Downgrade issues

[shahinmadambi585]

What are the known issues/bugs while downgrading from 17.6.1 to 17.3.5a (9800-40)?

[Leo Laohoo]

For obvious reasons there will be commands that are not "compatible" with 17.3.X.

[afsalperingodan · Accepted solution]

Downgrades are not officially supported, and config loss of new features can occur. However, as downgrades can happen in the real world, this document still lists the most common traps to avoid when downgrading.

To find the information you need, check the version you are downgrading from ( the version before the downgrade) from the below documents.
https://www.cisco.com/c/en/us/support/docs/wireless/catalyst-9800-series-wireless-controllers/216838-upgrade-and-downgrade-of-catalyst-9800-c.html#anc33

I hope this helps.

[Mark Elsen]

 - If you would decide to go ahead you can for instance afterwards use (CLI) show tech wireless and have the output reviewed by : https://cway.cisco.com/tools/WirelessAnalyzer/ , this remains useful when using other procedures too, to have a checkup of the configuration when you are on the targeted version.

 M.