As named “domain modes” in Windows 2000 time, Domain Functional Level and Forest Functional Level (introduced in Windows Server 2003) list has grown with the inception of two new Windows Server 2008 functional levels. While Domain Functional Level limits the OS of the DCs, a raise to the Forest Functional Level (in a multi-domain environment) can only be achieved after all child domains’ DFL have been met. Both Functional Levels do not dictate the type of OS you can run on your member servers. They dictate which OS can run on a DC and introduce new functionality to AD as you move up the ladder. Such as, to be able to take advantage of AD Recycle Bin functionality all your DCs must be running Windows Server 2008 R2 and the FFL must be at 2008 R2.
There are now 6 different types of Domain Functional Levels;
1. Windows 2000 Mixed (supports NT4/2000/2003 DCs)
2. Windows 2000 Native (supports 2000/2003 DCs)
3. Windows Server 2003 Interim (supports NT4/2003 DCs)
4. Windows Server 2003 (supports only 2003 DCs)
5. Windows Server 2008 (supports only 2008 DCs)
6. Windows Server 2008 R2 (supports only 2008 R2 DCs)
And five forest functional levels:
1. Windows 2000 (supports NT4/2000/2003 DCs)
2. Windows 2003 Interim (supports NT4/2003 DCs)
3. Windows Server 2003 (supports only 2003 DCs)
4. Windows Server 2008 (supports only 2008 DCs)
5. Windows Server 2008 R2 (supports only 2008 R2 DCs)
See this for list of features for different Functional Levels.
Good info Rick,
I remember years ago during the W2K days I’d hear the DFL/FFL question being asked on interviews. That would be a killer question now if someone had to spell out every feature.
I’d just refer them to this blog entry now
Talk to you later
Mike
Link | August 21st, 2009 at 10:57 am
Killer question indeed, especially if the question was to let alone describe all the different group nesting restrictions in each DFL/FFL
Thanks,
Link | August 21st, 2009 at 12:29 pm
Actually your are wrong.
DFL
1. Windows 2000 Mixed (supports NT4/2000/2003 DCs)
2. Windows 2000 Native (supports 2000/2003 DCs) + W2K8 + W2K8R2
3. Windows Server 2003 Interim (supports NT4/2003 DCs)
4. Windows Server 2003 (supports only 2003 DCs) + W2K8 + W2K8R2
5. Windows Server 2008 (supports only 2008 DCs) + W2K8R2
6. Windows Server 2008 R2 (supports only 2008 R2 DCs)
And
FFL
1. Windows 2000 (supports NT4/2000/2003 DCs) + W2K8 + W2K8R2
2. Windows 2003 Interim (supports NT4/2003 DCs)
3. Windows Server 2003 (supports only 2003 DCs) + W2K8 + W2K8R2
4. Windows Server 2008 (supports only 2008 DCs) + W2K8R2
5. Windows Server 2008 R2 (supports only 2008 R2 DCs)
Link | October 16th, 2009 at 5:26 pm
Nikolas, Good point. The list that I covered had the original list as to what particular functional level covered which DCs originally. Usually all down level native modes allow the introduction of newer OS DCs.
Link | October 19th, 2009 at 1:20 pm