What would be the best recommendations and practices for DFL/FFL raise in the environment

Question

Hi All,

I currently have an environment with FFL Windows Server 2003 and the Domain Controllers are on Windows Server 2016. I have to perform an upgrade of those Domain controllers to Windows Server 2019 for which I would need to perform a DFL and FFL raise.

What should be the best practices that should be followed for performing DFL and FFL Raise?

Thank you.

Answer 1

Hi Garima Das,

Thank you for posting in Q&A forum.

Raise the Domain Functional Level

From the Administrator Tools panel, select Active Directory Domains and Trust.

Right-click the root domain for which you want to raise the domain functional level and select Raise Domain Functional Level.

Select an available Domain Functional Level and then click on Raise.

This raises the functional level of a domain.

Raise forest functional level (need do on root domain)

Go to Administrative Tools and open Active Directory Domains and Trusts

In the left pane, right-click on Active Directory Domains and Trusts and select Raise Forest Functional Level.

You will see a list of forest functional levels that are available. Select the required functional level. In this case, select Windows Server 2016.

Click Raise.

You will get a warning message. Read the message and click OK.

Please note:

1. Please raise DFL before FFL
2. Please do the operation with admin account
3. Please note the DFL need higher or equal to FFL

Hope the information above is helpful.

If you have any question or concern, please feel free to let us know.

Best Regards,

Daisy Zhou

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Answer 2

The two prerequisites to introducing the first 2019 or 2022 domain controller are that domain functional level needs to be 2008 or higher and older sysvol FRS replication needs to have been migrated to DFSR

I'd use dcdiag / repadmin tools to verify health correcting all errors found before starting any operations. Then stand up the new 2019 or 2022, patch it fully, license it, join existing domain, add active directory domain services, promote it also making it a GC (recommended), transfer FSMO roles over (optional), transfer pdc emulator role (optional), use dcdiag / repadmin tools to again verify health, when all is good you can decommission / demote old one.

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Answer 3

Hi @Garima Das

In order to promote the first domain controller on your existing forest with DFL and FFL Windows 2003 You should perform the following steps:

1. Raise the DFL to Windows 2008 or higher to be able to migrate the system replication of sysvol FRS to DFS
2. Migrate the system replication od sysvol folder from FRS to DFS-R : Migration of FRS to DFSR SYSVOL
3. Promote you first domain controller Windows 2019 or higher

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