troubleshooting DNS

  • Thread starter Thread starter Rob
  • Start date Start date
R

Rob

I cannot get the internal DNS to find anything external. I have Forwarders
configured, and both the internal and external NICs pointing to the internal
DNS.

If a do a NSLOOKUP, it times out. If I do a NSLOOKUP, and change the server
to an external DNS server, it resolves.

All Ideas on troubleshooting this would be appreciated.

(BTW, it is listening on the internal NIC. I changed it to listen on both
NICs, but it didn't make a difference)

Thanks in advance

Rob
 
Rob said:
I cannot get the internal DNS to find anything external. I have Forwarders
configured, and both the internal and external NICs pointing to the internal
DNS.
If a do a NSLOOKUP, it times out. If I do a NSLOOKUP, and change the server
to an external DNS server, it resolves.
Click to expand...

What happens if you extend the time out?
Have you tried the NSLookup from the DNS server itself (to prove it can
reach
the internet), including an explicit DNS server.

Do you have a "." (root) domain configured (automatically) in the DNS zones?
(If so delete it.)
All Ideas on troubleshooting this would be appreciated.

(BTW, it is listening on the internal NIC. I changed it to listen on both
NICs, but it didn't make a difference)
Click to expand...
 
Yes I have exteneded the time to 15 sec. All the nslookup has been on the
server itself, and again, if I change nslookup's server to an external
address, it resolves.

I'll check on the root domain.
 
In
Rob said:
I cannot get the internal DNS to find anything external. I have
Forwarders configured, and both the internal and external NICs
pointing to the internal DNS.

If a do a NSLOOKUP, it times out. If I do a NSLOOKUP, and change the
server to an external DNS server, it resolves.
Click to expand...

You mean you get that message saying it cannot find your server? It maybe
simply that you don't have a reverse zone.

Can you post the exact message you're getting (just copy and paste it here
please)?

Thanks


--
Regards,
Ace

Please direct all replies to the newsgroup so all can benefit.
This posting is provided "AS IS" with no warranties.

Ace Fekay, MCSE 2000, MCSE+I, MCSA, MCT, MVP
Microsoft Windows MVP - Active Directory
 
Found problem.

ISP changed their DNS servers address. Discovered this by pinging address of
the first DNS server in my list. I had been testing with the second DNS
server on my list (only because I had it memorized). Changed the order and
solved the problem.

Thanks for you input.

Rob
 
Rob said:
Yes I have exteneded the time to 15 sec. All the nslookup has been on the
server itself, and again, if I change nslookup's server to an external
address, it resolves.
Click to expand...

Ok, the reason I do this is to insure that the "server" can also
be a DNS client -- it eliminates or locates firewall issue and
insures the forwarder actually works.
I'll check on the root domain.
Click to expand...

Remember to check the "Advanced" properties if nothing else is
the problem. Seldom is this set incorrectly without you realizing it
but it could happen.

Also double check your "forwarder" if you are using one -- and
cross check that with the explicit NSLookup request.
 
Rob said:
Found problem.

ISP changed their DNS servers address. Discovered this by pinging address of
the first DNS server in my list. I had been testing with the second DNS
server on my list (only because I had it memorized). Changed the order and
solved the problem.
Click to expand...

I read this after my latest post, but I am glad the last thing I said was,
"recheck your forwarder and cross-check with NSLookup." <grin>
 
Hello,

Can you provide us with a netdiag? or at least perfom a netdiag to see is
anything else is going on?
Do you have the root zone within your DNS console? Since you mentioned that
you can configure forwarders, I take it that you don't.
What service pack level are you at?
Does the event log state anything at all?
If you restart the DNS service, does it resolve for a few minutes and then
quit?
If you clear the DNS cache, does it resolve and then quit?

301423 HOW TO: Install the Windows 2000 Support Tools to a Windows 2000
http://support.microsoft.com/?id=301423

Link to netdiag KB article.
321708 HOW TO: Use the Network Diagnostics Tool (Netdiag.exe) in Windows
2000
http://support.microsoft.com/?id=321708


Shane Brasher
MCSE (2003,2000,NT),MCSA Security, Network+, A+
Microsoft Technical Support

This posting is provided "AS IS" with no warranties, and confers no rights.
 
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