Dotted decimal notation is a presentation format for numerical data, particularly used in the representation of IP addresses in the IPv4 (Internet Protocol version 4) system. It consists of a string of decimal numbers, each ranging from 0 to 255, separated by dots (full stops). This format divides a 32-bit numeric address into four 8-bit segments, known as octets, making the addresses more human-readable and easier to work with in network settings and configurations.
The primary use of dotted decimal notation is in computer networking, where it serves as a method to write IPv4 addresses. An IPv4 address, under this system, is commonly written using quad-dotted notation, comprising four decimal integers. Each integer represents an octet (or 8 bits) of the address, with the entire address spanning 32 bits. For example, the loopback address, typically used for testing, is represented as 127.0.0.1.
Dotted decimal notation is crucial for configuring network devices, troubleshooting network issues, and managing network connections. It simplifies the process of identifying and differentiating IP addresses for humans, as opposed to dealing directly with binary numbers. This notation is widely supported by network devices and is essential for network administrators and IT professionals.
IPv4 addresses using dotted decimal notation can also be presented in CIDR notation, where the IP address is followed by a slash and a number indicating the length of the associated routing prefix. For example, 127.0.0.1/8 specifies that the IP address has an eight-bit routing prefix.
Despite its widespread use and human readability, dotted decimal notation has limitations, such as the limited address space of IPv4, which is nearing exhaustion. This limitation has led to the development and adoption of IPv6, which uses 128 bits for addresses and is expressed in hexadecimal notation, separated by colons, to accommodate a vastly larger number of unique addresses.
In summary, dotted decimal notation is a key component in the representation and management of IPv4 addresses, making it easier for humans to read, understand, and work with IP addresses in various networking contexts.