Actually, if you feed your network through a router, all PCs appear to have the same IP online. Although each PC obviously can't have it's own, the router masks it.
I am on a four-PC network, according to the router my IP is 82.47.89.46, however.. my personal IP is something totally different. So, yeah.. he is right- if he is running his network through a router, all PCs will appear to have the same IP.