Updates to Legacy IPv4-related IANA Registries
draft-vyncke-intarea-legacy-registries-00

int-area                                                       É. Vyncke
Internet-Draft                                                     Cisco
Intended status: Standards Track                            16 June 2026
Expires: 18 December 2026

             Updates to Legacy IPv4-related IANA Registries
               draft-vyncke-intarea-legacy-registries-00

Abstract

   IANA maintains several registries that were created for IPv4
   extensions.  As the IPv4 core specification is no longer being
   extended and as some registries do not have a defined IANA
   registration procedure, these registries need to be updated to
   indicate a registration procedure or to reflect the current practice
   that defining such extensions is not recommended.

Discussion Venues

   This note is to be removed before publishing as an RFC.

   Discussion of this document takes place on the Internet Area Working
   Group Working Group mailing list (int-area@ietf.org), which is
   archived at https://mailarchive.ietf.org/arch/browse/int-area/.

   Source for this draft and an issue tracker can be found at
   https://github.com/evyncke/draft-vyncke-intarea-legacy-registries.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

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   This Internet-Draft will expire on 18 December 2026.

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Copyright Notice

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Justification . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Operational Considerations  . . . . . . . . . . . . . . . . .   3
   3.  Security Considerations . . . . . . . . . . . . . . . . . . .   3
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   3
   5.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   4
     5.1.  Normative References  . . . . . . . . . . . . . . . . . .   4
     5.2.  Informative References  . . . . . . . . . . . . . . . . .   4
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .   5
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   6

1.  Introduction

   Several registries were created for IPv4-related protocol elements
   [RFC791].  These registries were created by [RFC1700], which in turn
   was obsoleted by [RFC3232] which handed these registries to IANA.

   The IPv4 core specification [RFC791] is no longer being extended (see
   also [IAB_IPV4]) and more modern mechanisms are defined to manage
   names.  Also, some IANA registries do not have a defined registration
   policy (Section 4 of [RFC8126]).  Therefore, this document closes
   some relevant IANA registries and changes the registration procedure
   for others.  See more in Section 1.1.

   The information in the closed registries is still valid and
   registrations already in these registries can still be updated per
   the guidance in Section 9.6 of [RFC8126].

1.1.  Justification

   The justifications for the changes to IANA registries listed in
   Section 4 are as follows:

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   [DHC_NETWARE]:  Registrations are to be closed as Netware is not
      extended anymore.

   [IP_OPTIONS]:  It is commonly understood that the use of IPv4 options
      is broken [NOT_AN_OPTION].  The registration procedure is set to
      "IESG approval" ([RFC8126], Section 4.10); it is expected that the
      IESG won't approve any new IPv4 option.

   [IP_TTL]:  This registry should not have been created as the IPv4
      Time to Live (TTL) (Section 3.1 of [RFC791]) header field can be
      freely selected by source nodes.

   [MACHINE_NAMES] and [TERMINAL_TYPES]:  There are no defined
      registration procedures for these two registries.  Moreover, there
      were no registrations made to these registries in the last two
      decades.  This document specifies the registration procedure as
      "First Come First Served" ([RFC8126], Section 4.4).

2.  Operational Considerations

   As some registries are closed, they cannot be extended but the
   existing values are still valid (i.e., unless they are deprecated by
   a future document, they can still be used).  These changes do not
   impact existing operations that use already registered values.

   The use of IPv4 options on the public Internet is broken.  Solutions
   that rely on defining such options are not reliable.  More robust
   alternative means should be explored.

3.  Security Considerations

   There is no new security considerations introduced by this document
   except for the registries whose registration policy is changed to
   "First Come First Served".  Concretely, registrations are still
   possible to such registries with the risk of having unusable non-
   sensible data added to it, but the IANA policy is to apply common
   sense filtering on the content and amount of registrations.

4.  IANA Considerations

   This document requests IANA to close the following registry per
   Section 9.6 of [RFC8126] and add a reference to this document:

   *  The "NetWare/IP Option Type 63 Sub-Option Codes" registry under
      the "Dynamic Host Configuration Protocol (DHCP) and Bootstrap
      Protocol (BOOTP) Parameters" registry group [DHC_NETWARE].

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   This document requests IANA to set the registration procedure to
   "IESG approval" ([RFC8126], Section 4.10) with a reference to this
   document for the following registry:

   *  The "IP Option Numbers" registry under the "Internet Protocol
      Version 4 (IPv4) Parameters" registry group [IP_OPTIONS].

   This document requests IANA to set the registration procedure to
   "First Come First Served" ([RFC8126], Section 4.4) with a reference
   to this document for the following registries:

   *  The "Machine Names" registry group [MACHINE_NAMES].

   *  The "Terminal Type Names" registry group [TERMINAL_TYPES].

   This document also requests IANA to completely remove the "IP Time to
   Live Parameter" registry under the "Internet Protocol Version 4
   (IPv4) Parameters" registry group [IP_TTL].  If not possible, then
   IANA is requested to replace the existing note with the following
   note:

      There is no registry for the IPv4 Time To Live (TTL) as it is set
      by the node operating system or the node application.  Recommended
      default TTL value for IPv4 is 64 [RFC791][RFC1122].

5.  References

5.1.  Normative References

   [RFC791]   Postel, J., "Internet Protocol", STD 5, RFC 791,
              DOI 10.17487/RFC0791, September 1981,
              <https://www.rfc-editor.org/rfc/rfc791>.

   [RFC1122]  Braden, R., Ed., "Requirements for Internet Hosts -
              Communication Layers", STD 3, RFC 1122,
              DOI 10.17487/RFC1122, October 1989,
              <https://www.rfc-editor.org/rfc/rfc1122>.

   [RFC8126]  Cotton, M., Leiba, B., and T. Narten, "Guidelines for
              Writing an IANA Considerations Section in RFCs", BCP 26,
              RFC 8126, DOI 10.17487/RFC8126, June 2017,
              <https://www.rfc-editor.org/rfc/rfc8126>.

5.2.  Informative References

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   [DHC_NETWARE]
              IANA, "NetWare/IP Option Type 63 Sub-Option Codes",
              <https://www.iana.org/assignments/bootp-dhcp-parameters/
              bootp-dhcp-parameters.xhtml#type-63-sub-options>.

   [IAB_IPV4] "IAB Statement on IPv6", 7 November 2016,
              <https://datatracker.ietf.org/doc/statement-iab-statement-
              on-ipv6/>.

   [IP_OPTIONS]
              IANA, "IP Option Numbers",
              <https://www.iana.org/assignments/ip-parameters/ip-
              parameters.xhtml#ip-parameters-1>.

   [IP_TTL]   IANA, "IP Time to Live Parameter",
              <https://www.iana.org/assignments/ip-parameters/ip-
              parameters.xhtml#ip-parameters-2>.

   [MACHINE_NAMES]
              IANA, "Machine Names", <https://www.iana.org/assignments/
              machine-names/machine-names.xhtml>.

   [NOT_AN_OPTION]
              Fonseca, R., Porter, G. M., Katz, R. H., Shenker, S., and
              I. Stoica, "IP Options are not an option", December 2005,
              <https://www2.eecs.berkeley.edu/Pubs/TechRpts/2005/EECS-
              2005-24.pdf>.

   [RFC1700]  Reynolds, J. and J. Postel, "Assigned Numbers", RFC 1700,
              DOI 10.17487/RFC1700, October 1994,
              <https://www.rfc-editor.org/rfc/rfc1700>.

   [RFC3232]  Reynolds, J., Ed., "Assigned Numbers: RFC 1700 is Replaced
              by an On-line Database", RFC 3232, DOI 10.17487/RFC3232,
              January 2002, <https://www.rfc-editor.org/rfc/rfc3232>.

   [TERMINAL_TYPES]
              IANA, "Terminal Type Names",
              <https://www.iana.org/assignments/terminal-type-names/
              terminal-type-names.xhtml>.

Acknowledgments

   Thanks to Mohamed Boucadair for the initial idea and deep review.
   Thanks also to Amanda Baber for the initial list of legacy registries
   or registries without any specified registration procedures.  Other
   thanks for reviewers: Tommy Jensen.

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Author's Address

   Éric Vyncke
   Cisco
   De Kleetlaan, 6A
   Diegem
   Belgium
   Email: evyncke@cisco.com

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