If I perform an NSLookup from each of my 4 x W2k3 domain controllers to for
example www.google.com

NSLOOKUP www.google.com

2 servers return correct answers

But 2 return a 'DNS request timed out' message

Why would this be ?

"goundhog" <goundhog@discussions.microsoft.com> wrote in message
news:9B86769F-7E20-4382-AC17-3CE0AC9475C4@microsoft.com...
> If I perform an NSLookup from each of my 4 x W2k3 domain controllers to
> for
> example www.google.com
>
> NSLOOKUP www.google.com

Stick the DNS Server IP on the end of the command to do these tests
explicitly.

NSLOOKUP www.google.com Each.DNS.server.ToTest

> 2 servers return correct answers
>
> But 2 return a 'DNS request timed out' message
>
> Why would this be ?

DNS servers not working? DNS servers with firewalls?

DNS servers mutually forwarding to each other?

Intermediary firewalls?

etc.

Hi Herb

Thanks for the reply - interestingly enough - there are NO DNS issues in
our domain - all name resolution works fine - and users can browse the
Internet fine

I noticed this issue when I was troubleshooting something else

All the servers point to each other in DNS - but the 2 that can't resolve
an NSLOOKUP query are behind a different make of firewall

Why would a firewall interfere with NSLookup ?

Thanks

Scott

"goundhog" <goundhog@discussions.microsoft.com> wrote in message
news:15377E3D-4D28-4CBF-8A72-146FCA0E4346@microsoft.com...
> Hi Herb
>
> Thanks for the reply - interestingly enough - there are NO DNS issues in
> our domain - all name resolution works fine - and users can browse the
> Internet fine
>
> I noticed this issue when I was troubleshooting something else
>
> All the servers point to each other in DNS - but the 2 that can't resolve
> an NSLOOKUP query are behind a different make of firewall
>
> Why would a firewall interfere with NSLookup ?

UDP or TCP 53 requests blocked OR some firewalls limit the max
size of a UDP packet (to 512 bytes IIRC) and cause problems for
DNS server.