7Internet Engineering Task Force (IETF) D. Eastlake 3rd
8Request for Comments: 6895 Huawei
11Updates: 1183, 2845, 2930, 3597
12Category: Best Current Practice
16 Domain Name System (DNS) IANA Considerations
20 This document specifies Internet Assigned Numbers Authority (IANA)
21 parameter assignment considerations for the allocation of Domain Name
22 System (DNS) resource record types, CLASSes, operation codes, error
23 codes, DNS protocol message header bits, and AFSDB resource record
24 subtypes. It obsoletes RFC 6195 and updates RFCs 1183, 2845, 2930,
29 This memo documents an Internet Best Current Practice.
31 This document is a product of the Internet Engineering Task Force
32 (IETF). It represents the consensus of the IETF community. It has
33 received public review and has been approved for publication by the
34 Internet Engineering Steering Group (IESG). Further information on
35 BCPs is available in Section 2 of RFC 5741.
37 Information about the current status of this document, any errata,
38 and how to provide feedback on it may be obtained at
39 http://www.rfc-editor.org/info/rfc6895.
43 Copyright (c) 2013 IETF Trust and the persons identified as the
44 document authors. All rights reserved.
46 This document is subject to BCP 78 and the IETF Trust's Legal
47 Provisions Relating to IETF Documents
48 (http://trustee.ietf.org/license-info) in effect on the date of
49 publication of this document. Please review these documents
50 carefully, as they describe your rights and restrictions with respect
51 to this document. Code Components extracted from this document must
52 include Simplified BSD License text as described in Section 4.e of
53 the Trust Legal Provisions and are provided without warranty as
54 described in the Simplified BSD License.
58Eastlake Best Current Practice [Page 1]
60RFC 6895 DNS IANA Considerations April 2013
65 1. Introduction ....................................................2
66 1.1. Terminology ................................................3
67 2. DNS Query/Response Headers ......................................3
68 2.1. One Spare Bit? .............................................4
69 2.2. OpCode Assignment ..........................................4
70 2.3. RCODE Assignment ...........................................4
71 3. DNS Resource Records ............................................6
72 3.1. RRTYPE IANA Considerations .................................7
73 3.1.1. DNS RRTYPE Allocation Policy ........................8
74 3.1.2. DNS RRTYPE Expert Guidelines .......................10
75 3.1.3. Special Note on the OPT RR .........................10
76 3.1.4. The AFSDB RR Subtype Field .........................10
77 3.2. RR CLASS IANA Considerations ..............................11
78 3.3. Label Considerations ......................................13
79 3.3.1. Label Types ........................................13
80 3.3.2. Label Contents and Use .............................13
81 4. Security Considerations ........................................14
82 5. IANA Considerations ............................................14
83 Appendix A. RRTYPE Allocation Template ............................15
84 Appendix B. Changes from RFC 6195 .................................16
85 Normative References ..............................................17
86 Informative References ............................................18
87 Acknowledgements ..................................................19
91 The Domain Name System (DNS) provides replicated distributed secure
92 hierarchical databases that store "resource records" (RRs) under
93 domain names. DNS data is structured into CLASSes and zones that can
94 be independently maintained. Familiarity with [RFC1034], [RFC1035],
95 [RFC2136], [RFC2181], and [RFC4033] is assumed.
97 This document provides, either directly or by reference, the general
98 IANA parameter assignment considerations that apply across DNS query
99 and response headers and all RRs. There may be additional IANA
100 considerations that apply to only a particular RRTYPE or
101 query/response OpCode. See the specific RFC defining that RRTYPE or
102 query/response OpCode for such considerations if they have been
103 defined, except for AFSDB RR considerations [RFC1183], which are
104 included herein. This RFC obsoletes [RFC6195]; however, the only
105 significant changes are those to the RRTYPE IANA allocation process,
106 aimed at streamlining it and clarifying the expected behavior of the
107 parties involved, and the closing of the AFSDB subtype registry.
109 IANA currently maintains a web page of DNS parameters available from
110 <http://www.iana.org>.
114Eastlake Best Current Practice [Page 2]
116RFC 6895 DNS IANA Considerations April 2013
121 "Standards Action", "IETF Review", "Specification Required", and
122 "Private Use" are as defined in [RFC5226].
1242. DNS Query/Response Headers
126 The header for DNS queries and responses contains field/bits in the
127 following diagram taken from [RFC2136]:
130 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
131 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
133 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
134 |QR| OpCode |AA|TC|RD|RA| Z|AD|CD| RCODE |
135 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
137 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
139 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
141 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
143 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
145 The ID field identifies the query and is echoed in the response so
148 The QR bit indicates whether the header is for a query or a response.
150 The AA, TC, RD, RA, and CD bits are each theoretically meaningful
151 only in queries or only in responses, depending on the bit. The AD
152 bit was only meaningful in responses but is expected to have a
153 separate but related meaning in queries (see Section 5.7 of
154 [RFC6840]). Only the RD and CD bits are expected to be copied from
155 the query to the response; however, some DNS implementations copy all
156 the query header as the initial value of the response header. Thus,
157 any attempt to use a "query" bit with a different meaning in a
158 response or to define a query meaning for a "response" bit may be
159 dangerous, given the existing implementation. Meanings for these
160 bits may only be assigned by a Standards Action.
162 The unsigned integer fields query count (QDCOUNT), answer count
163 (ANCOUNT), authority count (NSCOUNT), and additional information
164 count (ARCOUNT) express the number of records in each section for all
165 OpCodes except Update [RFC2136]. These fields have the same
170Eastlake Best Current Practice [Page 3]
172RFC 6895 DNS IANA Considerations April 2013
175 structure and data type for Update but are instead the counts for the
176 zone (ZOCOUNT), prerequisite (PRCOUNT), update (UPCOUNT), and
177 additional information (ARCOUNT) sections.
181 There have been ancient DNS implementations for which the Z bit being
182 on in a query meant that only a response from the primary server for
183 a zone is acceptable. It is believed that current DNS
184 implementations ignore this bit.
186 Assigning a meaning to the Z bit requires a Standards Action.
1882.2. OpCode Assignment
190 Currently, DNS OpCodes are assigned as follows:
192 OpCode Name Reference
195 1 IQuery (Inverse Query, OBSOLETE) [RFC3425]
202 Although the Status OpCode is reserved in [RFC1035], its behavior has
203 not been specified. New OpCode assignments require a Standards
204 Action with early allocation permitted as specified in [RFC4020].
208 It would appear from the DNS header above that only four bits of
209 RCODE, or response/error code, are available. However, RCODEs can
210 appear not only at the top level of a DNS response but also inside
211 TSIG RRs [RFC2845], TKEY RRs [RFC2930], and extended by OPT RRs
212 [RFC6891]. The OPT RR provides an 8-bit extension to the 4 header
213 bits, resulting in a 12-bit RCODE field, and the TSIG and TKEY RRs
214 have a 16-bit field designated in their RFCs as the "Error" field.
216 Error codes appearing in the DNS header and in these other RR types
217 all refer to the same error code space with the exception of error
218 code 16, which has a different meaning in the OPT RR than in the TSIG
219 RR, and error code 9, whose variations are described after the table
220 below. The duplicate assignment of 16 was accidental. To the extent
221 that any prior RFCs imply any sort of different error number space
222 for the OPT, TSIG, or TKEY RRs, they are superseded by this unified
226Eastlake Best Current Practice [Page 4]
228RFC 6895 DNS IANA Considerations April 2013
231 DNS error number space. (This paragraph is the reason this document
232 updates [RFC2845] and [RFC2930].) With the existing exceptions of
233 error numbers 9 and 16, the same error number must not be assigned
234 for different errors even if they would only occur in different RR
235 types. See table below.
237 RCODE Name Description Reference
241 0 NoError No Error [RFC1035]
242 1 FormErr Format Error [RFC1035]
243 2 ServFail Server Failure [RFC1035]
244 3 NXDomain Non-Existent Domain [RFC1035]
245 4 NotImp Not Implemented [RFC1035]
246 5 Refused Query Refused [RFC1035]
247 6 YXDomain Name Exists when it should not [RFC2136]
248 7 YXRRSet RR Set Exists when it should not [RFC2136]
249 8 NXRRSet RR Set that should exist does not [RFC2136]
250 9 NotAuth Server Not Authoritative for zone [RFC2136]
251 9 NotAuth Not Authorized [RFC2845]
252 10 NotZone Name not contained in zone [RFC2136]
257 16 BADVERS Bad OPT Version [RFC6891]
258 16 BADSIG TSIG Signature Failure [RFC2845]
259 17 BADKEY Key not recognized [RFC2845]
260 18 BADTIME Signature out of time window [RFC2845]
261 19 BADMODE Bad TKEY Mode [RFC2930]
262 20 BADNAME Duplicate key name [RFC2930]
263 21 BADALG Algorithm not supported [RFC2930]
264 22 BADTRUNC Bad Truncation [RFC4635]
267 0x0017 - 0x0F00 Unassigned
270 0x0F01 - 0x0FFF Reserved for Private Use
273 0x1000 - 0xFFFE Unassigned
276 0xFFFF Reserved; can only be allocated by Standards
282Eastlake Best Current Practice [Page 5]
284RFC 6895 DNS IANA Considerations April 2013
287 Note on error number 9 (NotAuth): This error number means either
288 "Not Authoritative" [RFC2136] or "Not Authorized" [RFC2845]. If 9
289 appears as the RCODE in the header of a DNS response without a
290 TSIG RR or with a TSIG RR having a zero error field, then it means
291 "Not Authoritative". If 9 appears as the RCODE in the header of a
292 DNS response that includes a TSIG RR with a non-zero error field,
293 then it means "Not Authorized".
295 Since it is important that RCODEs be understood for interoperability,
296 assignment of a new RCODE in the ranges listed above as "Unassigned"
297 requires an IETF Review.
2993. DNS Resource Records
301 All RRs have the same top-level format, shown in the figure below
302 taken from [RFC1035].
305 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
306 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
311 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
313 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
315 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
318 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
320 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--|
323 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
325 NAME is an owner name, i.e., the name of the node to which this
326 resource record pertains. NAMEs are specific to a CLASS as described
327 in Section 3.2. NAMEs consist of an ordered sequence of one or more
328 labels, each of which has a label type [RFC1035] [RFC6891].
330 TYPE is a 2-octet unsigned integer containing one of the RRTYPE
331 codes. See Section 3.1.
333 CLASS is a 2-octet unsigned integer containing one of the RR CLASS
334 codes. See Section 3.2.
338Eastlake Best Current Practice [Page 6]
340RFC 6895 DNS IANA Considerations April 2013
343 TTL is a 4-octet (32-bit) unsigned integer that specifies, for data
344 TYPEs, the number of seconds that the resource record may be cached
345 before the source of the information should again be consulted. Zero
346 is interpreted to mean that the RR can only be used for the
347 transaction in progress.
349 RDLENGTH is an unsigned 16-bit integer that specifies the length in
350 octets of the RDATA field.
352 RDATA is a variable-length string of octets that constitutes the
353 resource. The format of this information varies according to the
354 TYPE and, in some cases, the CLASS of the resource record.
3563.1. RRTYPE IANA Considerations
358 There are three subcategories of RRTYPE numbers: data TYPEs, QTYPEs,
361 Data TYPEs are the means of storing data. QTYPES can only be used in
362 queries. Meta-TYPEs designate transient data associated with a
363 particular DNS message and, in some cases, can also be used in
364 queries. Thus far, data TYPEs have been assigned from 1 upward, plus
365 the block from 100 through 103, and from 32,768 upward, while Q and
366 Meta-TYPEs have been assigned from 255 downward except for the OPT
367 Meta-RR, which is assigned TYPE 41. There have been DNS
368 implementations that made caching decisions based on the top bit of
369 the bottom byte of the RRTYPE.
371 There are currently three Meta-TYPEs assigned: OPT [RFC6891], TSIG
372 [RFC2845], and TKEY [RFC2930]. There are currently five QTYPEs
373 assigned: * (ALL/ANY), MAILA, MAILB, AXFR, and IXFR.
375 Allocated RRTYPEs have mnemonics that must be completely disjoint
376 from the mnemonics used for CLASSes and that must match the regular
377 expression below. In addition, the generic CLASS and RRTYPE names
378 specified in Section 5 of [RFC3597] cannot be assigned as new RRTYPE
381 [A-Z][A-Z0-9\-]*[A-Z0-9]
394Eastlake Best Current Practice [Page 7]
396RFC 6895 DNS IANA Considerations April 2013
399 Considerations for the allocation of new RRTYPEs are as follows:
402 Hexadecimal Assignment Policy
405 0x0000 RRTYPE zero is used as a special indicator for the
406 SIG(0) RR [RFC2931] [RFC4034] and in other
407 circumstances and must never be allocated for
411 0x0001 - 0x007F Remaining RRTYPEs in this range are assigned for
412 data TYPEs by the DNS RRTYPE Allocation Policy as
413 specified in Section 3.1.1.
416 0x0080 - 0x00FF Remaining RRTYPEs in this range are assigned for Q
417 and Meta-TYPEs by the DNS RRTYPE Allocation Policy
418 as specified in Section 3.1.1.
421 0x0100 - 0xEFFF Remaining RRTYPEs in this range are assigned for
422 data RRTYPEs by the DNS RRTYPE Allocation Policy
423 as specified in Section 3.1.1. (32,768 and 32,769
424 (0x8000 and 0x8001) have been assigned.)
427 0xF000 - 0xFEFF Reserved for future use. IETF Review required to
431 0xFF00 - 0xFFFE Reserved for Private Use.
434 0xFFFF Reserved (Standards Action)
4363.1.1. DNS RRTYPE Allocation Policy
438 Parameter values specified in Section 3.1 above, as assigned based on
439 DNS RRTYPE Allocation Policy, are allocated by Expert Review if they
440 meet the two requirements listed below. There will be a pool of a
441 small number of Experts appointed by the IESG. Each application will
442 be judged by an Expert selected by IANA. In any case where the
443 selected Expert is unavailable or states they have a conflict of
444 interest, IANA may select another Expert from the pool. Some
445 guidelines for the Experts are given in Section 3.1.2.
450Eastlake Best Current Practice [Page 8]
452RFC 6895 DNS IANA Considerations April 2013
455 RRTYPEs that do not meet the requirements below may nonetheless be
456 allocated by a Standards Action with early allocation permitted as
457 specified in [RFC4020].
459 1. A complete template as specified in Appendix A has been posted to
460 the dns-rrtype-applications@ietf.org mailing list and received by
463 Note that the posting of partially completed, draft, or formally
464 submitted templates to dnsext@ietf.org by the applicant or Expert
465 for comment and discussion is highly encouraged. Before formal
466 submission of an RRTYPE template, we recommend submitting it for
467 community review and considering the responses in order to reduce
468 the probability of initial rejection and the need for modification
471 2. The RR for which an RRTYPE code is being requested is either (a) a
472 data TYPE that can be handled as an Unknown RR as described in
473 [RFC3597] or (b) a Meta-TYPE whose processing is optional, i.e.,
474 it is safe to simply discard RRs with that Meta-TYPE in queries or
477 Note that such RRs may include additional section processing,
478 provided such processing is optional.
480 After the applicant submits their formal application to IANA by
481 sending the completed template specified in Appendix A to the
482 dns-rrtype-applications@ietf.org mailing list, IANA appoints an
483 Expert and sends the completed template to the Expert, copying the
484 applicant. No more than two weeks after receiving the application,
485 the Expert shall explicitly approve or reject the application,
486 informing IANA, the applicant, and the dnsext@ietf.org mailing list.
487 A rejection should include the reason for rejection and may include
488 suggestions for improvement. The Expert should consult with other
489 technical experts and the dnsext@ietf.org mailing list as necessary.
490 If the Expert does not approve the application within this period, it
491 is considered rejected. IANA should report non-responsive Experts to
494 IANA shall maintain a public archive of approved templates. In
495 addition, if the required description of the RRTYPE applied for is
496 referenced by URL, a copy of the document so referenced should be
497 included in the archive.
506Eastlake Best Current Practice [Page 9]
508RFC 6895 DNS IANA Considerations April 2013
5113.1.2. DNS RRTYPE Expert Guidelines
513 The Designated Expert should normally be lenient, preferring to
514 approve most requests. However, the Expert should usually reject any
515 RRTYPE allocation request that meets one or more of the following
518 1. The request was documented in a manner that was not sufficiently
519 clear or complete to evaluate or implement. (Additional
520 documentation can be provided during the Expert Review period.)
522 2. The proposed RRTYPE or RRTYPEs affect DNS processing and do not
523 meet the criteria in point 2 of Section 3.1.1 above.
525 3. Application use as documented makes incorrect assumptions about
526 DNS protocol behavior, such as wildcards, CNAME, DNAME, etc.
528 4. An excessive number of RRTYPE values is being requested when the
529 purpose could be met with a smaller number of values or with
5323.1.3. Special Note on the OPT RR
534 The OPT (OPTion) RR (RRTYPE 41) and its IANA considerations are
535 specified in [RFC6891]. Its primary purpose is to extend the
536 effective field size of various DNS fields, including RCODE, label
537 type, OpCode, flag bits, and RDATA size. In particular, for
538 resolvers and servers that recognize it, it extends the RCODE field
5413.1.4. The AFSDB RR Subtype Field
543 The AFSDB RR [RFC1183] is a CLASS-insensitive RR that has the same
544 RDATA field structure as the MX RR [RFC1035], but the 16-bit unsigned
545 integer field at the beginning of the RDATA is interpreted as a
546 subtype as shown below. Use of the AFSDB RR to locate AFS cell
547 database servers was deprecated by [RFC5864]. This subtype registry
548 is hereby closed, and allocation of new subtypes is no longer
562Eastlake Best Current Practice [Page 10]
564RFC 6895 DNS IANA Considerations April 2013
568 Hexadecimal Assignment Policy
571 0x0000 Reserved; registry closed
574 0x0001 AFS v3.0 Location Service [RFC1183]
577 0x0002 DCE/NCA root cell directory node [RFC1183]
580 0x0003 - 0xFEFF Not allocated; registry closed
583 0xFF00 - 0xFFFE Private Use
586 0xFFFF Reserved; registry closed
5883.2. RR CLASS IANA Considerations
590 There are currently two subcategories of DNS CLASSes: normal, data-
591 containing classes; and QCLASSes that are only meaningful in queries
594 DNS CLASSes have been little used but constitute another dimension of
595 the DNS distributed database. In particular, there is no necessary
596 relationship between the namespace or root servers for one data CLASS
597 and those for another data CLASS. The same DNS NAME can have
598 completely different meanings in different CLASSes. The label types
599 are the same, and the null label is usable only as root in every
600 CLASS. As global networking and DNS have evolved, the IN, or
601 Internet, CLASS has dominated DNS use.
603 As yet, there has not been a requirement for "Meta-CLASSes". That
604 would be a CLASS to designate transient data associated with a
605 particular DNS message, which might be usable in queries. However,
606 it is possible that there might be a future requirement for one or
609 Assigned CLASSes have mnemonics that must be completely disjoint from
610 the mnemonics used for RRTYPEs and that must match the regular
611 expression below. In addition, the generic CLASS and RRTYPE names
612 specified in Section 5 of [RFC3597] cannot be assigned as new CLASS
618Eastlake Best Current Practice [Page 11]
620RFC 6895 DNS IANA Considerations April 2013
623 [A-Z][A-Z0-9\-]*[A-Z0-9]
627 The current CLASS assignments and considerations for future
628 assignments are as follows:
631 Hexadecimal Assignment / Policy, Reference
634 0x0000 Reserved; assignment requires a Standards Action.
637 0x0001 Internet (IN) [RFC1035]
640 0x0002 Available for assignment by IETF Review as a data
644 0x0003 Chaos (CH) [Moon1981]
647 0x0004 Hesiod (HS) [Dyer1987]
650 0x0005 - 0x007F Available for assignment by IETF Review for data
654 0x0080 - 0x00FD Available for assignment by IETF Review for
655 QCLASSes and Meta-CLASSes only.
658 0x00FE QCLASS NONE [RFC2136]
661 0x00FF QCLASS * (ANY) [RFC1035]
664 0x0100 - 0x7FFF Available for assignment by IETF Review.
667 0x8000 - 0xDFFF Available for assignment to data CLASSes only;
668 Specification Required.
674Eastlake Best Current Practice [Page 12]
676RFC 6895 DNS IANA Considerations April 2013
680 0xE000 - 0xFEFF Available for assignment to QCLASSes and
681 Meta-CLASSes only; Specification Required.
684 0xFF00 - 0xFFFE Private Use
687 0xFFFF Reserved; can only be assigned by a Standards
6903.3. Label Considerations
692 DNS NAMEs are sequences of labels [RFC1035].
696 At the present time, there are two categories of label types: data
697 labels and compression labels. Compression labels are pointers to
698 data labels elsewhere within an RR or DNS message and are intended to
699 shorten the wire encoding of NAMEs.
701 The two existing data label types are sometimes referred to as Text
702 and Binary. Text labels can, in fact, include any octet value
703 including zero-value octets, but many current uses involve only
704 printing ASCII characters [US-ASCII]. For retrieval, Text labels are
705 defined to treat ASCII uppercase and lowercase letter codes as
706 matching [RFC4343]. Binary labels are bit sequences [RFC2673]. The
707 Binary Label type is Historic [RFC6891].
7093.3.2. Label Contents and Use
711 The last label in each NAME is "ROOT", which is the zero-length
712 label. By definition, the null or ROOT label cannot be used for any
715 NAMEs are local to a CLASS. The Hesiod [Dyer1987] and Chaos
716 [Moon1981] CLASSes are for essentially local use. The IN, or
717 Internet, CLASS is thus the only DNS CLASS in global use on the
718 Internet at this time.
720 A somewhat out-of-date description of name allocation in the IN CLASS
721 is given in [RFC1591]. Some information on reserved top-level domain
722 names is in BCP 32 [RFC2606].
730Eastlake Best Current Practice [Page 13]
732RFC 6895 DNS IANA Considerations April 2013
7354. Security Considerations
737 This document addresses IANA considerations in the allocation of
738 general DNS parameters, not security. See [RFC4033], [RFC4034], and
739 [RFC4035] for secure DNS considerations.
7415. IANA Considerations
743 This document consists entirely of DNS IANA considerations.
745 IANA has established a process for accepting Appendix A templates and
746 selecting an Expert from those appointed to review such template form
747 applications. IANA forwards the template to the Expert, copying the
748 applicant. IANA archives and makes available all approved RRTYPE
749 allocation templates and referred documentation (unless it is readily
750 available at a stable URI). It is the duty of the applicant to post
751 the formal application template to the
752 dns-rrtype-applications@ietf.org mailing list, which IANA will
753 monitor. The dnsext@ietf.org mailing list is for community
754 discussion and comment. See Section 3.1 and Appendix A for more
786Eastlake Best Current Practice [Page 14]
788RFC 6895 DNS IANA Considerations April 2013
791Appendix A. RRTYPE Allocation Template
793 DNS RRTYPE PARAMETER ALLOCATION TEMPLATE
795 When ready for formal consideration, this template is to be submitted
796 to IANA for processing by emailing the template to dns-rrtype-
797 applications@ietf.org.
801 B.1 Submission Type: [ ] New RRTYPE [ ] Modification to RRTYPE
802 B.2 Kind of RR: [ ] Data RR [ ] Meta-RR
804 C. Contact Information for submitter (will be publicly posted):
806 International telephone number:
807 Other contact handles:
809 D. Motivation for the new RRTYPE application.
810 Please keep this part at a high level to inform the Expert and
811 reviewers about uses of the RRTYPE. Most reviewers will be DNS
812 experts that may have limited knowledge of your application space.
814 E. Description of the proposed RR type.
815 This description can be provided in-line in the template, as an
816 attachment, or with a publicly available URL.
818 F. What existing RRTYPE or RRTYPEs come closest to filling that need
819 and why are they unsatisfactory?
821 G. What mnemonic is requested for the new RRTYPE (optional)?
823 Note: If a mnemonic is not supplied, not allowed, or duplicates an
824 existing RRTYPE or CLASS mnemonic, the Expert will assign a
827 H. Does the requested RRTYPE make use of any existing IANA registry
828 or require the creation of a new IANA subregistry in DNS
829 Parameters? If so, please indicate which registry is to be used
830 or created. If a new subregistry is needed, specify the
831 allocation policy for it and its initial contents. Also include
832 what the modification procedures will be.
834 I. Does the proposal require/expect any changes in DNS
835 servers/resolvers that prevent the new type from being processed
836 as an unknown RRTYPE (see [RFC3597])?
842Eastlake Best Current Practice [Page 15]
844RFC 6895 DNS IANA Considerations April 2013
847Appendix B. Changes from RFC 6195
849 Dropped description of changes from RFC 5395 to [RFC6195], since
850 those changes have already happened and we don't need to do them
851 again. Added description of changes from [RFC6195] to this document.
853 Cut back RRTYPE Expert Review period to two weeks and eliminated the
854 mandatory dnsext@ietf.org comment period. Changed workflow
855 description for RRTYPE review and allocation to correspond more
856 closely to actual practice.
858 Closed the AFSDB subtype registry and added an informative reference
859 to [RFC5864] where the use of the AFSDB RR to locate AFS cell
860 database servers is deprecated.
862 Clarified IANA archiving of referenced documentation as well as
863 approved RRTYPE application template.
865 In the RRTYPE application template, changed the label of question "B"
866 to "B.1" and added "B.2" to ask about the kind of RR.
868 Added text and an exclusory regular expression to Sections 3.1 and
869 3.2 to prohibit the use of a slight generalization of the generic
870 CLASS and RRTYPE names specified in [RFC3597] as the mnemonics for
871 new CLASSes and RRTYPEs.
873 Parenthetically listed "ANY" as well as "ALL" as a meaning for the
876 Clarified that there is one DNS error number space for headers, OPT
877 extended headers, TSIG RRs, and TKEY RRs. Noted that this is
878 considered to update [RFC2845] and [RFC2930]. Noted the overloading
879 of error number 9 as well as 16.
881 Updated references for revised versions.
883 Incorporated a number of editorial changes and typo fixes.
898Eastlake Best Current Practice [Page 16]
900RFC 6895 DNS IANA Considerations April 2013
905 [RFC1034] Mockapetris, P., "Domain names - concepts and
906 facilities", STD 13, RFC 1034, November 1987.
908 [RFC1035] Mockapetris, P., "Domain names - implementation and
909 specification", STD 13, RFC 1035, November 1987.
911 [RFC1996] Vixie, P., "A Mechanism for Prompt Notification of Zone
912 Changes (DNS NOTIFY)", RFC 1996, August 1996.
914 [RFC2136] Vixie, P., Ed., Thomson, S., Rekhter, Y., and J. Bound,
915 "Dynamic Updates in the Domain Name System (DNS UPDATE)",
916 RFC 2136, April 1997.
918 [RFC2181] Elz, R. and R. Bush, "Clarifications to the DNS
919 Specification", RFC 2181, July 1997.
921 [RFC2845] Vixie, P., Gudmundsson, O., Eastlake 3rd, D., and B.
922 Wellington, "Secret Key Transaction Authentication for
923 DNS (TSIG)", RFC 2845, May 2000.
925 [RFC2930] Eastlake 3rd, D., "Secret Key Establishment for DNS (TKEY
926 RR)", RFC 2930, September 2000.
928 [RFC3425] Lawrence, D., "Obsoleting IQUERY", RFC 3425,
931 [RFC3597] Gustafsson, A., "Handling of Unknown DNS Resource Record
932 (RR) Types", RFC 3597, September 2003.
934 [RFC4020] Kompella, K. and A. Zinin, "Early IANA Allocation of
935 Standards Track Code Points", BCP 100, RFC 4020,
938 [RFC4033] Arends, R., Austein, R., Larson, M., Massey, D., and S.
939 Rose, "DNS Security Introduction and Requirements",
940 RFC 4033, March 2005.
942 [RFC4034] Arends, R., Austein, R., Larson, M., Massey, D., and S.
943 Rose, "Resource Records for the DNS Security Extensions",
944 RFC 4034, March 2005.
946 [RFC4035] Arends, R., Austein, R., Larson, M., Massey, D., and S.
947 Rose, "Protocol Modifications for the DNS Security
948 Extensions", RFC 4035, March 2005.
954Eastlake Best Current Practice [Page 17]
956RFC 6895 DNS IANA Considerations April 2013
959 [RFC4635] Eastlake 3rd, D., "HMAC SHA (Hashed Message
960 Authentication Code, Secure Hash Algorithm) TSIG
961 Algorithm Identifiers", RFC 4635, August 2006.
963 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
964 IANA Considerations Section in RFCs", BCP 26, RFC 5226,
967 [RFC6840] Weiler, S., Ed., and D. Blacka, Ed., "Clarifications and
968 Implementation Notes for DNS Security (DNSSEC)",
969 RFC 6840, February 2013.
971 [RFC6891] Damas, J., Graff, M., and Vixie, P., "Extension
972 Mechanisms for DNS (EDNS(0))", STD 75, RFC 6891, April
975 [US-ASCII] American National Standards Institute (formerly United
976 States of America Standards Institute), "USA Code for
977 Information Interchange", ANSI X3.4-1968, 1968.
979 ANSI X3.4-1968 has been replaced by newer versions with
980 slight modifications, but the 1968 version remains
981 definitive for the Internet.
983Informative References
985 [Dyer1987] Dyer, S., and F. Hsu, "Hesiod", Project Athena Technical
986 Plan - Name Service, April 1987.
988 [Moon1981] Moon, D., "Chaosnet", A.I. Memo 628, Massachusetts
989 Institute of Technology Artificial Intelligence
990 Laboratory, June 1981.
992 [RFC1183] Everhart, C., Mamakos, L., Ullmann, R., and P.
993 Mockapetris, "New DNS RR Definitions", RFC 1183,
996 [RFC1591] Postel, J., "Domain Name System Structure and
997 Delegation", RFC 1591, March 1994.
999 [RFC2606] Eastlake 3rd, D. and A. Panitz, "Reserved Top Level DNS
1000 Names", BCP 32, RFC 2606, June 1999.
1002 [RFC2673] Crawford, M., "Binary Labels in the Domain Name System",
1003 RFC 2673, August 1999.
1005 [RFC2931] Eastlake 3rd, D., "DNS Request and Transaction Signatures
1006 ( SIG(0)s )", RFC 2931, September 2000.
1010Eastlake Best Current Practice [Page 18]
1012RFC 6895 DNS IANA Considerations April 2013
1015 [RFC4343] Eastlake 3rd, D., "Domain Name System (DNS) Case
1016 Insensitivity Clarification", RFC 4343, January 2006.
1018 [RFC5864] Allbery, R., "DNS SRV Resource Records for AFS",
1019 RFC 5864, April 2010.
1021 [RFC6195] Eastlake 3rd, D., "Domain Name System (DNS) IANA
1022 Considerations", RFC 6195, March 2011.
1026 Alfred Hoenes' contributions are gratefully acknowledged as are those
1027 by Mark Andrews, Dick Franks, and Michael Sheldon.
1031 Donald E. Eastlake 3rd
1037 Phone: +1-508-333-2270
1038 EMail: d3e3e3@gmail.com
1066Eastlake Best Current Practice [Page 19]