DNSOP Working Group                                          P. van Dijk
Internet-Draft                                                  PowerDNS
Intended status: Standards Track                               L. Peltan
Expires: 8 September 2022                                         CZ.NIC
                                                                 O. Sury
                                             Internet Systems Consortium
                                                               W. Toorop
                                                              NLnet Labs
                                                           K. Monshouwer

                                                            P. Thomassen
                                 deSEC, SSE - Secure Systems Engineering
                                                            7 March 2022

                           DNS Catalog Zones


   This document describes a method for automatic DNS zone provisioning
   among DNS primary and secondary nameservers by storing and
   transferring the catalog of zones to be provisioned as one or more
   regular DNS zones.

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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   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on 8 September 2022.

Copyright Notice

   Copyright (c) 2022 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
   and restrictions with respect to this document.  Code Components
   extracted from this document must include Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Description . . . . . . . . . . . . . . . . . . . . . . . . .   4
   4.  Catalog Zone Structure  . . . . . . . . . . . . . . . . . . .   4
     4.1.  SOA and NS Records  . . . . . . . . . . . . . . . . . . .   4
     4.2.  Member Zones  . . . . . . . . . . . . . . . . . . . . . .   4
     4.3.  Global Properties . . . . . . . . . . . . . . . . . . . .   5
       4.3.1.  Schema Version (version property) . . . . . . . . . .   6
     4.4.  Member Zone Properties  . . . . . . . . . . . . . . . . .   6
       4.4.1.  Change of Ownership (coo property)  . . . . . . . . .   6
       4.4.2.  Groups (group property) . . . . . . . . . . . . . . .   7
     4.5.  Custom Properties (*.ext properties)  . . . . . . . . . .   8
   5.  Nameserver Behavior . . . . . . . . . . . . . . . . . . . . .   9
     5.1.  General Requirements  . . . . . . . . . . . . . . . . . .   9
     5.2.  Member zone name clash  . . . . . . . . . . . . . . . . .   9
     5.3.  Member zone removal . . . . . . . . . . . . . . . . . . .  10
     5.4.  Member node name change . . . . . . . . . . . . . . . . .  10
     5.5.  Migrating member zones between catalogs . . . . . . . . .  10
     5.6.  Zone associated state reset . . . . . . . . . . . . . . .  11
   6.  Implementation Notes  . . . . . . . . . . . . . . . . . . . .  11
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  11
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  12
   9.  Normative References  . . . . . . . . . . . . . . . . . . . .  12
   10. Informative References  . . . . . . . . . . . . . . . . . . .  13
   Appendix A.  Implementation Status  . . . . . . . . . . . . . . .  14
   Appendix B.  Change History (to be removed before final
           publication)  . . . . . . . . . . . . . . . . . . . . . .  14
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  17

1.  Introduction

   The content of a DNS zone is synchronized amongst its primary and
   secondary nameservers using AXFR and IXFR.  However, the list of
   zones served by the primary (called a catalog in [RFC1035]) is not
   automatically synchronized with the secondaries.  To add or remove a
   zone, the administrator of a DNS nameserver farm not only has to add
   or remove the zone from the primary, they must also add/remove the

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   zone from all secondaries, either manually or via an external
   application.  This can be both inconvenient and error-prone; it is
   also dependent on the nameserver implementation.

   This document describes a method in which the catalog is represented
   as a regular DNS zone (called a "catalog zone" here), and transferred
   using DNS zone transfers.  As zones are added to or removed from the
   catalog zone, these changes are distributed to the secondary
   nameservers in the normal way.  The secondary nameservers then
   add/remove/modify the zones they serve in accordance with the changes
   to the catalog zone.  Other use-cases of nameserver remote
   configuration by catalog zones are possible, where the catalog
   consumer might not be a secondary.

2.  Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "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.

   Catalog zone  A DNS zone containing a DNS catalog, that is, a list of
      DNS zones and associated properties.

   Member zone  A DNS zone whose configuration is published inside a
      catalog zone.

   Member node  The DNS name in the Catalog zone representing a Member

   $CATZ  Used in examples as a placeholder to represent the domain name
      of the catalog zone itself. $OLDCATZ and $NEWCATZ are used to
      discuss migration a member zone from one catalog zone $OLDCATZ to
      another catalog zone $NEWCATZ.

   Catalog producer  An entity that generates and is responsible for the
      contents of the catalog zone.

   Catalog consumer  An entity that extracts information from the
      catalog zone (such as a DNS server that configures itself
      according to the catalog zone's contents).

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3.  Description

   A catalog zone is a DNS zone whose contents are specially crafted.
   Its records primarily constitute a list of PTR records referencing
   other DNS zones (so-called "member zones").  The catalog zone may
   contain other records indicating additional metadata (so-called
   "properties") associated with these member zones.

   Catalog consumers SHOULD ignore any RR in the catalog zone which is
   meaningless or useless to the implementation.

   Authoritative servers may be preconfigured with multiple catalog
   zones, each associated with a different set of configurations.

   Although the contents of a catalog zone are interpreted and acted
   upon by nameservers, a catalog zone is a regular DNS zone and so must
   adhere to the standards for such zones.

   A catalog zone is primarily intended for the management of a farm of
   authoritative nameservers.  The content of catalog zones may not be
   accessible from any recursive nameserver.

4.  Catalog Zone Structure

4.1.  SOA and NS Records

   As with any other DNS zone, a catalog zone MUST have a syntactically
   correct SOA record and at least one NS record at its apex.

   The SOA record's SERIAL, REFRESH, RETRY and EXPIRE fields [RFC1035]
   are used during zone transfer.  A catalog zone's SOA SERIAL field
   MUST increase when an update is made to the catalog zone's contents
   as per serial number arithmetic defined in [RFC1982].  Otherwise,
   catalog consumers might not notice updates to the catalog zone's

   There is no requirement to be able to query the catalog zone via
   recursive nameservers.  Catalog consumers MUST ignore and MUST NOT
   assume or require NS records at the apex.  However, at least one is
   still required so that catalog zones are syntactically correct DNS
   zones.  A single NS RR with a NSDNAME field containing the absolute
   name "invalid." is RECOMMENDED [RFC2606].

4.2.  Member Zones

   The list of member zones is specified as a collection of member
   nodes, represented by domain names under the owner name "zones" where
   "zones" is a direct child domain of the catalog zone.

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   The names of member zones are represented on the RDATA side (instead
   of as a part of owner names) of a PTR record, so that all valid
   domain names may be represented regardless of their length [RFC1035].
   This PTR record MUST be the only record in the PTR RRset with the
   same name.  More than one record in the RRset denotes a broken
   catalog zone which MUST NOT be processed (see Section 5.1).

   For example, if a catalog zone lists three zones "example.com.",
   "example.net." and "example.org.", the member node RRs would appear
   as follows:

   <unique-1>.zones.$CATZ 0 IN PTR example.com.
   <unique-2>.zones.$CATZ 0 IN PTR example.net.
   <unique-3>.zones.$CATZ 0 IN PTR example.org.

   where <unique-N> is a label that tags each record in the collection.
   <unique-N> has an unique value in the collection.

   Member node labels carry no informational meaning beyond labeling
   member zones.  A changed label may indicate that the state for a zone
   needs to be reset (see Section 5.6).

   Having the zones uniquely tagged with the <unique-N> label ensures
   that additional RRs can be added below the member node (see
   Section 4.4).

   The CLASS field of every RR in a catalog zone MUST be IN (1).

   The TTL field's value is not defined by this memo.  Catalog zones are
   for authoritative nameserver management only and are not intended for
   general querying via recursive resolvers.

4.3.  Global Properties

   Apart from catalog zone metadata stored at the apex (NS, SOA and the
   like), catalog zone information is stored in the form of
   "properties".  Catalog consumers SHOULD ignore properties they do not

   This specification defines a number of so-called properties, as well
   as a mechanism to allow implementers to store additional information
   in the catalog zone with Custom properties, see Section 4.5.  The
   meaning of such custom properties is determined by the implementation
   in question.

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   Some properties are defined at the global level; others are scoped to
   apply only to a specific member zone.  This document defines a single
   mandatory global property in Section 4.3.1.  Member-specific
   properties are described in Section 4.4.

   More properties may be defined in future documents.

4.3.1.  Schema Version (version property)

   The catalog zone schema version is specified by an integer value
   embedded in a TXT RR named version.$CATZ.  All catalog zones MUST
   have a TXT RRset named version.$CATZ with exactly one RR.  Catalog
   consumers MUST NOT apply catalog zone processing to zones without the
   expected value in the version.$CATZ TXT RR, but they may be
   transferred as ordinary zones.  For this memo, the value of the
   version.CATZ TXT RR MUST be set to "2", i.e.:

   version.$CATZ 0 IN TXT "2"

   NB: Version 1 was used in a draft version of this memo and reflected
   the implementation first found in BIND 9.11.

4.4.  Member Zone Properties

   Each member zone MAY have one or more additional properties,
   described in this chapter.  These properties are completely optional
   and catalog consumers SHOULD ignore those it does not understand.
   Member zone properties are represented by RRsets below the
   corresponding member node.

4.4.1.  Change of Ownership (coo property)

   The coo property facilitates controlled migration of a member zone
   from one catalog to another.

   A Change Of Ownership is signaled by the coo property in the catalog
   zone currently "owning" the zone.  The name of the new catalog is in
   the value of a PTR record in the old catalog.  For example if member
   "example.com." will migrate from catalog zone $OLDCATZ to catalog
   zone $NEWCATZ, this appears in the $OLDCATZ catalog zone as follows:

   <unique-N>.zones.$OLDCATZ 0 IN PTR example.com.
   coo.<unique-N>.zones.$OLDCATZ 0 IN PTR $NEWCATZ

   The PTR RRset MUST consist of a single PTR record.  More than one
   record in the RRset denotes a broken catalog zone which MUST NOT be
   processed (see Section 5.1).

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   When a consumer of catalog zone $OLDCATZ receives an update which
   adds or changes a coo property for a member zone in $OLDCATZ
   signalling a new owner $NEWCATZ, it does _not_ migrate the member
   zone immediately.

   This is because the catalog consumer may not have the <unique-N>
   identifier associated with the member zone in $NEWCATZ and because
   name servers do not index Resource Records by RDATA, it may not know
   whether or not the member zone is configured in $NEWCATZ at all.  It
   may have to wait for an update of $NEWCATZ adding or changing that
   member zone.  When a consumer of catalog zone $NEWCATZ receives an
   update of $NEWCATZ which adds or changes a member zone, _and_ that
   consumer had the member zone associated with $OLDCATZ, _and_ there is
   a coo property of the member zone in $OLDCATZ pointing to $NEWCATZ,
   _only then_ it will reconfigure the member zone with the for $NEWCATZ
   preconfigured settings.

   Unless the member node label (i.e. <unique-N>) for the member is the
   same in $NEWCATZ, all associated state for a just migrated zone MUST
   be reset (see Section 5.6).  Note that the owner of $OLDCATZ allows
   for the zone associated state to be taken over by the owner of
   $NEWCATZ by default.  To prevent the takeover, the owner of $OLDCATZ
   has to enforce a zone state reset by changing the member node label
   (see Section 5.6) before or simultaneous with adding the coo
   property. (see also Section 7)

   The old owner may remove the member zone containing the coo property
   from $OLDCATZ once it has been established that all its consumers
   have processed the Change of Ownership.

4.4.2.  Groups (group property)

   With a group property, consumer(s) can be signalled to treat some
   member zones within the catalog zone differently.

   The consumer MAY apply different configuration options when
   processing member zones, based on the value of the group property.
   The exact handling of configuration referred to by the group property
   value is left to the consumer's implementation and configuration.
   The property is defined by a TXT record in the sub-node labelled

   The producer MAY assign a group property to all, some, or none of the
   member zones within a catalog zone.  The producer MUST NOT assign
   more than one group property to one member zone.

   The consumer MUST ignore either all or none of the group properties
   in a catalog zone.

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   The value of the TXT record MUST be at most 255 octets long and MUST
   NOT contain whitespace characters.  The consumer MUST interpret the
   value case-sensitively.  Example

   <unique-1>.zones.$CATZ        0 IN PTR    example.com.
   group.<unique-1>.zones.$CATZ  0 IN TXT    sign-with-nsec3
   <unique-2>.zones.$CATZ        0 IN PTR    example.net.
   group.<unique-2>.zones.$CATZ  0 IN TXT    nodnssec

   In this case, the consumer might be implemented and configured in the
   way that the member zones with "nodnssec" group assigned will not be
   signed with DNSSEC, and the zones with "sign-with-nsec3" group
   assigned will be signed with DNSSEC with NSEC3 chain.

   By generating the catalog zone (snippet) above, the producer signals
   how the consumer shall treat DNSSEC for the zones example.net. and
   example.com., respectively.

4.5.  Custom Properties (*.ext properties)

   Implementations and operators of catalog zones may choose to provide
   their own properties.  Custom properties can occur both globally, or
   for a specific member zone.  To prevent a name clash with future
   properties, such properties should be represented below the label

   ext is not a placeholder, so a custom property would have domains
   names as follows:

<your-property>.ext.$CATZ                   # for a global custom property
<your-property>.ext.<unique-N>.zones.$CATZ  # for a member zone custom property

   <your-property> may consist of one or more labels.

   Implementations MAY use such properties on the member zone level to
   store additional information about member zones, for example to flag
   them for specific treatment (such as ...).

   Further, implementations MAY use custom properties on the global
   level to store additional information about the catalog zone itself.
   While there may be many use cases for this, a plausible one is to
   store default values for custom properties on the global level, then
   overriding them using a property of the same name on the member level
   (= under the ext label of the member node) if so desired.  A property
   description should clearly say what semantics apply, and whether a
   property is global, member, or both.

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   The meaning of the custom properties described in this section is
   determined by the implementation alone, without expectation of
   interoperability.  A catalog consumer SHOULD ignore custom properties
   it does not understand.

5.  Nameserver Behavior

5.1.  General Requirements

   As it is a regular DNS zone, a catalog zone can be transferred using
   DNS zone transfers among nameservers.

   Although they are regular DNS zones, catalog zones contain only
   information for the management of a set of authoritative nameservers.
   For this reason, operators may want to limit the systems able to
   query these zones.  It may be inconvenient to serve some contents of
   catalog zones via DNS queries anyway due to the nature of their
   representation.  A separate method of querying entries inside the
   catalog zone may be made available by nameserver implementations (see
   Section 6).

   Catalog updates should be automatic, i.e., when a nameserver that
   supports catalog zones completes a zone transfer for a catalog zone,
   it SHOULD apply changes to the catalog within the running nameserver
   automatically without any manual intervention.

   As with regular zones, primary and secondary nameservers for a
   catalog zone may be operated by different administrators.  The
   secondary nameservers may be configured as catalog consumer to
   synchronize catalog zones from the primary, but the primary's
   administrators may not have any administrative access to the

   Nameservers MAY allow loading and transfer of broken zones with
   incorrect catalog zone syntax (as they are treated as regular zones),
   but catalog consumers MUST NOT process such broken zones as catalog
   zones.  For the purpose of catalog processing, the broken catalogs
   MUST be ignored.

5.2.  Member zone name clash

   If there is a clash between an existing zone's name (either from an
   existing member zone or otherwise configured zone) and an incoming
   member zone's name (via transfer or update), the new instance of the
   zone MUST be ignored and an error SHOULD be logged.

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   A clash between an existing member zone's name and an incoming member
   zone's name (via transfer or update), may be an attempt to migrate a
   zone to a different catalog, but should not be treated as one except
   as described in {#cooproperty}.

5.3.  Member zone removal

   When a member zone is removed from a specific catalog zone, an
   authoritative server MUST NOT remove the zone and associated state
   data if the zone was not configured from that specific catalog zone.
   Only when the zone was configured from a specific catalog zone, and
   the zone is removed as a member from that specific catalog zone, the
   zone and associated state (such as zone data and DNSSEC keys) MUST be

5.4.  Member node name change

   When via a single update or transfer, the member node's label value
   (<unique-N>) changes, catalog consumers MUST process this as a member
   zone removal including all the zone's associated state (as described
   in Section 5.3), immediately followed by processing the member as a
   newly to be configured zone in the same catalog.

5.5.  Migrating member zones between catalogs

   If all consumers of the catalog zones involved support the coo
   property, it is RECOMMENDED to perform migration of a member zone by
   following the procedure described in Section 4.4.1.  Otherwise a
   migration of member zone from a catalog zone $OLDCATZ to a catalog
   zone $NEWCATZ has to be done by: first removing the member zone from
   $OLDCATZ; second adding the member zone to $NEWCATZ.

   If in the process of a migration some consumers of the involved
   catalog zones did not catch the removal of the member zone from
   $OLDCATZ yet (because of a lost packet or down time or otherwise),
   but did already see the update of $NEWCATZ, they may consider the
   update adding the member zone in $NEWCATZ to be a name clash (see
   Section 5.2) and as a consequence the member is not migrated to
   $NEWCATZ.  This possibility needs to be anticipated with a member
   zone migration.  Recovery from such a situation is out of the scope
   of this document.  It may for example entail a manually forced
   retransfer of $NEWCATZ to consumers after they have been detected to
   have received and processed the removal of the member zone from

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5.6.  Zone associated state reset

   It may be desirable to reset state (such as zone data and DNSSEC
   keys) associated with a member zone.

   A zone state reset may be performed by a change of the member node's
   name (see Section 5.4).

6.  Implementation Notes

   Catalog zones on secondary nameservers would have to be setup
   manually, perhaps as static configuration, similar to how ordinary
   DNS zones are configured.  The secondary additionally needs to be
   configured as a catalog consumer for the catalog zone to enable
   processing of the member zones in the catalog, such as automatic
   synchronized of the member zones for secondary service.

   An administrator may want to look at data inside a catalog zone.
   Typical queries might include dumping the list of member zones,
   dumping a member zone's effective configuration, querying a specific
   property value of a member zone, etc.  Because of the structure of
   catalog zones, it may not be possible to perform these queries
   intuitively, or in some cases, at all, using DNS QUERY.  For example,
   it is not possible to enumerate the contents of a multi-valued
   property (such as the list of member zones) with a single QUERY.
   Implementations are therefore advised to provide a tool that uses
   either the output of AXFR or an out-of-band method to perform queries
   on catalog zones.

7.  Security Considerations

   As catalog zones are transmitted using DNS zone transfers, it is
   RECOMMENDED that catalog zone transfer are protected from unexpected
   modifications by way of authentication, for example by using TSIG
   [RFC8945], or Strict or Mutual TLS authentication with DNS Zone
   transfer over TLS [RFC9103].

   Use of DNS UPDATE [RFC2136] to modify the content of catalog zones
   SHOULD similarly be authenticated.

   Zone transfers of member zones SHOULD similarly be authenticated.
   TSIG shared secrets used for member zones SHOULD NOT be mentioned in
   the catalog zone data.  However, key identifiers may be shared within
   catalog zones.

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   Catalog zones reveal the zones served by the consumers of the catalog
   zone.  It is RECOMMENDED to limit the systems able to query these
   zones.  It is RECOMMENDED to transfer catalog zones confidentially

   Administrative control over what zones are served from the configured
   name servers shifts completely from the server operator (consumer) to
   the "owner" (producer) of the catalog zone content.

   With migration of member zones between catalogs using the coo
   property, it is possible for the owner of the target catalog (i.e.
   $NEWCATZ) to take over all associated state with the zone from the
   original owner (i.e. $OLDCATZ) by maintaining the same member node
   label (i.e. <unique-N>).  To prevent the takeover of the zone
   associated state, the original owner has to enforce a zone state
   reset by changing the member node label (see Section 5.6) before or
   simultaneously with adding the coo property.

8.  Acknowledgements

   Our deepest thanks and appreciation go to Stephen Morris, Ray Bellis
   and Witold Krecicki who initiated this draft and did the bulk of the

   Catalog zones originated as the chosen method among various proposals
   that were evaluated at ISC for easy zone management.  The chosen
   method of storing the catalog as a regular DNS zone was proposed by
   Stephen Morris.

   The initial authors discovered that Paul Vixie's earlier [Metazones]
   proposal implemented a similar approach and reviewed it.  Catalog
   zones borrows some syntax ideas from Metazones, as both share this
   scheme of representing the catalog as a regular DNS zone.

   Thanks to Leo Vandewoestijne.  Leo's presentation in the DNS devroom
   at the FOSDEM'20 [FOSDEM20] was one of the motivations to take up and
   continue the effort of standardizing catalog zones.

   Thanks to Brian Conry, Klaus Darilion, Brian Dickson, Tony Finch,
   Evan Hunt, Shane Kerr, Patrik Lundin, Victoria Risk, Petr Spacek and
   Carsten Strotmann for reviewing draft proposals and offering comments
   and suggestions.

9.  Normative References

   [RFC1035]  Mockapetris, P., "Domain names - implementation and
              specification", STD 13, RFC 1035, DOI 10.17487/RFC1035,
              November 1987, <https://www.rfc-editor.org/info/rfc1035>.

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   [RFC1982]  Elz, R. and R. Bush, "Serial Number Arithmetic", RFC 1982,
              DOI 10.17487/RFC1982, August 1996,

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,

   [RFC2136]  Vixie, P., Ed., Thomson, S., Rekhter, Y., and J. Bound,
              "Dynamic Updates in the Domain Name System (DNS UPDATE)",
              RFC 2136, DOI 10.17487/RFC2136, April 1997,

   [RFC2606]  Eastlake 3rd, D. and A. Panitz, "Reserved Top Level DNS
              Names", BCP 32, RFC 2606, DOI 10.17487/RFC2606, June 1999,

   [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>.

   [RFC8945]  Dupont, F., Morris, S., Vixie, P., Eastlake 3rd, D.,
              Gudmundsson, O., and B. Wellington, "Secret Key
              Transaction Authentication for DNS (TSIG)", STD 93,
              RFC 8945, DOI 10.17487/RFC8945, November 2020,

   [RFC9103]  Toorop, W., Dickinson, S., Sahib, S., Aras, P., and A.
              Mankin, "DNS Zone Transfer over TLS", RFC 9103,
              DOI 10.17487/RFC9103, August 2021,

10.  Informative References

   [FOSDEM20] Vandewoestijne, L., "Extending Catalog zones - another
              approach in automating maintenance", 2020,

              Vixie, P., "Federated Domain Name Service Using DNS
              Metazones", 2005,

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Appendix A.  Implementation Status

   *Note to the RFC Editor*: please remove this entire section before

   In the following implementation status descriptions, "DNS Catalog
   Zones" refers to DNS Catalog Zones as described in this document.

   *  Knot DNS 3.1 (released August 2, 2021) supports full producing and
      consuming of catalog zones, including the group property.

   *  PowerDNS has a proof of concept external program called PowerCATZ
      (https://github.com/PowerDNS/powercatz/), that can process DNS
      Catalog Zones.

   *  Proof of concept python scripts (https://github.com/IETF-
      Hackathon/NSDCatZ) that can be used for both generating and
      consuming DNS Catalog Zones with NSD have been developed during
      the hackathon at the IETF-109.

   Interoperability between the above implementations has been tested
   during the hackathon at the IETF-109.

Appendix B.  Change History (to be removed before final publication)

   *  draft-muks-dnsop-dns-catalog-zones-00

   |  Initial public draft.

   *  draft-muks-dnsop-dns-catalog-zones-01

   |  Added Witold, Ray as authors.  Fixed typos, consistency issues.
   |  Fixed references.  Updated Area.  Removed newly introduced custom
   |  RR TYPEs.  Changed schema version to 1.  Changed TSIG requirement
   |  from MUST to SHOULD.  Removed restrictive language about use of
   |  DNS QUERY.  When zones are introduced into a catalog zone, a
   |  primary SHOULD first make the new zones available for transfers
   |  first (instead of MUST).  Updated examples, esp. use IPv6 in
   |  examples per Fred Baker.  Add catalog zone example.

   *  draft-muks-dnsop-dns-catalog-zones-02

   |  Addressed some review comments by Patrik Lundin.

   *  draft-muks-dnsop-dns-catalog-zones-03

   |  Revision bump.

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   *  draft-muks-dnsop-dns-catalog-zones-04

   |  Reordering of sections into more logical order.  Separation of
   |  multi-valued properties into their own category.

   *  draft-toorop-dnsop-dns-catalog-zones-00

   |  New authors to pickup the editor pen on this draft
   |  Remove data type definitions for zone properties Removing
   |  configuration of member zones through zone properties altogether
   |  Remove Open issues and discussion Appendix, which was about zone
   |  options (including primary/secondary relationships) only.

   *  draft-toorop-dnsop-dns-catalog-zones-01

   |  Added a new section "The Serial Property", introducing a new
   |  mechanism which can help with disseminating zones from the primary
   |  to the secondary nameservers in a timely fashion more reliably.
   |  Three different ways to provide a "serial" property with a member
   |  zone are offered to or the workgroup for discussion.
   |  Added a new section "Implementation Status", listing production
   |  ready, upcoming and Proof of Concept implementations, and
   |  reporting on interoperability of the different implementations.

   *  draft-toorop-dnsop-dns-catalog-zones-02

   |  Adding the coo property for zone migration in a controlled fashion
   |  Adding the group property for reconfigure settings of member zones
   |  in an atomic update
   |  Adding the epoch property to reset zone associated state in a
   |  controlled fashion

   *  draft-toorop-dnsop-dns-catalog-zones-03

   |  Big cleanup!
   |  Introducing the terms catalog consumer and catalog producer
   |  Reorganized topics to create a more coherent whole
   |  Properties all have consistent format now

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   |  Try to assume the least possible from implementations w.r.t.:
   |  1) Predictability of the <unique-N> IDs of member zones
   |  2) Whether or not fallback catalog zones can be found for a member
   |  3) Whether or not a catalog consumer can maintain state

   *  draft-toorop-dnsop-dns-catalog-zones-04

   |  Move Implementation status to appendix
   |  Miscellaneous textual improvements
   |  coo property points to $NEWCATZ (and not zones.$NEWCATZ)
   |  Remove suggestion to increase serial and remove member zone from
   |  $OLDCATZ after migration
   |  More consistent usage of the terms catalog consumer and catalog
   |  producer throughout the document
   |  Better (safer) description of resetting refresh timers of member
   |  zones with the serial property
   |  Removing a member MUST remove zone associated state
   |  Make authentication requirements a bit less prescriptive in
   |  security considerations
   |  Updated implementation status for KnotDNS
   |  Describe member node name changes and update "Zone associated
   |  state reset" to use that as the mechanism for it.
   |  Add Peter Thomassen as co-author
   |  Complete removal of the epoch property.  We consider consumer
   |  optimizations with predictable member node labels (for example
   |  based on a hash) out of the scope of this document.
   |  Miscellaneous editorial improvements

   *  draft-toorop-dnsop-dns-catalog-zones-05

   |  Add Kees Monshouwer as co-author
   |  Removed the "serial" property

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   |  Allow custom properties on the global level

Authors' Addresses

   Peter van Dijk
   Den Haag
   Email: peter.van.dijk@powerdns.com

   Libor Peltan
   Email: libor.peltan@nic.cz

   Ondrej Sury
   Internet Systems Consortium
   Email: ondrej@isc.org

   Willem Toorop
   NLnet Labs
   Science Park 400
   1098 XH Amsterdam
   Email: willem@nlnetlabs.nl

   Kees Monshouwer
   Email: mind@monshouwer.eu

   Peter Thomassen
   deSEC, SSE - Secure Systems Engineering
   Email: peter@desec.io

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