RFC 1752 Recommendation for IPng January 1995 10.2 Address Length . . . . . . . . . . . . . . . . . . . . . 19 11. IPng Recommendation. . . . . . . . . . . . . . . . . . . 19 11.1 IPng Criteria Document and IPng. . . . . . . . . . . . . 20 11.2 IPv6. . . . . . . . . . . . . . . . . . . . . . . . . . 21 12. IPv6 Overview . . . . . . . . . . . . . . . . . . . . . 21 12.1 IPv6 Header Format . . . . . . . . . . . . . . . . . . . 24 12.2 Extension Headers. . . . . . . . . . . . . . . . . . . . 25 12.2.1 Hop-by-Hop Option Header . . . . . . . . . . . . . . . . 25 12.2.2 IPv6 Header Options. . . . . . . . . . . . . . . . . . . 26 12.2.3 Routing Header . . . . . . . . . . . . . . . . . . . . . 27 12.2.4 Fragment Header. . . . . . . . . . . . . . . . . . . . . 28 12.2.5 Authentication Header. . . . . . . . . . . . . . . . . . 29 12.2.6 Privacy Header . . . . . . . . . . . . . . . . . . . . . 30 12.2.7 End-to-End Option Header . . . . . . . . . . . . . . . . 32 13. IPng Working Group . . . . . . . . . . . . . . . . . . . 32 14. IPng Reviewer . . . . . . . . . . . . . . . . . . . . . 33 15. Address Autoconfiguration. . . . . . . . . . . . . . . . 33 16. Transition . . . . . . . . . . . . . . . . . . . . . . . 34 16.1 Transition - Short Term. . . . . . . . . . . . . . . . . 35 16.2 Transition - Long Term . . . . . . . . . . . . . . . . . 36 17. Other Address Families . . . . . . . . . . . . . . . . . 37 18. Impact on Other IETF Standards . . . . . . . . . . . . . 38 19. Impact on non-IETF standards and on products . . . . . . 39 20. APIs . . . . . . . . . . . . . . . . . . . . . . . . . . 39 21. Future of the IPng Area and Working Groups . . . . . . . 40 22. Security Considerations. . . . . . . . . . . . . . . . . 40 23. Authors' Addresses . . . . . . . . . . . . . . . . . . . 43 Appendix A Summary of Recommendations . . . . . . . . . . . . . 44 Appendix B IPng Area Directorate. . . . . . . . . . . . . . . . 45 Appendix C Documents Referred to the IPng Working Groups. . . . 46 Appendix D IPng Proposal Overviews. . . . . . . . . . . . . . . 46 Appendix E RFC 1550 White Papers. . . . . . . . . . . . . . . . 47 Appendix F Additional References. . . . . . . . . . . . . . . . 48 Appendix G Acknowledgments. . . . . . . . . . . . . . . . . . . 52 1. Summary The IETF started its effort to select a successor to IPv4 in late 1990 when projections indicated that the Internet address space would become an increasingly limiting resource. Several parallel efforts then started exploring ways to resolve these address limitations while at the same time providing additional functionality. The IETF formed the IPng Area in late 1993 to investigate the various proposals and recommend how to proceed. We developed an IPng technical criteria document and evaluated the various proposals against it. All were found wanting to some degree. After this evaluation, a revised proposal was offered by one of the working Bradner & Mankin