MSDCS zone missing

Question

I seem to have an issue with our AD/DNS, the structure looks like:

but the BPA gives me an error:

Issue:
The Active Directory integrated DNS zone _msdcs.<domain> was not found.

Impact:
DNS queries for the Active Directory integrated zone _msdcs.<domain> might fail.

Resolution:
Restore the Active Directory integrated DNS zone _msdcs.<domain>

Now we've got 4 DC's in total: 2 running Server 2008 R2, 2 running Server 2003. The older ones will be retired sometime this year. Actually everything seems to be working ok (if something isn't then we don't know about it), we've got quite a few .NET applications authenticating against AD, no DNS issues from what I can tell and various bits on the network point to all 4 controllers.

Furthermore a dcdiag /dnsall comes up with all passes. Is this something I should be worried about?

Solution

Well, notwithstanding the fact that a Google search for The Active Directory integrated DNS zone _msdcs.<domain> was not found would have told you the same thing, much faster...

This is an issue you see in domains created under Windows 2000 and elevated to 2008, that doesn't actually usually create problems. (But it's pretty trivial to correct, so you may as well correct it, right?) See this thread here, Tim Baldwin's answer (mostly quoted below) is correct.

Win2000 implemented _msdcs as a subfolder of the DNS zone. The recommended config for 2003 and 2008 AD-Integrated DNS zones, is that _msdcs be moved to a separate AD-integrated primary zone as _msdcs.ForestFQDN. However, the zones created in 2000 are not changed to this config when DNS is upgraded or migrated 2003 or 2008.

To fix this you need to manually create a new "separate"active directory integrated primary zone _msdcs.ForestFQDN and remove the old subfolder under the existing primary zone. (after successful config and replication). Then run your best practices analyzer in 2008R2 and see the problem is no longer...

Comments

[hyp]

It seems my google powers are fading... thanks for your help.