May 20, 2023

IPv4, also known as Internet Protocol version 4, is a protocol used for identifying and communicating with computers and other devices on the internet. It is the fourth iteration of the Internet Protocol, and is still widely used today, despite being largely superseded by IPv6.


The purpose of IPv4 is to provide a common language for devices to communicate over the internet. Every device that connects to the internet is assigned a unique IPv4 address, which is used to route data from one device to another. This allows computers, smartphones, and other internet-connected devices to communicate with each other, even if they are located on opposite sides of the world.


IPv4 is used in a wide range of internet-connected devices, from desktop computers to smartphones, tablets, and other mobile devices. It is also used in servers and other network devices, such as routers and switches.

IPv4 addresses are 32-bit numbers, which are typically represented in dotted-decimal notation. This means that they are written in four groups of numbers, separated by periods. For example, the IPv4 address is commonly used as the default IP address for routers and other network devices.

IPv4 addresses are unique, meaning that no two devices on the internet can have the same IP address. This is important for ensuring that data is correctly routed to the intended recipient, and for preventing conflicts that can occur when two devices try to use the same IP address.

IPv4 addresses are also hierarchical, meaning that they are divided into different classes that indicate the network and host portions of the address. This allows network administrators to allocate IP addresses in a way that makes sense for their organization, and to manage their network more effectively.


Despite its widespread use, IPv4 has several limitations that have become increasingly problematic as the number of internet-connected devices has grown. One of the biggest limitations of IPv4 is its address space, which is limited to just over 4 billion unique addresses.

This may sound like a large number, but it is actually quite small when you consider that there are now more than 7 billion people in the world, many of whom own multiple internet-connected devices. As a result, the available pool of IPv4 addresses has been rapidly depleted, and it is now becoming difficult to allocate new addresses to devices that need them.

Another limitation of IPv4 is its lack of support for certain types of traffic, such as multicast and anycast. These types of traffic are becoming increasingly important for applications such as streaming video and other forms of real-time communication, which require the ability to send data to multiple recipients simultaneously.

Finally, IPv4 is also vulnerable to certain types of security threats, such as denial-of-service attacks and IP spoofing. These attacks can be used to disrupt network traffic or to impersonate legitimate devices on the network, which can lead to data theft or other security breaches.


To address these limitations, a new version of the Internet Protocol, called IPv6, has been developed. IPv6 uses 128-bit addresses, which provide a vastly expanded address space that can support trillions of unique devices.

IPv6 also provides improved support for multicast and anycast traffic, as well as enhanced security features that make it more resistant to attacks. However, adoption of IPv6 has been slow, due in part to the fact that it requires significant changes to network infrastructure and software.

Despite the benefits of IPv6, IPv4 will likely continue to be used for many years to come, particularly in legacy systems and devices that do not support IPv6. As a result, network administrators will need to continue to manage and maintain their IPv4 networks, while also planning for the eventual transition to IPv6.