RE: OT: Cisco VSS

I've deployed a few VSS cores.

1. make sure you get the proper hardware for the VSS.

2. Make sure to have at least 2 VSLs (sup/sup, 10G mod/10G mod).

3. Be careful with code upgrades. SXH 1 - 3 was deferred due to nasty route
update (or lack there of) issues.

4. Keep in mind older line cards may not work with VSS.

5. Once the VSLs are up and the VSS is active, DO NOT CHANGE THE VSL PORTS.
The config may seem wrong but it is not.

6. Up until recent SXI code versions, the only ways to detect a "split brain"
scenario were PaGP+ dual active and BFD. To me, these approaches are like
cutting a leg off to help someone walk again -- doesn't really work and is
prone to issues. A bug / issues with a far end switch running PaGP+ could
easily impact a VSS core as the response to shut down one WHOLE core (sans
ports specified no to). The clean up to bring the core back to full capacity
can be longer than just rebooting the whole core (I have seen this on 2
occasions).

7. If you run latest SXI, run fast hellos for VSS dual active detection.

8. Make sure your services modules are running the latest code that is stable
and supports VSS. VSS support for services modules came in SXI.

9. Adapt your design model to handle the changes in VSS (no HSRP, no spanning
tree primary / secondary root, etc.) Also, single attached services can have
issues during a dual-active event where a core is shut.

Hope this helps !

Travis

> Date: Sat, 21 Nov 2009 08:49:25 -0600
> Subject: OT: Cisco VSS
> From: ccie.09_at_gmail.com
> To: ccielab_at_groupstudy.com
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> I am planning to upgrade two Cat6513 to VSS (inter chassis link through
> Sup720). Any one with experience can share some pros and cons please?
>
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Received on Sun Nov 22 2009 - 03:31:30 ART