No DNS Resolution at all...

[ktigre]

I have a Windows NT 4.0 PC that just will not do names resolution. I can ping any IP, but beyond that I can't ping

http://www.microsoft.com,

I get bad IP. I have DNS servers specified in TCP/IP, the hosts file still has localhost in it, I've tried reinstalling the network components, gone through a fair amount of the registry comparing with a good machine that can access the internet and ping successfully, and they seem identical. The only thing I noticed is I did a Netmon trace and it never seems to do a DNS request. it does however to a NCP request for

http://www.microsoft.com.dallas

(dallas is the users current login context)

The only other thing of note is it was working previously, however we were using a proxy server for internet access with an old interceptor firewall. We are now using a Cisco Pix 525 with Websense. The problem started when we made this changeover, but we cannot take it back.

Anyone have any other things for me to try? I'm trying to avoid having to rebuild the PC because other than being able to get on the internet, it's working flawlessly.

Thanks.

 

[FilthPig]

Make sure your firewall has port 53 (DNS) open to outgoing traffic. Marc Creviere

 

[ktigre]

Actually there are 4 PC's doing this, and then we have 350+ that access the internet perfectly. I know the problem is local to the PC, but can't seem to find out what.

 

[FilthPig]

Hrm.. If you're using DHCP, check and make sure it doesn't have another (invalid) DNS server specified, since manually entered values override DHCP. What does nslookup return? Marc Creviere

 

[ktigre]

I SOLVED IT!!!

I used Regmon from Sysinternals and found that the key TCP existed under HKLM\System\CCS\Services. The PC was hitting this key, looking for the Parameters folder under it, found it and then couldn't find the DHCPNameServer key under that. I removed the TCP key and it then jumped over the TCP key and found the name server entry and started doing lookups.