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Community Member

Upgrade Cat6500 doc info

Hello everyone,

I have successfully upgraded both 6509's, but the mentioned “0 to 3 seconds switchover time” (SSO mode) in the “Catalyst 6000/6500 Series Switches with Redundant Supervisor Engines Software Image Upgrade Configuration Example” was a little bit underestimated.

I experienced longer switchover due to a reset of all cards (exept the SUP720). This was a bit unexpected. Can you give any reason for this?

And will this happen again in a future upgrade?

We also wonder if the card rebooted at the same time or one per one?

Someone has a document who explained that?


Re: Upgrade Cat6500 doc info


Are you running SSO/NSF? Running NSF along with SSO will dramatically cut down fail over times within your chassis. Please see the following link.



Community Member

Re: Upgrade Cat6500 doc info

I already had this information, but I still have no info on what happens with the line cards during a “high availability software upgrade”…

Do they reboot?

At the same time?

One after the other?

for information, I'm in SSO mode.


Community Member

Re: Upgrade Cat6500 doc info

Your question is answered in the document you referenced (the document id should be 71585). The explanation is under step 12 of the Software Update/Native Mode section. To summarize, after you upgrade the standby sup, it will come up in RPR mode because the IOS versions don't match.

Will it happen in a future upgrade? Yes.

Also, the linecards all reset at the time the failover occurs.

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