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charman100

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Configuring Subnetted Reverse DNS

Hi,

I have a main headquarters (HO) and various branch sites with the following subnets:

HO -192.168.1.0/24
Site1 – 192.168.2.0/26
Site2 – 192.168.2.64/26
Site3 – 192.168.3.0/26
Site4 – 192.168.3.64/26

Each branch site does not have a local DNS server.  All hosts at the branches use the DNS server (2008 R2) at HO for name resolution.  Ideally, I would like to create separate Reverse DNS Lookup Zones for each site taking into account the /26 instead of the default classful /24 boundary when a zone is created.  

I have read articles such as http://support.microsoft.com/kb/174419, however it goes into delegation with parent/child etc. which I don’t believe is applicable in my situation as the branches have no DNS servers of their own.   Any clarification and assistance would be greatly appreciated.

Thank you!
Avatar of Svet Paperov
Svet Paperov
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Is there any reason to do that? There is NO any advantages of splitting the Reverse DNS lookup zone. The reverse dns lookup zone serves only to get the FQDN of a host from its IP address and only the IT support tools like ping -a could make use of that information. In AD domain the reverse dns lookup zone is optional.
The reverse lookup zones can be classless for class a and class b addresses, but for class c address, you should just rely the single class C range. As long as all the networks can be supernet into a single class C network, there is no need for them to be divided. More information on planning the reverse lookup can be found on technet (http://technet.microsoft.com/en-us/library/cc961414.aspx)

In your case, you need a three reverse zones, one for each class C network.

Best of Luck!
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charman100

ASKER

Unfortunately, I inherited the subnets as they are.  My preference would have been for each site have a /24.  I currently do have 3 zones configured as suggested.  I understand that there is no need or technical benefit to splitting it further and that limiting the number of zones can simplify things and even be a best practice.  However for organizational purposes, having records from 2 different sites in one zone doesn't feel "clean".  If anyone can let me know if it can be done it would be greatly appreciated.  If not, I'll have to accept the current configuration of 3 zones.

Thanks!
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Svet Paperov
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