Why Is IPv6 Adoption Slow?

Why Is IPv6 Adoption Slow?

IPv6, the most recent version of the Internet Protocol, was designed to overcome the address space limitations of IPv4, which has been overwhelmed by the explosion of the digital ecosystem. Put simply, the world will run out of IP addresses unless there is a broad switch to the new system. Although major companies like Google, Meta, Microsoft, and YouTube are gradually adopting IPv6, the overall adoption of this technologically superior protocol has been slow: As of November 2023, only 22% of websites have made the switch. What is slowing the adoption of IPv6? We at Gcore will share our theories about causes and solutions.

Why IPv6 Adoption Matters

IPv6 has a 128-bit address format that allows for a vastly larger number of unique IP addresses than its predecessor, IPv4. The latter uses a 32-bit address format and has an address catalog sufficient for only four billion devices. All devices—such as computers, smartphones, game consoles, security cameras, and smart home devices like thermostats—need their own IP address. With a looming explosion of gadgets estimated at 30 billion devices by 2030, IPv4’s limited address capacity falls short.

Enter IPv6. This new protocol version is expected to generate 340 undecillion (340 trillion³) addresses, more than enough to accommodate the projected surge of devices in the near future and beyond. In addition to expanding the address space, IPv6 offers these improvements:

  • Streamlined network management: Unlike IPv4, which requires manual configuration or external servers like DHCP (Dynamic Host Configuration Protocol,) IPv6 supports stateless address autoconfiguration (SLAAC,) which allows devices to configure their own IPv6 addresses. This is good news for the smart city, agriculture, and finance industries where multiple devices and device types work simultaneously. SLAAC reduces the need for administrators to manually assign IPs, lowering administrative overhead.
  • Efficient routing and packet processing: IPv6 has a simple header structure and provides hierarchical addressing and prefix aggregation. In simple terms, IPv6 is designed to be simple to use, organizes addresses in levels for easy sorting, and groups similar addresses together for efficient data delivery. These features together reduce the cost of packet processing, the size of routing tables, and the number of IP prefixes, bolstering routing efficiency compared to IPv4.
  • Support for new technologies: IPv6 was designed to accommodate emerging technologies such as the 5G and Internet of Things (IoT) devices of the future. It offers heightened support for quality of service (QoS) functionalities such as traffic shaping as well as packet classification, marking, and queueing—by class and traffic type—to optimize user experience. This level of sophistication in handling network traffic ensures that IPv6 will be compatible with, and highly efficient for, future technological advancements in device manufacturing.

4 Reasons for Slow IPv6 Adoption

Although IPv6 has been available for over two decades and offers several technical benefits over IPv4, it has not yet successfully replaced it. Let’s consider the major reasons for the slow adoption of IPv6.

1. IPv4 Resilience Technologies

To manage the IPv4 address scarcity problem and reduce the need for immediate transitioning to IPv6, organizations and internet service providers (ISPs) have adopted workarounds such as IPv4 leasing, network address translation (NAT,) and Classless Inter-Domain Routing (CIDR.) What do these mean?

  • IPv4 leasing enables IPv4 address holders to lease out unused space at agreed costs.
  • NAT maps multiple device IPs (from a private network) to one public IPv4 address during packet transfer.
  • CIDR removes IP address class boundaries and enables the segmentation of IPv4 address spaces into subnets to accommodate various addressing schemes.

The collective application of these technologies has drastically reduced the urgency to switch to IPv6, since these techniques continue to increase exponentially the number of devices on a single IP. However, load balancing and traffic rerouting become more cumbersome, and these solutions are still limited in the number of additional IPv4 addresses they offer.

2. Compatibility and Complexity

Most existing systems (computers, networks, routers) were designed to work with IPv4, and unfortunately, IPv6 lacks backward compatibility with these legacy systems and network devices. This means organizations might need a comprehensive network infrastructure upgrade to support IPv6, which can be a complex and expensive undertaking.

Transitioning to IPv6 may also affect customers whose devices are not IPv6-compatible. To avoid revenue loss possibly caused by customer migration to IPv4-compatible competitors, organizations can be understandably hesitant to adopt IPv6.

In addition, while IPv6’s SLAAC is generally an advantage, it does not contain the DNS information required to translate domain names easily into IP addresses.

3. Cost of Transition

As mentioned above, due to compatibility gaps, transitioning to IPv6 requires system upgrades. This could mean the purchase and deployment of new—and often expensive—network infrastructure, such as routers and switches.

The IT departments of many organizations are familiar only with IPv4 infrastructure and addresses. Adopting IPv6 will require investment in IT staff training and software migration, which can pose significant costs, especially for entities with intricate network configurations.

4. ISP Unreadiness

ISPs play a pivotal role in the transition to IPv6. However, the challenges of IPv6 incompatibility and cost inefficiency are even more pronounced due to ISPs’ slow adoption thereof. Since ISPs control large segments of the network and its associated infrastructure, organizations may consider it inefficient to transition to IPv6 at this time, especially when many ISPs lack the facilities for its effective implementation. In addition, without robust IPv6 support from ISPs, users might encounter connectivity issues or restricted access to IPv6-enabled websites, further slowing its adoption.

6 Ways to Encourage IPv6 Adoption

Several past attempts have been made to accelerate the adoption of IPv6, but they have had little success. For example, the Internet Engineering Task Force (IETF) created a now-deprecated set of working groups aimed at standardizing IPv6, ensuring its traffic routing, and facilitating its adoption through IPv4-in-IPv6 compatibility mechanisms. However, the impact of this effort and other similar initiatives has been minimal. With that being said, let’s take a look at six potential solutions for the future.

1. Synergy Between the Technical and Financial Benefits of IPV6

To promote IPv6 adoption, it’s important to emphasize to potential adopters how it can elevate technical capabilities and offer financial gains. For instance, research by the National Institute of Standards and Technology estimated the benefits of certain IPv6 use cases (such as VoIP and remote access products and services) to be over $10 billion per year globally, a persuasive motivator for IPv6 adoption. Evidence of performance improvement and more efficient network management by organizations that embraced IPv6 (like Apple and LinkedIn) further validates the advantages of the transition, both technical and financial.

2. Prioritization of the Pure/Native IPv6 Single Stack

One barrier to IPv6 adoption is the persistence of IPv4 workarounds. Phasing out these makeshift IPv4/IPv6 workarounds and prioritizing pure IPv6 is crucial to incentivize the broad adoption of IPv6.

Promoting IPv6’s advantages beyond the number of IP addresses it offers strengthens the case for a single-stack approach. For example, in addition to removing the complexities introduced by NAT, IPv6 boasts addresses in a simplified hexadecimal format and clearer demarcation between network and host portions, making it easier to route traffic and perform subnetting.

3. ISP Support

In order to provision IPv6 services, an ISP must make many changes, including address configuration, setting up routing protocols like OSPFv3 and BGP, and implementing security mechanisms such as IPsec on network infrastructure. ISPs must assign IPv6 address blocks to their customers and ensure seamless connectivity between IPv6-enabled devices. They must also ensure IPv6-compatible DNS infrastructure is available, including DNS servers that can handle AAAA records for matching domain names to IPv6 addresses. This allows users to access websites and services over IPv6 without any DNS-related barriers.

Given these complexities, ISPs also need to invest in upskilling their network engineers for efficient IPv6 deployment and management. Transitioning to IPv6 is a complex, costly process for ISPs requiring broad and deep support. That support must come from measures including infrastructure subsidies, expert contributions, and employee training. Without it, the foundations of IPv6 adoption cannot be made adequately strong for widespread adoption.

4. Government Intervention

Governments the world over can drive IPv6 adoption through awareness programs and regulations. While in the private sector IPv6 adoption is mostly voluntary, this need not be the case with government agencies, who can set the pace.

For instance, the US government has been a proponent of IPv6, having previously set mandates for federal agencies to upgrade before the end of June 2008, and is looking to achieve another milestone with new regulations: The Office of Management and Budget has mandated that by the end of 2025, 80% of IP-enabled assets on federal networks should be operating in IPv6-only environments.

Offering financial incentives to organizations that adopt IPv6 can also influence ISPs to take the necessary steps. These incentives can be in the form of tax incentives, in addition to providing the necessary tools for a smooth transition. Taiwan has announced plans to drive the adoption of IPv6 and other technological innovations through a $1 billion program. Similarly, as of June 2023, Germany has one of the highest IPv6 adoption rates at 68%, achieving this in part by obtaining a large number of IPv6 prefixes for citizens’ use.

5. Cross-Stakeholder Collaboration

Legacy systems that are not easily replaceable or upgradeable, such as on-premises hard disks, may pose challenges during the transition. Stakeholder collaboration, involving ISPs, network operators, content providers, and equipment manufacturers, can accelerate the development of best practices, technologies, and documentation for the IPv6 protocol. Sharing this knowledge and experience via quarterly reports, IPv6-centric webinars and conferences, and white papers can provide transparency during the migration process. Information sharing can additionally help key stakeholders such as ISPs, network administrators, and CDNs to address compatibility issues.

6. Thorough Testing and Ongoing Community Support

Meticulous testing of IPv6 adoptions is indispensable to identify any new issues that might arise with its increasing adoption and work toward resolving them smoothly. Stakeholders such as the Internet Society (ISOC) and IETF have organized coordinated test events in the past. As IPv6 adoption grows, ISPs and organizations such as these can foster support communities for collective troubleshooting and innovation to develop IPv6-specific technologies to optimize its use.


As the demand for IP addresses continues to rise, IPv6, with its expansive address capability, underpins the sustainable growth of IoT. Making a plan to adopt IPv6 is a wise first step to take now to position your organization for future success. However, successful transitions and accelerated adoption both hinge on the collaborative efforts of governments and key internet players.

At Gcore, we understand the importance of IPv6 adoption. Our entire infrastructure supports both IPv6 and IPv4, and we offer these options as standard to all our CDN and DNS customers. If you need help setting up IPv6, don’t hesitate to get in touch with our expert support team who will guide you through the process. You can also consult our product documentation, which includes information about using IPv6 in numerous contexts.

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