C9500 IOS upgradation without downtime

[zohebS]

Hi There,

We have a pair of Cisco 9500 switches configured in a stack, with one switch operating as the active unit and the other in standby mode. We need to upgrade the IOS on these switches without any downtime, as the location is highly critical and cannot tolerate any interruptions. Are there any methods or procedures we can use to achieve this?

[Georg Pauwen]

Hello,

I think if the switches are in an SVL configuration, you can do an ISSU:

https://video.cisco.com/detail/video/6349996334112

[balaji.bandi]

1. what is the version code running ?

2. what IOS XE code you looking to upgrade ?

3. is end devise attached to Cat 9500 SVL - all are dual home (single homed will have downtime 15-20minutes - when the switch rebooting)

ISSU works as per chart, if you moving from 16.X to 17.X ISSU not work, so you need complete downtime to switch to reboot.

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst_standalones/b-in-service-software-upgrade-issu.html

Note : always take backup configuration out of the box, give enough time for the upgrade process, if possible to have console access in case required to collect any logs.

collect more information pre-test and post-test validate, and at last read the release notes and advises and caveats.

[Leo Laohoo]

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@zohebS wrote:
We need to upgrade the IOS on these switches without any downtime

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Have a look at the attached document.  And, most importantly, never perform an ISSU without TAC Proactive Case  &  make sure the TAC Agent on is with you on a WebEx call to "witness" the entire ISSU process.  One of the main task of the TAC Agent is to intervene in the likelihood event when ISSU fails and the VSS goes into a "ping pong" state and the network becomes unstable and unmanageable.

Although  CSCwh29442 & CSCwh76420 only applies to Catalyst 9800 WLC, it is still worth noting.