Upgrading Supervisor Engine and VSS


We are trying to form a VSS between an old existing 6500 series and a new one. And also we are upgrading Supervisor Engine of the Old switch. We are required to do it with minimum downtime.

Is it possible to leave the old supervisor engine… in slot 5 and inserting another one in slot six? will vss be formed between supervisor engine in slot 6 of old switch and supervisor engine in slot 5 in the new switch?

Is there any good way?


Hi Justine,

This is definitely something you want to think through before taking any action. I would start upgrading the supervisor in your current switch.

Check the documentation of your new supervisor. You can find the slots that you can use for some of the supervisors here:

Globally, it goes like this:

  • Save your IOS image and startup configuration to an external location.
  • Think about your VLANs. Save the VLAN database or think about using VTP to sync your VLANs later.
  • Think about SNMPv3 (if you use this). It’s not stored in the startup configuration.
  • Think about SSH crypto keys, these are also not stored in the startup configuration.
  • Insert new supervisor in slot.
  • Wait for supervisor to boot.
  • Copy IOS image from current supervisor to new supervisor.
  • Save your config. Config should be synced to the new standby supervisor.
  • Reset the new standby supervisor (how-module module x reset)
  • Make new standby supervisor the active one (redundancy force switchover)
  • Remove the old supervisor


Much appreciation sir