IPv4

IPv4 stands for Internet Protocol version 4, which is a set of rules for sending and receiving data over the internet. It was the first version of the internet protocol to be widely used and forms the foundation of most internet communications today.

An IPv4 address is a unique identifier assigned to each device connected to a network. This address enables devices like computers, smartphones, and servers to find and communicate with each other. An IPv4 address consists of four numbers separated by periods, with each number ranging from 0 to 255. For example, an IPv4 address might look like this: 192.168.1.1.

Each of these four numbers in the IPv4 address is called an octet, and together they create a 32-bit number. Because of this 32-bit structure, IPv4 can support around 4.3 billion unique addresses. While this might seem like a lot, the explosion of internet-connected devices has led to a shortage of available IPv4 addresses.

IPv4 addresses are divided into different classes based on their range and the size of the networks they support. The most commonly used classes are Class A, Class B, and Class C. Each class has a different default subnet mask, which is used to separate the network portion of the address from the host portion. For example, a Class A address has a default subnet mask of 255.0.0.0, meaning the first octet identifies the network, and the remaining three identify individual devices on that network.

IPv4 also supports techniques like subnetting and CIDR (Classless Inter-Domain Routing) to efficiently use the available address space and manage large networks. Subnetting divides a single network into smaller, more manageable pieces, while CIDR allows more flexible allocation of IP addresses.

While IPv4 has been incredibly successful, its limitations have led to the development of a new protocol called IPv6, which offers a much larger address space. However, IPv4 remains in widespread use and continues to be essential for many aspects of internet operations.