i want to ask what is the procedure to connect a 7921 with a uc 520 via an ap521. i am trying with leap auth from the 7921 with radius server enabled on the uc and authentication from the ap to uc but i got an error every 10 sec from the ap that the radius server is dead/alive and the ip phone is always unable to authenticate. if i change the authentication method to wep the ip phone isa able to connect to ap but is not able to get an ip (vlan's are working fine, also and the dhcp)
You are running local radius on the UC500 or you have an external radius server?
In any case, you must configure the radius server on the AP520 side. Not sure if you have the unified or standalone version here. Unified is pretty straight forward, where you enter the IP and the shared key, which would match the radius side.
If the AP520 is standalone, then I have attached a sample AP config for an 802.11b/g AP, where the radius config must be entered as well as the server groups, which is then applied to an SSID.
Below are the sample commands to enable local radius on an IOS device.
nas 10.0.0.5 key 0
user cisco nthash 0