Just putting this out there to see if anyone has any good info or experiences to share before proceeding with this process.
I currently has a network with 1 Forest and 3 Domains. Within that there are a total of 10 Domain Controllers spread out between each of the domains within this forest. All of the Domain Controllers are running Windows Server 2008 R2 as their OS, but Active Directory is running under 2003 functional level for both the forst and domain.
I am at a point where i would like to raise both the forest and domain functional levels from 2003 to 2008 R2. Just looking for any insight anyone may be able to share. Specifically i want to ensure that all of our applications will continue to function and not have any issues authenicating. We have over 1000 servers and over 5000 end users. Apps range from Office, Exchange, SQL, Sharepoint, etc.