Upgrading Active Directory domain functionality level

[mwilliamsess]

I am wanting to upgrade from Windows 2000 native to Windows 2003 server. We have 3 domain controllers all running Windows 2003 server. We do have some other member servers running Windows 2000 server. I was thinking it wouldn't be a problem since all of our domain controllers are 2003. Is this correct?

 

[Teknoratti]

You shouldn't have a problem upgrading to Windows 2003 other than the notion of Security group functionality with Windows 2000 native and Windows 2003 as it is in Windows 2000 Mixed mode for Win NT 4. You wont be able to establish universal groups on that server unless you raise the functional level.