Detailed IPv6 Adoption Review

5 min read
10 September 2021
Vincentas Grinius

The past, the present and the future of IPv6.

IPv6 adoption

IPv6 adoption has been a big topic in the industry since IPv6 inception. Internet Protocol version 6 is a communication protocol that enables sending and receiving packets of information. Billions of internet-connected devices, including personal computers or mobile devices, rely on IPv6.

Major websites and internet service providers (ISPs) enable IPv6, and the IPv6 internet society is growing; however, this growth is not as smooth as intended. IPv6 was first introduced in 1995. June 8, 2011, was declared the World IPv6 Day, and major companies across the globe enabled IPv6 on their websites for 24 hours.

Today, global IPv6 adoption doesn’t even reach 20%. What is the current IPv6 adoption progress, and what are the most significant IPv6 adoption challenges? Our detailed IPv6 adoption review provides answers to these questions.

What is IPv6, and how was it introduced?

IPv6 is an alternative to IPv4, developed by the Internet Engineering Task Force (IETF) to address the imminent IPv4 exhaustion. The initial plan was for IPv6 to replace IPv4; however, that hasn’t happened, primarily due to technical and financial constraints.

An IPv6 address is 128-bits long and has eight groups of hexadecimal characters separated by colons. There are nearly 4.3 billion IP addresses in the IPv4 infrastructure. The IPv6 infrastructure has approximately 3.4×1038 IP addresses, which is 340 undecillion, or 340 trillion trillion trillion. 

IPv6 possesses features that IPv4 does not, and the most significant benefit of IPv6 is the level of performance and security that IPv4 cannot match. IPv6 requires the use of IPsec, and it has a more straightforward packet header. Furthermore, the header extension can extend the protocol without affecting the core packet structure.

While IPv6 may be superior in some regard, the technical differences cause obstacles, preventing IPv4 and IPv6 from communicating directly.

IPv6 address anatomy with hexadecimal and binary notations.
IPv6 address anatomy

What about IPv5?

IPv5, also known as the Internet Stream Protocol (ST), was an experimental protocol, first defined in 1979. Although it went through revisions and updates, it was never implemented for public use.

IPv5 was primarily designed as a transport protocol for the Network Voice Protocol (NVP). Its purpose was to expand IPv4 with the capability to transport human speech, similarly to the Voice-over-Internet Protocol (VoIP) that emerged in 1995.

The failure of IPv5 was completely technical, and the main problems stemmed from QoS (Quality of Service) related obstacles as well as massive CPU and memory consumption. The IPv5 test phase lasted almost 20 years, which is close to the current duration of IPv6 adoption.

The IETF has drafted IPv7 and IPv8 concepts as well; however, they are purely experimental and will not be deployed for public use, just like IPv5. 

Internet Protocol Development Roadmap
Internet Protocol development roadmap

IPv6 adoption progress

According to Google’s IPv6 Adoption statistics, the availability of IPv6 connectivity among Google users reached 37% in August 2021. IPv6 adoption by country statistics show that India leads with 61%, while Germany is in second place with 49% of IPv6 adoption. 119 countries have initiated IPv6 deployment; however, the remaining haven’t yet introduced IPv6 to their networks.

There’s clear progress in IPv6 adoption in Asian and South American countries, while African countries are yet to make any notable jumps. Reliance Jio Infocomm Ltd., an Indian mobile operator, is at the top of the list of network operators adopting IPv6 globally. In August 2021, it was at 91.43% in IPv6 adoption. T-Mobile USA, the operator that leads IPv6 adoption in the US, ranks 6th with around 91.21% of IPv6 introduced to their network.

Some of the biggest telecom companies in the US have already adopted significant IPv6 resources to their networks. This advancement comes from sheer necessity and scalability issues caused by the IPv4 shortage. Unfortunately, companies run into problems related to Network Address Translation (NAT) and the dual-stack environment.

Furthermore, although most IPv6 deployment occurs in the telecom industry, many web servers are still running IPv4. At the time of publication, the usage statistics of IPv6 as a site element on the web showed a 19.4% IPv6 adoption rate.

Biggest challenges adopting IPv6

These are some of the most common issues concerning IPv6:

  • Medium-sized enterprises, commercial companies and small businesses are not ready for IPv6. They usually outsource service providers to handle new technology, which means they might not have dedicated teams to handle the move from IPv4 to IPv6. Unfortunately, IPv6 deployment is not attractive because of the required costs and time. 
  • Customers are not pushing for change. If customers do not understand or care about IPv6, companies are unlikely to find the motivation to move forward. Especially since shifting to IPv6 comes with technical obstacles, which might lead to endless complaints from users.
  • ISPs are not ready to support IPv6 traffic. Some internet service providers might not be ready to handle IPv6 routing protocols, translate IPv4-only websites into IPv6 or support IPv6 DNS resolution. It is possible to hire a secondary ISP to enable IPv6 communications from a website. Unfortunately, this is not a cheap solution.
  • An IPv4 router cannot be upgraded to an IPv6 router. Not all routers are IPv6-compatible, which means businesses might need to replace equipment, which is never convenient or cost-efficient. A solution to this problem would be wiring an IPv6 router next to an IPv4 router. In this setup, it is possible to perform tunneling; however, that is not the safest solution.
  • IPv4/IPv6 tunneling mechanism is vulnerable. IPv6 over IPv4 tunneling encapsulates IPv6 packets within IPv4 headers, which is how packets are carried over to the IPv6 routing infrastructure. However, routers do not check the content of the packets. Furthermore, addresses of IPv6 hosts and relay routers are vulnerable to spoofing

Main differences of IPv6

IPv6 should have replaced IPv4. While the latter continues to support most of the internet today, if we compare IPv4 vs. IPv6, the latter is the more advantageous Internet Protocol in several regards.

  • IPsec. IP Security suite is integrated into IPv6, which provides enhanced data security and authentication. While IPsec is available for the IPv4 infrastructure as well, its use is not required. If appropriate security is not configured for IPv4, IPv6 is, by default, much safer. 
  • IPv6 doesn’t require NAT. Network Address Translation prolongs the lifespan of IPv4 addresses. With the help of this technology, it is possible to use one IP address to represent a group of computers outside the network. The IPv6 infrastructure has enough IP addresses, and it doesn’t require NAT.
  • Auto-configuration. With IPv4, you need to configure a new system if you want it to communicate with others. IPv6 doesn’t require that. While there’s still the option to perform manual configuration, IPv6 devices can self-configure using IPv6 stateless auto-configuration.
  • Efficient multicast routing. IPv4 uses IGMP (Internet Group Management Protocol) to manage communication between hosts and multicast groups. IPv6 uses MLD (Multicast Listener Discovery) instead. With the help of multicast, it is possible to ensure that bandwidth-heavy packet flows go to multiple destinations simultaneously.
  • Simplified header format. The IPv4 header length can vary between 20 to 60 bytes. The IPv6 header is simplified and is always 40 bytes. This IPv6 header has no options, but additional extension headers exist.
  • Simplified routing. The size of the IPv6 routing table has reduced, which leads to simplified and more efficient routing

Will IPv6 become a major protocol?

It is not yet clear how IPv6 will evolve. Some believe that IPv6 will completely replace IPv4. Others trust that IPv6 will exist as a parallel internet and dominate IoT and automotive industries. Overall, there’s little evidence suggesting that IPv6 will disintegrate. 

Looking at the statistics, we can see that many telecoms are heavily adopting IPv6, despite the fact that web servers are still at the early stage of IPv6 adoption. Due to this, we might need IPv4 as a necessary resource for the end-user, the home internet user.

All in all, it is unlikely that IPv6 will replace IPv4 completely in the near future because many countries are yet to start the IPv6 deployment process, which is highly time-consuming and presents significant technical boundaries.

Watch our webinar to learn more.

IPXO Webinar: When Will IPv6 Replace IPv4?

About the author

Vincentas Grinius


Vincentas is a business-driven geek with over 15+ years of network, infrastructure and internet policy experience. As a CEO at IPXO, the Internet Protocol platform, Vincentas focuses on helping address complex network management issues and the global IPv4 shortage.
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