Adding a Windows Server 2012 R2 DC to an Existing Domain

When talking about including Windows Server 2012, the following question occurred more often recently:

Is my Active Directory Domain ready to add a W2012R2 domain controller?

This article will help you with that.

Prequesitions for Adding a Windows Server 2012 R2 to the Domain

It depends on the following factors whether or not a domain can add a W2012R2 domain controller:

1. The domain functional level has to be at least W2003.
2. The forest functional level has to be at least W2003.
3. The forest scheme has to be ready for W2012R2.
4. The domain has to be ready for W2012R2.

Checking Domain und Forest Functional Level for W2003 Standard

You can find out the first two prequesitions easily if you check the domain settings in ”Active Directory and Computers”.

Checking the Scheme of the Forest

In order to find out whether or not a forest is ready with adprep/forestprep you can use some lines of PowerShell. The scheme object has “objectVersion” as a feature that allows you to find out the scheme’s version. In a forest which contains several domains you can query the schema from the root domain of the forest. Here is an example with a domain named “DOM01.com”.

With this domain the scheme has the information Version 47- what does it mean?

The following chart lists the most important well-known scheme versions:

Thus the domain from above has a scheme in the version „Windows Server 2008 R2“.

Checking the Domain

The last of the four important prequestions is to find out whether or not the domain is ready. (at adprep/domainprep status). To do so, check the „revision“of the object „CN=ActiveDirectoryUpdate,CN=DomainUpdates,CN=System,DC=DOM01,DC=com“. This could be one of those:

Now that domain has a revision=3. That means it is Windows Server 2008.