An IP address is not necessary for either the wired PC/Laptop NIC nor the Etherdongle. It all works with multicast addresses and neither of them requiere and IP address to be configured. I have a wireless connection on my laptop, but use the wired port for the etherdongle. The wireless laptop connection has an IP address it gets from the router,but has nothing to do with the wired NIC. The wired NIC does not have an IP address assigned. I do not think the etherdongle even attempts to get and IP address from your router. A straight-thru patch cable may work between the computer and the etherdongle, but I'm not sure. I use a crossover cable between the ED and my laptop. Hope some of this helps.