Hi We have a network of about 100 workstations that have dedicated T1 internet connections. For some reason I am having DNS resolution problems. Just about everyday someone calls and they say they cannot get online. It does not affect the entire network at once and I have found that when they cannot access a site by hostname an IP address of a website will go through. Then, after the site pulls up by IPaddress they can once again access any site by host name. We all access the internet through the same router and have the same TCP/IP settings as far as DNS addresses and default gateways go. What has me stumped is that when one user cannot access anything online by hostname I can on another workstation. I have tried using a different DNS Server address and that has not worked. I have verified the router configuration. Not sure what my next step should be? Anyone ever had this problem? We only have one subnet on our network 10.1.1.~ subnet. Only the one router that acts as the gateway to the Internet. Thanks in advance.

The last time i seen similar strange dns problem, it was caused by the router. router was not protected by a ups and then was possibly affected by a power failure. Router trouble result in lost of UDP packets (mostly dns packets). For mysterious unknown reason, it corrupt the NIC (intel pro 100).

I found the problem. In TCP/IP settings I was using a second address of our dial up gateway for both the IP Gateway and DNS resolution address for redundency. The problem is that the Dialup connection is down more than up and I was under the impression that Windows only used those second addresses if the primary address (T1 gateway) went down. Once I removed the secondary IP gateway and secondary DNS address of the modem server we stopped loosing connenctivity.