We want to upgrade two controllers (5508) in cluster with HA AP-SSO enabled. Could you please give me some recommandations before doing the upgrade? I do not know if all of the APs on the active Wlc will be automatically transfered to the standby one during the upgrade. As both wlcs are located on a critical site, I want to minimize the downtime and want to avoid any problem!
Thanks a lot for your advices
If your WLC are in HA AP SSO mode, then do this:
1. Push the firmware upgrade to the active controller. The active controller will push the firmware to the hot standby controller;
2. DO NOT REBOOT;
3. Do an AP pre-download;
4. Once the pre-download is complete, reload the pairs.