Expanding the IPv6 Documentation Space
draft-ietf-v6ops-rfc3849-update-05

V6OPS                                                          G. Huston
Internet-Draft                                                     APNIC
Updates: 3849 (if approved)                                  N. Buraglio
Intended status: Informational                   Energy Sciences Network
Expires: 31 December 2024                                   29 June 2024

                 Expanding the IPv6 Documentation Space
                   draft-ietf-v6ops-rfc3849-update-05

Abstract

   The document describes the reservation of an additional IPv6 address
   prefix for use in documentation.  This update to RFC 3849 expands on
   the existing 2001:db8::/32 address block with the reservation of an
   additional, larger prefix.  The addition of a /20 allows documented
   examples to more closely reflect a broader range of realistic,
   current deployment scenarios and more closely aligns with
   contemporary allocation models for large networks.

Status of This Memo

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   This Internet-Draft will expire on 31 December 2024.

Copyright Notice

   Copyright (c) 2024 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights
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   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Current Assignment and Allocation Data  . . . . . . . . . . .   3
   3.  Filtering and appropriate use . . . . . . . . . . . . . . . .   3
   4.  Conventions and Definitions . . . . . . . . . . . . . . . . .   3
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   3
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   3
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   3
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .   3
     7.2.  Informative References  . . . . . . . . . . . . . . . . .   4
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .   4
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   4

1.  Introduction

   [RFC3849] introduced 2001:db8::/32, describing the use of the IPv6
   address prefix 2001:db8::/32 as a reserved prefix for use in
   documentation.  The rationale for this reservation was to reduce the
   likelihood of conflict and confusion when relating documented
   examples to deployed systems.

   As the global deployment of IPv6 expands and evolves, individual IPv6
   network deployment scenarios have also increased is size and
   diversity, and there is a requirement for documentation to reflect
   this increased diversity and scope.  The original 2001:db8::/32
   reservation is inadequate to describe many realistic current
   deployment scenarios.

   Without this additional address allocation, documentation address
   prefixes are drawn from address blocks already allocated or assigned
   to existing organizations or to well known ISPs, or drawn from the
   currently unallocated address pool.  Such use conflicts with existing
   or future allocations or assignments of IPv6 address space.  The
   reservation of a further /20 IPv6 address prefix from the Global
   Unicast Address pool [RFC4291] for documentation purposes avoids such
   conflicts.

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2.  Current Assignment and Allocation Data

   According to the allocation and assignment data published by the
   Regional Internet Registries, [NROStatsReport], in August 2023 some
   25.9% of all 62,770 recorded IPv6 unicast allocations and assignments
   are larger than a /32 in size.  The most common allocation or
   assignment size is a /29, used in 24.8% of cases.

   The four largest assignments made to end users have been /19s, but
   these allocations were made before the RIRs' address allocation
   policies moved away from the use of a fixed /48 site address prefix
   IPv6 address assignment policies, and in the foreseeable future its
   unlikely that individual networks require more than a /20.  It is
   believed that a reservation of a /20 would cover the documentation
   needs as they relate the broad range of realistic network
   deployments.

3.  Filtering and appropriate use

   Documentation prefixes are for the use or relaying configuration and
   documentation examples and as such MUST NOT be used for actual
   traffic, MUST NOT be globally advertised, and SHOULD NOT be used
   internally for routed production traffic or other connectivity.
   Documentation prefixes should be considered bogon and filtered in
   routing advertisements as appropriate.

4.  Conventions and Definitions

   None.

5.  Security Considerations

   This special use prefix should be marked as and considered [BOGON].
   As is appropriate with bogon prefixes, packets whose src/dst belongs
   to this prefix should be dropped and disallowed over the public
   Internet.

6.  IANA Considerations

   IANA is to record the reservation of TBD::/20 in the IANA IPv6
   Special-Purpose Address Registry; [IANAIPv6SPAR].  The Source,
   Destination, Forwardable, Globally Reachable and Reserved-by-Protocol
   fields should be recorded as False.  There is no Termination Date for
   this entry.  The name of the reservation is “Documentation".

7.  References

7.1.  Normative References

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   [IANAIPv6SPAR]
              "IANA IPv6 Special-Purpose Address Registry", n.d.,
              <https://www.iana.org/assignments/iana-ipv6-special-
              registry/iana-ipv6-special-registry.xhtml>.

7.2.  Informative References

   [BOGON]    "Team Cymru Bogon Guide", n.d., <https://www.team-
              cymru.com/post/unravelling-the-mystery-of-bogons-a-senior-
              stakeholder-and-it-professional-guide>.

   [NROStatsReport]
              "NRO Stats Report", n.d.,
              <https://ftp.ripe.net/pub/stats/ripencc/nro-stats/latest/
              nro-delegated-stats>.

   [RFC3849]  Huston, G., Lord, A., and P. Smith, "IPv6 Address Prefix
              Reserved for Documentation", RFC 3849,
              DOI 10.17487/RFC3849, July 2004,
              <https://www.rfc-editor.org/rfc/rfc3849>.

   [RFC4291]  Hinden, R. and S. Deering, "IP Version 6 Addressing
              Architecture", RFC 4291, DOI 10.17487/RFC4291, February
              2006, <https://www.rfc-editor.org/rfc/rfc4291>.

Acknowledgments

   The authors would like to acknowledge the valuable input from XiPeng
   Xiao, Chris Cummings, Russ White, Kevin Myers, Ed Horley, Tom
   Coffeen, and Scott Hogg.

Authors' Addresses

   Geoff Huston
   APNIC
   Email: gih@apnic.net

   Nick Buraglio
   Energy Sciences Network
   Email: buraglio@forwardingplane.net

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