How to Understand IP Addresses

An IP (Internet Protocol) address is a numerical sequence that uniquely identifies a given computer, or host, within a network on the Internet at a given time. To be able to use the Internet, your computer needs an IP address to identify it.

Difficulty: Easy

Instructions

Things You'll Need:

• Internet Access

1. Understand that when you log on to the Internet, your ISP (or other Internet company) typically assigns you an IP address for your current session. This address normally changes each time you dial up. If you connect to the Internet from a local-area network, like you might at work, you might have an IP address permanently assigned to your computer.

2. Realize that when you send an e-mail, access a Web page, or try to send or gather other information to or from the Internet, your Internet program looks up a target IP address (such as a Web page URL).

3. Recognize that when the target IP address is located, your IP address is sent to the target address, at which point information, such as Web page data, is sent to your address from the target.

Tips & Warnings

• The Domain Name System is what enables you to type in names (such as "www.ehow.com") instead of numerical IP addresses. (See "How to Understand the Domain Name System.")
• IP addresses are always in the format of four numbers from 0 to 255, separated by dots. A typical IP address might be "216.12.124.2". This is also referred to as a 32-bit number. Each area in the IP address represents 1 byte - 8 bits - of the computer's memory.
• IP addresses may be static or dynamic. A dynamic address is assigned only for the length of time of a given Internet session - for instance, from the time you dial up to the time you terminate your connection. A static address is assigned permanently. Most ISPs assign dynamic addresses; you get one when you dial in. DSL users have static addresses.