I have 3 subnets, lets call them,, and I also have an Active Directory Forest (all DCs/FFL/DFL @ Server 2008 R2) with 2 subdomains, we will call them contoso.com, a.contoso.com, and b.contoso.com.

Organizing forward lookup zones is easy, contoso.com zon on the contoso.com domain controllers, a.contoso.com zone on the a.contoso.com domain controller, etc.

Reverse lookup zones are becoming an issue. For instance, the reverse lookup zone for is on the DNS servers in contoso.com, but some servers in the a.contoso.com and b.contoso.com domains are also on the subnet. As a result, when a server on the 10.10.1 subnet is a member of the a.contoso.com subdomain, there is no reverse lookup zone for the subnet.

AFAIK, if I create the reverse lookup zone for in the b.contoso.com domain, it will create the recors, but DNS servers in the contoso.com domain will be unaware of it. What is the proper procesure to get correct reverse lookup information across the board automatically?

  • 2
    You say you have three subnets, but the way you've written the question, it's all one subnet.
    – MDMarra
    Jan 10 '14 at 19:26

Create the rDNS zone(s) in the parent domain. Configure the rDNS zone to be Active Directory integrated, configure the zone replication to "To all DNS servers running on domain controllers in this forest".

  • I was just typing this up when you replied. Spot on, this is working. Thank you so much.
    – TonyD
    Jan 10 '14 at 19:44
  • Glad to help...
    – joeqwerty
    Jan 10 '14 at 19:47

Ok, after some searching and testing I figured out the answer. Asuming you can delete all of the reverse lookup zones in the sub domains do the following:

  1. delete all of the reverse lookup zones from the subdomains a.contoso.com and b.contoso.com
  2. in the forest root domain contoso.com, create all of the reverse lookup zones
  3. Right click on each reverse lookup zone, click on properties
  4. On the general tab, next to replication, click change
  5. Select the first radio button "to all DNS servers....in this forest"

The reverse lookup zones will now replicate to other forests bi directionally.

If there is a better way to do this that does not involve so much cross forest

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