Hi, I'm trying to authenticate on the command line like this: ntlm_auth --username=nmm --domain=upn.domain.com The result is: NT_STATUS_NO_SUCH_USER: No such user (0xc0000064) The upn.domain.com is not a domain, but an Alternative UPN suffix configured on Active Directory. The user has the upn.domain.com as logon domain, but the domain on the pre-windows 2000 field is the real domain, and I can't change that. When using a real domain, everything works as expected. Is this a known limitation of Samba or am I missing something? Thanks, Nuno Marques