Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I installed a new modem, for which I had to enable DHCP, and ever since our network has not been able to resolve domain names in our local development environment.

If I am to log on to the server and open up a browser, the FQDN is resolved at the root of our IIS server, but any sub domains are not.

However, on network machines, whilst we have no problems connecting to the network no local domains are being resolved, including the FQDN.

NS lookup returns the default gateway address of the server, but nothing else.

I am slowly learning about DNS here, but I am trying to keep the office network up while I plod away at this, so blindly fiddling with DHCP settings doesn't help me.

Any advice would be appreciated. I've done a lot of the troubleshooting stuff already, but as this would appear to relate to the new modem and DHCP, I'm trying to target this specifically, and it's difficult to find the info I'm looking for.

This is on a Windows Server 2003, running IIS 6.0


share|improve this question

Your modem is likely pushing out DNS server settings to your clients, which is why you can't resolve local names. On one of your workstations open up a command prompt and run ipconfig /all and check to see what your DNS server(s) are set to. If they AREN'T the DNS servers for your network, you will need to change the DHCP settings on your modem to push out your network's DNS servers. Your network DNS servers should then forward non local domains queries to an external DNS server or utilize root hints.

share|improve this answer
Thanks. I should have explained further. We have a wireless router, and we also have a wireless modem (which operates through the router - wireless is disabled). The latter is the troublemaker. So we have DNS settings on the router, and DNS/DHCP on the modem. And you wonder why I get confused. If I change either, the internet goes down. – user1100149 Jan 31 '12 at 13:44

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.