we have a ACS 4.1 install with 5 acs servers, 25 remote switches and over 800 xp users all doing certificate based machine authentication that work perfectly fine. We are also using a guest vlan in our sites to auth fail a guest user onto the guest vlan so they can get internet access. We had to reduce the dot1x timers so dot1x would fail(45 sec) before windows DHCP fails(approx 55 sec) This has worked fine for the last year with all of our xp machines. We put in a new 4510 into our main building last week for user access and we are running into a issue with developer boxes that are running 2003 server or 2003 x64. What happens is that the when they reboot, the authentication process takes too long and they auth fail and get put into the auth fail vlan. They then get authenticated 20 sec later and they are authenticated in the guest vlan and remain stuck there until I bounce the port. I have a TAC case opened just wanted to see if anyone else has seen this or could duplicate. Very weird and specific to 2003 server 2003 server x64 with Broadcom drivers. Thanks in advance.
I have this problem too.