Converting 2019 AD to 2016 AD

[AndyMP]

I have a Windows 2019 Server based Active Directory environment. It contains both Windows 2019 and Windows 2016 Domain Controllers. One of the Windows 2019 Domain Controllers holds the FSMO roles and GC. Can I convert the Domain to a Windows 2016 Domain by transferring the FSMO roles to a Windows 2016 Domain Controller?

[JanoschUlmer]

Forgot to add the link to the technical communities: Windows Server Community (microsoft.com)

[AndyMP]

Hello Janosch,

Thank you for your answer and forum guidance.

Best regards,

Andy

[JanoschUlmer · Accepted solution]

@AndyMP : thank you for your post. Note that this community is not targeted to offer technical help for specific features, but intended to for discussing product releases, strategy relevant for Microsoft partners.

When you need technical help/expertise, you can raise an advisory ticket via https://aka.ms/technicalservices, or you you can reach out to the technical communities (Where there are much more people with technical expertise on this are monitoring the forum): 

That said - WS2019 does not include new Domain/forest functional modes, newest mode is still 2016. So, running a WS2019 as DC does not make this a Windows Server 2019 domain, it is still a domain with a functional mode of 2016 or lower. So, no issue to have both 2016 & 2019 DCs in the same domain and no issue to move FSMO roles.

See also Active Directory Domain Services Functional Levels in Windows Server | Microsoft Docs & Transfer or seize FSMO roles - Windows Server | Microsoft Docs