I have two dynamic ips from Comcast. One computer is connected directly to the switch-for my son's games. He has two computers in his room with separate ips. The other computers in the house are connected to the router. The cable modem is connected to the switch. I have been able to use separate ips this way. One for my son and the other IP off of the router for several other computers in the house. However, the router only has 4 ports. I want to add more computers to the router side. I want to leave my son's separate ip connected to the switch. HELP!