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In looking at the AD partitions using ADSIEdit I see that both the Domain partition and the DomainDnsZones partitions have a DC=RootDNSServers container which both contain objects of dnsNode class representing the Root Hint servers. I have two questions about this:

  1. Why are the Root Hints being stored in AD? I always understood that they were loaded from the "C:\Windows\System32\dns\cache.dns" file.

  2. Why are they stored in both the Domain and the DomainDnsZones partitions?

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up vote 2 down vote accepted

They can be loaded from the cache.dns server, but they also can be loaded from active directory.

If your DNS server is also a DC, it will automatically load root hints from AD first. If it is not a DC, it will use the cache.dns file.

Any customization of the Root Hints are stored at:


As Shane mentioned, I believe the copy in the Domain partition is used for backwards compatibility.

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I think the cache.dns file is actually the 'main' store, but it's overwritten every so often if it doesn't match AD. Also, with regard to why it's stored in both places - I think it's only populated into the domain partition these days to keep compatibility with Windows 2000 DNS servers. – Shane Madden Apr 27 '12 at 1:15
Updated my answer, looks like the cache.dns file is only used when set to not load from AD. – HostBits Apr 27 '12 at 2:12

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