Cisco 6509 VSS FSU UPGRADE

[asemeniuc23]

Hello,

Im going to upgrade ios on cat 6509 vss (each switch has 1 sup 720-10G) from version 12.2(33)SXJ7 to 15.1(2)SY6. Up to cisco documentation this procedure cannot be done within eFSU mode (only FSU).

The steps that I will perform are next:

1. Upload new IOS on active and standby sups

2. Change bootvar (boot system)

3. Reload the standby supervisor. Here the stby sup will come with new version of IOS (15.1(2)SY6) and questions:

How the VSS will work with to different IOSs? Will it face split brane on VSS? Or only redundancy mode will change from SSO to RPR until I bring up the second sup with new IOS?

Thanks in advance!

[Leo Laohoo]

3. Reload the standby supervisor. Here the stby sup will come with new version of IOS (15.1(2)SY6) and questions:

If the standby supervisor boots up with a different IOS compared to the active supervisor card, the standby supervisor card might boot into ROMmon. 

Step 3 should be reload both (active and standby supervisor card).

[asemeniuc23]

Thanks for your reply.
Up to cisco documentation only redundancy mode should be changed from SSO to RPR.

"During the FSU procedure, a software version mismatch between the VSS active and the VSS standby chassis causes the system to boot in RPR redundancy mode, which is stateless and causes a hard reset of the all modules. As a result, the FSU procedure requires system downtime corresponding to the RPR switchover time."

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst6500/ios/12-2SX/configuration/guide/book/vss.html#wp1169328

Isn't it?

[Leo Laohoo]

Search for some of my posts in regards to FSU/eFSU in this forum.