9407R Dual supervisors upgrade

[Drev]

Hi,

I am upgrading a C9407R (2 supervisors installed) form 16.12.4 to 17.3.4

and another one from 16.9.2 to 17.3.4

I know I cannot use ISSU to jump form 16.X to 17.X (don't really need ISSU anyway).

I see some conflicting information on the Net on how to upgrade a 9400 with 2 sups!

My question is:

Should I use the install command with the 2 sup connected or should I install command on only one sup at a time?

-->remove standby sup > upgrade active > put back inactive > remove newly upgraded sup > then upgrade the last one?

With command: "install add file bootflash:cat9k_iosxe.17.03.04.SPA.bin activate commit" both cases.

In my understanding, it should be fine if I upgrade with both supervisors connected. Just checking if I am not missing something/issues with a particular IOS version.

Thanks guys!

[Leo Laohoo · Accepted solution]

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@Drev wrote:

With command: "install add file bootflash:cat9k_iosxe.17.03.04.SPA.bin activate commit" both cases.

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This command will push the package files from the active supervisor to the secondary supervisor.  
Because of the "commit" option, the process will may reconfigure the boot variable to the new package.conf (or maybe not -- a bug).  

After this process, the entire chassis will reboot. 

Be mindful this upgrade is from 16.X.X to 17.X.X and this will include a mandatory microcode upgrade which will take around 14 minutes.  

[Drev]

Thanks for confirming Leo!

Yes, I did upgrade my 9400s with single sup and it took more than 10 min to upgrade.

Also found that it is only for version 16.6.1 (and maybe prior version?) that you have to do one sup at a time:

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9400/software/release/17-1/release_notes/ol-17-1-9400.html#task_kj5_ypx_rjb

Thanks!