I need to upgrade our 2 core switches. We have 2 existing 6509 with Supervisor 1A cards. They run IOS on the route processor side and CatOS on the switch side.
We've purchased 2 6509 with the sup720. I have enough space that I have them racked right next to our existing 6509s. I have the 2 setup as a VSS pair, and now I'm wondering where to go from here.
Is there a best practice on how to perform an upgrade like this? Do I configure these new switches exactly like the old ones and then do a major switchover all in one night? Any other suggestions?
by having setup a VSS pair you have already done something different.
You can insert the new device in the network with higher STP priority.
As usual takes care of VTP parameters to avoid problems with revision numbers.
phase a: connection to the two current core switches with STP parameters that make it not the root bridge.
make one current core switch the root bridge for all vlans
configure the VSS to be a VTP server in the right VTP domain
phase b: you move the backup uplink of each access switch to the new VSS pair.
(this can be done if you have the same root bridge for all vlans)
you need also to migrate a link to wan routers to the VSS
make the new VSS the root bridge for all vlans
phase D : migrate to VSS the second uplink of each access layer switch.
This can be a way to handle the migration
e) if everything is working fine you can power off the old core switches
Hope to help