you are 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),
