IPv6 Development in China and Tencent Cloud's Large-Scale Transformation Practice

This article discusses the development history of IPv6 in China and Tencent Cloud's IPv6 transformation practice. Since RIPE NCC first allocated IPv6 addresses in 1999, China has undergone a challenging journey in IPv6 adoption, with usage rates remaining below 2% for years. In 2017, the Chinese government issued the "Action Plan for Promoting Internet Protocol Version 6 (IPv6) Scale Deployment," marking a significant policy push. By 2019, key milestones included the Ministry of Industry and Information Technology's IPv6 readiness initiative, the establishment of an IPv6 root server in Nansha, and the formal depletion of all 4.3 billion IPv4 addresses globally.

Tencent Cloud faced enormous challenges in IPv6 transformation due to its complex product ecosystem spanning over 50 categories and 100+ sub-products. The transformation roadmap was executed in four phases: (1) IPv6 NAT64 transition technology with DNS support, (2) dual-stack support for VPC, subnets, cloud servers, ENIs, and CLB, (3) dual-stack support for DDoS protection, security groups, IP library, WAF, and HTTPDNS, (4) dual-stack support for IaaS and PaaS products including CDB, COS, and API Gateway.

Key technical innovations include: developing a next-generation SDN controller supporting IPv4/IPv6 dual-stack for managing millions of VPCs, implementing a four-dimensional intelligent defense system (Zeus) for IPv6 DDoS protection using /56 address block storage and query optimization, and creating an intelligent IPv6 address management system for automated address allocation, configuration, monitoring, and recovery. The project "Mobile Internet IPv6 Technology Research and Large-Scale Application" won the 2019 China Communications Society Science and Technology Award First Prize. As of 2019, Tencent Cloud has completed IPv6 transformation for over 40 products including cloud hosts, VPC networks, load balancing, and CDN, supporting over 150 million IPv6 users.