We have instant AP105's and dozens of iPad 2's, Mac OsX laptops, and a variety of other devices. We have two SSID's set up. One for guests and the AP assigns the IP and the guests get a captive page. The other SSID is encrypted PKS and clients receive IP from DHCP. A couple weeks ago, students devices that always connect to the privileged SSID automatically started connecting to the guest network instead.
Not all students devices will do this, but not always the same student either. Not always the same AP, but the busiest AP's end up with the most devices connected as guest. For example, one AP may show 40 devices connected and 6 will be to guest. While 40 devices might be a lot, they are not all being used at the same time. We have had problems with slow speeds if they do, but never a problem with the device not connecting to the privileged SSID automatically. To get them to connect to the correct SSID I may have to have the device forget the network and re-add it - or sometimes if I choose the privileged SSID it will connect. easily. But the next day, after the devices go home for the night, they may be connecting to guest again.
Two things have changed - in December we moved our DC from Windows 2003 to Windows 2012. And a couple weeks ago I updated the firmware on our instant AP's to the newest available (6.3x) .
It seems as if maybe the device is timing out trying to send or get authentication or IP information and then reverts to the guest network. I am not sure how to verify that would be the issue. If it is the issue, I am not sure what to tweak. Any ideas?
Or maybe the firmware version has a glitch?
If you have experienced this issue, any insight would be appreciated.