idnits 2.17.1 draft-ietf-dnsop-dns-catalog-zones-01.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == Using lowercase 'not' together with uppercase 'MUST', 'SHALL', 'SHOULD', or 'RECOMMENDED' is not an accepted usage according to RFC 2119. Please use uppercase 'NOT' together with RFC 2119 keywords (if that is what you mean). Found 'MUST not' in this paragraph: When a "serial" property is present for a member zone and it matches the SOA serial of that member zone, implementations of catalog zones which are secondary for that member zone MAY ignore the refresh time in the SOA record of the member zone and rely on updates via the "serial" property of the member zone. A refresh timer of a catalog zone MUST not be ignored. -- The document date (4 December 2020) is 1239 days in the past. Is this intentional? -- Found something which looks like a code comment -- if you have code sections in the document, please surround them with '' and '' lines. Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) No issues found here. Summary: 0 errors (**), 0 flaws (~~), 2 warnings (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 DNSOP Working Group P. van Dijk 3 Internet-Draft PowerDNS 4 Intended status: Standards Track L. Peltan 5 Expires: 7 June 2021 CZ.NIC 6 O. Sury 7 Internet Systems Consortium 8 W. Toorop 9 NLnet Labs 10 L. Vandewoestijne 11 4 December 2020 13 DNS Catalog Zones 14 draft-ietf-dnsop-dns-catalog-zones-01 16 Abstract 18 This document describes a method for automatic DNS zone provisioning 19 among DNS primary and secondary nameservers by storing and 20 transferring the catalog of zones to be provisioned as one or more 21 regular DNS zones. 23 Status of This Memo 25 This Internet-Draft is submitted in full conformance with the 26 provisions of BCP 78 and BCP 79. 28 Internet-Drafts are working documents of the Internet Engineering 29 Task Force (IETF). Note that other groups may also distribute 30 working documents as Internet-Drafts. The list of current Internet- 31 Drafts is at https://datatracker.ietf.org/drafts/current/. 33 Internet-Drafts are draft documents valid for a maximum of six months 34 and may be updated, replaced, or obsoleted by other documents at any 35 time. It is inappropriate to use Internet-Drafts as reference 36 material or to cite them other than as "work in progress." 38 This Internet-Draft will expire on 7 June 2021. 40 Copyright Notice 42 Copyright (c) 2020 IETF Trust and the persons identified as the 43 document authors. All rights reserved. 45 This document is subject to BCP 78 and the IETF Trust's Legal 46 Provisions Relating to IETF Documents (https://trustee.ietf.org/ 47 license-info) in effect on the date of publication of this document. 48 Please review these documents carefully, as they describe your rights 49 and restrictions with respect to this document. Code Components 50 extracted from this document must include Simplified BSD License text 51 as described in Section 4.e of the Trust Legal Provisions and are 52 provided without warranty as described in the Simplified BSD License. 54 Table of Contents 56 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 57 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 58 3. Description . . . . . . . . . . . . . . . . . . . . . . . . . 3 59 4. Catalog Zone Structure . . . . . . . . . . . . . . . . . . . 4 60 4.1. SOA and NS Records . . . . . . . . . . . . . . . . . . . 4 61 4.2. Catalog Zone Schema Version . . . . . . . . . . . . . . . 4 62 4.3. List of Member Zones . . . . . . . . . . . . . . . . . . 5 63 5. The Serial Property . . . . . . . . . . . . . . . . . . . . . 6 64 5.1. The SERIAL Resource Record . . . . . . . . . . . . . . . 7 65 5.2. SERIAL RDATA Wire Format . . . . . . . . . . . . . . . . 7 66 5.2.1. The Serial Field . . . . . . . . . . . . . . . . . . 7 67 5.3. SERIAL Presentation Format . . . . . . . . . . . . . . . 7 68 5.4. SERIAL RR Usage - option 1 . . . . . . . . . . . . . . . 7 69 5.5. SERIAL RR Usage - option 2 . . . . . . . . . . . . . . . 8 70 5.6. Serial property as TXT RR - option 3 . . . . . . . . . . 8 71 6. Nameserver Behavior . . . . . . . . . . . . . . . . . . . . . 8 72 6.1. General Requirements . . . . . . . . . . . . . . . . . . 8 73 7. Updating Catalog Zones . . . . . . . . . . . . . . . . . . . 10 74 7.1. Implementation Notes . . . . . . . . . . . . . . . . . . 10 75 8. Implementation Status . . . . . . . . . . . . . . . . . . . . 10 76 9. Security Considerations . . . . . . . . . . . . . . . . . . . 11 77 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 78 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11 79 12. Normative References . . . . . . . . . . . . . . . . . . . . 12 80 13. Informative References . . . . . . . . . . . . . . . . . . . 13 81 Appendix A. Change History (to be removed before final 82 publication) . . . . . . . . . . . . . . . . . . . . . . 13 83 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14 85 1. Introduction 87 The data in a DNS zone is synchronized amongst its primary and 88 secondary nameservers using AXFR and IXFR. However, the list of 89 zones served by the primary (called a catalog in [RFC1035]) is not 90 automatically synchronized with the secondaries. To add or remove a 91 zone, the administrator of a DNS nameserver farm not only has to add 92 or remove the zone from the primary, they must also add/remove the 93 zone from all secondaries, either manually or via an external 94 application. This can be both inconvenient and error-prone; it is 95 also dependent on the nameserver implementation. 97 This document describes a method in which the catalog is represented 98 as a regular DNS zone (called a "catalog zone" here), and transferred 99 using DNS zone transfers. As zones are added to or removed from the 100 catalog zone, the changes are propagated to the secondary nameservers 101 in the normal way. The secondary nameservers then add/remove/modify 102 the zones they serve in accordance with the changes to the zone. 104 The contents and representation of catalog zones are described in 105 Section 3. Nameserver behavior is described in Section 6. 107 2. Terminology 109 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 110 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 111 "OPTIONAL" in this document are to be interpreted as described in BCP 112 14 [RFC2119] [RFC8174] when, and only when, they appear in all 113 capitals, as shown here. 115 Catalog zone A DNS zone containing a DNS catalog, that is, a list of 116 DNS zones. 118 Member zone A DNS zone whose configuration is published inside a 119 catalog zone. 121 $CATZ Used in examples as a placeholder to represent the domain name 122 of the catalog zone itself (c.f. $ORIGIN). 124 3. Description 126 A catalog zone is a specially crafted DNS zone that contains, as DNS 127 zone data: 129 * A list of DNS zones (called "member zones"). 131 Implementations of catalog zones SHOULD ignore any RR in the catalog 132 zone which is meaningless or useless to the implementation. 134 Authoritative servers may be preconfigured with multiple catalog 135 zones, each associated with a different set of configurations. A 136 member zone can as such be reconfigured with a different set of 137 preconfigured settings by removing it as a member of one catalog zone 138 and making it a member of another. 140 An implementation of catalog zones MAY allow the catalog to contain 141 other catalog zones as member zones. 143 Although the contents of a catalog zone are interpreted and acted 144 upon by nameservers, a catalog zone is a regular DNS zone and so must 145 adhere to the standards for such zones. 147 A catalog zone is primarily intended for the management of a farm of 148 authoritative nameservers. It is not expected that the content of 149 catalog zones will be accessible from any recursive nameserver. 151 4. Catalog Zone Structure 153 4.1. SOA and NS Records 155 As with any other DNS zone, a catalog zone MUST have a syntactically 156 correct SOA record and at least one NS record at its apex. 158 The SOA record's SERIAL, REFRESH, RETRY and EXPIRE fields [RFC1035] 159 are used during zone transfer. A catalog zone's SOA SERIAL field 160 MUST increase when an update is made to the catalog zone's contents 161 as per serial number arithmetic defined in [RFC1982]. Otherwise, 162 secondary nameservers might not notice updates to the catalog zone's 163 contents. 165 Should the zone be made available for querying, the SOA record's 166 MINIMUM field's value is the negative cache time (as defined in 167 [RFC2308]). Since recursive nameservers are not expected to be able 168 to access (and subsequently cache) entries from a catalog zone a 169 value of zero (0) is RECOMMENDED. 171 There is no requirement to be able to query the catalog zone via 172 recursive nameservers. Implementations of catalog zones MUST ignore 173 and MUST NOT assume or require NS records at the apex. However, at 174 least one is still required so that catalog zones are syntactically 175 correct DNS zones. A single NS RR with an NSDNAME field containing 176 the absolute name "invalid." is RECOMMENDED [RFC2606]. 178 4.2. Catalog Zone Schema Version 180 The catalog zone schema version is specified by an integer value 181 embeded in a TXT RR named "version.$CATZ". All catalog zones MUST 182 have a TXT RRset named "version.$CATZ" with at least one RR. Primary 183 and secondary nameservers MUST NOT use catalog zones without the 184 expected value in one of the RRs in the "version.$CATZ" TXT RRset, 185 but they may be transferred as ordinary zones. For this memo, the 186 value of one of the RRs in the "version.CATZ" TXT RRset MUST be set 187 to "2", i.e. 189 version.$CATZ 0 IN TXT "2" 190 NB: Version 1 was used in a draft version of this memo and reflected 191 the implementation first found in BIND 9.11. 193 4.3. List of Member Zones 195 The list of member zones is specified as a collection of domain names 196 under the owner name "zones" where "zones" is a direct child domain 197 of the catalog zone. 199 The names of member zones are represented on the RDATA side (instead 200 of as a part of owner names) so that all valid domain names may be 201 represented regardless of their length [RFC1035]. 203 For example, if a catalog zone lists three zones "example.com.", 204 "example.net." and "example.org.", the RRs would appear as follows: 206 .zones.$CATZ 0 IN PTR example.com. 207 .zones.$CATZ 0 IN PTR example.net. 208 .zones.$CATZ 0 IN PTR example.org. 210 where "" is a label that tags each record in the 211 collection. Nameservers MUST accept catalog zones even with those 212 labels not really unique; they MAY warn the user in such case. 214 Having a large number of member zones in a single RRset may cause the 215 RRset to be too large to be conveyed via DNS messages which make up a 216 zone transfer. Having the zones uniquely tagged with the "" label ensures the list of member zones can be split over multiple 218 DNS messages in a zone transfer. 220 The "" label also enables the state for a zone to be 221 reset. (see Section 6.1, Paragraph 9) As long as no zone state needs 222 to be reset at the authoritative nameservers, the unique label 223 associated with a zone SHOULD remain the same. 225 The CLASS field of every RR in a catalog zone MUST be IN (1). 227 The TTL field's value is not specially defined by this memo. Catalog 228 zones are for authoritative nameserver management only and are not 229 intended for general querying via recursive resolvers and therefore a 230 value of zero (0) is RECOMMENDED. 232 Each RRSet of catalog zone, with the exception of the zone apex, 233 SHOULD consist of just one RR. It's acceptable to generate owner 234 names with the help of a sufficiently strong hash function, with 235 small probablity that unrelated records fall within the same RRSet. 237 5. The Serial Property 239 The current default mechanism for prompting notifications of zone 240 changes from a primary nameserver to the secondaries via DNS NOTIFY 241 [RFC1996], can be unreliable due to packet loss, or secondary 242 nameservers temporarily not being reachable. In such cases the 243 secondary might pick up the change only after the refresh timer runs 244 out, which might be long and out of the control of the nameserver 245 operator. Low refresh values in the zones being served can alleviate 246 update delays, but burdens the primary nameserver more severely with 247 more refresh queries, especially with larger numbers of secondary 248 nameservers serving large numbers of zones. Alternatively updates of 249 zones MAY be signalled via catalog zones with the help of a "serial" 250 property. 252 The serial number in the SOA record of the most recent version of a 253 member zone MAY be provided by a "serial" property. When a "serial" 254 property is present for a member zone, implementations of catalog 255 zones MAY assume this number to be the current serial number in the 256 SOA record of the most recent version of the member zone. 258 Nameservers that are secondary for that member zone, MAY compare the 259 "serial" property with the SOA serial since the last time the zone 260 was fetched. When the "serial" property is larger, the secondary MAY 261 initiate a zone tranfer immediately without doing a SOA query first. 262 The transfer MUST be aborted immediately when the serial number of 263 the SOA resource record in the transfer is not larger than the SOA 264 serial of the zone currently being served. In that case the zone 265 transfer should be retried after the time given in the retry field of 266 the SOA record of the member zone, or earlier if a new SOA serial 267 number is learned via an updated "serial" property, or via NOTIFY 268 [RFC1996]. 270 When a "serial" property is present for a member zone and it matches 271 the SOA serial of that member zone, implementations of catalog zones 272 which are secondary for that member zone MAY ignore the refresh time 273 in the SOA record of the member zone and rely on updates via the 274 "serial" property of the member zone. A refresh timer of a catalog 275 zone MUST not be ignored. 277 Primary nameservers MAY be configured to omit sending DNS NOTIFY 278 messages to secondary nameservers which are known to process the 279 "serial" property of the member zones in that catalog. However they 280 MAY also combine signalling of zone changes with the "serial" 281 property of a member zone, as well as sending DNS NOTIFY messages, to 282 anticipate slow updates of the catalog zone (due to packet loss or 283 other reasons) and to cater for secondaries that do not process the 284 "serial" property. 286 All comparisons of serial numbers MUST use "Serial number 287 arithmetic", as defined in [RFC1982] 289 *Note to the DNSOP Working Group*: In this section we present three 290 ways to provide a "serial" property with a member zone. The first 291 two ways make use of a new Resource Record type: SERIAL as described 292 in Section 5.1, Section 5.2 and Section 5.3. The two different ways 293 to provide a "serial" property with the SERIAL RR are described in 294 Section 5.4 and Section 5.5 respectively. The third way is with a 295 TXT RR and is described in Section 5.6. 297 5.1. The SERIAL Resource Record 299 The "serial" property value is provided with a SERIAL Resource 300 Record. The Type value for the SERIAL RR is TBD. The SERIAL RR is 301 class independent. The RDATA of the resource record consist of a 302 single field: Serial. 304 5.2. SERIAL RDATA Wire Format 306 The SERIAL RDATA wire format is encoded as follows: 308 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 309 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 310 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 311 | Serial | 312 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 314 5.2.1. The Serial Field 316 The Serial field is a 32-bit unsigned integer in network byte order. 317 It is the serial number of the member zone's SOA record ([RFC1035] 318 section 3.3.13). 320 5.3. SERIAL Presentation Format 322 The presentation format of the RDATA portion is as follows: 324 The Serial fields is represented as an unsigned decimal integer. 326 5.4. SERIAL RR Usage - option 1 328 The "serial" property of a member zone is provided by a SERIAL RRset 329 with a single SERIAL RR named "serial..zones.$CATZ". 331 For example, if a catalog zone lists three zones "example.com.", 332 "example.net." and "example.org.", and a "serial" property is 333 provided for each of them, the RRs would appear as follows: 335 .zones.$CATZ 0 IN PTR example.com. 336 serial..zones.$CATZ 0 IN SERIAL 2020111712 337 .zones.$CATZ 0 IN PTR example.net. 338 serial..zones.$CATZ 0 IN SERIAL 2020111709 339 .zones.$CATZ 0 IN PTR example.org. 340 serial..zones.$CATZ 0 IN SERIAL 2020112405 342 5.5. SERIAL RR Usage - option 2 344 The "serial" property of a member zone is provided by a SERIAL RRset 345 on the same owner name as the PTR RR of the member zone. 347 For example, if a catalog zone lists three zones "example.com.", 348 "example.net." and "example.org.", and a "serial" property is 349 provided for each of them, the RRs would appear as follows: 351 .zones.$CATZ 0 IN PTR example.com. 352 .zones.$CATZ 0 IN SERIAL 2020111712 353 .zones.$CATZ 0 IN PTR example.net. 354 .zones.$CATZ 0 IN SERIAL 2020111709 355 .zones.$CATZ 0 IN PTR example.org. 356 .zones.$CATZ 0 IN SERIAL 2020112405 358 5.6. Serial property as TXT RR - option 3 360 The "serial" property of a member zone is provided by a TXT RRset 361 with a single TXT RR named "serial..zones.$CATZ". The 362 TXT RR contains a single RDATA field consisting of the textual 363 representation of the SOA serial number. 365 For example, if a catalog zone lists three zones "example.com.", 366 "example.net." and "example.org.", and a "serial" property is 367 provided for each of them, the RRs would appear as follows: 369 .zones.$CATZ 0 IN PTR example.com. 370 serial..zones.$CATZ 0 IN TXT 2020111712 371 .zones.$CATZ 0 IN PTR example.net. 372 serial..zones.$CATZ 0 IN TXT 2020111709 373 .zones.$CATZ 0 IN PTR example.org. 374 serial..zones.$CATZ 0 IN TXT 2020112405 376 6. Nameserver Behavior 378 6.1. General Requirements 380 As it is a regular DNS zone, a catalog zone can be transferred using 381 DNS zone transfers among nameservers. 383 Although they are regular DNS zones, catalog zones contain only 384 information for the management of a set of authoritative nameservers. 385 For this reason, operators may want to limit the systems able to 386 query these zones. It may be inconvenient to serve some contents of 387 catalog zones via DNS queries anyway due to the nature of their 388 representation. A separate method of querying entries inside the 389 catalog zone may be made available by nameserver implementations (see 390 Section 7.1). 392 Catalog updates should be automatic, i.e., when a nameserver that 393 supports catalog zones completes a zone transfer for a catalog zone, 394 it SHOULD apply changes to the catalog within the running nameserver 395 automatically without any manual intervention. 397 As with regular zones, primary and secondary nameservers for a 398 catalog zone may be operated by different administrators. The 399 secondary nameservers may be configured to synchronize catalog zones 400 from the primary, but the primary's administrators may not have any 401 administrative access to the secondaries. 403 A catalog zone can be updated via DNS UPDATE on a reference primary 404 nameserver, or via zone transfers. Nameservers MAY allow loading and 405 transfer of broken zones with incorrect catalog zone syntax (as they 406 are treated as regular zones), but nameservers MUST NOT process such 407 broken zones as catalog zones. For the purpose of catalog 408 processing, the broken catalogs MUST be ignored. If a broken catalog 409 zone was transferred, the newly transferred catalog zone MUST be 410 ignored (but the older copy of the catalog zone SHOULD be left 411 running subject to values in SOA fields). 413 If there is a clash between an existing member zone's name and an 414 incoming member zone's name (via transfer or update), the new 415 instance of the zone MUST be ignored and an error SHOULD be logged. 417 When zones are introduced into a catalog zone, a primary SHOULD first 418 make the new zones available for transfers before making the updated 419 catalog zone available for transfer, or sending NOTIFY for the 420 catalog zone to secondaries. Note that secondary nameservers may 421 attempt to transfer the catalog zone upon refresh timeout, so care 422 must be taken to make the member zones available before any update to 423 the list of member zones is visible in the catalog zone. 425 When zones are deleted from a catalog zone, a primary MAY delete the 426 member zone immediately after notifying secondaries. It is up to the 427 secondary nameserver to handle this condition correctly. 429 When the "" label of a member zone changes, all its 430 associated state MUST be reset, including the zone itself. This can 431 be relevant for example when zone ownership is changed. In that case 432 one does not want the new owner to inherit the metadata. Other 433 situations might be resetting DNSSEC state, or forcing a new zone 434 transfer. A simple removal followed by an addition of the member 435 zone would be insufficient for this purpose because it is infeasible 436 for secondaries to track, due to missed notifies or being offline 437 during the removal/addition. 439 7. Updating Catalog Zones 441 TBD: Explain updating catalog zones using DNS UPDATE. 443 7.1. Implementation Notes 445 Catalog zones on secondary nameservers would have to be setup 446 manually, perhaps as static configuration, similar to how ordinary 447 DNS zones are configured. Members of such catalog zones will be 448 automatically synchronized by the secondary after the catalog zone is 449 configured. 451 An administrator may want to look at data inside a catalog zone. 452 Typical queries might include dumping the list of member zones, 453 dumping a member zone's effective configuration, querying a specific 454 property value of a member zone, etc. Because of the structure of 455 catalog zones, it may not be possible to perform these queries 456 intuitively, or in some cases, at all, using DNS QUERY. For example 457 it is not possible to enumerate the contents of a multi-valued 458 property (such as the list of member zones) with a single QUERY. 459 Implementations are therefore advised to provide a tool that uses 460 either the output of AXFR or an out-of-band method to perform queries 461 on catalog zones. 463 8. Implementation Status 465 *Note to the RFC Editor*: please remove this entire section before 466 publication. 468 In the following implementation status descriptions, "DNS Catalog 469 Zones" refers to DNS Catalog Zones as described in this document. 471 * Knot DNS has processing of DNS Catalog Zones since Knot DNS 472 Version 3.0.0, which was released on September 9, 2020. 474 * Knot DNS has generation of DNS Catalog Zones on a development 475 branch (https://gitlab.nic.cz/knot/knot-dns/-/tree/ 476 catalog_generate). 478 * PowerDNS has a proof of concept external program called PowerCATZ 479 (https://github.com/PowerDNS/powercatz/), that can process DNS 480 Catalog Zones. 482 * Proof of concept python scripts (https://github.com/IETF- 483 Hackathon/NSDCatZ) that can be used for both generating and 484 consuming DNS Catalog Zones with NSD have been developed during 485 the hackathon at the IETF-109. 487 Interoperability between the above implementations has been tested 488 during the hackathon at the IETF-109. 490 9. Security Considerations 492 As catalog zones are transmitted using DNS zone transfers, it is key 493 for these transfers to be protected from unexpected modifications on 494 the route. So, catalog zone transfers SHOULD be authenticated using 495 TSIG [RFC8945]. A primary nameserver SHOULD NOT serve a catalog zone 496 for transfer without using TSIG and a secondary nameserver SHOULD 497 abandon an update to a catalog zone that was received without using 498 TSIG. 500 Use of DNS UPDATE [RFC2136] to modify the content of catalog zones 501 SHOULD similarly be authenticated using TSIG. 503 Zone transfers of member zones SHOULD similarly be authenticated 504 using TSIG [RFC8945]. The TSIG shared secrets used for member zones 505 MUST NOT be mentioned anywhere in the catalog zone data. However, 506 key identifiers may be shared within catalog zones. 508 Catalog zones do not need to be signed using DNSSEC, their zone 509 transfers being authenticated by TSIG. Signed zones MUST be handled 510 normally by nameservers, and their contents MUST NOT be DNSSEC- 511 validated. 513 10. IANA Considerations 515 This document has no IANA actions. 517 # 519 11. Acknowledgements 521 Our deepest thanks and appreciation go to Stephen Morris, Ray Bellis 522 and Witold Krecicki who initiated this draft and did the bulk of the 523 work. 525 Catalog zones originated as the chosen method among various proposals 526 that were evaluated at ISC for easy zone management. The chosen 527 method of storing the catalog as a regular DNS zone was proposed by 528 Stephen Morris. 530 The initial authors discovered that Paul Vixie's earlier [Metazones] 531 proposal implemented a similar approach and reviewed it. Catalog 532 zones borrows some syntax ideas from Metazones, as both share this 533 scheme of representing the catalog as a regular DNS zone. 535 Thanks to Brian Conry, Tony Finch, Evan Hunt, Patrik Lundin, Victoria 536 Risk and Carsten Strotmann, for reviewing draft proposals and 537 offering comments and suggestions. 539 Thanks to Klaus Darilion who came up with the idea for the "serial" 540 property during the hackathon at the IETF-109. Thanks also to Shane 541 Kerr, Petr Spacek, Brian Dickson for further brainstorming and 542 discussing the "serial" property and how it would work best with 543 catalog zones. 545 12. Normative References 547 [RFC1035] Mockapetris, P., "Domain names - implementation and 548 specification", STD 13, RFC 1035, DOI 10.17487/RFC1035, 549 November 1987, . 551 [RFC1982] Elz, R. and R. Bush, "Serial Number Arithmetic", RFC 1982, 552 DOI 10.17487/RFC1982, August 1996, 553 . 555 [RFC1996] Vixie, P., "A Mechanism for Prompt Notification of Zone 556 Changes (DNS NOTIFY)", RFC 1996, DOI 10.17487/RFC1996, 557 August 1996, . 559 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 560 Requirement Levels", BCP 14, RFC 2119, 561 DOI 10.17487/RFC2119, March 1997, 562 . 564 [RFC2136] Vixie, P., Ed., Thomson, S., Rekhter, Y., and J. Bound, 565 "Dynamic Updates in the Domain Name System (DNS UPDATE)", 566 RFC 2136, DOI 10.17487/RFC2136, April 1997, 567 . 569 [RFC2308] Andrews, M., "Negative Caching of DNS Queries (DNS 570 NCACHE)", RFC 2308, DOI 10.17487/RFC2308, March 1998, 571 . 573 [RFC2606] Eastlake 3rd, D. and A. Panitz, "Reserved Top Level DNS 574 Names", BCP 32, RFC 2606, DOI 10.17487/RFC2606, June 1999, 575 . 577 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 578 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 579 May 2017, . 581 [RFC8945] Dupont, F., Morris, S., Vixie, P., Eastlake 3rd, D., 582 Gudmundsson, O., and B. Wellington, "Secret Key 583 Transaction Authentication for DNS (TSIG)", STD 93, 584 RFC 8945, DOI 10.17487/RFC8945, November 2020, 585 . 587 13. Informative References 589 [Metazones] 590 Vixie, P., "Federated Domain Name Service Using DNS 591 Metazones", 2005, . 593 Appendix A. Change History (to be removed before final publication) 595 * draft-muks-dnsop-dns-catalog-zones-00 597 | Initial public draft. 599 * draft-muks-dnsop-dns-catalog-zones-01 601 | Added Witold, Ray as authors. Fixed typos, consistency issues. 602 | Fixed references. Updated Area. Removed newly introduced custom 603 | RR TYPEs. Changed schema version to 1. Changed TSIG requirement 604 | from MUST to SHOULD. Removed restrictive language about use of 605 | DNS QUERY. When zones are introduced into a catalog zone, a 606 | primary SHOULD first make the new zones available for transfers 607 | first (instead of MUST). Updated examples, esp. use IPv6 in 608 | examples per Fred Baker. Add catalog zone example. 610 * draft-muks-dnsop-dns-catalog-zones-02 612 | Addressed some review comments by Patrik Lundin. 614 * draft-muks-dnsop-dns-catalog-zones-03 616 | Revision bump. 618 * draft-muks-dnsop-dns-catalog-zones-04 619 | Reordering of sections into more logical order. Separation of 620 | multi-valued properties into their own category. 622 * draft-toorop-dnsop-dns-catalog-zones-00 624 | New authors to pickup the editor pen on this draft 626 * draft-toorop-dnsop-dns-catalog-zones-01 628 | Remove data type definitions for zone properties Removing 629 | configuration of member zones through zone properties altogether 630 | 631 | Remove Open issues and discussion Appendix, which was about zone 632 | options (including primary/secondary relationships) only. 634 Authors' Addresses 636 Peter van Dijk 637 PowerDNS 638 Den Haag 639 Netherlands 641 Email: peter.van.dijk@powerdns.com 643 Libor Peltan 644 CZ.NIC 645 Czechia 647 Email: libor.peltan@nic.cz 649 Ondrej Sury 650 Internet Systems Consortium 651 Czechia 653 Email: ondrej@isc.org 655 Willem Toorop 656 NLnet Labs 657 Science Park 400 658 1098 XH Amsterdam 659 Netherlands 661 Email: willem@nlnetlabs.nl 662 Leo Vandewoestijne 663 Netherlands 665 Email: leo@dns.company