trying to debug a "broadband" setup (because your LAN setup will be "debugged" before you even try adding "broadband" into the mix)! One way to accomplish this, is to buy or build a "router" with "NAT" (Network Address Translation) ability, that knows how to work with an external modem (as well as the more "normal" broadband/ethernet connection). If your LAN is "small enough" (5 machines max using the internet), and you
Gifford dial up intenet access, Gifford, WA up intenet access dial Gifford
Gifford up intenet access, dial Washington, Gifford dial up intenet access