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Nameservers for the Address and Routing Parameter Area ("arpa") Domain

The information below is for an old version of the document that is already published as an RFC.
Document Type
This is an older version of an Internet-Draft that was ultimately published as RFC 9120.
Authors Kim Davies , Jari Arkko
Last updated 2021-10-29 (Latest revision 2021-07-12)
Replaces draft-iana-arpa-authoritative-servers
RFC stream Internet Architecture Board (IAB)
Intended RFC status Informational
Stream IAB state Published RFC
Consensus boilerplate Yes
IAB shepherd (None)
Network Working Group                                          K. Davies
Internet-Draft                                                      IANA
Updates: 3172 (if approved)                                     J. Arkko
Intended status: Informational                                  Ericsson
Expires: January 13, 2022                                  July 12, 2021

 Nameservers for the Address and Routing Parameter Area ("arpa") Domain


   This document describes revisions to operational practices to
   separate function of the "arpa" top-level domain in the DNS from its
   historical operation alongside the DNS root zone.

Status of This Memo

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

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
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   Drafts is at

   Internet-Drafts are draft documents valid for a maximum of six months
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   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on January 13, 2022.

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   Copyright (c) 2021 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Requirements for the "arpa" zone  . . . . . . . . . . . . . .   3
   3.  Transition Process  . . . . . . . . . . . . . . . . . . . . .   3
     3.1.  Dedicated nameserver hostnames  . . . . . . . . . . . . .   3
     3.2.  Separation of infrastructure  . . . . . . . . . . . . . .   4
     3.3.  Zone administration . . . . . . . . . . . . . . . . . . .   4
     3.4.  Conclusion of process . . . . . . . . . . . . . . . . . .   4
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   5
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   5
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   5
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .   5
     6.2.  Informative References  . . . . . . . . . . . . . . . . .   5
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .   6
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   6

1.  Introduction

   The "arpa" top-level domain [RFC3172] is designated as an
   "infrastructure domain" to support techniques defined by Internet
   standards.  Zones under the "arpa" domain provide various mappings,
   such as IP addresses to domain names and E.164 numbers to URIs.  It
   also contains special use names such as "home", which is a non-unique
   name used in residential networks.

   Historically, the "arpa" zone has been hosted on almost all of the
   root nameservers, and [RFC3172] envisages the "arpa" domain to be
   "sufficiently critical that the operational requirements for the root
   nameservers apply to the operational requirements of the "arpa"
   servers".  To date, this has been implemented by serving the "arpa"
   domain directly on a subset of the root server infrastructure.

   This bundling of root nameserver and "arpa" nameserver operations has
   entwined management of the zones' contents and their infrastructure.
   As a result, some proposals under consideration by the IETF involving
   the "arpa" zone have been discarded due to the risk of conflict with
   operations associated with managing the content of the root zone, or
   administering the root nameservers.

   The separation described in this document resolves operational
   impacts of synchronizing edits to the root zone and the "arpa" zone
   by eliminating the current dependency and allowing more tailored
   operations based on the unique requirements of each zone.

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2.  Requirements for the "arpa" zone

   The "arpa" domain continues to play a role in critical Internet
   operations, and this change does not propose weakening operational
   requirements described in [RFC3172] for the domain.  Future
   operational requirements for the "arpa" domain are encouraged to
   follow strong baseline requirements such as those documented in

   Changes to the administration of the "arpa" zone do not alter the
   management practices of other zones delegated within the "arpa"
   namespace.  For example, "" would continue to be managed in
   accordance with [RFC5855].

3.  Transition Process

   The process will dedicate new hostnames to the servers authoritative
   for the "arpa" zone, but will initially serve the "arpa" zone from
   the same hosts.

   Once completed, subsequent transitional phases could include using
   new hosts to replace or augment the existing root nameserver hosts,
   and separation of the editing and distribution of the "arpa" zone
   from necessarily being connected to the root zone.  Any future
   management considerations regarding how such changes may be performed
   are beyond the scope of this document.

3.1.  Dedicated nameserver hostnames

   Consistent with the use of the "arpa" namespace itself to host name
   servers for other delegations in the "arpa" zone ([RFC5855]), this
   document specifies a new namespace of "", with the nameserver
   set for the "arpa" zone to be initially labelled as follows:

   Dedicated hostnames eliminate a logical dependency that requires the
   coordinated editing of the nameservers for the "arpa" zone and the
   root zone.  This component of this transition does not require the
   underlying hosts that provide "arpa" name service (that is, the root
   nameservers) be altered.  The "arpa" zone will initially map the new
   hostnames to the same IP addresses that already provide service under
   the respective hostnames within

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   Because these nameservers are completely within the "arpa" zone, they
   will require glue records in the root zone.  This is consistent with
   current practice and requires no operational changes to the root

3.2.  Separation of infrastructure

   After initially migrating the "arpa" zone to use hostnames that are
   not shared with the root zone, the underlying name service is
   expected to evolve such that it no longer directly aligns to a subset
   of root nameserver instances.  With no shared infrastructure between
   the root nameservers and the "arpa" nameservers, future novel
   applications for the "arpa" zone may be possible.

   Any subsequent changes to the parties providing name service for the
   zone is considered a normal management responsibility, and would be
   performed in accordance with [RFC3172].

3.3.  Zone administration

   Publication of the "arpa" zone file to the authoritative "arpa" name
   servers is currently undertaken alongside the root zone maintenance
   functions.  Upon the separation of the "arpa" infrastructure from the
   root nameserver infrastructure, publication of the "arpa" zone no
   longer necessarily needs to be technically linked or inter-related to
   the root zone publication mechanisms.

3.4.  Conclusion of process

   Full technical separation of operations of the "arpa" zone and root
   zone minimally requires the following to be satisfied:

   o  The "arpa" zone no longer shares any hostnames in its NS-set with
      the root zone;

   o  The hosts that provide authoritative name service are not the same
      hosts as the root nameservers, do not share any IPv4 or IPv6
      addresses with the root servers, and are sufficiently separately
      provisioned such that any unique "arpa" zone requirements can be
      deployed without affecting how root zone service is provided;

   o  The editorial and publication process for the "arpa" zone has any
      common dependencies with the root zone process removed, so that
      the "arpa" zone can be managed, edited and provisioned wholly
      independently of the root zone.

   Such separation is ultimately sought to allow for novel uses of the
   "arpa" zone without the risk of inadvertantly impacting root zone and

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   root server operations.  It is recognized that achieving this state
   requires a deliberative process involving significant coordination to
   ensure impacts are minimized.

4.  IANA Considerations

   The IANA shall coordinate the creation of the "" namespace and
   populate it with address records that reflect the IP addresses of the
   contemporary root servers documented within "" as its
   initial state.  The namespace may either be provisioned directly
   within the "arpa" zone (as an empty non-terminal), or through
   establishing a dedicated "" zone, according to operational

   The IANA will initially migrate the 12 NS records for the "arpa" zone
   to point to their respective new entries in the "" domain.

   Subsequently, the IAB and IANA will consult and coordinate with all
   relevant parties on activity to reduce or eliminate reliance upon
   root zone and root server infrastructure for serving the "arpa" zone.
   Such changes will be performed in compliance with [RFC3172] and shall
   be conducted with all due care and deliberation to mitigate potential
   impacts on critical infrastructure.

5.  Security Considerations

   The security of the "arpa" zone is not necessarily impacted by any
   aspects of these changes.  Robust practices associated with
   administering the content of the zone (including signing the zone
   with DNSSEC) as well as its distribution will continue to be

6.  References

6.1.  Normative References

   [RFC3172]  Huston, G., Ed., "Management Guidelines & Operational
              Requirements for the Address and Routing Parameter Area
              Domain ("arpa")", BCP 52, RFC 3172, DOI 10.17487/RFC3172,
              September 2001, <>.

6.2.  Informative References

   [RFC5855]  Abley, J. and T. Manderson, "Nameservers for IPv4 and IPv6
              Reverse Zones", BCP 155, RFC 5855, DOI 10.17487/RFC5855,
              May 2010, <>.

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   [RFC7720]  Blanchet, M. and L-J. Liman, "DNS Root Name Service
              Protocol and Deployment Requirements", BCP 40, RFC 7720,
              DOI 10.17487/RFC7720, December 2015,


   Thank you Alyssa Cooper, Michelle Cotton, Lars-Johan Liman, Wes
   Hardaker, Ted Hardie, Paul Hoffman, Russ Housley, Oscar Robles-Garay,
   Duane Wessels and Suzanne Woolf for providing review and feedback.

Authors' Addresses

   Kim Davies
   Internet Assigned Numbers Authority
   12025 Waterfront Drive
   Los Angeles  90094
   United States of America


   Jari Arkko
   Ericsson Research
   02700 Kauniainen


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