All of the remote LAPs in our environment initally join the controller via DHCP Option 43. Sometimes they first IP address in the Option 43 setting may not be the same as the WLC configured as primary. After they boot and join a controller, will they automatically move to the controller thats configured as primary?
You need to set the primary, secondary and or tertiary WLC. After the ap joins for the first time, it will know of that WLC along with the other WLC in the same mobility group. If you require the AP to know of its primary, secondary and or tertiary, you need to define that in the access point.