Domain – A duplicate name has been detected on the TCP network

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I installed my domain controller and DNS with two NIC on the server. Both NICs have their own separate IP addresses in the same subnet and were not teamed. Both IP address were registered in the DNS and I found them in Forward and reverse lookup zone.

Everything was working Ok except the following error in the event log.

"A duplicate name has been detected on the TCP network......"

I have realized that this is because of the second NIC.

My question is

  1. If i disable the second NIC, what happen to those DNS record
    associated with the second ip address?
  2. How do I remove all the DNS recored for the disabled NIC?
  3. There are A record, some record with the name (same as parent
    folder), PTR record and may be more. How do i disable second NIC and
    remove all the associated DNS recoreds? Please help.

Best Answer

If I disable the second NIC, what happen to those DNS record associated with the second ip address?

They will stay there for a week or two if you have scavenging enabled on your DNS server. If you do not have scavenging enabled on your DNS server, they will stay there until you manually delete them.

How do I remove all the DNS recored for the disabled NIC?

Drill through your DNS server and delete every record you see that references the IP address of the NIC that you did not want registered.

There are A record, some record with the name (same as parent folder), PTR record and may be more. How do i disable second NIC and remove all the associated DNS recoreds? Please help.

You don't have to completely disable the second NIC. You can just uncheck the box that says "register this connection in DNS" in the TCP/IP properties of the second NIC.

But anyway, after doing that, you either wait for scavenging to take out the old records, or you painstakingly drill through and delete every SRV and A record that references the old IP address.

For the @ (Same as parent folder) ones, those are NS records. For those, just right-click the zone, go to the Nameservers tab, and remove that server with the incorrect IP address as a name server for that zone.

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