802.1x with machine authentication and XP SP3

Hello experts,

I am running a small project with Windows XP SP3 native supplicants using
machine authentication towards cisco 3560 switches and the newest Cisco ACS
5.0. Machine authentication is done via PEAP/MSCHAPv2 towards Microsoft AD.
I am having a lot of troubles, mainly because my poor knowledge of Microsoft
technologies. Here is one of them - the most most common reasons for
computers to fail authentication towards AD:

Invalid EAP payload type

cisco has reported this to happen when there is a problem with the supplicant.
Unfortunately, my supplicants are having such problems from time to time
only.

In addition, i have updated the PCs, applied one hotfix for fixing up failed
authentication after reboot and made all the recommended settings through
Group Policy. The issue appears in the middle of the day, not after reboot or
any other specific activity.

Any help will be appreciated,

Regards,
Lora

Blogs and organic groups at http://www.ccie.net
Received on Fri Oct 02 2009 - 16:04:44 ART