Recently I met problem with old Cisco AP (model AIR-AP1231G). The problem was in the connection between WLC and AP. The procedure with new LWAPP\CAPWAP AP look like this:
– AP with factory ios for autonomy work try to find WLC when loading;
– if AP did not find WLC, it stays to live like Autonomous AP
– if AP found the WLC, it downloads LWAPP\CAPWAP ios from WLC, then reboots, then it transforms to LWAPP AP and may working only through controller.
The AP may find WLC with simple broadcast search (if AP and WLC are living in the one L2 domain) or with help of ip address that AP got from DHCP option 43.
The problem was that such old AP even with most fresh ios didn’t find controller – it just did not understand option 43 from DHCP. It find WLC when is living in the one L2 domain, but did not found over IP. The problem has solved by directly manual update ios to CAPWAP ios (same ios that AP must download from controller). It is trivial decision, but you may spend many useless time for debugging if you don’t know about it. I don’t meet this problem with new (N-compatibility) AP.