Upgrade Domain Functional Level From 2003 To 2008 R2

Once completed we would like to then raise the domain functional level of our forest and the domains from 2003 mixed mode to 2008 native mode.

Upgrade domain functional level from 2003 to 2008 r2. Upgrading the pdc of a windows nt 4 0 domain as a child domain in an existing windows server 2003 forest where interim forest functional levels had been configured by using the ldp exe file or the adsiedit msc file permits security groups to use linked value replication after the operating system version upgrade. Perform an in place upgrade of all existing domain controllers running windows 2000 in the forest to domain controllers running windows server 2003. The second restriction for which there is a limited exception on windows server 2008 r2 is that once upgraded the domain or forest functional level cannot later be downgraded.

Before you raise the domain functional level you must upgrade all windows server 2003 based domain controllers in that domain to windows server 2008 or windows server 2008 r2. Introduce newly installed windows server 2008 based or windows server 2008 r2 based domain controllers into the forest and then retire all domain controllers running windows 2000. Restarted kdc service on all the domain controllers and still had a couple of.

To be safe we restarted all the domain controllers since we were. Our exchange environment is already on 2010. We are in the process of replacing all of our windows 2003 domain controllers with windows 2008 r2 domain controllers.

If the domain functional level is set to windows server 2008 r2 it cannot be rolled back for example to windows server 2003. Starting in windows server 2008 r2 however. The only purpose that having such ability would serve would be so that downlevel dcs could be added to the domain.

Event id 15 s come through. After raising domain and forest functional levels from 2003 to server 2008 r2 we started to get a few event id 15 on the domain controllers for a couple of service accounts.