If you look at your router's configuration page, you should be able to find a page with the allocation for each computer - it'll probably be labled DHCP. In this way, you can reuse more or less the whole address space of IP in your intranet without colliding with a valuable global address. For incoming traffic, it catches the return packets, and routes them to the correct internal address. There are several ways to find a routers public IP address, but sites like IP Chicken,, , or make this easy.
So every computer's traffic appears to come from that one IP address. It passes all that traffic along the one link with the one global IP address provided by your ISP. That way is NAT, or Network Address Translation.Įssentially your router hands out IPs to every machine in your space - office, house, whatever - and handles all traffic behind itself. The reason is that there is a finite number of IPs in the world, so there has to be some way of conserving them. If there is any box at all in between your computer and your ISP, your computer will probably have a different IP. This is very unusual, that a (non-server) computer is directly connected to the internet as a whole. Unless you are connecting directly to your ISP - no router, no wireless - this would not be what shows up in ipconfig. will show you the address that your ISP has provided to you: this is the IP address that everyone else in the world can see, and the one that is blocked.