What is IPv4 Address and its Role in the Network?

An IPv4 address is a numerical label assigned to each device (such as a computer, smartphone, or router) connected to an Internet Protocol version 4 (IPv4) network. It serves as a unique identifier that enables devices to communicate with each other within a network and also facilitates communication between networks.

IPv4 addresses are 32-bit binary numbers, typically represented in a human-readable decimal format called "dotted-decimal notation." In this notation, an IPv4 address consists of four sets of numbers separated by periods, with each set ranging from 0 to 255. 

The role of an IPv4 address in a network is crucial. It allows devices to send and receive data packets across the internet or any TCP/IP-based network. Each device within a network, including servers, routers, and client devices, must have a unique IPv4 address to ensure proper delivery of data.

IPv4 addresses are used in several network protocols, including the Internet Protocol itself (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and many others. These protocols use the IPv4 address to route data packets from the source device to the destination device.

However, the availability of IPv4 addresses is limited due to the rapid growth of the internet and the increasing number of connected devices. To address this issue, a newer version called IPv6 (Internet Protocol version 6) was introduced, which uses 128-bit addresses and provides a significantly larger address space. IPv6 aims to overcome the limitations of IPv4 and support the ever-expanding network requirements of the modern digital era.

IPv4 Address Allocation

IPv4 address allocation refers to the process of distributing and assigning IPv4 addresses to organizations and entities that require them for their networks. The allocation of IPv4 addresses is managed by the Internet Assigned Numbers Authority (IANA) in coordination with five Regional Internet Registries (RIRs) around the world. The RIRs are:

1. American Registry for Internet Numbers (ARIN) - responsible for North America, South America, and sub-Saharan Africa.

2. Réseaux IP Européens Network Coordination Centre (RIPE NCC) - responsible for Europe, the Middle East, and Central Asia.

3. Asia-Pacific Network Information Centre (APNIC) - responsible for Asia and the Pacific region.

4. Latin American and Caribbean Internet Addresses Registry (LACNIC) - responsible for Latin America and the Caribbean region.

5. African Network Information Centre (AFRINIC) - responsible for Africa.

The process of IPv4 address allocation involves the following steps:

1. IANA Allocation: IANA initially allocates large blocks of IPv4 addresses to the RIRs, who in turn distribute them to Local Internet Registries (LIRs) within their respective regions.

2. RIR Allocation: The RIRs further allocate IPv4 address blocks to LIRs, which are typically Internet Service Providers (ISPs), large organizations, or national registries. The LIRs are responsible for managing and assigning IPv4 addresses to their customers or network users.

3. End-User Allocation: The LIRs assign smaller sub-blocks of IPv4 addresses to end-users, such as businesses, institutions, or individuals, based on their specific needs and requirements.

4. Address Assignment: The end-users configure the assigned IPv4 addresses on their network devices, such as routers, servers, and client devices, to enable communication within their networks and with other networks.

It's important to note that due to the depletion of the IPv4 address pool, the supply of new IPv4 addresses is limited. This scarcity has led to the adoption of IPv6, which provides a vastly larger address space and is intended to replace IPv4 in the long term. IPv6 adoption allows for the continued growth of internet-connected devices and the expansion of network capabilities.

Types of IPv4 Addresses

We have two types of IP addresses, namely public IP addresses and private IP addresses.