no response to Access-Challenge

[Vieri]

Hi,

Sorry for the rookie question but I'd like to know what I can make of the following:

I have just one wireless device, an access point and a freeradius server.

When the supplicant tries to connect I can see the following messages in FR over and over:

rad_recv: Access-Request packet from...

...

Sending Access-Challenge of id 46 to 10.215.146.130 port 2048
        EAP-Message = 0x010200061920
        Message-Authenticator = 0x00000000000000000000000000000000
        State = 0x2bd535b12bd72c983ec1de5e3f93e675
Finished request 18.
Going to the next request
Waking up in 4.9 seconds.
Cleaning up request 18 ID 46 with timestamp +771
Ready to process requests.

There are quite a few Access-Request/Access-Challenge pairs (it goes on for about a minute or two) until the supplicant finally succeeds to connect with TLS handshakes and so on (WPA2+AES+EAP-TLS).

What can be causing this delay?
It's as if the "conversation were out of sync" or as if one side weren't "listening".
Could it be AP, the client supplicant, the wlan driver?

If I were to use a packet sniffer like wireshark, what "filter" could I apply and what should I look for?

Ideas are welcome.

Thanks

Vieri