Problem with ACS device authentication in 802.1x

[benchj]

We have implemented 802.1x on an ACS server running 4.1.  They can log in and get authenticated but later they will drop out and to get authenticated back on the network they have to remove the ethernet cable and reconnect.  It  is not occuring at all supported locations but intermittently across the network.  We are using the VISTA supplicant.

[ansalaza]

Please let us see the configuration of the Switchport (show run int TYPE X/X)

1) To find out if the Switch is receiving the request from the Vista Supplicant try enabling these debugs:

debug aaa authentication

debug aaa authorization

debug dot1x all

2) To find out if the Switch if relaying the request back to the ACS Server, please enable this debug:

debug radius

Also see the status of the port while testing:

show dot1x interface TYPE X/X details [show dot1x interface fa0/3 details]

Do you receive any type of authentication requests in the ACS Server before unplug/plug ethernet cable?

HTH,