Network Working Group M. Blanchet Internet-Draft Viagenie Expires: December 31, 2001 July 2, 2001 IPv6 Address Space Reserved for Documentation draft-blanchet-ngtrans-exampleaddr-01 Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on December 31, 2001. Copyright Notice Copyright (C) The Internet Society (2001). All Rights Reserved. Abstract To reduce the likelihood of conflict and confusion, an IPv6 prefix is reserved for use in examples in RFCs, books, documentation, and the like. Since site local addresses have special meaning in IPv6, these cannot be used in many example situations and are confusing. Instead, an IPv6 prefix 3ffe:ffff::/32 is reserved in the range of the test address space. 1. Rationale IPv6 introduces many types of addresses in its addressing architecture [1], like scoped addresses (link-local, site-local) and global addresses. It also introduces mechanisms for renumbering Blanchet Expires December 31, 2001 [Page 1] Internet-Draft IPv6 Address Space Reserved for DocumentationJuly 2001 [2][5]. Since IPv6 has many new ways to use addresses, this means an increase use of examples and scenarios for documenting the use of addresses. RFCs, vendor documentation, books and the like use examples with addresses. Authors always have an issue of using: already allocated addresses, not currently allocated addresses or private (site-local in IPv6) addresses in their examples. Using the configuration examples in a real environment can cause a problem. If the example uses site-local as global address example, then the actual mechanism for handling scoped addresses with site-local scoping can not be done. If allocated addresses are used, then this obviously can make address spoofing inadvertly if the environment is connected to the internet. Same could happen for a non-currently allocated address space that becomes allocated. Similar, but different, discussion also applies to top level domain names and some have been reserved for similar purposes [4]. 2. Non Use This reserved address space MUST NOT be used for private networks or test networks. Use instead site-local [1]. 3. Multicast Multicast addresses can also be reserved for documentation using this document reserved address space together with the Unicast prefix- based proposal [6] for multicast addresses. 4. Assignment The prefix 3ffe:ffff::/32, out of the test address space [3] currently used on the 6bone, is reserved for the purpose of this draft. The 6bone and the Internet MUST never use that prefix. A /32 was chosen as a compromise. Multiple site prefixes and multihoming could not be demonstrated with a prefix greater than /47. A /24, which could be used for multiple TLA in exchange examples, was seen as too much space consumed for documentation. The compromise was /32. 3ffe:ffff::/32 was chosen as the last /32 in the current reserved test space[3]. 5. IANA Considerations IANA reserves 3ffe:ffff::/32 address space out of the test address space so that no one will ever receive this allocation, even if the 3ffe::/16 test address space is reallocated. Blanchet Expires December 31, 2001 [Page 2] Internet-Draft IPv6 Address Space Reserved for DocumentationJuly 2001 6. Security Considerations This document encourages the use of test addresses in documentation so that less issues will arise from people that could instead use address space already allocated or to be allocated in the future. These could cause ip address spoofing. This proposal minimize such possible conflicts. 7. Acknowledgements In alphabetical order, Alain Durand, Robert Elz, Bob Fink and Dave Thaler contributed to the discussion and improvements of this draft. References [1] Hinden, R. and S. Deering, "IP Version 6 Addressing Architecture", RFC 2373, July 1998. [2] Thomson, S. and T. Narten, "IPv6 Stateless Address Autoconfiguration", RFC 2462, December 1998. [3] Hinden, R., Fink, R. and J. Postel, "IPv6 Testing Address Allocation", RFC 2471, December 1998. [4] Eastlake, D. and A. Panitz, "Reserved Top Level DNS Names", BCP 32, RFC 2606, June 1999. [5] Crawford, M., "Router Renumbering for IPv6", RFC 2894, August 2000. [6] Haberman, B. and D. Thaler, "Unicast-Prefix-based IPv6 Multicast Addresses", Internet-draft, Work in progress draft-ietf-ipngwg- uni-based-mcast-01.txt, January 2001. Author's Address Marc Blanchet Viagenie 2875 boul. Laurier, bureau 300 Sainte-Foy, QC G1V 2M2 Canada Phone: +1 418 656 9254 EMail: Marc.Blanchet@viagenie.qc.ca URI: http://www.viagenie.qc.ca/ Blanchet Expires December 31, 2001 [Page 3] Internet-Draft IPv6 Address Space Reserved for DocumentationJuly 2001 Full Copyright Statement Copyright (C) The Internet Society (2001). All Rights Reserved. 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