idnits 2.17.1 draft-ietf-dnsext-rfc6195bis-05.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 the creation date from RFC1183, updated by this document, for RFC5378 checks: 1990-10-01) -- The document seems to lack a disclaimer for pre-RFC5378 work, but may have content which was first submitted before 10 November 2008. If you have contacted all the original authors and they are all willing to grant the BCP78 rights to the IETF Trust, then this is fine, and you can ignore this comment. If not, you may need to add the pre-RFC5378 disclaimer. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (October 13, 2012) is 4175 days in the past. Is this intentional? Checking references for intended status: Best Current Practice ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Missing Reference: 'A-Z' is mentioned on line 516, but not defined == Missing Reference: 'A-Z0-9' is mentioned on line 516, but not defined ** Obsolete normative reference: RFC 2845 (Obsoleted by RFC 8945) ** Obsolete normative reference: RFC 4020 (Obsoleted by RFC 7120) ** Obsolete normative reference: RFC 4635 (Obsoleted by RFC 8945) ** Obsolete normative reference: RFC 5226 (Obsoleted by RFC 8126) -- Possible downref: Normative reference to a draft: ref. 'RFC2671bis' -- Possible downref: Non-RFC (?) normative reference: ref. 'US-ASCII' -- Obsolete informational reference (is this intentional?): RFC 2673 (Obsoleted by RFC 6891) -- Obsolete informational reference (is this intentional?): RFC 6195 (Obsoleted by RFC 6895) Summary: 4 errors (**), 0 flaws (~~), 3 warnings (==), 6 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 INTERNET-DRAFT Donald Eastlake 2 Obsoletes: 6195 Huawei 3 Updates: 1183, 2845, 2930, 3597 4 Intended status: Best Current Practice 5 Expires: April 12, 2013 October 13, 2012 7 Domain Name System (DNS) IANA Considerations 8 10 Abstract 12 This document specifies Internet Assigned Number Authority (IANA) 13 parameter assignment considerations for the allocation of Domain Name 14 System (DNS) resource record types, CLASSes, operation codes, error 15 codes, DNS protocol message header bits, and AFSDB resource record 16 subtypes. It obsoletes RFC 6195 and updates RFCs 1183, 2845, 2930, 17 and 3597. 19 Status of This Memo 21 This Internet-Draft is submitted to IETF in full conformance with the 22 provisions of BCP 78 and BCP 79. 24 Distribution of this draft is unlimited. It is intended to become the 25 new BCP 42 obsoleting RFC 6195. Comments should be sent to the DNS 26 Extensions Working Group mailing list . 28 Internet-Drafts are working documents of the Internet Engineering 29 Task Force (IETF), its areas, and its working groups. Note that 30 other groups may also distribute working documents as Internet- 31 Drafts. 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 The list of current Internet-Drafts can be accessed at 39 http://www.ietf.org/1id-abstracts.html. The list of Internet-Draft 40 Shadow Directories can be accessed at 41 http://www.ietf.org/shadow.html. 43 Table of Contents 45 1. Introduction............................................3 46 1.1 Terminology............................................3 47 1.2 Acknowledgements.......................................3 49 2. DNS Query/Response Headers..............................4 50 2.1 One Spare Bit?.........................................5 51 2.2 OpCode Assignment......................................5 52 2.3 RCODE Assignment.......................................5 54 3. DNS Resource Records....................................8 55 3.1 RRTYPE IANA Considerations.............................9 56 3.1.1 DNS RRTYPE Allocation Policy........................10 57 3.1.2 DNS RRTYPE Expert Guidelines........................11 58 3.1.3 Special Note on the OPT RR..........................12 59 3.1.4 The AFSDB RR Subtype Field..........................12 60 3.2 RR CLASS IANA Considerations..........................12 61 3.3. Label Considerations.................................14 62 3.3.1 Label Types.........................................14 63 3.3.2 Label Contents and Use..............................15 65 4. Security Considerations................................16 66 5. IANA Considerations....................................16 68 Appendix A: RRTYPE Allocation Template....................17 69 Appendix B: Changes From RFC 6195.........................18 71 Normative References......................................19 72 Informative References....................................20 74 1. Introduction 76 The Domain Name System (DNS) provides replicated distributed secure 77 hierarchical databases that store "resource records" (RRs) under 78 domain names. DNS data is structured into CLASSes and zones that can 79 be independently maintained. Familiarity with [RFC1034], [RFC1035], 80 [RFC2136], [RFC2181], and [RFC4033] is assumed. 82 This document provides, either directly or by reference, the general 83 IANA parameter assignment considerations that apply across DNS query 84 and response headers and all RRs. There may be additional IANA 85 considerations that apply to only a particular RRTYPE or 86 query/response OpCode. See the specific RFC defining that RRTYPE or 87 query/response OpCode for such considerations if they have been 88 defined, except for AFSDB RR considerations [RFC1183], which are 89 included herein. This RFC obsoletes [RFC6195]; however, the only 90 significant changes are those to the RRTYPE IANA allocation process, 91 aimed at streamlining it and clarifying the expected behavior of the 92 parties involved, and the closing of the AFSDB sub-type registry. 94 IANA currently maintains a web page of DNS parameters available from 95 http://www.iana.org. 97 1.1 Terminology 99 "Standards Action", "IETF Review", "Specification Required", and 100 "Private Use" are as defined in [RFC5226]. 102 1.2 Acknowledgements 104 Alfred Hoenes' contributions are gratefully acknowledged as are those 105 by Mark Andrews, Dick Franks, and Michael Sheldon. 107 2. DNS Query/Response Headers 109 The header for DNS queries and responses contains field/bits in the 110 following diagram taken from [RFC2136]: 112 1 1 1 1 1 1 113 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 114 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 115 | ID | 116 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 117 |QR| OpCode |AA|TC|RD|RA| Z|AD|CD| RCODE | 118 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 119 | QDCOUNT/ZOCOUNT | 120 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 121 | ANCOUNT/PRCOUNT | 122 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 123 | NSCOUNT/UPCOUNT | 124 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 125 | ARCOUNT | 126 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 128 The ID field identifies the query and is echoed in the response so 129 they can be matched. 131 The QR bit indicates whether the header is for a query or a response. 133 The AA, TC, RD, RA, and CD bits are each theoretically meaningful 134 only in queries or only in responses, depending on the bit. The AD 135 bit was only meaningful in responses but is expected to have a 136 separate but related meaning in queries (see Section 5.7 of 137 [RFCdnssecbisup]). Only the RD and CD bits are expected to be copied 138 from the query to the response; however, some DNS implementations 139 copy all the query header as the initial value of the response 140 header. Thus, any attempt to use a "query" bit with a different 141 meaning in a response or to define a query meaning for a "response" 142 bit may be dangerous, given existing implementation. Meanings for 143 these bits may only be assigned by a Standards Action. 145 The unsigned integer fields query count (QDCOUNT), answer count 146 (ANCOUNT), authority count (NSCOUNT), and additional information 147 count (ARCOUNT) express the number of records in each section for all 148 OpCodes except Update [RFC2136]. These fields have the same structure 149 and data type for Update but are instead the counts for the zone 150 (ZOCOUNT), prerequisite (PRCOUNT), update (UPCOUNT), and additional 151 information (ARCOUNT) sections. 153 2.1 One Spare Bit? 155 There have been ancient DNS implementations for which the Z bit being 156 on in a query meant that only a response from the primary server for 157 a zone is acceptable. It is believed that current DNS implementations 158 ignore this bit. 160 Assigning a meaning to the Z bit requires a Standards Action. 162 2.2 OpCode Assignment 164 Currently, DNS OpCodes are assigned as follows: 166 OpCode Name Reference 168 0 Query [RFC1035] 169 1 IQuery (Inverse Query, Obsolete) [RFC3425] 170 2 Status [RFC1035] 171 3 available for assignment 172 4 Notify [RFC1996] 173 5 Update [RFC2136] 174 6-15 available for assignment 176 Although the Status OpCode is reserved in [RFC1035], its behavior has 177 not been specified. New OpCode assignments require a Standards Action 178 with early allocation permitted as specified in [RFC4020]. 180 2.3 RCODE Assignment 182 It would appear from the DNS header above that only four bits of 183 RCODE, or response/error code, are available. However, RCODEs can 184 appear not only at the top level of a DNS response but also inside 185 TSIG RRs [RFC2845], TKEY RRs [RFC2930], and extended by OPT RRs 186 [RFC2671bis]. The OPT RR provides an 8-bit extension to the 4 header 187 bits resulting in a 12-bit RCODE field, and the TSIG and TKEY RRs 188 have a 16-bit field designated in their RFCs as the "Error" field. 190 Error codes appearing in the DNS header and in these other RR types 191 all refer to the same error code space with the exception of error 192 code 16, which has a different meaning in the OPT RR than in the TSIG 193 RR, and error code 9 whose variations are described after the table 194 below. The duplicate assignment of 16 was accidental. To the extent 195 that any prior RFCs imply any sort of different error number space 196 for the OPT, TSIG, or TKEY RRs, they are superseded by this unified 197 DNS error number space. (This paragraph is the reason this document 198 updates [RFC2845] and [RFC2930].) With the existing exceptions of 199 error numbers 9 and 16, the same error number must not be assigned 200 for different errors even if they would only occur in different RR 201 types. See table below. 203 RCODE Name Description Reference 204 Decimal 205 Hexadecimal 207 0 NoError No Error [RFC1035] 208 1 FormErr Format Error [RFC1035] 209 2 ServFail Server Failure [RFC1035] 210 3 NXDomain Non-Existent Domain [RFC1035] 211 4 NotImp Not Implemented [RFC1035] 212 5 Refused Query Refused [RFC1035] 213 6 YXDomain Name Exists when it should not [RFC2136] 214 7 YXRRSet RR Set Exists when it should not [RFC2136] 215 8 NXRRSet RR Set that should exist does not [RFC2136] 216 9 NotAuth Server Not Authoritative for zone [RFC2136] 217 9 NotAuth Not Authorized [RFC2845] 218 10 NotZone Name not contained in zone [RFC2136] 220 11 - 15 221 0xB - 0xF Available for assignment 223 16 BADVERS Bad OPT Version [RFC2671bis] 224 16 BADSIG TSIG Signature Failure [RFC2845] 225 17 BADKEY Key not recognized [RFC2845] 226 18 BADTIME Signature out of time window [RFC2845] 227 19 BADMODE Bad TKEY Mode [RFC2930] 228 20 BADNAME Duplicate key name [RFC2930] 229 21 BADALG Algorithm not supported [RFC2930] 230 22 BADTRUC Bad Truncation [RFC4635] 232 23 - 3,840 233 0x0017 - 0x0F00 Available for assignment 235 3,841 - 4,095 236 0x0F01 - 0x0FFF Private Use 238 4,096 - 65,534 239 0x1000 - 0xFFFE Available for assignment 241 65,535 242 0xFFFF Reserved, can only be allocated by a Standards 243 Action. 245 Note on error number 9 (NotAuth): This error number means either "Not 246 Authoritative" [RFC2136] or "Not Authorized" [RFC2845]. If 9 247 appears as the RCODE in the header of a DNS response without a 248 TSIG RR or with a TSIG RR having a zero error field, then it means 249 "Not Authoritative". If 9 appears as the RCODE in the header of a 250 DNS response that includes a TSIG RR with a non-zero error field, 251 then it means "Not Authorized". 253 Since it is important that RCODEs be understood for interoperability, 254 assignment of a new RCODE in the ranges listed above as "Available 255 for assignment" requires an IETF Review. 257 3. DNS Resource Records 259 All RRs have the same top-level format, shown in the figure below 260 taken from [RFC1035]. 262 1 1 1 1 1 1 263 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 264 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 265 | | 266 / / 267 / NAME / 268 / / 269 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 270 | TYPE | 271 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 272 | CLASS | 273 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 274 | TTL | 275 | | 276 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 277 | RDLENGTH | 278 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 279 / RDATA / 280 / / 281 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 283 NAME is an owner name, i.e., the name of the node to which this 284 resource record pertains. NAMEs are specific to a CLASS as described 285 in Section 3.2. NAMEs consist of an ordered sequence of one or more 286 labels, each of which has a label type [RFC1035] [RFC2671bis]. 288 TYPE is a 2-octet unsigned integer containing one of the RRTYPE 289 codes. See Section 3.1. 291 CLASS is a 2-octet unsigned integer containing one of the RR CLASS 292 codes. See Section 3.2. 294 TTL is a 4-octet (32-bit) unsigned integer that specifies, for data 295 TYPEs, the number of seconds that the resource record may be cached 296 before the source of the information should again be consulted. Zero 297 is interpreted to mean that the RR can only be used for the 298 transaction in progress. 300 RDLENGTH is an unsigned 16-bit integer that specifies the length in 301 octets of the RDATA field. 303 RDATA is a variable-length string of octets that constitutes the 304 resource. The format of this information varies according to the TYPE 305 and, in some cases, the CLASS of the resource record. 307 3.1 RRTYPE IANA Considerations 309 There are three subcategories of RRTYPE numbers: data TYPEs, QTYPEs, 310 and Meta-TYPEs. 312 Data TYPEs are the means of storing data. QTYPES can only be used in 313 queries. Meta-TYPEs designate transient data associated with a 314 particular DNS message and, in some cases, can also be used in 315 queries. Thus far, data TYPEs have been assigned from 1 upward, plus 316 the block from 100 through 103, and from 32,768 upward, while Q and 317 Meta-TYPEs have been assigned from 255 downward except for the OPT 318 Meta-RR, which is assigned TYPE 41. There have been DNS 319 implementations that made caching decisions based on the top bit of 320 the bottom byte of the RRTYPE. 322 There are currently three Meta-TYPEs assigned: OPT [RFC2671bis], TSIG 323 [RFC2845], and TKEY [RFC2930]. There are currently five QTYPEs 324 assigned: * (ALL/ANY), MAILA, MAILB, AXFR, and IXFR. 326 Allocated RRTYPEs have mnemonics that must be completely disjoint 327 from the mnemonics used for CLASSes and that must match the regular 328 expression below. In addition, the generic CLASS and RRTYPE names 329 specified in Section 5 of [RFC3597] cannot be assigned as new RRTYPE 330 mnemonics. 332 [A-Z][A-Z0-9\-]*[A-Z0-9] 333 but not 334 (TYPE|CLASS)[0-9]* 336 Considerations for the allocation of new RRTYPEs are as follows: 338 Decimal 339 Hexadecimal Assignment Policy 341 0 342 0x0000 RRTYPE zero is used as a special indicator for the 343 SIG (0) RR [RFC2931] [RFC4034] and in other 344 circumstances, and it must never be allocated for 345 ordinary use. 347 1 - 127 348 0x0001 - 0x007F Remaining RRTYPEs in this range are assigned for 349 data TYPEs by the DNS RRTYPE Allocation Policy as 350 specified in Section 3.1.1. 352 128 - 255 353 0x0080 - 0x00FF Remaining RRTYPEs in this range are assigned for Q 354 and Meta-TYPEs by the DNS RRTYPE Allocation Policy 355 as specified in Section 3.1.1. 357 256 - 61,439 358 0x0100 - 0xEFFF Remaining RRTYPEs in this range are assigned for 359 data RRTYPEs by the DNS RRTYPE Allocation Policy as 360 specified in Section 3.1.1. (32,768 and 32,769 361 (0x8000 and 0x8001) have been assigned.) 363 61,440 - 65,279 364 0xF000 - 0xFEFF Reserved for future use. IETF Review required to 365 define use. 367 65,280 - 65,534 368 0xFF00 - 0xFFFE Private Use. 370 65,535 371 0xFFFF Reserved, can only be assigned by a Standards 372 Action. 374 3.1.1 DNS RRTYPE Allocation Policy 376 Parameter values specified in Section 3.1 above as assigned based on 377 DNS RRTYPE Allocation Policy, are allocated by Expert Review if they 378 meet the two requirements listed below. There will be a pool of a 379 small number of Experts appointed by the IESG. Each application will 380 be judged by an Expert selected by IANA. In any case where the 381 selected Expert is unavailable or states they have a conflict of 382 interest, IANA may select another Expert from the pool. Some 383 guidelines for the Experts are given in Section 3.1.2. 385 RRTYPEs that do not meet the requirements below may nonetheless be 386 allocated by a Standards Action with early allocation permitted as 387 specified in [RFC4020]. 389 1. A complete template as specified in Appendix A has been posted to 390 the dns-rrtype-applications@ietf.org mailing list and received by 391 the Expert. 392 Note that the posting of partially completed, draft, or 393 formally submitted templates to dnsext@ietf.org by the applicant 394 or Expert for comment and discussion is highly encouraged. Formal 395 submission of an RRTYPE template without consideration of some 396 community review can be expected to increase the probability of 397 initial rejection leading to a need to re-submit after 398 modification. 400 2. The RR for which an RRTYPE code is being requested is either (a) a 401 data TYPE that can be handled as an Unknown RR as described in 402 [RFC3597] or (b) a Meta-TYPE whose processing is optional, i.e., 403 it is safe to simply discard RRs with that Meta-TYPE in queries or 404 responses. 406 Note that such RRs may include additional section processing, 407 provided such processing is optional. 409 After the applicant submits their formal application to IANA by 410 sending the completed template specified in Appendix A to the dns- 411 rrtype-applications@ietf.org mailing list, IANA appoints an Expert 412 and sends the completed template to the Expert copying the applicant. 413 No more than two weeks after receiving the application the Expert 414 shall explicitly approve or reject the application, informing IANA, 415 the applicant, and the dnsext@ietf.org mailing list. A rejection 416 should include the reason for rejection and may include suggestions 417 for improvement. The Expert should consult with other technical 418 experts and the dnsext@ietf.org mailing list as necessary. If the 419 Expert does not approve the application within this period, it is 420 considered rejected. IANA should report non-responsive Experts to the 421 IESG. 423 IANA shall maintain a public archive of approved templates. In 424 addition, if the required description of the RRTYPE applied for is 425 referenced by URL, a copy of the document so referenced should be 426 included in the archive. 428 3.1.2 DNS RRTYPE Expert Guidelines 430 The Designated Expert should normally be lenient, preferring to 431 approve most requests. However, the Expert should usually reject any 432 RRTYPE allocation request that meets one or more of the following 433 criteria: 435 1. Was documented in a manner that was not sufficiently clear or 436 complete to evaluate or implement. (Additional documentation can 437 be provided during the Expert review period.) 439 2. The proposed RRTYPE or RRTYPEs affect DNS processing and do not 440 meet the criteria in point 2 of Section 3.1.1 above. 442 3. Application use as documented makes incorrect assumptions about 443 DNS protocol behavior, such as wild cards, CNAME, DNAME, etc. 445 4. An excessive number of RRTYPE values is being requested when the 446 purpose could be met with a smaller number or with Private Use 447 values. 449 3.1.3 Special Note on the OPT RR 451 The OPT (OPTion) RR (RRTYPE 41) and its IANA considerations are 452 specified in [RFC2671bis]. Its primary purpose is to extend the 453 effective field size of various DNS fields including RCODE, label 454 type, OpCode, flag bits, and RDATA size. In particular, for resolvers 455 and servers that recognize it, it extends the RCODE field from 4 to 456 12 bits. 458 3.1.4 The AFSDB RR Subtype Field 460 The AFSDB RR [RFC1183] is a CLASS-insensitive RR that has the same 461 RDATA field structure as the MX RR [RFC1035], but the 16-bit unsigned 462 integer field at the beginning of the RDATA is interpreted as a 463 subtype as shown below. Use of the AFSDB RR to locate AFS cell 464 database servers was deprecated by [RFC5864]. This subtype registry 465 is hereby closed and allocation of new subtypes is no longer 466 permitted. 468 Decimal 469 Hexadecimal Assignment Policy 471 0 472 0x0000 Reserved, registry closed 474 1 475 0x0001 AFS v3.0 Location Service [RFC1183] 477 2 478 0x0002 DCE/NCA root cell directory node [RFC1183] 480 3 - 65,279 481 0x0003 - 0xFEFF Not allocated, registry closed 483 65,280 - 65,534 484 0xFF00 - 0xFFFE Private Use 486 65,535 487 0xFFFF Reserved, registry closed 489 3.2 RR CLASS IANA Considerations 491 There are currently two subcategories of DNS CLASSes: normal, data- 492 containing classes and QCLASSes that are only meaningful in queries 493 or updates. 495 DNS CLASSes have been little used but constitute another dimension of 496 the DNS distributed database. In particular, there is no necessary 497 relationship between the name space or root servers for one data 498 CLASS and those for another data CLASS. The same DNS NAME can have 499 completely different meanings in different CLASSes. The label types 500 are the same, and the null label is usable only as root in every 501 CLASS. As global networking and DNS have evolved, the IN, or 502 Internet, CLASS has dominated DNS use. 504 As yet, there has not been a requirement for "meta-CLASSes". That 505 would be a CLASS to designate transient data associated with a 506 particular DNS message, which might be usable in queries. However, it 507 is possible that there might be a future requirement for one or more 508 "meta-CLASSes". 510 Assigned CLASSes have mnemonics that must be completely disjoint from 511 the mnemonics used for RRTYPEs and that must match the regular 512 expression below. In addition, the generic CLASS and RRTYPE names 513 specified in Section 5 of [RFC3597] cannot be assigned as new CLASS 514 mnemonics. 516 [A-Z][A-Z0-9\-]*[A-Z0-9] 517 but not 518 (CLASS|RRTYPE)[0-9]* 520 The current CLASS assignments and considerations for future 521 assignments are as follows: 523 Decimal 524 Hexadecimal Assignment / Policy, Reference 526 0 527 0x0000 Reserved; assignment requires a Standards Action 529 1 530 0x0001 Internet (IN) [RFC1035] 532 2 533 0x0002 Available for assignment by IETF Review as a data 534 CLASS 536 3 537 0x0003 Chaos (CH) [Moon1981] 539 4 540 0x0004 Hesiod (HS) [Dyer1987] 542 5 - 127 543 0x0005 - 0x007F Available for assignment by IETF Review for data 544 CLASSes only 546 128 - 253 547 0x0080 - 0x00FD Available for assignment by IETF Review for 548 QCLASSes and meta-CLASSes only 550 254 551 0x00FE QCLASS NONE [RFC2136] 553 255 554 0x00FF QCLASS * (ANY) [RFC1035] 556 256 - 32,767 557 0x0100 - 0x7FFF Available for assignment by IETF Review 559 32,768 - 57,343 560 0x8000 - 0xDFFF Available for assignment to data CLASSes only; 561 Specification Required 563 57,344 - 65,279 564 0xE000 - 0xFEFF Available for assignment to QCLASSes and meta- 565 CLASSes only; Specification Required 567 65,280 - 65,534 568 0xFF00 - 0xFFFE Private Use 570 65,535 571 0xFFFF Reserved; can only be assigned by a Standards 572 Action 574 3.3. Label Considerations 576 DNS NAMEs are sequences of labels [RFC1035]. 578 3.3.1 Label Types 580 At the present time, there are two categories of label types: data 581 labels and compression labels. Compression labels are pointers to 582 data labels elsewhere within an RR or DNS message and are intended to 583 shorten the wire encoding of NAMEs. 585 The two existing data label types are sometimes referred to as Text 586 and Binary. Text labels can, in fact, include any octet value 587 including zero-value octets, but many current uses involve only 588 printing ASCII characters [US-ASCII]. For retrieval, Text labels are 589 defined to treat ASCII upper and lower case letter codes as matching 590 [RFC4343]. Binary labels are bit sequences [RFC2673]. The Binary 591 label type is Historic [RFC2671bis]. 593 3.3.2 Label Contents and Use 595 The last label in each NAME is "ROOT", which is the zero-length 596 label. By definition, the null or ROOT label cannot be used for any 597 other NAME purpose. 599 NAMEs are local to a CLASS. The Hesiod [Dyer1987] and Chaos 600 [Moon1981] CLASSes are for essentially local use. The IN, or 601 Internet, CLASS is thus the only DNS CLASS in global use on the 602 Internet at this time. 604 A somewhat out-of-date description of name allocation in the IN Class 605 is given in [RFC1591]. Some information on reserved top-level domain 606 names is in BCP 32 [RFC2606]. 608 4. Security Considerations 610 This document addresses IANA considerations in the allocation of 611 general DNS parameters, not security. See [RFC4033], [RFC4034], and 612 [RFC4035] for secure DNS considerations. 614 5. IANA Considerations 616 This document consists entirely of DNS IANA Considerations. 618 IANA has established a process for accepting Appendix A templates and 619 selecting an Expert from those appointed to review such template form 620 applications. IANA forwards the template to the Expert copying the 621 applicant. IANA archives and makes available all approved RRTYPE 622 allocation templates and referred documentation (unless it is readily 623 available at a stable URI). It is the duty of the applicant to post 624 the formal application template to the dns-rrtype- 625 applications@ietf.org mailing list, which IANA will monitor. The 626 dnsext@ietf.org mailing list is for community discussion and comment. 627 See Section 3.1 and Appendix A for more details. 629 Appendix A: RRTYPE Allocation Template 631 DNS RRTYPE PARAMETER ALLOCATION TEMPLATE 633 When ready for formal consideration, this template is to be submitted 634 to IANA for processing by emailing the template to dns-rrtype- 635 applications@ietf.org. 637 A. Submission Date: 639 B.1 Submission Type: [ ] New RRTYPE [ ] Modification to RRTYPE 640 B.2 Kind of RR: [ ] Data RR [ ] Meta-RR 642 C. Contact Information for submitter (will be publicly posted): 643 Name: 644 Email Address: 645 International telephone number: 646 Other contact handles: 648 D. Motivation for the new RRTYPE application. 649 Please keep this part at a high level to inform the Expert and 650 reviewers about uses of the RRTYPE. Most reviewers will be DNS 651 experts that may have limited knowledge of your application space. 653 E. Description of the proposed RR type. 654 This description can be provided in-line in the template, as an 655 attachment, or with a publicly available URL. 657 F. What existing RRTYPE or RRTYPEs come closest to filling that need 658 and why are they unsatisfactory? 660 G. What mnemonic is requested for the new RRTYPE (optional)? 661 Note: If a mnemonic is not supplied, not allowed, or duplicates an 662 existing RRTYPE or CLASS mnemonic, the Expert will assign a 663 mnemonic. 665 H. Does the requested RRTYPE make use of any existing IANA registry 666 or require the creation of a new IANA sub-registry in DNS 667 Parameters? If so, please indicate which registry is to be used 668 or created. If a new sub-registry is needed, specify the 669 allocation policy for it and its initial contents. Also include 670 what the modification procedures will be. 672 I. Does the proposal require/expect any changes in DNS 673 servers/resolvers that prevent the new type from being processed 674 as an unknown RRTYPE (see [RFC3597])? 676 J. Comments: 678 Appendix B: Changes From RFC 6195 680 Drop description of changes from RFC 5395 to [RFC6195] since those 681 changes have already happened and we don't need to do them again. Add 682 description of changes from [RFC6195] to this document. 684 Cut back RRTYPE Expert review period to two weeks and eliminate the 685 mandatory dnsext@ietf.org comment period. Change workflow description 686 for RRTYPE review and allocation to correspond more closely to actual 687 practice. 689 Close the AFSDB sub-type registry and add an informative reference to 690 [RFC5864] where the use of the AFSDB RR to locate AFS cell database 691 servers is deprecated. 693 Clarify IANA archiving of referenced documentation as well as 694 approved RRTYPE application template. 696 In the RRTYPE application template, change the label of question "B" 697 to "B.1" and add "B.2" to ask about the kind of RR. 699 Addition of text and an exclusory regular expression to Sections 3.1 700 and 3.2 to prohibit the use of a slight generalization of the generic 701 CLASS and RRTYPE names specified in [RFC3597] as the mnemonics for 702 new CLASSes and RRTYPEes. 704 Parenthetically list "ANY" and well as "ALL" as a meaning for the "*" 705 RRTYPE. 707 Clarify that there is one DNS error number space for headers, OPT 708 extended headers, TSIG RRs, and TKEY RRs. Note that this is 709 considered to update [RFC2845] and [RFC2930]. Note the overloading of 710 error number 9 as well as 16. 712 Update references for revised versions. 714 A number of editorial changes and typo fixes. 716 Normative References 718 [RFC1034] - Mockapetris, P., "Domain names - concepts and 719 facilities", STD 13, RFC 1034, November 1987. 721 [RFC1035] - Mockapetris, P., "Domain names - implementation and 722 specification", STD 13, RFC 1035, November 1987. 724 [RFC1996] - Vixie, P., "A Mechanism for Prompt Notification of Zone 725 Changes (DNS NOTIFY)", RFC 1996, August 1996. 727 [RFC2136] - Vixie, P., Ed., Thomson, S., Rekhter, Y., and J. Bound, 728 "Dynamic Updates in the Domain Name System (DNS UPDATE)", 729 RFC 2136, April 1997. 731 [RFC2181] - Elz, R. and R. Bush, "Clarifications to the DNS 732 Specification", RFC 2181, July 1997. 734 [RFC2845] - Vixie, P., Gudmundsson, O., Eastlake 3rd, D., and B. 735 Wellington, "Secret Key Transaction Authentication for 736 DNS (TSIG)", RFC 2845, May 2000. 738 [RFC2930] - Eastlake 3rd, D., "Secret Key Establishment for DNS (TKEY 739 RR)", RFC 2930, September 2000. 741 [RFC3425] - Lawrence, D., "Obsoleting IQUERY", RFC 3425, November 742 2002. 744 [RFC3597] - Gustafsson, A., "Handling of Unknown DNS Resource Record 745 (RR) Types", RFC 3597, September 2003. 747 [RFC4020] - Kompella, K. and A. Zinin, "Early IANA Allocation of 748 Standards Track Code Points", BCP 100, RFC 4020, February 749 2005. 751 [RFC4033] - Arends, R., Austein, R., Larson, M., Massey, D., and S. 752 Rose, "DNS Security Introduction and Requirements", RFC 753 4033, March 2005. 755 [RFC4034] - Arends, R., Austein, R., Larson, M., Massey, D., and S. 756 Rose, "Resource Records for the DNS Security Extensions", 757 RFC 4034, March 2005. 759 [RFC4035] - Arends, R., Austein, R., Larson, M., Massey, D., and S. 760 Rose, "Protocol Modifications for the DNS Security 761 Extensions", RFC 4035, March 2005. 763 [RFC4635] - Eastlake 3rd, D., "HMAC SHA (Hashed Message 764 Authentication Code, Secure Hash Algorithm) TSIG 765 Algorithm Identifiers", RFC 4635, August 2006. 767 [RFC5226] - Narten, T. and H. Alvestrand, "Guidelines for Writing an 768 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 769 May 2008. 771 [RFC2671bis] - Damas, J., Graff, M., and Vixie, P., "Extension 772 Mechanisms for DNS (EDNS0)", draft-ietf-dnsext- 773 rfc2671bis-edns0, work in progress. 775 [RFCdnssecbisup] - Weiler, A. and D. Blacka, "Clarifications and 776 Implementation Notes for DNSSECbis", draft-ietf-dnsext- 777 dnssec-bis-updates, work in progress. 779 [US-ASCII] - American National Standards Institute (formerly United 780 States of America Standards Institute), "USA Code for 781 Information Interchange", ANSI X3.4-1968, 1968. ANSI 782 X3.4-1968 has been replaced by newer versions with slight 783 modifications, but the 1968 version remains definitive 784 for the Internet. 786 Informative References 788 [Dyer1987] - Dyer, S., and F. Hsu, "Hesiod", Project Athena Technical 789 Plan - Name Service, April 1987. 791 [Moon1981] - Moon, D., "Chaosnet", A.I. Memo 628, Massachusetts 792 Institute of Technology Artificial Intelligence 793 Laboratory, June 1981. 795 [RFC1183] - Everhart, C., Mamakos, L., Ullmann, R., and P. 796 Mockapetris, "New DNS RR Definitions", RFC 1183, October 797 1990. 799 [RFC1591] - Postel, J., "Domain Name System Structure and 800 Delegation", RFC 1591, March 1994. 802 [RFC2606] - Eastlake 3rd, D. and A. Panitz, "Reserved Top Level DNS 803 Names", BCP 32, RFC 2606, June 1999. 805 [RFC2673] - Crawford, M., "Binary Labels in the Domain Name System", 806 RFC 2673, August 1999. 808 [RFC2931] - Eastlake 3rd, D., "DNS Request and Transaction Signatures 809 ( SIG(0)s )", RFC 2931, September 2000. 811 [RFC4343] - Eastlake 3rd, D., "Domain Name System (DNS) Case 812 Insensitivity Clarification", RFC 4343, January 2006. 814 [RFC5864] - Allbery, R., "DNS SRV Resource Records for AFS", RFC 815 5864, April 2010. 817 [RFC6195] - Eastlake 3rd, D., "Domain Name System (DNS) IANA 818 Considerations", RFC 6195, March 2011. 820 Author's Address 822 Donald E. Eastlake 3rd 823 Huawei R&D USA 824 155 Beaver Street 825 Milford, MA 01757 USA 827 Telephone: +1-508-333-2270 828 email: d3e3e3@gmail.com 830 Copyright and IPR Provisions 832 Copyright (c) 2012 IETF Trust and the persons identified as the 833 document authors. All rights reserved. 835 This document is subject to BCP 78 and the IETF Trust's Legal 836 Provisions Relating to IETF Documents 837 (http://trustee.ietf.org/license-info) in effect on the date of 838 publication of this document. Please review these documents 839 carefully, as they describe your rights and restrictions with respect 840 to this document. Code Components extracted from this document must 841 include Simplified BSD License text as described in Section 4.e of 842 the Trust Legal Provisions and are provided without warranty as 843 described in the Simplified BSD License.