Minimum domain and forest levels for Server 2012
A colleague asked yesterday if a 2012 domain controller could be added alongside 2003 domain controllers. What he actually wanted to ask was what are the minimum domain and forest levels required to support 2012 domain controller functionality. It stumped me for a bit, and I was fairly sure I knew the answer, but felt the need to double-check. I was correct in my first thought that 2003 is the minimum supported level, domain or forest. For a further detail, and a hugely detailed and thorough post on this, refer to :
An impressive bit of writing and should prove invaluable to anyone looking to start a migration process from an older AD generation.
Not mentioned, and something I will try and check on is whether you still need to migrate SYSVOL replication from FRS to DFSR, something that needed to (or ideally should) be done following a migration from 2003 to 2008/R2. By migration in this instance, I refer to the upgrade of a domain by adding one or more new (2012) domain controllers to an older AD, and then decommissioning the older domain controllers out, leaving only the new ones. It’s a nice way of doing things as it can reduce the requirement for any downtime, assuming of course that the plan has been carefully researched in advance. some of the older domain and forest level raises could not be reversed, whereas 2008 started to introduce the ability to reverse the raise.
For info on the FRS to DFSR migration, refer to (amongst others) :
To clarify, if you’re migrating from 2003, it still needs to be done, I just don’t know offhand if 2012 does it automatically or if it’s still a manual step, as with 2008/R2. I’m going to guess it is still manual. An often missed step in the grand scheme of things.