I took over this small windows network from another admin who is no longer involved. It's a simple setup, one bare metal server with Windows 2016 as a DC and fileserver, all in one. With less than 10 users, I guess that's ok.
Unfortunately, something seems to be off with the DNS configuration. I noticed that I can't access the server using the hostname but it works fine using the IP address.
nslookup servername (simple or fqdn), run right on the DC or from a client, does not work, the error message is particularly confusing:
> nslookup dc1 Server: dc1.example.com Address: 192.168.1.8 *** dc1 wasn't found by dc1.example.com: Non-existent domain
So, dc1.example.com confirms that it can't find dc1.example.com.
Funny enough, the reverse lookup, i.e. using the IP address instead of the hostname, seems to work fine, it actually gives back dc1.example.com.
By the way, nslookup using client names works fine in both directions, it's really just the DC I can't query using hostname/fqdn.
I'm no DNS expert but the entries on the server seem fine. There are 2 forward zones, one with the prefix _mscds, and in both forward zones, there is an A record for dc1 with the correct IP address. The reverse lookup zone seems set up alright as well.
dcdiag /test:dns did not complain about anything.
All in all, everything else seems to work fine within the network, the users have no complaints. I'd still prefer to fix this but after having worked at this for several hours, I'm a bit stumped. Hopefully someone here knows how to untie this knot.