An IP address, which stands for Internet Protocol address, is a distinct numerical identifier given to each device participating in a computer network that uses the Internet Protocol for its communications. It plays two critical roles: pinpointing the host or network interface and specifying the device's position within the network.
IP addresses consist of a 32-bit number divided into four segments called octets, each separated by a dot. Every octet holds a decimal value from 0 to 255. For instance, a typical IP might look like 192.168.0.1. This address is split into two sections: the network segment and the host segment. The network part identifies the specific network the device is on, while the host part isolates the individual device within that network.
IP addresses primarily fall into two categories: IPv4 and IPv6.
Internet Protocol version 4, known as IPv4, is the most prevalent IP addressing format. Through a 32-bit address space, IPv4 supports around 4.3 billion unique addresses. However, with the internet's rapid expansion, IPv4 addresses have become increasingly limited.
To overcome IPv4’s constraints, Internet Protocol version 6, or IPv6, was introduced. It features a 128-bit address space, offering virtually limitless unique addresses. As more devices go online, IPv6 adoption continues to rise, meeting the demand for more addresses.
IP addresses can be either dynamic or static in nature.
Dynamic IP addresses are distributed to devices through a Dynamic Host Configuration Protocol (DHCP) server. These addresses are temporary and tend to change with each new network connection. ISPs favor dynamic IPs as they help manage address space efficiently.
Static IP addresses are those allocated manually and remain unchanged over time. Devices needing a stable address, such as servers or network printers, typically use static IPs. These addresses are less common and might incur extra charges.
Another way to categorize IP addresses is as either public or private.
Public IP addresses are distinct globally and accessible via the internet. ISPs assign these addresses, allowing devices to be recognized on the public network. Such addresses are vital for devices that must interact with other devices beyond their internal network.
Private IP addresses are intended for internal network use and cannot be accessed from the wider internet. They facilitate communication among devices within the same local network. Private IPs fall within specified ranges, like 192.168.0.0 to 192.168.255.255, and are not globally routable.
Regional internet registries (RIRs) and internet service providers (ISPs) are responsible for the allocation of IP addresses.
RIRs oversee the distribution and registration of IP addresses within designated areas. They provide ISPs with blocks of IP addresses, which are then assigned to individual customers.
ISPs supply end-users with internet access and receive IP address blocks from RIRs to meet customer demands.
IP addresses are fundamental for identifying and locating devices on networks. Available as IPv4 or IPv6, they can be either dynamic or static, public or private. A comprehensive understanding of IP addresses is essential for network administrators, ISPs, and anyone involved in computer network operations.
