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) Lightning Talk: IPv6 adoption is killing my throughput

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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(Video) To IPv6 - The Dual-stack Adoption Advisory Panel


  • Networking
  • Internet
  • Internet of Things

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) IPv6 Adoption over Internet Exchanges


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.

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.

What is the main reason for using IPv6? ›

The primary function of IPv6 is to allow for more unique TCP/IP address identifiers to be created, now that we've run out of the 4.3 billion created with IPv4. This is one of the main reasons why IPv6 is such an important innovation for the Internet of Things (IoT).

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.

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 address example? ›

An IPv6 address is represented as eight groups of four hexadecimal digits, each group representing 16 bits The groups are separated by colons (:). An example of an IPv6 address is: 2001:0db8:85a3:0000:0000:8a2e:0370:7334.

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.

Why the transition to IPv6 is 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.

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.

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.

Does anyone actually use IPv6? ›

Most ISPs support it, most major websites use it, all modern network equipment natively supports it but every company I've worked at still hands out IPv4 to the clients then converts. Even where I work is a pretty big company that is quick to adopt most tech but we still use v4.

How will IPv6 impact society? ›

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.

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.

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.

How is IPv6 address generated? ›

Hosts automatically create IPv6 addresses by combining the subnet prefix with an interface ID that is generated from an interface's MAC address. In the absence of routers, a host can generate only link-local addresses. Link-local addresses can only be used for communication with nodes on the same link.

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.

Why is IPv6 replace IPv4? ›

The Internet Protocol version 6 (IPv6) is more advanced and has better features compared to IPv4. It has the capability to provide an infinite number of addresses. It is replacing IPv4 to accommodate the growing number of networks worldwide and help solve the IP address exhaustion problem.

How many IPv6 addresses are there? ›

How many IP addresses does IPv6 support? Well, without knowing the exact implementation details, we can get a rough estimate based on the fact that it uses 128 bits. So 2 to the power of 128 ends up being 340,282,366,920,938,000,000,000,000,000,000,000,000 unique IP addresses.

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.

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.

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.

What type of IPv6 address is fe80 :: 8cfl 2c42 FFDE da1c? ›

god dammit god dammit god daMMIT
What type of IPv6 address is fe80::8cf1:2c42:ffde:da1c?link local address
If a host's IPv6 address contains the network adapter's MAC address within the last 64 bits of the IPv6 address, what standard is being used?EUI-64
78 more rows

What factors are causing the transition from IPv4 to IPv6? ›

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.

What are the challenges shifting from IPv4 to IPv6? ›

Difficulty in detecting and managing unknown or unauthorized IPv6 assets on existing IPv4 production networks. The added complexity of operating parallel IPv4 and IPv6 networks. A lack of IPv6 maturity in security products. The proliferation of IPv6 and IPv4 tunnels can complicate defenses.

What are the disadvantages of making a transition from IPv4 to IPv6? ›

During the transition from IPv4 to IPv6 confusion may persist due to lack of backward compatibility. Internet service providers have to pay to support IPv6 to shuffle between different protocols thoroughly.

Why hasn't IPv6 been fully adopted yet? ›

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.

Why are we still using IPv4? ›

IPv4 was first released in 1983 and is currently widely used as an IP address for a variety of systems. It aids in the identification of systems in a network through the use of an address. The 32-bit address, which may store multiple addresses, is employed.

Is there an IPv8? ›

IPv8 is a networking layer which offers identities, communication with some robustness, and provides hooks for higher layers. For instance, our Internet-deployed reputation functions and ledger-based storage of reputation data. IPv8 is designed as a mechanism to build trust.

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.

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.

Which ISP use IPv6? ›

Top 25 internet service providers for IPv6 in United States (unique addresses, Sep 2022)
ISPUnique IPv6 addresses
1.The Constant Company12,943
2.AT&T Services, Inc.3,617
4.Comcast Cable Communications, LLC3,029
21 more rows

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.

What is one factor increasing the adoption of IPv6 network addresses? ›

The IPv4 address exhaustion was the major driver to develop IPv6. But by the time the IPv6 specification had matured, NAT was already used all over the internet, extending the lifetime of the IPv4 protocol. NAT can be deployed incrementally in the internet at a low cost while also providing some basic security.

What are the cons of IPV6? ›

Disadvantages of IPV6:
  • Creating a smooth transition from IPV4 to IPV6.
  • IPV6 is not available to machines that run IPV4.
  • Time to convert over to IPV6.
  • IPV4 is still widely used & the world is slow to convert to IPV6.
  • Any costs incurred by the user as a result of having to replace an IPV4 machine.

Can IPV6 cause DNS problems? ›

Internet Protocol Version 6 (IPv6) is the latest version of the internet protocol that identifies devices on the internet and a local network. However, IPv6 can also cause the “DNS server is not responding” issue.

What are some advantages of switching to IPV6? ›

Key benefits to IPv6 include:
  • No more NAT (Network Address Translation)
  • Auto-configuration.
  • No more private address collisions.
  • Better multicast routing.
  • Simpler header format.
  • Simplified, more efficient routing.
  • True quality of service (QoS), also called "flow labeling"
  • Built-in authentication and privacy support.

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.

How do I enable IPv6 on my router? ›

To set up a fixed IPv6 Internet connection:
  1. Launch an Internet browser from a computer or wireless device that is connected to the network.
  2. Enter the router user name and password. ...
  3. Select ADVANCED > Advanced Setup > IPv6. ...
  4. In the Internet Connection Type list, select Fixed.
16 Jul 2022

How do IPv6 addresses work? ›

Format of an IPv6 address

In precise terms, an IPv6 address is 128 bits long and is arranged in eight groups, each of which is 16 bits. Each group is expressed as four hexadecimal digits and the groups are separated by colons. An IPv6 address is split into two parts: a network and a node component.

Why does my Iphone have 3 IPv6 addresses? ›

You will get a different IPv6 address for each unique interface/MAC address. So your wifi and cellular will have two different ones. Once you VPN to a network, you will get a third IPv6.

How does IPv6 routing work? ›

Routing in IPv6 is almost identical to IPv4 routing under CIDR. The only difference is the addresses are 128-bit IPv6 addresses instead of 32-bit IPv4 addresses. With very straightforward extensions, all of IPv4's routing algorithms, such as OSPF, RIP, IDRP, IS-IS, can be used to route IPv6.

What is IPv6 vs IPv4? ›

IPv4 is a 32-Bit IP address, whereas IPv6 is a 128-Bit IP address. IPv4 is a numeric addressing method, whereas IPv6 is an alphanumeric addressing method. IPv4 binary bits are separated by a dot(.), whereas IPv6 binary bits are separated by a colon(:). IPv4 offers 12 header fields, whereas IPv6 offers 8 header fields.

What is IPv6 and IPv4? ›

An IPv4 is a 32-bit decimal address. It contains 4 octets or fields separated by 'dot', and each field is 8-bit in size. The number that each field contains should be in the range of 0-255. Whereas an IPv6 is a 128-bit hexadecimal address. It contains 8 fields separated by a colon, and each field is 16-bit in size.

What is the difference between IPv4 & 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 IPv4 and IPv6 used for? ›

IPv6 (Internet Protocol version 6) is the sixth revision to the Internet Protocol and the successor to IPv4. It functions similarly to IPv4 in that it provides the unique IP addresses necessary for Internet-enabled devices to communicate.

Why are we adapting IPv6 instead of IPv4? ›

The purpose of deploying IPv6 is to ensure network growth and continued interconnectivity when IPv4 address space becomes depleted and difficult to obtain. In addition, as the global Internet continues to expand, it is likely that an increasing number of Internet sites will only be available via IPv6.

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.

Why is IPv6 preferred over IPv4? ›

IPv6 (Internet Protocol version 6) is the next version after IPv4. Instead of the 32 bits used by IPv4 for addressing, IPv6 uses 128 bits for the same purpose - which theoretically makes it possible to assign 2 128 addresses - hence, it offers long term solutions to most of the problems that emerged while using IPv4.

Which is faster IPv4 or IPv6? ›

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.

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.

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.

Who uses IPv6? ›

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

What is IPv6 and do I need it? ›

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.

Is IPv6 more secure? ›

IPv6 Encryption

IPv6 is also more secure for name resolution. The Secure Neighbor Discovery (SEND) protocol enables cryptographic confirmation of a host's identity upon connection, making naming-based attacks more difficult.


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