Networking: Basics about IP address

**Abigaill** · 29-09-2010

I would like to know my IP address. I know that I can see it by typing ipconfig in cmd, or going to the website as "whatsmyip.org/" or by clicking on the "Wireless Network Connection" at the bottom right at the clock on your PC. Only problem is that it is different everywhere.

That is, the IP address in ipconfig, and on the "Wireless network connection" are the same. But it is completely different from the one I get up on the "http://www.whatsmyip.org/". Moreover, I just got a new password from a site, and the email had the IP address behind the request for new password. However, it was all together different from what appeared above. Why is it so? Is it perhaps true that one address (from "whatsmyip.org/" is the address of my router and the other (from ipconfig in cmd) is the PC's address?

If this is so, how come the site know about my IP address? If I have an address for the router, and an address for my PC, what can the rest of the internet can see? Router's address? PC's address? Or both of them?

**Big Fish** · 29-09-2010

Is it perhaps true that one address (from "whatsmyip.org/" is the address of my router and the other (from ipconfig in cmd) is the PC's address?

That's true. All computers on your local network which are connected to the router will get the same IP address on whatsmyip. Router will thus take care to distinguish between computers on your local network with the local IP addresses. IP address that the site can see is the one which comes from whatsmyip.

**Lemog** · 29-09-2010

In a standard home network, you will very often have one IP address behind the router, and a single IP address while browsing the Internet. Both of these can be different once again as they are allocated dynamically. Nevertheless, it is often the case that machines on a home network will have the same local ip address every time you turn on your machine. These are either in the range 10.0.0.x or 192.168.x.x.

**Connect_Me** · 29-09-2010

You have another router on your local network. Then the router will assign your computer an IP, usually a standard "local IP" such as 192.168.0.1 and like. But the router has an IP that has been allocated from the ISP. This however is an "Internet IP". So, in practice, your PC does not really connected to the internet, it's your router that is connected to the internet. Your PC is connected to the internet through the router and then the router will only forward the data traffic between you and other computers/servers on the Internet. At the same time the router will "translate" IP addresses automatically.

So when you check IP with ipconfig, you will see IP of the router assigned to your PC. When you go to one site that can show yours IP, you will see IP that internet provider has assigned to the router. So it's the router's IP that you can actually see when you check your "internet-IP".

**Abigaill** · 29-09-2010

So does that mean the IP will change if you reboot/reset the router ? It will therefore say that it is router address that the internet can see, while the local addresses are only seen by the router?