Wireless Access

I have a WLC and I have a SSID with Radius Authentication, it was working but after a while it stops working:

 

I did a tracebuf:

 

(PA-TB-WCONTROLLER01) #show auth-tracebuf mac 94:65:9c:45...
(PA-TB-WCONTROLLER01) #show auth-tracebuf mac 94:65:9c:45:7a:31

Auth Trace Buffer
-----------------


May 25 07:13:23  station-up             *  94:65:9c:45:7a:31  40:e3:d6:51:77:90  -  -  wpa2 aes
May 25 07:13:23  eap-id-req            <-  94:65:9c:45:7a:31  40:e3:d6:51:77:90  1  5
May 25 07:13:26  station-down           *  94:65:9c:45:7a:31  40:e3:d6:51:77:90  -  -
May 25 07:18:16  station-up             *  94:65:9c:45:7a:31  40:e3:d6:51:77:90  -  -  wpa2 aes
May 25 07:18:16  eap-id-req            <-  94:65:9c:45:7a:31  40:e3:d6:51:77:90  1  5
May 25 07:18:19  station-down           *  94:65:9c:45:7a:31  40:e3:d6:51:77:90  -  -
May 25 07:18:36  station-up             *  94:65:9c:45:7a:31  40:e3:d6:51:77:90  -  -  wpa2 aes
May 25 07:18:36  eap-id-req            <-  94:65:9c:45:7a:31  40:e3:d6:51:77:90  1  5
May 25 07:18:39  station-down           *  94:65:9c:45:7a:31  40:e3:d6:51:77:90  -  -

 

 

Was that client previously successful at authentication?

 

What is providing the radius service? Can you check to see if the requests are hitting the server?

Yes, we had no problems before, what additional test can i perform?

is a NPS server, I'll try to get access to that.

Test using the controller aaa test server
Make sure your certificate hasn't expired ?
Have you guys made any changes on the RADIUS server shared key or the NAS IP address on the controller?

Test with aaa test-server is successful but when trying from computer is failing.

The client seems to be failing when the AP/Controller asks for an EAP-ID request.  What client is this and how is the client configured for 802.1x?