Main wireless controller and Anchor WLC OS version compatibility

[Herman2018]

Hi, we have one main wireless controller 55xx and one mobility anchor controller 55xx for some WLANs (SSIDs). Now we need to upgrade the main wireless controller OS to support the latest catalyst 9K access points, but anchor WLC os is still 8.5.x, do we need to upgrade anchor WLC OS as well? Can anyone advise please? Thanks in advance!

[Mark Elsen]

  - You don't (FYI) : https://www.cisco.com/c/en/us/td/docs/wireless/compatibility/matrix/compatibility-matrix.html#ircm_aireos_rls

 M.

[Haydn Andrews]

Given the 55xx are EOL I would be planning for it. You will need to ensure the anchor is running the IRCM image in the 8.5 train to keep using as an anchor