Pham Tien Huy presents during the IPv6 Deployment session at APNIC 60.

At APNIC 60, during the IPv6 Deployment session, several presentations explored the state of IPv6 research, deployment, and adoption - from scanning techniques and national transition strategies to operational rollouts. Together, they highlighted how IPv6 continues to evolve across research, policy, and practice, with a clear shift towards IPv6-only. This post explores those presentations.

Survey on IPv6 scanning techniques and a new target generation algorithm for IPv6 Scanning

Presenter: Ren Gang, Tsinghua University

Understanding the active IPv6 address space is critical for cybersecurity, and the challenge is the same for both defenders and attackers: How to map the active space.

Passive monitoring can reveal patterns of usage, while active scanning has been highly effective in IPv4. But with IPv6's vast space, scanning relies on smart target generation using seed data and modelling. This carries risks such as repeatedly scanning addresses that resolve to a single host.

IPv6 scanning has evolved from simple statistical models (2015) to cluster models in the early 2020s and now to Machine Learning (ML). In this presentation, Ren introduced RGen/RPattern, a real-time pattern mining algorithm that reflects the dynamics of address selection in handsets, DHCPv6, SLAAC, and NDP.

Experiments showed RGen/RPattern achieved a 58% hit rate, which is 23% higher than the current benchmark, 6Subpattern. The study also flagged ongoing difficulties with 'seedless' regions, pointing to future work in seed collection and deep learning. The key lesson: ML-based models significantly improve hit rates when scanning for active IPv6 addresses.

Watch Ren's APNIC 60 presentation now:

IPv6 and IPv6-only promotion and deployment of Viet Nam

Presenter: Nguyen Van Binh, VNNIC

As highlighted in Vu The Binh's keynote, Viet Nam is a massive regional and global success story of IPv6 penetration. The economy of 100 million people has 80 million online, with above 60% visible in the economy from independent measurement and over 80% IPv6-capable in the mobile sector, as assessed by the Viet Nam ISP industry. Nguyen Van Binh's talk drilled down into some of the approaches that have helped achieve this growth.

Viet Nam began its IPv6 journey by participating in World IPv6 Day in 2011 and committing to deploy IPv6 on a national level. By 2013, an official launch of IPv6 at VNIX in the DNS behind the Top-Level Domain (TLD) signalled continuing commitment. 2021 onwards saw a commitment to IPv6 deployment in government, leading to 94% of government agencies having IPv6 visibility.

The move to 'IPv6-only' is seen as a way to build on this history, avoid supply chain issues in IPv4, take advantage of full-stack IPv6 capability in 5G-onward telecommunications equipment, and provide for equity in the competitive Vietnamese market. An economy-wide move to IPv6 is even more compelling when coupled with increasing Internet of Things (IoT) deployment for national asset management in roads, public utilities, weather and related monitoring, as a way of managing consistency, and enabling end-to-end communications.

The roadmap targets 2027 as the 30th year of Viet Nam Internet to signal progress, and a 2030 to 2032 target for withdrawal of IPv4 from public-facing services, with a view to an IPv6-only future beyond 2032.

Much of the forward planning depends on training and public communications as inputs to policy planning and deployment in the industry. VNNIC has invested in both and continues to provide technical guidance and support towards the national strategic targets, with demonstration networks pilots deployed on LAN and Wi-Fi as IPv6-only, with NAT64 and DNS64 to allow interconnection with IPv4 resources.

VNNIC recommends that ISPs, content providers and government agencies should begin their pilots in 2025 / 2026, and that related parties, collaborating to deliver outcomes, should improve links to the National Internet Registry (NIR) and Regional Internet Registry (RIR) processes.

VNNIC is confident Viet Nam will continue to be a leading Internet economy, with significant contributions to regional technology deployment and governance. Their stated goal is to turn an IPv6-only Internet from vision to reality.

View the slides and watch the APNIC 60 presentation now.

Measuring the transition: What the data tells us about IPv6-only adoption

Presenter: Geoff Huston, APNIC

Geoff opened by recalling the early Internet era, when networks were built around costly central mainframes. Communications were expensive to manage, and edge devices were simple and wholly dependent on the centre. As the network expanded, connecting mainframes to one another, many assumed that making the network itself 'smart' was the natural path forward.

Today, the opposite is true. Edge devices are powerful, and most functions have collapsed onto a single protocol stack: Internet Protocol (IP). The future is far more likely to see IP carry everything than to see the return of specialized, separate protocols.

He noted that physical layer technology has improved by orders of magnitude. As chip density has grown (following Moore's Law), both ends of a fibre can handle far more sophisticated signal processing, unlocking greater bandwidth over longer distances. Storage has followed the same curve, with costs per byte falling sharply. Compute, storage, and bandwidth have shifted from scarcity to abundance.

This abundance has transformed content delivery. The focus is no longer on reaching the centre but on serving from the edge, reducing round-trip time, loss, and congestion. Cheap compute and storage make replication easy, enabling faster and more resilient services.

But Moore's Law is nearing its limits. As processing gains flatten, the added cost of IPv4 - particularly NAT processing and address translation in the network core - becomes harder to justify. IPv6 offers a simpler, lower-cost model, and many large providers have deployed it. For most, this has meant dual-stack; for late adopters in large economies facing expensive IPv4, an IPv6-only approach is increasingly attractive.

Geoff argued that DNS has become the new 'glue' of the Internet. It maps ephemeral IP addresses to names, masks the dual-stack nature of deployment, and reduces the urgency of moving to IPv6-only. In this model, the integrity and coherence of DNS naming matter more than routing complexity.

His conclusion: IPv6 remains essential, but the real foundation of tomorrow's Internet may be the DNS - to ensure names resolve consistently and securely, regardless of which address family lies underneath.

Watch Geoff's APNIC 60 presentation now:

IPv6 for 5G, IoT, and the industrial Internet

Presenter: Pham Tien Huy, VNPT Group

The 'Industrial Internet' refers to the ecosystem of interconnected devices, primarily sensors, that enable highly autonomous systems in modern factories and industrial environments such as mining and construction. In Viet Nam, nearly 15 million Industrial IoT devices are expected by 2027, a figure that underscores the limitations of IPv4, particularly as global IoT deployments scale into the billions.

When choosing between dual-stack and IPv6-only, both offer clear trade-offs. Dual-stack enables a smoother transition and broad compatibility, making it appear a convenient 'quick win' with flexibility and reliability. However, it also introduces greater complexity, raising operational costs for management and troubleshooting. Devices face higher CPU and memory demands, which can strain power budgets and distract from their core IoT functions. Meanwhile, networks must continue to bear the burdens of address management and CGNAT, limiting the long-term benefits.

With an IPv6-only deployment, the architecture becomes far simpler - inherently scalable, with end-to-end communication preserved without mediation. This makes it attractive as a long-term solution. However, it carries significant risks for integrating legacy systems, adds transition and deployment costs, and requires greater investment in training to ensure operator readiness. As a result, IPv6-only may be better suited as a long-term goal rather than the default for immediate deployments.

The IETF reports indicate that around half of operators currently run dual-stack, while most IPv6-only deployments are concentrated in the mobile sector. Many large economies, including Viet Nam, are planning significant IPv6-only rollouts through to 2030. This trend likely reflects the IPv6-ready supply chain underpinning 5G and future 6G technologies, from core network hardware to edge device chipsets and radio systems.

VNPT has set a 2030 target for full IPv6 transition. Since launching IPv6 for mobile in 2018, it has achieved 75% IPv6 adoption across Fibre-to-the-Home (FTTH) connections, 89% of mobile subscribers, and 100% of Internet Data Centres (IDCs) by 2025. This progress provides a strong five-year window to move toward IPv6-only service delivery.

Globally, fewer than half of devices support IPv6, which creates significant back-pressure against a fully IPv6-only Internet. Added to this are limited business incentives, capability gaps in applications, and supply shortfalls from some manufacturers, all of which represent roadblocks to a smooth transition.

On the other hand, Apple's decision in iOS 9 to implement dual-stack had a major impact on edge device IPv6 capability. While Android 12 and newer devices are fully dual-stack enabled, many older Android 11 (and earlier) devices remain in use. These can generally support dual-stack, but require more manual configuration. IoT device manufacturing resembles the Android ecosystem more than Apple's - it is highly fragmented, with significant gaps in supply chain awareness of IPv6 requirements.

The key recommendation is to foster IPv6 ecosystem growth by promoting adoption, improving training, providing industry support, and offering tax or other incentives aligned with each economy's policy goals.

View the slides and watch the APNIC 60 presentation now:

cPanel's IPv6 overhaul: Easy IPv6 for millions!

Presenter: Luke Thompson, The Network Crew Ltd

IPv6 was first deployed in cPanel in 2013, but the implementation was unconventional and challenged'. It required shared IPv6 alongside a separate range for each hosted service, with numerous dependencies patched to maintain stability.

A seven-year effort has now delivered a cleaner, more robust re-implementation.

From 2017, developers adopted a /64 per hosting environment and a /128 per tenant, deliberately omitting a reservation model to simplify management. cPanel and WebHost Manager (WHM), sold by Nick Kostn Jr, have since grown significantly alongside alternative management systems. Today, over one million sites run on cPanel and WHM globally, with only a small fraction using dual-stack.

The Network Crew (TNC) collaborated with WebPros and APNIC to achieve a 'KISS' (Keep It Simple, Silly) outcome, minimizing complexity. APNIC's Technical Assistance Program (TAP) provided guidance on IPv6 address management best practices during the software development process.

TNC relocated to a NEXTDC data centre, requiring coordinated changes to switches, routers, hypervizors, Proxmox, and cPanel deployments. The move stressed the live environment, providing real-world testing of system changes that directly informed ongoing software development.

Global Secure Layer's network engineers played a key role, guiding deployment and ensuring the underlying network was ready for safe operation. After acquiring an IPv4 /23 in 2018, TNC immediately received a /32 IPv6 prefix delegation from APNIC. This larger allocation provided ample 'slice-and-dice' flexibility, allowing client hosts to receive a /96 instead of the /128 originally assumed in the first cPanel IPv6 model.

The deployment prompted a re-evaluation of longstanding bugs in NGINX and CloudLinux, and testing of sub-prefix delegation revealed additional issues. Kernel bugs in Proxmox led to a switch to VirtIO, while RouterOS, VRRP, and iBGP configurations were updated to support the new network model. Path loss and failover behaviours were thoroughly tested, and Dell NOS switch management systems were replaced with HPE for simplicity and reliability.

The changes have now been fully tested in live deployment and officially released. IPv6 dual-stack is fully operational, with allocations rationalized: /64 per network segment, /96 per customer tenancy and location, and /128 per individual website. This also allows emails to be tracked by /96 prefixes, enabling SPF and DKIM to isolate potential email issues without affecting other customers.

Watch Luke's APNIC 60 presentation now:

Closing thoughts

From research advances in IPv6 scanning, to Viet Nam's national roadmap, to operational lessons from cPanel, the presentations during this session at APNIC 60 underscored both the progress made and the challenges ahead. IPv6 is no longer a theoretical upgrade, it is a critical enabler for the next phase of Internet growth.

The views expressed by the authors of this blog are their own and do not necessarily reflect the views of APNIC. Please note a Code of Conduct applies to this blog.