Remove a DNS Server

There may come a time when you want to remove a DNS server from your network. When you remove a DNS server, it is important to remember that your DNS server is likely part of a larger DNS infrastructure, and it likely performs key functions and contains records referencing those functions to the other DNS servers and clients in your organization. You would not want to simply delete the server from DNS and remove the DNS Server role from Server Manager without first making sure that there will not be an interruption of the name resolution service. Make sure that as you remove a DNS server that its functions are being taken over by another server and that the records and references to those services have been updated in your DNS database.

This process consists of four steps:

1. Delete the host (A) record for the server.
2. Modify the NS records for the zone so that the server being removed is no longer included on the list of authoritative servers.
3. Modify the Start of Authority (SOA) record for the zone to point to the new server responsible for the zone. (If you are using an Active Directory integrated zone, this is not necessary.)
4. Use the NSLookup tool to verify zone delegation to be certain that the resource records used for delegation are functioning with the appropriate changes and that they no longer look to the removed server.
   • Open a command prompt.
   • Type nslookup (rootserveripaddress), and press Enter.
   • Type nslookup, and press Enter.
   • Type set norecurse (this tells the root server not to perform a recursive query), and press Enter.
   • Type set q=ns (this sends the query for name server records to the root server).
   • Type the fully qualified domain name of the domain you are testing followed by a period. A list of name servers will be displayed.
   • Verify the NS and A records for the existing name server in the domain.