My Windows 7 clients are unable to join AD using the FQDN of the domain since the domain was upgraded to Server 2012/AD 2012 and the FSMO/GC role was transferred as part of the upgrade. We retired the old FSMO/GC holder and demoted it as part of the upgrade.
Clients can join the domain via the netbios name with no issues. I think this may have been a sporadic issue prior to the upgrade, but it's definitely become consistent in the weeks following it. dcdiag command returns no unusual messages.
Further complicating our situation is the fact that we are using a Linux based DNS server, so all service records were created by hand. My first thought is that the record for the new server was somehow incorrect, but we simply replaced the old server record with an exact duplicate with the host name change where appropriate. This record has been place since we first implemented AD as part of Server 2000, so it is entirely possible that the server record required for 2012 is different and a possible issue.
Any thoughts? This is not a show stopper, but something is definitely amiss.