C9200L IOS Release Cupertino-17.9.5 MD

[Battaralg]

Good Day, 

we're running C9200L-24P-4X as layer two switches in the environment with IOS Dublin-17.11.1, we started upgrading to the latest release Cupertino-17.9.5 . Some switches just worked fine and others completely lost connection even with devices that connected directly to the switch. Physical ports are blinking, no observation on device logs so we had to re-install the old version back ( Dublin-17.11.1) and it worked fine. 

anyone has experienced this? why does the upgrade work fine in some switches and others not?

Thanks,

[Torbjørn]

Sounds like something went wrong during installation, or the file was corrupted. Have you attempted to reinstall? Did you check the integrity of the downloaded file against the MD5 hash?

[Battaralg]

Yes I’ve nothing changed..

[balaji.bandi]

 Dublin-17.11.1  - is the latest compare to that mentioned upgrade 17.9.5 ? (so are you looking to downgrade ?)

is the Switch shipped with 17.11.1 ?

what is the reason of upgrade and downgrade ? as per cisco 17.9.4a or 17.9.5 is stable version still.

read the release notes before downgrade :

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9200/software/release/17-11/release_notes/ol-17-11-9200.html

Have you collected any logs from switch  when the problem occured.

can you post show version (from exiting working switch ?)

[Battaralg]

Not sure it was shipped with what but not  17.11.1. 

would be there a compatibility issue with C-2960 switch? As it’s connected to it via uplink and the other that has no communication issues connected to C9200L   

I didn't collect logs but all looks fine 

[balaji.bandi]

until we see the logs we can not say what could be the wrong.

when you downgrade to 17.9.5 that should work as expected.

Some switches just worked fine and others completely lost connection even with devices that connected directly to the switch. Physical ports are blinking

check some STP config also collect logs is very important here.

[Leo Laohoo]

Playing fire with 17.11.1. 

What could possibly go wrong?