What is IPv6, and why is adoption taking so long? (2023)

IPv6 has been in the works since 1998 to address the shortfall of IP addresses available under IPv4, yet despite its efficiency and security advantages, enterprise uptake is slow

By Josh Fruhlinger

Contributing writer, Network World |

What is IPv6, and why is adoption taking so long? (2)
(Video) THE Alan Hicks - Why IPv6 Will Never Be Adopted

For the most part the dire warnings about running out of internet addresses have ceased because, slowly but surely, migration from the world of Internet Protocol Version 4 (IPv4) to IPv6 has begun, and software is in place to prevent the address apocalypse that many were predicting.

But before we see where are and where we’re going with IPv6, let’s go back to the early days of internet addressing.

What is IPv6 and why is it important?

IPv6 is the latest version of the Internet Protocol, which identifies devices across the internet so they can be located. Every device that uses the internet is identified through its own IP address in order for internet communication to work. In that respect, it’s just like the street addresses and zip codes you need to know in order to mail a letter.

The previous version, IPv4, uses a 32-bit addressing scheme to support 4.3 billion devices, which was thought to be enough at the time it was implemented. However, with the growth of the internet, personal computers, smartphones and now Internet of Things, it became clear that the world needed more addresses.

Fortunately, the Internet Engineering Task Force (IETF) recognized this nearly 25 years ago. In 1998, it created IPv6, which instead uses 128-bit addressing to support approximately 340 trillion trillion (or 2 to the 128th power). Instead of the IPv4 address method of four sets of one- to three-digit numbers, IPv6 uses eight groups of four hexadecimal digits, separated by colons.

What are the benefits of IPv6?

In its work, the IETF not only added more address space, it included enhancements to IPv6 compared with IPv4. The IPv6 protocol can handle packets more efficiently, improve performance and increase security. It enables internet service providers to reduce the size of their routing tables by making them more hierarchical.

What do IPv6 addresses look like

You're probably familiar with IPv4 addresses, which are written in four parts separated by dots like this: Each part written in conventional Base 10 numerals represents an eight-bit binary number from 0 to 255 (000000 to 1111111, written in binary).

An IPv6 address looks like this: 2620:cc:8000:1c82:544c:cc2e:f2fa:5a9b. Instead of four numbers, there are eight, and they’re separated by colons rather than commas. And yes, they are all numbers. There are letters in there because IPv6 addresses are written in hexadecimal (Base 16) notation, which means 16 different symbols are required to uniquely represent the Base 10 numbers 1-16. The ones used are numerals 0-9 plus letters A-F. Each of these numbers represents a 16-bit binary number ranging from 000000000000 to 11111111111111.

Network address translation (NAT) and IPv6

Adoption of IPv6 has been delayed in part due to network address translation (NAT), which takes private IP addresses and turns them into public IP addresses. That way a corporate machine with a private IP address can send and receive packets from machines located outside the private network that have public IP addresses.

(Video) IPv6 space, simplification, and adoption

Without NAT, large corporations with thousands or tens of thousands of computers would devour enormous quantities of public IPv4 addresses if they wanted to communicate with the outside world. But those IPv4 addresses are limited and nearing exhaustion to the point of having to be rationed.

NAT helps alleviate the problem. With NAT, thousands of privately addressed computers can be presented to the public internet by a NAT machine such as a firewall or router.

The way NAT works is when a corporate computer with a private IP address sends a packet to a public IP address outside the corporate network, it first goes to the NAT device. The NAT notes the packet’s source and destination addresses in a translation table.

The NAT changes the source address of the packet to the public-facing address of the NAT device and sends it along to the external destination. When a packet replies, the NAT translates the destination address to the private IP address of the computer that initiated the communication. This can be done so that a single public IP address can represent multiple privately addressed computers.

Who is deploying IPv6?

As of March 2022, according to Google, the IPv6 adoption rate globally is around 34%, but in the U.S. it’s at about 46%.

Carrier networks and ISPs have been the first group to start deploying IPv6 on their networks, with mobile networks leading the charge. For example, T-Mobile USA has more than 90% of its traffic going over IPv6 as of March 2002, with Verizon Wireless close behind at 82.63%. Comcast and AT&T have their networks at 70% and 73%, respectively, according to the industry group World Ipv6 Launch. The past few years have seen broader IPv6 adoption in Asia and South America, with India currently standing at about 62% and the Indian wireless carrier Reliance Jio Infocomm topping World Ipv6 Launch's network adoption charts with more than 93%.

Just under 30% of the Alexa Top 1000 websites are currently reachable over IPv6, World IPv6 Launch says, a number that has remained stubbornly stagnant over recent years.

Enterprises are trailing in deployment. For instance, a RIPE Labs report on IPv6 adoption noted that U.S. use of IPv6 actually dropped from 2020 to 2021, and speculated that the reason might be that people who had worked at home early in the COVID-19 pandemic were returning to the office and IPv4-based corporate networks.

Complexity, costs, and time needed to complete a transition are all reasons that corporate IT is gun-shy over migration projects. In addition, many medium-sized and small enterprises outsource their networking needs to service providers, who themselves don't have a strong incentive to migrate in the absence of a push from their customers.

When will more deployments occur?

Enterprise resistance to large-scale IPv6 migration is slowing adoption overall. Patrick Hunter, Charter Communications' director of IT enterprise network and telecom, lays out many of the factors in play, noting that while most network administrators know migration is inevitable, nobody wants to necessarily wants to be a pioneer if the risk is causing problems for their own networks and applications.

(Video) IPv6 seminář 2022: Story of the UK IPv6 Council (Veronika McKillop)

As he puts it, admins have the attitude of "I’m not going to break things and make life difficult just because some insist everyone should hurry to the new protocol." Not all companies are resisting—Amazon is migrating its serverless and container AWS workloads to IPv6. But inertia, plus the fact that, as noted, widespread NAT use has staved off an IPv4 apocalypse, have reduced the incentives to make the move. The transition may not be complete until 2030 or later.

Nevertheless, as the price of IPv4 addresses begin to drop, the Internet Society suggests that enterprises sell off their existing IPv4 addresses to help fund IPv6 deployment. The Massachusetts Institute of Technology has done this, according to a note posted on GitHub. The university concluded that 8 million of its IPv4 addresses were “excess” and could be sold without impacting current or future needs since it also holds 20 nonillion IPv6 addresses. (A nonillion is the numeral one followed by 30 zeroes.)

In addition, as more deployments occur, more companies will start charging for the use of IPv4 addresses, while providing IPv6 services for free. UK-based ISP Mythic Beasts says “IPv6 connectivity comes as standard,” while “IPv4 connectivity is an optional extra.”

Pushing for a faster transition will take government action, though many Western governments don't have this on their to-do list. One country moving to IPv6 in a big way is China. In 2021, the Cyberspace Administration of China unveiled an ambitious roadmap, aiming to have 800 million active IPv6 users by the end of 2025.

When will IPv4 be “shut off”?

Most of the world “ran out” of new IPv4 addresses between 2011 and 2018 – but we won’t completely be out of them as IPv4 addresses get sold and re-used, and any leftover addresses will be used for IPv6 transitions.

There’s no official switch-off date, so people shouldn’t be worried that their internet access will suddenly go away one day. As more networks transition, more content sites support IPv6 and more end users upgrade their equipment for IPv6 capabilities, the world will slowly move away from IPv4.

Why is there no IPv5?

There was an IPv5 that was also known as Internet Stream Protocol, abbreviated simply as ST. It was designed for connection-oriented communications across IP networks with the intent of supporting voice and video.

It was successful at that task, and was used experimentally. One shortcoming that undermined its popular use was its 32-bit address scheme – the same scheme used by IPv4. As a result, it had the same problem that IPv4 had – a limited number of possible IP addresses. That led to the development and eventual adoption of IPv6. Even though IPv5 was never adopted publicly, it had used up the name IPv5.

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Josh Fruhlinger is a writer and editor who lives in Los Angeles.


Copyright © 2022 IDG Communications, Inc.

The 10 most powerful companies in enterprise networking 2022

(Video) virtualUKNOF August 2021 - IPv6 Adoption Growth in UK IXes


Why do you think IPv6 deployment is occurring so slowly? ›

The reasons for the gradual adoption are simple to understand. It's expensive. The Internet is made up of tens of millions of servers, routers, and switches that were designed to work with IPv4. Upgrading that infrastructure entails a significant capital investment.

How long does an IPv6 address take? ›

An IPv6 address is 128 bits in length and consists of eight, 16-bit fields, with each field bounded by a colon. Each field must contain a hexadecimal number, in contrast to the dotted-decimal notation of IPv4 addresses.

Why is IPv6 still not widely used? ›

Since IPv6 lacks particular routing protocol support, it relies solely on static routes. As a result, it is less popular than IPv4. In IPv4, widespread use of NAT (Network Address Translation) devices allows a single NAT address to mask thousands of addresses, enhancing end-to-end integrity and performance.

What was the reason that IPv6 was introduced? ›

The main reason for the development of IPv6 was to overcome the problem of IPv4 address exhaustion. With this issue in mind, the IETF also optimized the protocol in the general sense. To understand the need for IPv6 and why it is the successor of IPv4, we'll have to cover IPv4 briefly.

What is the main factor in slow adoption of IPv6? ›

Perhaps the primary reason IPv6 has been slow to take hold is because of network address translation (NAT), which has the ability to take a collection of private IP addresses and make them public.

What is IPv6 in networking? ›

An IPv6 address is a 128-bit alphanumeric value that identifies an endpoint device in an Internet Protocol Version 6 (IPv6) network. IPv6 is the successor to a previous addressing infrastructure, IPv4, which had limitations IPv6 was designed to overcome.

Is IPv6 faster than IPv4? ›

IPv6 is faster than IPv4 in network devices because it lacks network-address translation (NAT). Using IPv6 is a better choice for people that require high speed for their network processing.

What is an example of an IPv6 address? ›

The following are examples of valid IPv6 (normal) addresses: 2001:db8:3333:4444:5555:6666:7777:8888. 2001:db8:3333:4444:CCCC:DDDD:EEEE:FFFF.

How long will it take to exhaust IPv6? ›

Will IPv6 addresses run out eventually? In practical terms, no. There are 2^128 or 340 trillion, trillion, trillion IPv6 addresses, which is more than 100 times the number of atoms on the surface of the Earth. This will be more than sufficient to support trillions of Internet devices for the forseeable future.

What is the future of IPv6? ›

The possibility of adding on to the base of IPv4 technology is costly, labor intensive and error-prone, which is why IPv6 is the way of the future. IPv6 will not change the functionality of network video products, but it will make systems run more efficiently. Consider how people used to get mail.

Who is using IPv6 currently? ›

Broadband ISP
RankISPIPv6 Users (estimated)
1Reliance Jio237,600,764
4Vodafone India18,368,165
14 more rows
6 Jun 2018

Is IPv6 really necessary? ›

Do I need an IPv6 address? No. Not right now. You can still access websites such as Google and Facebook because they support both IPv4 and IPv6.

Why are we moving from IPv4 to IPv6? ›

IPv4 to IPv6: Advantages of Migration

IPv6 helps make routing more efficient and hierarchical by reducing the routing table size. With the help of ISPs, IPv6 assembles the prefixes of various customer networks and introduces them to IPv6 internet as one common prefix. This makes the process faster and productive.

How will IPv6 impact society in the future? ›

Using IPv6 can reduce the resources required to continue to support legacy IPv4 devices, which can also simplify network management and troubleshooting in some cases. Native IPv6 traffic can be expected to perform better and more reliably than IPv4 traffic using transitional techniques.

Why did we move from IPv4 to IPv6 protocol? ›

The rationale for transition is either the lack of IPv4 address space or the required use of new features in IPv6, or both. The IPv6 specification requires 100 per cent compatibility for the existing protocols. Compatibility is also required for existing applications during the transition.

Why is the switch from IPv4 to IPv6 so difficult? ›

The first big problem with the change from IPv4 to IPv6 is that one variety of IP data can't travel on a network set up to handle the other variety.

Should I disable IPv6? ›

Some users disable IPv6 on routers or devices because they don't run any applications or services that rely on IPv6. Disabling IPv6 is also common when troubleshooting network issues. However, service providers discourage users from disabling IPv6 and warn that it may cause connectivity problems.

Will IPv6 ever happen? ›

At our current rate of progress, IPv6 will be fully implemented on May 10, 2148 | VentureBeat.

What is IPv6 in simple words? ›

Internet Protocol version 6 (IPv6) is the most recent version of the Internet Protocol (IP), the communications protocol that provides an identification and location system for computers on networks and routes traffic across the Internet.

What is IPv6 and its importance? ›

IPv6 is the “next generation” of IP, which provides a vastly expanded address space. Using IPv6, the Internet will be able to grow to millions of times its current size, in terms of the numbers of people, devices and objects connected to it1.

What are the major goals of IPv6? ›

The goal for IPv6 is to supplement and eventually replace IPv4. IPv4 uses 32-bit addresses, which means there are only approximately 4.7 billion addresses available. IPv6, on the other hand, uses 128-bit addresses, resulting in approximately 340 undecillion available addresses.

Can IPv6 cause problems? ›

IPv6 uses a 128-bit address and can provide 340 undecillion IP addresses, while IPv4 is limited to 4.3 billion IP addresses. However, IPv6 implementation by ISPs and/or network admins can lead to various leaks and security issues. This way, your personal information can potentially compromised.

How many IPv6 addresses are there? ›

IPv6 uses a 128-bit address which allows for 2128 , or approximately 3.4 x 1038 addresses. 3.4 x 1038 is equal to 340 undecillion IP addresses. Therefore, there are 340,000,000,000,000,000,000,000,000,000,000,000,000 IPv6 addresses.

Why is IPv4 still used? ›

IPv4 is still the dominant internet protocol. A key benefit of IPv4 is its ease of deployment and widespread use. Because IPv4 is used so broadly, network administrators and other internet developers can assume it is everywhere because everyone is compelled to support it. That's how widespread it is.

What are the 3 types of IPv6 addresses? ›

The three types of IPv6 addresses are: unicast, anycast, and multicast. Unicast addresses identify a single interface. Anycast addresses identify a set of interfaces in such a way that a packet sent to an anycast address is delivered to a member of the set.

Does IPv6 have private addresses? ›

IPv6 defines unique local addresses in RFC 4193, providing a very large private address space from which each organization can randomly or pseudo-randomly allocate a 40-bit prefix, each of which allows 65536 organizational subnets.

Are all IPv6 addresses public? ›

Both public and private addresses exist in IPv6, but they are totally different in definition and application.

What is an advantage of using IPv6? ›

More Efficient Routing – IPv6 reduces the size of routing tables and makes routing more efficient and hierarchical. In IPv6 networks, fragmentation is handled by the source device, rather than a router, using a protocol for discovery of the path's maximum transmission unit.

Is IPv4 going away? ›

Something IPv4 simply no longer offers to support. We can expect to see more and more ISPs, content providers and national governments wake up to this in 2021. With an almost inexhaustible amount of IP addresses, ISPs can start to discover how IPv6 can offer efficiency and affordability.

What problems IPv6 solve? ›

IPv6 is designed to solve many of the problems of the current version of the Internet Protocol suite (known as IPv4) about address depletion, security, auto-configuration, extensibility, and so on.

Why is IPv6 important for future? ›

Larger address space. The main reason IPv6 was developed was to provide a solution for the eventual exhaustion of addresses in IPv4. Unlike its predecessor, IPv6 uses four times more bits to address devices on the internet. These extra bits provide an address space for approximately 3.4 x 10^ 38 devices.

Is there an ipv7? ›

IP version 7 was chosen in 1988 by R. Ullmann as the next IP version because he incorrectly assumed that version 6 was in use for ST-II. However, ST-II had reused version 5 of the original ST protocol.

Do cell phones use IPv6? ›

Cell phones running Android 4.3 or later come with the 464xlat (a widely supported IPv6 transition mechanism) built-in, although support for Dynamic Host Configuration Protocol for IPv6 (DHCPv6) is still missing.

How much is IPv6 really used now? ›

Today, almost a decade later, only 20.9% of all websites support IPv6. Although IPv6 has been deployed for a while now, the first major version of the Internet Protocol – IPv4 – has not disappeared. On the contrary, it is still the dominant IP version.

Do all computers have IPv6 address? ›

IPv6 allows for a theoretical 340,282,366,920,938,463,463,374,607,431,768,211,456, or 340 undecillion addresses. This means that every device on the internet can have a unique IPv6 address.

How do you know if you are using IPv6? ›

Check connection status

For wired connection through a router, right-click “Ethernet”, and for wireless connection right-click “Wi-Fi”, and then click “Status”. Click “Details”. If you see an IP address for IPv6 within the window marked with a red box, you are connected to the IPv6 network.

How secure is IPv6? ›

First, the good news: IPv6 as a protocol suite isn't inherently more or less secure than its predecessor. Just as with IPv4, the vast majority of security incidents arise from design and implementation issues rather than weaknesses in the underlying technology.

What is the main difference between IPv4 and IPv6? ›

The main difference between IPv4 and IPv6 is the address size of IP addresses. The IPv4 is a 32-bit address, whereas IPv6 is a 128-bit hexadecimal address. IPv6 provides a large address space, and it contains a simple header as compared to IPv4.

What is the advantages of IPv6 over IPv4? ›

More security

Because IPv6 uses 128-bit addresses, the pool of possible addresses is 340 undecillion (3.4×1038). IPv4's 32-bit addresses allow for only 4.3 billion addresses. A bigger pool of addresses obviously means more scalability, but, less obviously, it also means increased security.

Why is it important for the Internet community as a whole to adopt IPv6? ›

The header format of IPv4 packets limits the number of possible addresses for Internet devices to 4.3 billion, already inadequate for the multitude of devices now globally networked. IPv6 increased the address field size to permit a vastly larger number of addresses, 3.4 x 1038.

What is IPv4 and why is IPv6 set to replace it? ›

IPv4 is running out of unique IP addresses, so IPv6 aims to replace it. This article explains the difference between the two and why IPv6 adoption has been so slow. IP, short for Internet Protocol, is how devices connected to the internet locate and communicate with each other.

Can we convert IPv4 to IPv6? ›

IPv4 addresses can be converted to and represented as IPv6 addresses using either the 6to4 notation or in IPv4-mapped notation.

Can IPv4 talk to IPv6? ›

Also, you do not need a separate IPv6 client to talk with an IPv6 server. You need only to port their IPv4 client application to the new IPv6 API. The client can communicate with IPv4–only servers. The client can also communicate with IPv6 servers that run on either a dual host or an IPv6–only host.

Is IPv6 fully deployed? ›

Today, almost a decade later, only 20.9% of all websites support IPv6. Although IPv6 has been deployed for a while now, the first major version of the Internet Protocol – IPv4 – has not disappeared.

Is IPv6 widely used? ›

As of April 2022 Google's statistics show IPv6 availability of its users at around 34–38% depending on the day of the week (greater on weekends). Adoption is uneven across countries and Internet service providers. Many countries have 0% use while a few have over 50% use, such as India and Germany.

Who actually uses IPv6? ›

Broadband ISP
RankISPIPv6 Users (estimated)
1Reliance Jio237,600,764
4Vodafone India18,368,165
14 more rows
6 Jun 2018

What are the challenges of IPv6? ›

And because this version of the Internet Protocol (IP) carries the internet today, it is not surprising that many are already moving to the IPv6 address system.
IPv6 issues and challenges
  • Dual-stacking.
  • Header manipulation.
  • Flooding.
  • Mobility.
10 Dec 2021

How much of the Internet is using IPv6? ›

Our reports are updated daily. IPv6 is used by 21.5% of all the websites.

What is the future of IPv6? ›

The possibility of adding on to the base of IPv4 technology is costly, labor intensive and error-prone, which is why IPv6 is the way of the future. IPv6 will not change the functionality of network video products, but it will make systems run more efficiently. Consider how people used to get mail.

What is an advantage of using IPv6? ›

More Efficient Routing – IPv6 reduces the size of routing tables and makes routing more efficient and hierarchical. In IPv6 networks, fragmentation is handled by the source device, rather than a router, using a protocol for discovery of the path's maximum transmission unit.

Does IPv6 make Internet faster? ›

An IPv6 address has extended headers four times larger than IPv4 addresses. This added feature in the IPv6 address helps reduce the overhead of packet processing and header bandwidth, making the connection much faster.


1. IPv6 Adoption over Internet Exchanges
2. UKNOF26 - IPv4 exhaustion / IPv6 adoption within UK access networks
3. What is IPv6 and why does it matter? : Episode 8
(Cisco Meraki)
4. What Is IPv6? | IPv4 versus IPv6 Explained
5. IPv6 Adoption in South Africa: Barriers, Benefits and Government Interventions
(IST-Africa Institute)
6. virtualUKNOF November 2020 - IPv6 Adoption over Internet Exchanges
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