Is there any real way to get access points to stick to a specific controller?

[lbadman]

It doesn't seem to matter what we do for telling APs what controllers they should be on, our environment sees a lot of APs jumping off of a controller and going to another one (code version irrelevant). Today's example- an 8510 has thousands of APs all set up to only point to the 8510. Bring up 5508 on same subnet, watch hundreds of APs "let go" and jump to 5508 despite having only 8510 set up in their config. But there seems to be no rhyme or reason to the ones that let go and the ones that stay on the 8510. We manage all controllers on same subnet, and for years It has seemed like APs *generally* stay where you want them, but many get a mind of their own and move to another WLC;

Has anyone found a foolproof way to get them to stay put that does not involve anything ridiculously laborious?

[Saravanan Lakshmanan]

AP should have both ip and wlc name configured on primary/sec.

Rebooting the AP may bring it back to its primary controller.

Didn't 'AP-fallback - enabled' help at all.

From design perspective, Its not recommended to keep all APs in same subnet - creates unnecessary intra roaming on multi-controller environment, mobility messages, All WLCs receive management vlan broadcast & multicast,.... 

solution:-

Lightweight Access Point (LAP) Authorization

http://www.cisco.com/c/en/us/support/docs/wireless/4400-series-wireless-lan-controllers/98848-lap-auth-uwn-config.html