Not sure if anyone else has come across this issue or not, but, after upgrading to OSX Mountain Lion, I noticed I could no longer connect to any APs. The only one I could connect to was one that was still using WEP (yeah, I know...).

I'm almost %110 sure this is an OSX related issue, but, I finally found that if I changed the security profiles using WPA2 to using aes instead of tkip, I have no more issues with obtaining an IP from the dhcp server.

I verified this with 2 boxes (one being fresh out of the box with the generic setup), both RB751, running 5.19. I don't know if this transcends the RB751 series or not, but, I'm assuming it does.

Yep have the same problem myself.The good folks at Apple are blaming my AP's , that all worked flawlessly pre-upgrade.Good/sad to see someone having the same problem as myself.

Hi
AES CCM is better than TKIP encryption method.so What are you worried about?
i have same problem but my problem will be solved with TKIP and uncheking AES CCM.
be careful for connecting to device if both of TIKP and AES CCM will be checked AES CCM is selected for connection encryption because its stronger than TKIP.

Good Luck

I am worried about the 50 odd apple computers in my enterprise I need to now locate and manually changing a damn setting and the joyous "Internet is down" tickets that are going to get logged hah.

I am worried about the 50 odd apple computers in my enterprise I need to now locate and manually changing a damn setting and the joyous "Internet is down" tickets that are going to get logged hah.

Which setting are you changing on them? The best solution is mentioned above, change AP setting to AES. This will increase speed, reduce load, and increase security ... and also solve any Apple problems.

Which setting are you changing on them? The best solution is mentioned above, change AP setting to AES. This will increase speed, reduce load, and increase security ... and also solve any Apple problems.

Yes I agree.