ASN Prefix-based Addressing for IPv6
draft-kristoff-v6ops-asn-based-addressing-02

Internet Engineering Task Force                              J. Kristoff
Internet-Draft                                             Dataplane.org
Intended status: Standards Track                        26 November 2025
Expires: 30 May 2026

                  ASN Prefix-based Addressing for IPv6
              draft-kristoff-v6ops-asn-based-addressing-02

Abstract

   This document describes a method and policy for ASN prefix-based
   addressing for IPv6.

Status of This Memo

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   This Internet-Draft will expire on 30 May 2026.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   2
   2.  Address Space . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Example . . . . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Private, Reserved, Special Use, and Unallocated ASNs  . . . .   3
   5.  Registry Considerations . . . . . . . . . . . . . . . . . . .   3
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   3
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .   3
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   3
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   3
     8.2.  Informative References  . . . . . . . . . . . . . . . . .   4
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .   4
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   4

1.  Introduction

   This document defines an address allocation system (called "APbA")
   whereby an Autonomous System (AS) number is embedded as sub-prefix
   bits of an IPv6 address, resulting in approximately 1.2 quintillion
   addresses per AS.  Advantages of this mechanism include the ability
   to get allocate AS-specific and unique address space without an
   allocation protocol or registration process.  This system also makes
   it easy to determine an association between AS and address, which is
   useful for debugging and auditing purposes.

   This mechanism draws inspiration from [RFC3180].  Unlike that earlier
   specification however, this system applies specifically to unicast
   addressing, supports 32-bit ASNs, and provides significantly more
   addresses per AS.  Some administrative challenges identified by
   [RFC6034] remain and questions about the integration into modern
   technology such as [RFC6482] are addressed later in this document.

1.1.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

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2.  Address Space

   An IPv6 address with the prefix [IANA-assigned 16-bit prefix]
   indicates that the adress is a APbA address.  The embedded AS follows
   as a sub-prefix.  A 16-bit AS is left-padded with 0s.  The remaining
   96-bit suffix bits are locally significant and defined by the
   corresponding AS.

   Bits:  | 0 thru 15  |     16 thru 47    |    48 thru 127   |
          +------+---------------+-------------------+--------+
   Value: |    [TBD]   | 16 or 32 bit ASN  | Locally Assigned |
          +------+---------------+-------------------+--------+

                       Figure 1: APbA address format

3.  Example

   Consider, for example AS 64496.  Written in hex, we get an IPv6
   prefix of 3fff:0:fbf0::/48.

4.  Private, Reserved, Special Use, and Unallocated ASNs

   AS numbers may be reserved for private or special use.  They may also
   be unallocated.  These AS designations MUST be maintained when mapped
   to APbA addresses, which may render these addresses unavailable or
   inappropriate for public use.

5.  Registry Considerations

   Internet registries SHOULD provide service functions and support for
   APdA addresses.

6.  IANA Considerations

   This memo requests a 16-bit IPv6 address prefix assignment from IANA.

7.  Security Considerations

   APdA addresses SHOULD have corresponding ROAs [RFC6482] if externally
   and publicly routed on the Internet.  Network operators MAY reject
   APdA route announcments otherwise.

8.  References

8.1.  Normative References

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   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

8.2.  Informative References

   [RFC3180]  Meyer, D. and P. Lothberg, "GLOP Addressing in 233/8",
              BCP 53, RFC 3180, DOI 10.17487/RFC3180, September 2001,
              <https://www.rfc-editor.org/info/rfc3180>.

   [RFC6034]  Thaler, D., "Unicast-Prefix-Based IPv4 Multicast
              Addresses", RFC 6034, DOI 10.17487/RFC6034, October 2010,
              <https://www.rfc-editor.org/info/rfc6034>.

   [RFC6482]  Lepinski, M., Kent, S., and D. Kong, "A Profile for Route
              Origin Authorizations (ROAs)", RFC 6482,
              DOI 10.17487/RFC6482, February 2012,
              <https://www.rfc-editor.org/info/rfc6482>.

Acknowledgements

   The following individuals provided an array of feedback to help
   improve this document: Roland Dobbins.  Any remaining errors or
   imperfections are the sole responsbility of the document authors.

Author's Address

   John Kristoff
   Dataplane.org
   Chicago, IL 60605
   United States of America
   Phone: +1 312 493-0305
   Email: jtk@dataplane.org
   URI:   https://dataplane.org/jtk/

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