Understanding IPv4 vs. IPv6

Key takeaways

IPv4 was the first widespread internet protocol (IP) and is still in use; however, IPv6 is an improved IP that is gaining traction across platforms. 

• IPv4 is the fourth version of IP, launched in the late 1990s, but is facing a shortage of 32-bit IP addresses to meet device demand. 

• IPv6 is a newer protocol that uses 128-bit IP addresses to significantly increase the number of addresses available for new devices. 

• You can expect new devices to use IPv6, though the switch has been slow due to networking cost factors; however, the internet will continue to support both for the foreseeable future. 

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. Begin your career in IT with a Professional Certificate, such as the Google IT Support Professional Certificate. In just three months, you can build core skills in networking, computer assembly, and day-to-day IT tasks. 

What is an 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 IP suite and establishes the basic unit of data transfer as “packets.” The IP addresses and routes these packets so that they reach their destination within the network system.

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

Components of IP

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

• IP address: Each is unique for a 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 IP used for identifying devices on a network by assigning addresses to them. This was the first widespread IP distributed as the use of internet-connected devices took off in the late 1990s. 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 has essentially run out of available addresses for new devices, leading to a shortage of available IP addresses.

Pros of IPv4

• Compatible with the majority of websites

• Well-known technology

• Easy deployment

Cons of IPv4

• A limited number of unique IP addresses

• Limited scalability

• 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 feature 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

Which is faster, IPv4 or IPv6?

IPv6 is, by default, faster than IPv4 because it does not require network address translation (NAT). IPv6 also supports more efficient routing protocols due to the lack of NAT, a better neighbor discovery protocol, and simpler route aggregation. 

IPv4 vs. IPv6: Why are people switching to IPv6?

The transition from IPv4 to IPv6 started because IPv4 addresses were limited. 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 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?

Many major online platforms, like Google, Facebook, and YouTube, already have dual-stack environments that support IPv4 and IPv6. However, the adoption of IPv6 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: Skills, Education, and Salaries

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