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Is it possible to consolidate smaller subnets into a larger subnet for DNS reverse lookup zone? For instance, instead of using several subnets (176.0.10.in-addr.arpa, 176.4.10.in-addr.arpa, 177.0.10.in-addr.arpa, and 177.4.10.in-addr.arpa), can they all be combined into one large subnet (10.in-addr.arpa)?
I understand that older versions of Windows DNS are limited to creating reverse zones with /8, /16 and /24. Would this consolidation cause problems with Dynamic updates based of the DHCP scope? What is the best practice on DNS reverse zones?
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Hello,
Thank you for posting in Q&A forum.
Yes, you can consolidate smaller subnets into larger ones, which will not impact the DHCP dynamic update.
After the change you can double check it on DHCP Server if DHCP server is still configured to update DNS records properly.
To help other customers who may be facing the same issue, please don't forget to vote if the reply is helpful.
Best regards，
Jill Zhou
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It appears that the issue you are referring to can be resolved by following https://learn.microsoft.com/en-us/answers/questions/1086084/reverse-dns-not-dynamcially-updating
hth
Marcin
That is not the issue at all. I am asking if it possible to use a super subnet as a reverse zone instead of breaking down each subnet? Will using a super subnet work correctly? What is the best practice on reverse zones in DNS? Should you always break down the subnets?
As an example, I have the below subnets:
176.0.10.in-addr.arpa
176.4.10.in-addr.arpa
177.0.10.in-addr.arpa
177.4.10.in-addr.arpa
Can I use 10.in-addr.arpa to cover all them? Will reverse DNS work if this is setup this way?
Sorry posted twice by accident
Yes - this should work
There is no need to break down the IP address space into subnets
hth
Marcin
Thank you Marcin for a quick response. Is there any Microsoft Best Practice document that states the same? I am trying to be certain before moving forward and creating a bigger issue later down the line.
This might help https://serverfault.com/questions/643606/windows-reverse-lookup-zone-subnetting
Unfortunately the reference to the Microsoft content included in this thread is no longer available, but the thread itself indicates that this configuration is working.
I still would highly recommend testing this on your own (things change between OS versions)
hth
Marcin