Upgrading Lync to 2013 recently I came across a problem where the front end service simply wouldn’t start but would get stuck in “Starting” mode. I spent quite a bit of time trying to figure out what the problem was and got caught up in some false information on the technet forums that it was related to Server 2012. In fact the problem was fairly simple if you know whats going on under the hood. When the server firsts starts it synchronises user information from active directory, but here’s the kicker, if you have multiple domains in your active directory forest regardless of where the server lies, it will try to get user information from the other domains, if it can’t it won’t start, and in most cases you have probably like me only run the domain preparation step on the domain you want to use with Lync. There’s two ways to resolve this depending on your requirements,

  1. Run the domain preparation step on all domains in your active directory forest.
  2. (My Preferred) Limit the user replication to the domain you want to use with Lync with the following powershell: Set-CsUserReplicatorConfiguration -Identity global -ADDomainNamingContextList @{Add=“dc=fabrikam,dc=com”}

The PowerShell included above will limit the replication to the “fabrikam.com” domain only, misleading as the command may be (‘Add=') as default the value is null (you can check with “Get-CSUserReplicatorConfiguration”) which essentially means all domains. I didn’t find this issue to be that well documented or resolution 1, so hopefully this will help anyone else out there who has the same problem (and maybe remind myself if I ever want to include additional domains and can’t figure out why I can’t enable the users for Lync). Big thanks to “JMTTech” on the technet forums for this one http://social.technet.microsoft.com/Forums/nb-NO/lyncserverpreview/thread/07ec9d8c-b83e-4795-91b6-0d3344cd49e5