All radios assigned to a load group must belong to APs that are all controlled by the same controller. Availability mode can be configured only from the home controller on which the load group was created. Load balancing continues to operate if member APs fail over to the foreign controller as long as the WLAN (Wireless Local Area Network) service assignment remains the same.
To ensure that load balancing works properly in availability mode, enable synchronization of the system configuration and the WLAN services used by the load group when you configure availability mode. If you do not enable synchronization, the radios on any AP that fails over may be removed from their assigned load groups. For more about availability mode, see Configuring Availability Using the Availability Wizard.
If you have not configured synchronization, in a failover situation you are able to change the load balance group‘s WLAN service assignment from the VNS Configuration screens and the Wireless AP WLAN Assignment screens on the foreign controller.
If you have configured synchronization, you cannot change the WLAN assignments from the foreign controller. If you have not configured synchronization, you must configure the foreign controller to ensure that all AP radios in the load balance group have the same WLAN services assigned before the AP fails over, as originally configured for the load group. If the WLAN services assigned do not match when an AP fails over, the affected AP radios are removed from the load group. If you change the WLAN services to match after the AP fails over, the AP radios still are not allowed to be in the load group. Reconnect the AP to the home controller to have the radios become part of the load group again.