Extracting the DNS root hints from windows DNS servers
are simple procedure, before going to explain this I would like to explain how the root hints are configured in windows servers, if you have question like how root hints are configured and is DNS root hints are replicated through Active Directory replication then read further you will get all the answer
I came across below questions while taking inventory on DNS servers and DNS server configuration, yes I want to document root hints information from all the DNS servers from our network
Is root hints are comman across the Domain?
Is root hints are replicate from one Domain Controller to other?
How and where root hints are stored?
If the DNS server is a domain controller, root hints are loaded from the Active directory, if it’s standalone DNS servers and is not running on a domain controller and no root hints configured in Active Directory then root hints are loaded from a file called CACHE.DNS, stored in the systemroot\System32\Dns folder
And yes root hints are automatically be replicated to others Domain Controllers if multiple domain controllers exist in your Domain
Conclusion: No need to extract root hints information from all the DC on your Domains, extract from PDC is enough since the root hints are identical on all the DC’s and changes are replicated to other DC’s
More on DNS root hints, See the Microsoft page