A client of ours is still sitting at "Windows Server 2003" for both the "domain and forest" functional levels. They only have 1 x 2008 member server with the rest of the member servers being Server 2012 and Server 2012 R2 editions.
We are having SYSVOL replication issues (I believe that it is still trying to use FRS versus using DFS Replication as it should be. We are also having DNS issues that we believe may be related to this as well.
I want to raise both the domain and forest functional levels, is there a specific order that these need to be done in? Is there a reboot of any kind required? Services that need to be restarted?
I haven't done this in several years so any suggestions are greatly appreciated.