IP Address

Also known as an "IP number" or simply an "IP," this is a code made up of numbers separated by three dots that identifies a particular computer on the Internet. Every computer, whether it be a Web server or the computer you're using right now, requires an IP address to connect to the Internet. IP addresses consists of four sets of numbers from 0 to 255, separated by three dots. For example "66.72.98.236" or "216.239.115.148". Your Internet Service Provider (ISP), will assign you either a static IP address (which is always the same) or a dynamic IP address, (which changes everytime you log on). ISPs typically assign dial-up users a dynamic IP address each time they sign on because it reduces the number of IP addresses they must register. However, if you connect to the Internet through a network or broadband connection, it is more likely that you have a static IP address.

To find out what your computer's IP address is, click here.

ISPs and organizations usually apply to the InterNIC for a range of IP addresses so that all their clients have similar addresses. There are three classes of IP address sets that can be registered: Class C, which consists of 255 IP addresses, class B, which contains 65,000 IP addresses, and class A, which includes hundreds of thousands of IP addresses. Because there are so many computers now connected to the Internet, the InterNIC is actually running out of IP addresses. Therefore, Class A and Class B address blocks are very hard, if not impossible, to get. Most large companies have to register multiple Class C addresses instead. To resolve this problem, the Internet Engineering Task Force, which created the original IP address standard, is working on a new protocol called "IP Next Generation" or "IPng."

Published: 2002