What is IPv4?

What is IPv4?
Photo by Makarios Tang / Unsplash

Have you ever stopped to think about how the internet works and how your device can connect to websites and other devices? The answer lies in the use of IP's (internet protocols), specifically IPv4.

Key Points

IPv4 is a connectionless protocol that transmits data based on IP addresses and relies on routers to direct packets to their destination.
IPv4 has a maximum capacity of 4.3 billion unique IP addresses, which is expected to be depleted by the end of 2022.
Proper usage of IPv4 addresses can be more beneficial than moving to IPv6.

What is IPv4?

IPv4, or Internet Protocol version 4, is the foundation of the internet as we know it today. It is a connectionless protocol that doesn't establish a dedicated end-to-end connection before transmitting data. Instead, it sends data packets to their destination based on their IP address, relying on routers to direct the packets to their final destination.

But what is an IP address? It's a unique series of numbers that identifies a specific device on a network. It consists of four numbers separated by periods, with each number ranging from 0 to 255. For example, the IP address "192.168.0.1" could be used to identify a specific computer on a local network.

The Limitations of IPv4

Now, you might think, "That's all well and good, but what's the big deal about IPv4?" The main limitation of IPv4 is that it can only support a maximum of 4.3 billion unique IP addresses. With the increasing number of devices connected to the internet, the pool of available IPv4 addresses has been rapidly depleted. In fact, it's estimated that we will run out of IPv4 addresses by the end of 2022.

The Solution: IPv6

The solution to this problem is IPv6, the newer and improved version of the internet protocol. IPv6 supports a much larger number of unique IP addresses and is slowly being adopted by networks worldwide.

IPv6, the latest version of the Internet Protocol, was designed to support IPv4, its predecessor. Here are some ways that IPv6 makes this possible:

  • Dual Stack: This mechanism allows devices to run both IPv4 and IPv6 at the same time, enabling them to communicate with devices that use either protocol.
  • Tunneling: This feature encapsulates IPv6 packets inside IPv4 packets to transport them over an IPv4 network, making it possible for devices using IPv6 to communicate with devices using IPv4.
  • IPv6 over IPv4 Tunnels: This mechanism provides seamless connectivity between IPv6 and IPv4 networks by allowing IPv6 traffic to be transmitted over an IPv4 network.
  • IPv6-to-IPv4 Translation: This feature enables IPv6-only devices to communicate with IPv4-only devices by translating IPv6 packets into IPv4 packets and vice versa.

These mechanisms ensure that devices using either protocol can communicate with each other, making the transition to IPv6 smoother and more efficient. This is important because IPv6 offers many benefits over IPv4, including a larger address space, better security, and improved routing efficiency. By supporting IPv4, IPv6 makes it possible for the two protocols to coexist and for devices using either protocol to communicate with each other.

Making IPv4 Last

While IPv6 may seem like the future of the Internet Protocol, proper usage of IPv4 addresses can still be beneficial in many ways. Rather than making the costly and time-consuming move to IPv6, there are ways to make IPv4 last longer and still meet the needs of many businesses and individuals. One way to do this is through the use of Network Address Translation (NAT), which allows multiple devices to share a single IPv4 address. This can significantly extend the life of IPv4 addresses by reducing the number of addresses needed. Additionally, the use of Classless Inter-Domain Routing (CIDR) can also help conserve IPv4 addresses by allowing for more efficient use of address space. Another way to make IPv4 last longer is through the adoption of IPv6 transition technologies, which enable IPv4 and IPv6 to coexist and communicate with each other. By implementing these technologies and practicing efficient address management, IPv4 can continue to meet the needs of many businesses and individuals, while also delaying the need to switch to IPv6.

Security Benefits of IPv4

Did you know that IPv4, the Internet Protocol version 4, still offers some significant security benefits despite being an older protocol? One such benefit is the use of network address translation (NAT) which can hide the IP addresses of devices on a network, making it harder for attackers to identify and target them. This is like having an invisibility cloak for your devices! Another exciting security feature of IPv4 is the availability of firewalls and intrusion detection and prevention systems (IDS/IPS), which can help detect and block malicious traffic. And let's not forget virtual private networks (VPNs), which provide a secure way to access a network over the public internet. So, while IPv4 is not perfect and is being phased out in favor of IPv6, it still has important security features that can help keep your devices and network safe from cyber threats.


Understanding the inner workings of the internet can be a daunting task. Still, it's crucial to be a responsible and knowledgeable network administrator. So the next time you're browsing the internet or connecting to a device on your network, take a moment to appreciate the complex web of protocols and addresses that make it all possible.