Win2K Web Connection Trouble

I have a home network WIN 2K Advanced Server and all of the machines in the network connect to the web through a Linksys router for my cable modem. The WIN9x clients on the network connect to the web with no problems but the 2K and XP clients I have to reset the DHCP on them every time I want to connect and then it goes out after a couple of minutes and I have to reset it again.
All clients are using DHCP.