[SOLVED] At least for the most part - the immediate solution was to set my CentOS box to a static IP address and then connect it directly to the modem. Once that worked, I moved my machine's connection back to the router, but since the router's WAN connection settings don't seem to work (at all), I just plugged the modem and the Windows box into the router's LAN ports. Once I gave the Windows box it's own static IP address as well, both machines seem to be happy and can access the web through the router-acting-as-a-switch. Many thanks to JohnS for pointing and then guiding me in the right direction. Mark