Understanding IPv4 vs. IPv6

The internet has grown rapidly over the last decade, with 5.4 billion users worldwide in 2023, representing 67 percent of the global population, according to Statista [1]. Because of this, internet protocols (IP) have had to shift and adapt to meet new demands. While IPv4 started as the mainstream IP and is still used globally, IPv6 is a new and potentially improved IP that is increasingly gaining traction across platforms. 

Understanding the differences between IPv4 and IPv6 can help you better understand the internet and how it functions. Explore what makes each version unique, why the shift from IPv4 to IPv6 is happening, and what benefits and drawbacks you might find associated with each version.

What is an internet protocol?

The Internet Protocol (IP) is a set of rules and conventions for sending and receiving data packets over networks, including the internet. It serves as the fundamental communications protocol in the internet protocol suite and establishes the basic unit of data transfer as “packets.” The internet protocol addresses and routes these packets so that they reach their destination within the network system.

IP functions at the network layer of the OSI (open systems interconnection) model, providing identification for each device.

Read more: What Is TCP/IP?

Components of IP

Some common components you may hear referenced regarding internet protocols include the following. 

• IP address: are unique for each device connected to the internet or each group of devices connected to the internet. Depending on the network configurations, this address can either be static (permanent) or dynamic (temporary).

• Packet: Smaller pieces of data are handled as packets for more efficient routing and transfer.

• Routing: The IP address allows packets to route to their end destination correctly.

• Connectionless: IP is a connectionless protocol, meaning it doesn’t establish a dedicated end-to-end connection in the call. Each packet is an independent entity.

What is IPv4?

IPv4 (internet protocol version 4) is the fourth version of the internet protocol used for identifying devices on a network by assigning addresses to them. This was the first widespread internet protocol distributed as the use of internet-connected devices took off in the late 1900s. It employs a 32-bit numerical address format, leading to 4.3 billion available unique IP addresses. Because of the increasing number of internet-connected devices, IPv4 ran out of available addresses for new devices, leading to a shortage of available IP.

Pros of IPv4

• Simple and easy access to internet systems

• Compatible with the majority of websites

• Well-known technology

• Easy deployment

Cons of IPv4

• A limited number of unique IP addresses

• Limited scalability

• Limited IP addresses available abroad

• Lack of inherent internet security measures

What is IPv6?

IPv6 (internet protocol version 6) is an upgrade to IPv4, offering 128-bit IP addresses. With almost 340 undecillion (3.4 x 10^38) unique addresses, IPv6 solves the problem of address scarcity. IPv6 also introduces routing, network configuration, and security features enhancements over its predecessor. The protocol is more efficient, making it better suited for the modern internet landscape where countless IoT devices and high-demand services like streaming and cloud computing are common.

Pros of IPv6

• Larger number of IP addresses

• Stateless address autoconfiguration

• Improved performance outside the US

• One routable IP address representing an entire network

• Easier use of DHCPv6

Cons of IPv6

• Not yet universally supported

• Addresses are longer to support more addresses

• Expensive switch to new routing equipment

Why are people switching to IPv6?

The transition from IPv4 to IPv6 started because of limited IPv4 addresses. IPv4 provided nearly 4.3 billion available addresses, creating what seemed like a limitless supply of available addresses. However, with the internet’s explosion in popularity and the surge in connected devices, this available pool of IP addresses quickly decreased in size before running out in 2015. 

Techniques such as network address translation (NAT) enabled multiple devices to share a single IP address to cope with the shortfall. This means every device in your home or private network could have one IP address. While NAT provided temporary relief, it also introduced complexities that affect end-to-end connectivity.

In addition to offering vastly expanded address space, IPv6 offers several other benefits. For starters, IPv6 simplifies routing, which could lead to a more efficient Internet. The protocol also requires integral security features that were previously not required for IPv4. In addition, IPv6 can handle larger data payloads, improving the overall performance of network communications.

How quickly will the adoption of IPv6 happen?

While many major online platforms like Google, Facebook, and YouTube have fully migrated to IPv6, its adoption has been inconsistent across different sectors. Many enterprises have transitioned slowly due to the cost and network changes associated with updating existing network infrastructure. As a result, the majority of internet service providers (ISPs) and mobile operators currently support both IPv4 and IPv6 in a dual-stack operation. This ensures they can serve both older devices and networks that rely on IPv4 and newer ones that use IPv6.

The future of IPv6

Various initiatives, including mandates from governments and large organizations, are accelerating the transition to IPv6. However, IPv4 is not going to vanish overnight. The internet will continue to support both protocols for a foreseeable period. Over time, as IPv6 adoption becomes more widespread, many people expect the balance will tip increasingly in its favor, allowing for the continued expansion and evolution of the internet.

Read more: Entry-Level IT Support Jobs Overview: Skills, Education, Salaries

Getting started on Coursera

The popularity of the internet continues to expand globally, making knowledge of the adoption of IPv6 from IPv4 essential for many up-and-coming career fields. You can continue to boost your understanding of internet protocols with up-to-date courses offered by industry and academic professionals on Coursera. 

Consider starting with the Google IT Automation with Python Professional Certificate to build knowledge in relevant areas, such as configuration management, troubleshooting and debugging, and automation, at your own pace. Suitable for beginners, this six-course series is designed to help you gain essential knowledge and skills like working with Python scripts, using Git and GitHub for version control, and analyzing and troubleshooting real-world IT problems. To learn more about TCP/IP try the Introduction to TCP/IP from Yonsei Univerisity, also found on Coursera.