DNS Reverse Lookup Zone problem.

Posted on 2011-10-26
Medium Priority
Last Modified: 2012-05-12
We recently expanded a network by stealing a bit from the subnet mask.  We went from a to  In DNS, there is no Reverse Lookup Zone entry for the two new subnets.  My original two subnets both have entries, rather than having a single entry for the network.  Should there be only a single entry, and how do I repair/configure this?

I should add that originally, this was a single network of 255 IPs that was expanded by robbing a bit from the subnet mask (from to  It has been expanded again by robbing another bit from the subnet mask.  Originally, the network was 10.5.17.x and it went to 10.5.16.x and 10.5.17.x after the first expansion.  There are two reverse lookup zone entries for this network now, 10.5.16.x and 10.5.17.x.  Now that we have 10.5.18.x and 10.5.19.x after the recent subnet expansion, there are no reverse lookup zone entries for them.
Question by:CousinDupree
1 Comment
LVL 21

Accepted Solution

Papertrip earned 2000 total points
ID: 37032425
You can either make the reverse zone 5.10.in-addr.arpa and put all of your subnets in it, or create individual zones for each of your new subnets - 16.5.10.in-addr.arpa, 19.5.10.in-addr.arpa etc.

Personally I would create individual zones.

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