I see what your saying and that's why we had to go get a router a few years back. My pc, sisters, dad and mom share.

What I don't understand is how could my ISP think I'm using too many addresses when the cable modem can only except one cat5 at a time. And how would this explain me being able to get on the net minus the router with both my pc and then my sisters only a few minutes later. Are they able to differentiate between different pc's here at the house by the mac address/host name or something?