On 21 June 2023, the National Information Security Standardization Technical Committee (SAC/TC260) published the Guidelines for Practice of Cybersecurity Standard – IPv6 Address Assignment and Coding Rules – Interface Identifier. The Guidelines put forward the encoding methods and implementation requirements for IPv6 address interface identifiers (IID), aiming to provide guidance and reference for the activities of Internet access service providers and other relevant entities that dynamically assign IPv6 address IID through IPv6 networks.

The Guidelines propose two IPv6 IID encoding methods: the EUI-64 (64-bit Extended Unique Identifier) encoding method, and the cryptographic transformation encoding method. The former, with reference to IETF RFC 4291, applies to both the IID encoding when assigning IPv6 addresses to network terminals via DHCPv6 (Dynamic Host Configuration Protocol for IPv6) as well as the IID encoding generated by network terminals through SLAAC (Stateless Address Auto-configuration); the latter applies only to IID encoding when assigning IPv6 addresses to network terminals via DHCPv6.

In terms of implementation, the document states that

  • The two aforementioned encoding methods shall be adopted when operators such as Internet access service providers, application infrastructure service providers, and self-use network operators allocate IPv6 addresses that include IID to network terminals through DHCPv6;
  • IPv6 address allocation software and hardware should support the above encoding methods;
  • Network terminals should support DHCPv6 protocol and adopt EUI-64 encoding method to generate stateless IID.

The technical contents of the Guidelines are derived from an ongoing national standard project called IPv6 Address Assignment and Coding Rules – Interface Identifier. This standard is developed on the basis of a great number of international standards, including IETF RFC 3306, 3587, 4193, 4291, 6052, 7217, 7371, 7915, etc. TC260 claims that this standard will be consistent with the IPv6 standards of the IETF and other international SDOs, while reflecting China’s actual conditions and with a certain degree of innovation.

The release of the Guidelines reflects China’s eagerness to promote the large-scale application of IPv6, even though the official standard has not yet been finished. Relevant European stakeholders are advised to closely examine the guidelines and determine if there is significant discrepancy with relevant international standards.

The text of the guidelines (in Chinese) can be downloaded from https://www.tc260.org.cn/front/postDetail.html?id=20230625221638.

The draft for comments of the standard IPv6 Address Assignment and Coding Rules – Interface Identifier (in Chinese) can be found here.