Downgrading 9105 APs to 8.10 for 5520 WLC

[hbell]

My organization has been running 2702 APs connected to a 5520 controller.  We have purchased 9105 APs and will purchase a 9800 controller in the next procurement cycle (mid-to-late 2025). I know the 9105s can associate with and be controlled by the 5520, but they must be downgraded from the installed version 17 to 8.10 software.  The 9105s can pickup DHCP leases easily enough, but they don't automatically downgrade when connected to the 5520, and I'm looking for the steps to download the older ("new") image to these APs.  Can someone point me in the right direction?

[Leo Laohoo]

FN72424 - Later Versions of Some Wi-Fi 6 Access Points Fail to Join the WLAN Controller

[marce1000]

  - (deleted)

 M.

[Rich R]

That's not correct @marce1000 - they ARE supported on AireOS but the software must be up to date as per the field notice which Leo highlighted:
"AireOS
If a Cisco product runs Cisco AireOS 8.10.171.x or earlier, upgrade to Cisco AireOS 8.10.18x.0 or later."

@hbell upgrade your 5520 to 8.10.196.0 as per the TAC recommended link below.  You have not mentioned what version of code you are using but it is probably too old to support the current AP models.  If you wanted to downgrade the APs manually you could do so using TFTP or SCP and load the software directly to the AP:
https://software.cisco.com/download/home/286324892/type/286288051/release/15.3.3-JK11 (that's the 8.10.196.0 AP code)

[marce1000]

 - @Rich R  Yes , you are right ; I forgot the fact that there is a fix for aireos too = going to a sufficient recent release, 
                   however starting from a good business plan , it would have been better to have a 9800 controller included too.

 M.

[Rich R]

Agreed - and I think people often forget the option of 9800-CL virtualised (and/or cloud-based) WLC which may be a cheaper option to avoid the capex of buying physical appliances, even as an interim step.

@hbell the 9800-CL WLC software is free of charge (zero dollar cost).  You only need to buy the AP licenses (which you would have bought with the APs anyway) and the support (minimum 1 year mandatory)