It is derived from 6to4, a preexisting mechanism to transfer IPv6 packets over the IPv4 network, with the significant change that it operates entirely within the end-user’s ISP’s network, thus avoiding the major deploying ipv6 networks pdf download problems inherent in the original design of 6to4. A description of 6rd principles and of how they were first used by Free is published in RFC 5569.
The detailed 6rd specification prepared for standardization in the IETF is available as RFC 5969. In November 2007, Rémi Després — who was one of the creators of the Transpac data network in France in the 1970s — proposed to Free, the second largest ISP in France, to use the 6rd mechanism he had invented to rapidly deploy IPv6. While Free had until then no short-term plan to offer IPv6 service, Rani Assaf, the CTO of Free, immediately decided to implement the solution.
The first draft describing the 6rd mechanism and Free’s deployment was submitted to IETF on 9 February 2008. After improvements, it was published on 24 January 2010 as informational RFC 5569. In March 2010, a Working Group of the IETF approved that its latest draft on 6rd should become, after some more modifications, a standards-track RFC.