Alan, Probably you are right. Now I have fixed the issue. Simply I removed the freeradius & mysql from the server and then reinstalled the freeradius from yum installation. Then I followed the http://wiki.freeradius.org/guide/FreeRADIUS-Active-Directory-Integration-HOW... to configure all the necessary configuration file (not enable mysql database). Then it worked. Thanks everybody for your kind help! Regards, Edward Xie -----Original Message----- From: freeradius-users-bounces+edward.xie=guest-tek.com@lists.freeradius.org [mailto:freeradius-users-bounces+edward.xie=guest-tek.com@lists.freeradius.org] On Behalf Of A.L.M.Buxey@lboro.ac.uk Sent: February-26-14 1:47 AM To: FreeRadius users mailing list Subject: Re: freeradius failed to authenticate the users against windos active directory hi, you've configured your server to use SQL (MySQL) - thats not default config - and the SQL isnt working - so the server fails. Either fix the SQL issue or remove the calls to SQL in the server config files that you've got enabled alan - List info/subscribe/unsubscribe? See http://www.freeradius.org/list/users.html