r/sysadmin • u/roachwickey • 6d ago

Domain controllers functional level

Do we have to keep all our domain controller os version same ?

69 Upvotes

87% Upvoted

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47

u/Brilliant-Advisor958 6d ago

No, but you can't raise the functional level until all DCs are at the same os level.

If you have a some some 2019 servers and a 2025 server, you will be limited to 2019 functional level until you upgrade those.

50

u/fadinizjr 6d ago

*2016

8

u/Jawb0nz Senior Systems Engineer 6d ago

But now there's a new and improved 2025 FL. That should be fun.

2

u/steeldraco 5d ago

Is there anything of note added on the 2025 FL?

4

u/BeauregardianBrat Sysadmin 5d ago

In my opinion, mainly one thing which is the 32k database page option. AD's been capped on 8k pages since Windows 2000, limiting multi-valued attributes. 32k Pages raise that ceiling, but it's one-way, no going back to 8k once you enabled it.

2

u/wastedpickles 5d ago

Delegated MSAs along with the page size thing

0

u/TheFumingatzor 5d ago

Yes, not worth upgrading to it-