I have a netork with 30 desktop nodes, and three servers. All of the servers run NT4, with SP6a. All of the servers have static IP addresses, while all of the desktops use DHCP. We use a class A address range (10.0.0.*) internally, and connect to a Cisco PIX firewall to connect to the Internet across an ADSL line.
Here’s my problem:
I have noticed that some of my desktops will lose the ability to reach sites outside the firewall — but not all. For example, I am able to access TechRepublic right now to post this message. However, the desktop just outside my office can’t. I tried pinging 127.0.0.1, then pinging the PDC server, then the gateway, all successfully. I then tried pinging our mail server, which is in a DMZ between our internal network and the internet, and that was successful. However, when I tried pinging, say www.msn.com, I’d get the response “unknown host msn.com”. This message would be the same for any site name I’d input.
I have no idea what’s causing this, or how to proceed. There were no software/hardware changes from the previous day, when the desktop worked fine.
This is the third machine that has developed this problem. Please help!