Good afternoon. I was wondering if anyone here knows why I can't seem to be to establish a forest to forest trust? My group, gbrx.com wants to establish a trust with a company we aquired meridian rail (railservices.meridianrail.com). Here is the scenario: Railservices is behind a nated firewall. GBRX.com is not behind a nat. When i try to create the trust it gives me the following options: The name you specified is not a Valid Windows domain name. Is the specified name a kerberos v5 realm? THe domain controller trying to establish the trust on gbrx.com side is windows 2003 domain conroller running in windows 2000 native mode. THe domain controller on the meridian side is a windows 2003 dc running in windows 2003 native mode. Any ideas?

Cross Forest Trust are only supported in Windows Server 2003 forest functional level: http://support.microsoft.com/kb/322692 Activated features: all features in Interim Level, Defunct schema objects, Cross Forest Trust, Domain Rename, Dynamic auxiliary classes, InetOrgPerson objectClass change, Application Groups, 15-second intrasite replication frequency for Windows Server 2003 domain controllers upgraded from Windows 2000