chapter 6, “Clustering Switches.”For more information, see Chapter 6, “Clustering Switches” and Chapter 40, “Configuring HSRP and Enhanced Object Tracking.” Also see the Getting Started with Cisco Network Assistant, available on Cisco.com.

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 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, through the Ethernet management 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, page 45-10

•Replacing a Failed Command Switch with Another Switch, page 45-11These recovery procedures require that you have physical access to the switch. For information on command-capable switches, see the release notes.

Catalyst 3750-E and 3560-E Switch Software Configuration Guide

OL-9775-02 45-9