Clarification of IPv6 Address Allocation Policy The University of Auckland
School of Computer Science PB 92019 Auckland 1142 New Zealand brian.e.carpenter@gmail.com
Cisco Systems, Inc.
suresh.krishnan@gmail.com
University of Minnesota
Office of Information Technology Minneapolis MN 55455 United States of America farmer@umn.edu
INT 6man This document specifies the approval process for changes to the "IPv6 Address Space" registry. It also updates RFC 7249.
Status of This Memo This memo documents an Internet Best Current Practice. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on BCPs is available in Section 2 of RFC 7841. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at .
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Table of Contents
  • .  Introduction
  • .  Approval Level of IPv6 Address Allocations
  • .  IANA Considerations
  • .  Security Considerations
  • .  References
    • .  Normative References
    • .  Informative References
  • Acknowledgements
  • Authors' Addresses
Introduction Internet Protocol Version 6 (IPv6) and its address space are defined by and . The management of the IPv6 address space was delegated to IANA by , some years before the relationship between the IETF and IANA was formalized and registry details were clarified . Occasionally, IPv6 address space allocations are performed outside the scope of routine allocations to Regional Internet Registries (RIRs). For example, a substantial allocation was requested by an IETF document approved by the IESG , which moved the range 5f00::/16 from the "IPv6 Address Space" registry to the "IPv6 Special-Purpose Address Space" registry . At the time of writing, the allocation policy in the "IPv6 Address Space" registry was shown as "IESG approval", whereas a more stringent policy is appropriate for major allocations. The present document therefore strengthens the approval level needed for non-routine address allocations, which requires an update to . This document also clarifies the status of . This clarification is necessary because , a joint publication of the IAB and IESG following an IETF Last Call, was incorrectly listed in the RFC index at the time of writing as "Legacy", whereas it is part of the IETF Stream .
Approval Level of IPv6 Address Allocations Portions of the IPv6 address space are shown in the registry as "Reserved by IETF" . This is the address space held in reserve for future use if ever the 125-bit unicast space (2000::/3) is found inadequate or inappropriate. did not specify an allocation policy for this space. At some point, IANA listed "IESG approval". As defined in , this is a rather weak requirement ("Although there is no requirement that the request be documented in an RFC, the IESG has the discretion to request documents...") and is "a fall-back mechanism in the case where one of the other allowable approval mechanisms cannot be employed...". For something as important as the majority of the spare IPv6 address space, this process is clearly insufficient. The present document replaces the "IESG approval" process by the "IETF Review" process as defined by . The stricter "Standards Action" policy is not considered necessary, because there may be cases where opening up a new range of address space does not in fact require a new protocol standard. It may be noted that the allocation for , which was processed as a working group document, did indeed follow the more stringent "IETF Review" process proposed by this document. Indeed, the other two related registries cite the "IETF Review" policy, consistent with . This document therefore extends the first paragraph of as follows: OLD:
The vast bulk of the IPv6 address space (approximately 7/8ths of the whole address space) is reserved by the IETF , with the expectation that further assignment of globally unique unicast address space will be made from this reserved space in accordance with future needs.
NEW:
The vast bulk of the IPv6 address space (approximately 7/8ths of the whole address space) is reserved by the IETF , with the expectation that further assignment of globally unique unicast address space will be made from this reserved space in accordance with future needs, through "IETF Review" as defined in .
IANA Considerations IANA has updated the registration procedure of the "IPv6 Address Space" registry to "IETF Review".
Security Considerations The security considerations of apply. While having no direct security impact, carefully reviewed address allocation mechanisms are necessary to ensure operational address accountability.
References Normative References Guidelines for Writing an IANA Considerations Section in RFCs Many protocols make use of points of extensibility that use constants to identify various protocol parameters. To ensure that the values in these fields do not have conflicting uses and to promote interoperability, their allocations are often coordinated by a central record keeper. For IETF protocols, that role is filled by the Internet Assigned Numbers Authority (IANA). To make assignments in a given registry prudently, guidance describing the conditions under which new values should be assigned, as well as when and how modifications to existing values can be made, is needed. This document defines a framework for the documentation of these guidelines by specification authors, in order to assure that the provided guidance for the IANA Considerations is clear and addresses the various issues that are likely in the operation of a registry. This is the third edition of this document; it obsoletes RFC 5226. IP Version 6 Addressing Architecture This specification defines the addressing architecture of the IP Version 6 (IPv6) protocol. The document includes the IPv6 addressing model, text representations of IPv6 addresses, definition of IPv6 unicast addresses, anycast addresses, and multicast addresses, and an IPv6 node's required addresses. This document obsoletes RFC 3513, "IP Version 6 Addressing Architecture". [STANDARDS-TRACK] Internet Protocol, Version 6 (IPv6) Specification This document specifies version 6 of the Internet Protocol (IPv6). It obsoletes RFC 2460. Informative References IPv6 Address Space IANA IPv6 Global Unicast Address Space IANA IPv6 Special-Purpose Address Space IANA IPv6 Address Allocation Management Internet Architecture Board Internet Engineering Steering Group The IPv6 address space will be managed by the IANA for the good of the Internet community, with advice from the IAB and the IESG, by delegation to the regional registries. This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind. Memorandum of Understanding Concerning the Technical Work of the Internet Assigned Numbers Authority This document places on record the text of the Memorandum of Understanding concerning the technical work of the IANA that was signed on March 1, 2000 between the IETF and ICANN, and ratified by the ICANN Board on March 10, 2000. This memo provides information for the Internet community. The Internet Numbers Registry System This document provides information about the current Internet Numbers Registry System used in the distribution of globally unique Internet Protocol (IP) address space and autonomous system (AS) numbers. This document also provides information about the processes for further evolution of the Internet Numbers Registry System. This document replaces RFC 2050. This document does not propose any changes to the current Internet Numbers Registry System. Rather, it documents the Internet Numbers Registry System as it works today. Internet Numbers Registries RFC 7020 provides information about the Internet Numbers Registry System and how it is used in the distribution of autonomous system (AS) numbers and globally unique unicast Internet Protocol (IP) address space. This companion document identifies the IANA registries that are part of the Internet Numbers Registry System at this time. The RFC Series and RFC Editor This document describes the framework for an RFC Series and an RFC Editor function that incorporate the principles of organized community involvement and accountability that has become necessary as the Internet technical community has grown, thereby enabling the RFC Series to continue to fulfill its mandate. This document obsoletes RFC 4844. Segment Routing over IPv6 (SRv6) Segment Identifiers in the IPv6 Addressing Architecture Segment Routing over IPv6 (SRv6) uses IPv6 as the underlying data plane. Thus, Segment Identifiers (SIDs) used by SRv6 can resemble IPv6 addresses and behave like them while exhibiting slightly different behaviors in some situations. This document explores the characteristics of SRv6 SIDs and focuses on the relationship of SRv6 SIDs to the IPv6 Addressing Architecture. This document allocates and makes a dedicated prefix available for SRv6 SIDs.
Acknowledgements Useful comments were received from , , , , and others.
Authors' Addresses The University of Auckland
School of Computer Science PB 92019 Auckland 1142 New Zealand brian.e.carpenter@gmail.com
Cisco Systems, Inc.
suresh.krishnan@gmail.com
University of Minnesota
Office of Information Technology Minneapolis MN 55455 United States of America farmer@umn.edu