DNS record auto registered even the auto registration option was unchecked

Ensure "Register this connection's addresses in DNS" Is Unchecked

1. Open Network Connections on the DC.
2. Right-click NIC B and select Properties.
3. Select Internet Protocol Version 4 (TCP/IPv4) and click Properties.
4. Click Advanced, go to the DNS tab, and ensure the following:
   • "Register this connection's addresses in DNS" is unchecked.
   • "Use this connection's DNS suffix in DNS registration" is unchecked.

Disable Dynamic Registration via PowerShell

Run the following commands to ensure dynamic registration is disabled for NIC B:

1. List NICs with IP Details:
2. Get-DnsClient | Select-Object InterfaceAlias, InterfaceIndex, RegisterThisConnectionsAddress
   
3. Disable Dynamic Registration for NIC B: Replace InterfaceAlias with the name of NIC B:
4. Set-DnsClient -InterfaceAlias "NIC_B" -RegisterThisConnectionsAddress $false
   

5. Configure the Primary NIC for DNS Registration

   Ensure only the primary NIC (NIC A) is registering in DNS:

   1. Open the DNS Management Console.
   2. Navigate to the zone where the DC's records are stored.
   3. Manually delete any DNS records for NIC B's IP address.

6. Configure the "DisableDynamicUpdate" Registry Key

   Modify the registry to prevent dynamic updates for NIC B:

   1. Open Registry Editor (regedit).
7. HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\{GUID}