I have a Server 2012 domain controller which is unable to contact its own domain.
Troubleshooting has led to the discovery that whilst client computers can resolve addresses using the domain controller, the domain controller itself cannot. Furthermore, the domain controller is unable to resolve anything using any DNS server.
nslookup
Default Server: UnKnown
Address: 192.168.1.102
> google.co.nz
Server: UnKnown
Address: 192.168.1.102
*** UnKnown can't find google.co.nz: No response from server
> server 8.8.8.8
Default Server: [8.8.8.8]
Address: 8.8.8.8
> google.co.nz
Server: [8.8.8.8]
Address: 8.8.8.8
*** [8.8.8.8] can't find google.co.nz: No response from server
> server 127.0.0.1
Default Server: [127.0.0.1]
Address: 127.0.0.1
> google.co.nz
Server: [127.0.0.1]
Address: 127.0.0.1
*** [127.0.0.1] can't find google.co.nz: No response from server
I'm completely at a loss to explain why client computers can resolve via this server but it can't itself. Any ideas?
Best Answer
This isn't quite a full answer, just a question/suggestion.
Is the DC having any other connectivity issues? Have you checked to see if outbound port 53 tcp/udp is blocked somehow?
You can use nmap to test this: https://nmap.org/book/inst-windows.html