IPv4, or Internet Protocol version 4, is the fourth version of the Internet Protocol (IP) and it forms the foundation for the vast majority of internet traffic today. Established in 1981, IPv4 utilizes a 32-bit address scheme, allowing for approximately 4.3 billion unique addresses. Despite the emergence of IPv6, IPv4 remains the most widely used protocol for data exchange over the internet.
IPv4 addresses are typically represented in dot-decimal notation, consisting of four decimal numbers, each ranging from 0 to 255, separated by dots (e.g., 192.168.1.1). This method of addressing has enabled billions of devices to connect and communicate with each other over the internet for decades. However, with the exponential growth of the internet and the advent of the Internet of Things (IoT), the limitation of IPv4 addresses has become increasingly apparent, leading to the development and gradual adoption of IPv6.
Despite its limitations in address space, IPv4 includes features that have been fundamental to the development of the modern internet. These include the ability to fragment packets to fit smaller network links and the inclusion of a simple header which, despite its simplicity, provides robust routing functionality. IPv4 also supports various levels of Quality of Service (QoS), a critical feature for ensuring that data, voice, and video traffic is delivered efficiently.
The transition to IPv6 is underway due to its larger address space and improved security features. However, IPv4 continues to play a crucial role in today's internet infrastructure. Its widespread adoption and the vast infrastructure built around it mean that IPv4 and IPv6 are expected to coexist for many years to come, with dual-stack solutions allowing for compatibility between the two protocols.