19 January 2005

IP Address

The IP (Internet Protocol) address of every computer on a small network or on the giant Internet has to be unique. The IP address of a computer identifies it on the network and allows other computers to talk to it and exchange packets of data. The IP address is numeric in nature and its form is called a "dotted quad." This means that the address is composed of four sets of up to three numerals with each set separated by a period. The highest number in any set is 255. An example of an IP address is 164.128.1.12. To find out your IP address, click here.

There are two types of IP addresses – static and dynamic. A static IP address is assigned to a computer by an Internet service provider (ISP) to be its permanent address on the Internet. If you have more than one computer connected to the ISP, you need to have one static IP for each computer. If you want to connect more than one computer to the ISP, but have only one static IP, you would need a device called a router. The router allows you to share the one IP address among several computers.

It would be nice if there were enough static IP addresses for every computer on the Internet, but there are not. To get around that problem, many Internet service providers limit the number of static IP addresses they allocate and economize on the remaining number of IP addresses they possess by temporarily assigning an IP address to a requesting computer from a pool of IP addresses. The temporary IP address is called a dynamic IP address.