Clarity needed...

Hi guys,

I'm hoping someone can clarify this for me. I am reviewing domain and forest functional levels for the 294 exam and I am getting a little confused. The resources I have read state that in order for the forest functional level to be raised to Windows Server 2003 all domains need to be operating at the Windows Server 2003 functional level as well.

I've then read another article that states all domain controllers need to be running the Windows Server 2003 OS and the domains need to be operating at a minimum of Windows 2000 Native functional level in order to raise the forest functional level to Windows Server 2003.

Can anyone clarify which explanation is actually correct? I have tested this in my lab and it appears that the second explanation is more accurate but I just wanted to confirm as the practice questions I have done aren't consistent with this.

Thanks