I am facing the Authentication error in Concentrator.
Concentrator is integrated with AD.
2451 11/22/2009 13:20:35.550 SEV=3 AUTH/5 RPT=19132 126.96.36.199
Authentication rejected: Reason = Unspecified
handle = 396, server = 172.27.1.13, user = 23733, domain = <not specified>
Gotta following questions for you :-
1. Which authentication protocol is in use with AD ?
2. By any chance the user "23733" for whom you are seeing Authentication error, is a part of mulitple groups defined in AD ?
As a quick test., try to switch the VPN group to NT domain authentication and let me know how it goes...
If NT does not work then try LOCAL authentications.
Awaiting your response with answers to the questions asked above and the test results with NT and LOCAL ...