Resolution
When you have to perform a hardware upgrade of single Supervisor:
Perform a CatOS or IOS upgrade/downgrade if necessary.
Make sure the new Supervisor supports the already installed line cards.
Copy the current configuration to a TFTP server.
Download the configuration to the new Supervisor.
When you have to perform a hardware upgrade of both Supervisors running redundancy:
Perform a CatOS or IOS upgrade/downgrade on both Supervisors if necessary.
Make sure the new Supervisors support the already installed line cards.
Copy the current configuration to a TFTP server.
Download the configuration to the new Supervisor.
Make sure both Supervisors have the same software and hardware.
Make sure redundancy (if needed) is configured.
Note: If the Supervisor upgrade is to be performed on the chassis which is already in production, then to avoid unnecessary down time, you can use a spare chassis in order to configure the Supervisor that is going to be used.
For more information on the software upgrade, refer to Upgrading Software Images on Catalyst 4000/4500 Series Switches.
For further assistance and support, open a service request with Cisco Technical Support.
