What is an IP Address?

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Definition: An IP address is a binary number that uniquely identifies computers and other devices on a TCP/IP network.

Administrators set up and manage the IP addressing scheme for their networks. When troubleshooting connection problems, users of computer networks also should be familiar with how to find their IP address and reset it if necessary.

IP Address Standards and Notation

Two IP addressing standards are in use today.

The IPv4 standard is most familiar to people and supported everywhere on the Internet, but the newer IPv6 standard is gradually replacing it. IPv4 addresses consist of four bytes (32 bits), while IPv6 addresses are 16 bytes (128 bits) long.

An IPv4 address consists of a set of four numbers, each between 0 and 255. Computers store and work with an IP address as one combined (binary) value, but network devices displays them in human-readable forms. IPv4 uses dots to separate the individual numbers that range from to  IPv6 uses colons instead of dots to separate the numbers and also uses hexadecimal rather than decimal digits.

More: Internet Protocol Address Notation Explained

Public and Private IP Addresses

An IP address can be private - for use on a local area network (LAN), or public - for use on the Internet or other wide area network (WAN). IP addresses can be determined statically (assigned to a computer by a system administrator) or dynamically (assigned by another device on the network on demand).

More: What is a Public IP Address?, What is a Private IP Address?

Working With a Device's IP Address

Every device connected to an IP network - including computers, phones, printers, and Internet of Things gadgets, receives an IP address. Some devices like network routers can even have multiple addresses - one for each active network interface.

How to look up an IP address in use varies depending on the device but generally involve navigating through system settings menus. In a troubleshooting scenario, experienced users can look at their client IP address and verify whether it is valid for the network they are trying to use. Users can also sometimes restore a broken connection by learning how to release and renew their device's IP address.Being familiar with IP lookup and renewal procedures comes in handy when calling computer tech support personnel as they may need the user to walk through these steps to get their device back online.

IP geolocation technology enables Web sites to roughly determine a person's country and city location by the IP addresses their network is using. Sites sometimes use this information to control the kinds of content and advertising a user sees online. Some users prefer greater anonymity online and take steps to hide their IP address and avoid this kind of tracking.

More: Finding, Changing and Hiding an IP Address Tutorial

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