The user name in LDAP is of the form domainname\username. I wanted to configure the same username in the freeradius as well but different password than LDAP. Authentication fails on the Radius side with this kind of username. If freeradius doesn;t care, not sure why it fails for such usernames.

From: alan buxey <A.L.M.Buxey@lboro.ac.uk>
To: Crne We <crnewe@yahoo.com>; FreeRadius users mailing list <freeradius-users@lists.freeradius.org>
Sent: Wednesday, September 26, 2012 1:07 AM
Subject: Re: handling win domain name in username

Hi,
>    Environmnet: Freeradius with PAP on Windows
>                         Username: domain\user1
>                         password: *******
>    Looks like the Freeradius doesn't seem to like the windows domain name as
>    part of username?

FreeRADIUS doesnt care. your chosen authentication method cares.  if you dont want that 'domain'
to appear then use the prefix module and ensure you have that domain listed in proxy.conf eg

domain {
}

alan