IP address
An IP address (Internet Protocol address) is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication. An IP address serves two main functions: identifying the host, or network interface, and providing the location of the host in the network.
IP addresses are fundamental to the operation of the Internet. They are used by network devices, such as routers, to direct data packets to the correct destination. Just as a street address tells postal services where to deliver mail, an IP address tells network routers where to send data packets.
There are two main versions of the Internet Protocol currently in use:
- IPv4 (Internet Protocol version 4)
- IPv6 (Internet Protocol version 6)
Contents
Overview and Purpose
Every device connected to a network that uses the Internet Protocol—whether it's a computer, smartphone, server, or network printer—must have an IP address to communicate with other devices on that network or other networks, including the global Internet.
The IP address serves as an identifier for a specific device on a specific network. Routers examine the destination IP address in the header of incoming data packets to determine the best path to forward the packet towards its intended recipient.
IPv4
Internet Protocol version 4 (IPv4) is the most widely used version of the Internet Protocol. IPv4 addresses are 32-bit numbers. They are typically represented in dot-decimal notation, as four decimal numbers, each ranging from 0 to 255, separated by dots (e.g., `192.168.1.1`).
172.16.254.1
The 32-bit address space allows for approximately 4.3 billion unique addresses. Due to the massive growth of the Internet and the increasing number of connected devices, the supply of available IPv4 addresses has been depleted, leading to the development of IPv6.
IPv6
Internet Protocol version 6 (IPv6) was developed to address the limitations of IPv4, primarily the shortage of available addresses. IPv6 addresses are 128-bit numbers. They are typically represented as eight groups of four hexadecimal digits, separated by colons (e.g., `2001:0db8:85a3:0000:0000:8a2e:0370:7334`). Consecutive groups of zeros can often be abbreviated.
2001:0db8:85a3::8a2e:0370:7334
The 128-bit address space provides a vastly larger number of unique addresses (approximately $3.4 \times 10^{38}$), sufficient to accommodate the current and future growth of the Internet and connected devices.
How IP Addresses are Assigned
IP addresses can be assigned to devices in several ways:
- Static IP Address: A permanent address manually configured for a device. Static IPs are often used for servers, network printers, or other devices that need a consistent address for easy access.
- Dynamic IP Address: A temporary address assigned to a device automatically from a pool of available addresses by a DHCP server. This is the most common method for home computers, smartphones, and other client devices, as it simplifies network management. ISPs typically assign dynamic public IP addresses to home routers.
Public vs. Private IP Addresses
- Public IP Address: An IP address that is routable on the global Internet. Devices with public IP addresses can be directly accessed from anywhere on the Internet. ISPs assign public IP addresses to subscribers' network gateways (like home routers).
- Private IP Address: An IP address used within a private network (like a home network, a corporate LAN). Private IP addresses are not routable on the public Internet. Specific ranges of IP addresses are reserved for private networks (e.g., 192.168.0.0/16, 10.0.0.0/8). Devices within the same private network can communicate with each other using their private IPs. To access the public Internet, devices with private IPs typically use NAT on a router, which maps the private IP(s) to the network's single public IP address.
Importance
IP addresses are a foundational element of the Internet Protocol suite, enabling:
- Device Identification: Unique identification of millions or billions of devices on networks.
- Routing: Directing data packets across complex networks to their intended destination.
- Connectivity: Allowing devices to communicate with each other locally and globally.
See also
External links
- ARIN: IP Addresses (American Registry for Internet Numbers)
- RIPE NCC: About IPv6
