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Domain Name System (DNS) IANA Considerations

The information below is for an old version of the document.
Document Type
This is an older version of an Internet-Draft that was ultimately published as RFC 6895.
Author Donald E. Eastlake 3rd
Last updated 2012-05-02
Replaces draft-eastlake-dnsext-6195bis
RFC stream Internet Engineering Task Force (IETF)
Additional resources Mailing list discussion
Stream WG state WG Document
Document shepherd (None)
IESG IESG state Became RFC 6895 (Best Current Practice)
Consensus boilerplate Unknown
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INTERNET-DRAFT                                           Donald Eastlake
Obsoletes: 6195                                                   Huawei
Updates: 1183, 3597
Intended status: Best Current Practice
Expires: November 1, 2012                                    May 2, 2012

              Domain Name System (DNS) IANA Considerations


   This document specifies Internet Assigned Number Authority (IANA)
   parameter assignment considerations for the allocation of Domain Name
   System (DNS) resource record types, CLASSes, operation codes, error
   codes, DNS protocol message header bits, and AFSDB resource record
   subtypes.  It obsoletes RFC 6195.

Status of This Memo

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

   Distribution of this draft is unlimited. It is intended to become the
   new BCP 42 obsoleting RFC 6195. Comments should be sent to the DNS
   Extensions Working Group mailing list <>.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   The list of current Internet-Drafts can be accessed at

   The list of Internet-Draft Shadow Directories can be accessed at

D. Eastlake 3rd                                                 [Page 1]
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Table of Contents

      1. Introduction............................................3
      1.1. Terminology...........................................3
      1.2 Acknowledgement........................................3

      2. DNS Query/Response Headers..............................4
      2.1. One Spare Bit?........................................4
      2.2. OpCode Assignment.....................................5
      2.3. RCODE Assignment......................................5

      3. DNS Resource Records....................................7
      3.1. RRTYPE IANA Considerations............................8
      3.1.1. DNS RRTYPE Allocation Policy........................9
      3.1.2. DNS RRTYPE Expert Guidelines.......................10
      3.1.3. Special Note on the OPT RR.........................10
      3.1.4. The AFSDB RR Subtype Field.........................11
      3.2. RR CLASS IANA Considerations.........................11
      3.3. Label Considerations.................................13
      3.3.1. Label Types........................................13
      3.3.2. Label Contents and Use.............................13

      4. Security Considerations................................14
      5. IANA Considerations....................................14

      Appendix A: RRTYPE Allocation Template....................15
      Appendix B: Changes From RFC 6195.........................16

      Normative References......................................17
      Informative References....................................18

D. Eastlake 3rd                                                 [Page 2]
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1. Introduction

   The Domain Name System (DNS) provides replicated distributed secure
   hierarchical databases that store "resource records" (RRs) under
   domain names. DNS data is structured into CLASSes and zones that can
   be independently maintained. Familiarity with [RFC1034], [RFC1035],
   [RFC2136], [RFC2181], and [RFC4033] is assumed.

   This document provides, either directly or by reference, the general
   IANA parameter assignment considerations that apply across DNS query
   and response headers and all RRs. There may be additional IANA
   considerations that apply to only a particular RRTYPE or
   query/response OpCode. See the specific RFC defining that RRTYPE or
   query/response OpCode for such considerations if they have been
   defined, except for AFSDB RR considerations [RFC1183], which are
   included herein. This RFC obsoletes [RFC6195]; however, the only
   significant changes are those to the RRTYPE IANA allocation process,
   aimed at streamlining it and clarifying the expected behavior of the
   parties involved, and the closing of the AFSDB sub-type registry.

   IANA currently maintains a web page of DNS parameters available from

1.1. Terminology

   "Standards Action", "IETF Review", "Specification Required", and
   "Private Use" are as defined in [RFC5226].

1.2 Acknowledgement

   Alfred Hoenes contributions are gratefully acknowledged.

D. Eastlake 3rd                                                 [Page 3]
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2. DNS Query/Response Headers

   The header for DNS queries and responses contains field/bits in the
   following diagram taken from [RFC2136] and [RFC6195]:

                                              1  1  1  1  1  1
                0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
               |                      ID                       |
               |QR|   OpCode  |AA|TC|RD|RA| Z|AD|CD|   RCODE   |
               |                QDCOUNT/ZOCOUNT                |
               |                ANCOUNT/PRCOUNT                |
               |                NSCOUNT/UPCOUNT                |
               |                    ARCOUNT                    |

   The ID field identifies the query and is echoed in the response so
   they can be matched.

   The QR bit indicates whether the header is for a query or a response.

   The AA, TC, RD, RA, AD, and CD bits are each theoretically meaningful
   only in queries or only in responses, depending on the bit. However,
   some DNS implementations copy the query header as the initial value
   of the response header without clearing bits. Thus, any attempt to
   use a "query" bit with a different meaning in a response or to define
   a query meaning for a "response" bit is dangerous, given existing
   implementation. Such meanings may only be assigned by a Standards

   The unsigned integer fields query count (QDCOUNT), answer count
   (ANCOUNT), authority count (NSCOUNT), and additional information
   count (ARCOUNT) express the number of records in each section for all
   OpCodes except Update [RFC2136]. These fields have the same structure
   and data type for Update but are instead the counts for the zone
   (ZOCOUNT), prerequisite (PRCOUNT), update (UPCOUNT), and additional
   information (ARCOUNT) sections.

2.1. One Spare Bit?

   There have been ancient DNS implementations for which the Z bit being
   on in a query meant that only a response from the primary server for
   a zone is acceptable. It is believed that current DNS implementations

D. Eastlake 3rd                                                 [Page 4]
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   ignore this bit.

   Assigning a meaning to the Z bit requires a Standards Action.

2.2. OpCode Assignment

   Currently, DNS OpCodes are assigned as follows:

      OpCode Name                              Reference

       0     Query                             [RFC1035]
       1     IQuery  (Inverse Query, Obsolete) [RFC3425]
       2     Status                            [RFC1035]
       3     available for assignment
       4     Notify                            [RFC1996]
       5     Update                            [RFC2136]
      6-15   available for assignment

   New OpCode assignments require a Standards Action as modified by

2.3. RCODE Assignment

   It would appear from the DNS header above that only four bits of
   RCODE, or response/error code, are available. However, RCODEs can
   appear not only at the top level of a DNS response but also inside
   OPT RRs [RFC2671bis], TSIG RRs [RFC2845], and TKEY RRs [RFC2930]. The
   OPT RR provides an 8-bit extension resulting in a 12-bit RCODE field,
   and the TSIG and TKEY RRs have a 16-bit RCODE field.

   Error codes appearing in the DNS header and in these three RR types
   all refer to the same error code space with the single exception of
   error code 16, which has a different meaning in the OPT RR than in
   other contexts. This duplicate assignment was accidental. See table

D. Eastlake 3rd                                                 [Page 5]
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        RCODE   Name    Description                        Reference

         0    NoError   No Error                           [RFC1035]
         1    FormErr   Format Error                       [RFC1035]
         2    ServFail  Server Failure                     [RFC1035]
         3    NXDomain  Non-Existent Domain                [RFC1035]
         4    NotImp    Not Implemented                    [RFC1035]
         5    Refused   Query Refused                      [RFC1035]
         6    YXDomain  Name Exists when it should not     [RFC2136]
         7    YXRRSet   RR Set Exists when it should not   [RFC2136]
         8    NXRRSet   RR Set that should exist does not  [RFC2136]
         9    NotAuth   Server Not Authoritative for zone  [RFC2136]
        10    NotZone   Name not contained in zone         [RFC2136]

        11 - 15
       0xB - 0xF        Available for assignment

        16    BADVERS   Bad OPT Version                    [RFC2671bis]
        16    BADSIG    TSIG Signature Failure             [RFC2845]
        17    BADKEY    Key not recognized                 [RFC2845]
        18    BADTIME   Signature out of time window       [RFC2845]
        19    BADMODE   Bad TKEY Mode                      [RFC2930]
        20    BADNAME   Duplicate key name                 [RFC2930]
        21    BADALG    Algorithm not supported            [RFC2930]
        22    BADTRUC   Bad Truncation                     [RFC4635]

        23 - 3,840
    0x0017 - 0x0F00     Available for assignment

     3,841 - 4,095
    0x0F01 - 0x0FFF     Private Use

     4,096 - 65,534
    0x1000 - 0xFFFE     Available for assignment

    0xFFFF              Reserved, can only be allocated by a Standards

   Since it is important that RCODEs be understood for interoperability,
   assignment of a new RCODE in the ranges listed above as "Available
   for assignment" requires an IETF Review.

D. Eastlake 3rd                                                 [Page 6]
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3. DNS Resource Records

   All RRs have the same top-level format, shown in the figure below
   taken from [RFC1035].

                                       1  1  1  1  1  1
         0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
       |                                               |
       /                                               /
       /                     NAME                      /
       /                                               /
       |                     TYPE                      |
       |                     CLASS                     |
       |                     TTL                       |
       |                                               |
       |                   RDLENGTH                    |
       /                    RDATA                      /
       /                                               /

   NAME is an owner name, i.e., the name of the node to which this
   resource record pertains. NAMEs are specific to a CLASS as described
   in Section 3.2. NAMEs consist of an ordered sequence of one or more
   labels, each of which has a label type [RFC1035] [RFC2671bis].

   TYPE is a 2-octet unsigned integer containing one of the RRTYPE
   codes.  See Section 3.1.

   CLASS is a 2-octet unsigned integer containing one of the RR CLASS
   codes. See Section 3.2.

   TTL is a 4-octet (32-bit) unsigned integer that specifies, for data
   TYPEs, the number of seconds that the resource record may be cached
   before the source of the information should again be consulted. Zero
   is interpreted to mean that the RR can only be used for the
   transaction in progress.

   RDLENGTH is an unsigned 16-bit integer that specifies the length in
   octets of the RDATA field.

   RDATA is a variable-length string of octets that constitutes the
   resource. The format of this information varies according to the TYPE
   and, in some cases, the CLASS of the resource record.

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3.1. RRTYPE IANA Considerations

   There are three subcategories of RRTYPE numbers: data TYPEs, QTYPEs,
   and Meta-TYPEs.

   Data TYPEs are the means of storing data. QTYPES can only be used in
   queries. Meta-TYPEs designate transient data associated with a
   particular DNS message and, in some cases, can also be used in
   queries.  Thus far, data TYPEs have been assigned from 1 upward, plus
   the block from 100 through 103, and from 32,768 upward, while Q and
   Meta-TYPEs have been assigned from 255 downward except for the OPT
   Meta-RR, which is assigned TYPE 41. There have been DNS
   implementations that made caching decisions based on the top bit of
   the bottom byte of the RRTYPE.

   There are currently three Meta-TYPEs assigned: OPT [RFC2671bis], TSIG
   [RFC2845], and TKEY [RFC2930]. There are currently five QTYPEs
   assigned: * (ALL), MAILA, MAILB, AXFR, and IXFR.

   RRTYPEs have mnemonics that must be completely disjoint from the
   mnemonics used for CLASSes and that must match the following regular


   Considerations for the allocation of new RRTYPEs are as follows:

   Hexadecimal     Assignment Policy

   0x0000            RRTYPE zero is used as a special indicator for the
                     SIG (0) RR [RFC2931] [RFC4034] and in other
                     circumstances, and it must never be allocated for
                     ordinary use.

        1 - 127
   0x0001 - 0x007F   Remaining RRTYPEs in this range are assigned for
                     data TYPEs by the DNS RRTYPE Allocation Policy as
                     specified in Section 3.1.1.

        128 - 255
   0x0080 - 0x00FF   Remaining RRTYPEs in this range are assigned for Q
                     and Meta-TYPEs by the DNS RRTYPE Allocation Policy
                     as specified in Section 3.1.1.

D. Eastlake 3rd                                                 [Page 8]
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      256 - 61,439
   0x0100 - 0xEFFF   Remaining RRTYPEs in this range are assigned for
                     data RRTYPEs by the DNS RRTYPE Allocation Policy as
                     specified in Section 3.1.1. (32,768 and 32,769
                     (0x8000 and 0x8001) have been assigned.)

   61,440 - 65,279
   0xF000 - 0xFEFF   Reserved for future use. IETF Review required to
                     define use.

   65,280 - 65,534
   0xFF00 - 0xFFFE   Private Use.

   0xFFFF            Reserved, can only be assigned by a Standards

3.1.1. DNS RRTYPE Allocation Policy

   Parameter values specified in Section 3.1 above, as assigned based on
   DNS RRTYPE Allocation Policy, are allocated by Expert Review if they
   meet the two requirements listed below. There will be a pool of a
   small number of Experts appointed by the IESG. Each application will
   be judged by an Expert selected by IANA. In any case where the
   selected Expert is unavailable or states they have a conflict of
   interest, IANA may select another Expert from the pool.

   Some guidelines for the Experts are given in Section 3.1.2. RRTYPEs
   that do not meet the requirements below may nonetheless be allocated
   by a Standards Action as modified by [RFC4020].

   1. A complete template as specified in Appendix A has been posted to
      the mailing list and received by
      the Expert.
         Note that the posting of partially completed, draft, or
      formally submitted templates to by the applicant
      or Expert for comment and discussion is highly encouraged. Formal
      submission of an RRTYPE template without consideration of some
      community review can be expected to increase the probability of
      initial rejection leading to a need to re-submit after

   2. The RR for which an RRTYPE code is being requested is either (a) a
      data TYPE that can be handled as an Unknown RR as described in
      [RFC3597] or (b) a Meta-TYPE whose processing is optional, i.e.,
      it is safe to simply discard RRs with that Meta-TYPE in queries or
         Note that such RRs may include additional section processing,

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      provided such processing is optional.

   After the applicant submits their formal application to IANA by
   sending the completed template specified in Appendix A to the dns- mailing list, IANA appoints an Expert
   and sends the completed template to the Expert copying the applicant.
   No more than two weeks after receiving the application the Expert
   shall explicitly approve or reject the application, informing IANA,
   the applicant, and the mailing list. The Expert
   should consult with other technical experts and the
   mailing list as necessary. If the Expert does not approve the
   application within this period, it is considered rejected. IANA
   should report non-responsive Experts to the IESG.

   IANA shall maintain a public archive of approved templates. In
   addition, if the required description of the RRTYPE applied for is
   referenced by URL, a copy of the document so referenced should be
   included in the archive.

3.1.2. DNS RRTYPE Expert Guidelines

   The Expert should normally reject any RRTYPE allocation request that
   meets one or more of the following criteria:

   1. Was documented in a manner that was not sufficiently clear or
      complete to evaluate or implement.  (Additional documentation can
      be provided during the Expert review period.)

   2. The proposed RRTYPE or RRTYPEs affect DNS processing and do not
      meet the criteria in point 2 of Section 3.1.1 above.

   3. Application use as documented makes incorrect assumptions about
      DNS protocol behavior, such as wild cards, CNAME, DNAME, etc.

   4. An excessive number of RRTYPE values is being requested when the
      purpose could be met with a smaller number or with Private Use

3.1.3. Special Note on the OPT RR

   The OPT (OPTion) RR (RRTYPE 41) and its IANA considerations are
   specified in [RFC2671bis]. Its primary purpose is to extend the
   effective field size of various DNS fields including RCODE, label
   type, OpCode, flag bits, and RDATA size. In particular, for resolvers
   and servers that recognize it, it extends the RCODE field from 4 to
   12 bits.

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3.1.4. The AFSDB RR Subtype Field

   The AFSDB RR [RFC1183] is a CLASS-insensitive RR that has the same
   RDATA field structure as the MX RR [RFC1035], but the 16-bit unsigned
   integer field at the beginning of the RDATA is interpreted as a
   subtype as show below. This subtype registry is closed and allocation
   of new subtypes is no longer permitted.

   Hexadecimal       Assignment Policy

   0x0000            Reserved, registry closed

   0x0001            AFS v3.0 Location Service [RFC1183]

   0x0002            DCE/NCA root cell directory node [RFC1183]

        3 - 65,279
   0x0003 - 0xFEFF   Not allocated, registry closed

   65,280 - 65,534
   0xFF00 - 0xFFFE   Private Use

   0xFFFF            Reserved, registry closed

3.2. RR CLASS IANA Considerations

   There are currently two subcategories of DNS CLASSes: normal, data-
   containing classes and QCLASSes that are only meaningful in queries
   or updates.

   DNS CLASSes have been little used but constitute another dimension of
   the DNS distributed database. In particular, there is no necessary
   relationship between the name space or root servers for one data
   CLASS and those for another data CLASS. The same DNS NAME can have
   completely different meanings in different CLASSes. The label types
   are the same, and the null label is usable only as root in every
   CLASS.  As global networking and DNS have evolved, the IN, or
   Internet, CLASS has dominated DNS use.

   As yet, there has not been a requirement for "meta-CLASSes". That
   would be a CLASS to designate transient data associated with a
   particular DNS message, which might be usable in queries. However, it
   is possible that there might be a future requirement for one or more

D. Eastlake 3rd                                                [Page 11]
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   CLASSes have mnemonics that must be completely disjoint from the
   mnemonics used for RRTYPEs and that must match the following regular


   The current CLASS assignments and considerations for future
   assignments are as follows:

   Hexadecimal       Assignment / Policy, Reference

   0x0000            Reserved; assignment requires a Standards Action

   0x0001            Internet (IN) [RFC1035]

   0x0002            Available for assignment by IETF Review as a data

   0x0003            Chaos (CH) [Moon1981]

   0x0004            Hesiod (HS) [Dyer1987]

        5 - 127
   0x0005 - 0x007F   Available for assignment by IETF Review for data
                     CLASSes only

      128 - 253
   0x0080 - 0x00FD   Available for assignment by IETF Review for
                     QCLASSes and meta-CLASSes only

   0x00FE            QCLASS NONE [RFC2136]

   0x00FF            QCLASS * (ANY) [RFC1035]

      256 - 32,767
   0x0100 - 0x7FFF   Available for assignment by IETF Review

   32,768 - 57,343
   0x8000 - 0xDFFF   Assigned for data CLASSes only; Specification
                     Required for new assignments

D. Eastlake 3rd                                                [Page 12]
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   57,344 - 65,279
   0xE000 - 0xFEFF   Assigned for QCLASSes and meta-CLASSes only;
                     Specification Required for new assignments

   65,280 - 65,534
   0xFF00 - 0xFFFE   Private Use

   0xFFFF            Reserved; can only be assigned by a Standards

3.3. Label Considerations

   DNS NAMEs are sequences of labels [RFC1035].

3.3.1. Label Types

   At the present time, there are two categories of label types: data
   labels and compression labels. Compression labels are pointers to
   data labels elsewhere within an RR or DNS message and are intended to
   shorten the wire encoding of NAMEs.

   The two existing data label types are sometimes referred to as Text
   and Binary. Text labels can, in fact, include any octet value
   including zero-value octets, but many current uses involve only
   printing ASCII characters [RFC20]. For retrieval, Text labels are
   defined to treat ASCII upper and lower case letter codes as matching
   [RFC4343]. Binary labels are bit sequences [RFC2673]. The Binary
   label type is Historic [RFC2671bis].

3.3.2. Label Contents and Use

   The last label in each NAME is "ROOT", which is the zero-length
   label.  By definition, the null or ROOT label cannot be used for any
   other NAME purpose.

   NAMEs are local to a CLASS. The Hesiod [Dyer1987] and Chaos
   [Moon1981] CLASSes are for essentially local use. The IN, or
   Internet, CLASS is thus the only DNS CLASS in global use on the
   Internet at this time.

   A somewhat out-of-date description of name allocation in the IN Class
   is given in [RFC1591]. Some information on reserved top-level domain
   names is in BCP 32 [RFC2606].

D. Eastlake 3rd                                                [Page 13]
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4. Security Considerations

   This document addresses IANA considerations in the allocation of
   general DNS parameters, not security. See [RFC4033], [RFC4034], and
   [RFC4035] for secure DNS considerations.

5. IANA Considerations

   This document consists entirely of DNS IANA Considerations.

   IANA has established a process for accepting Appendix A templates and
   selecting an Expert from those appointed to review such template form
   applications. IANA forwards the template to the Expert copying the
   applicant. IANA archives and makes available all approved RRTYPE
   allocation templates and referred documentation (unless it is readily
   available at a stable URI). It is the duty of the applicant to post
   the formal application template to the dns-rrtype- mailing list, which IANA will monitor. The mailing list is for community discussion and comment.
   See Section 3.1 and Appendix A for more details.

D. Eastlake 3rd                                                [Page 14]
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Appendix A: RRTYPE Allocation Template


   When ready for formal consideration, this template is to be submitted
   to IANA for processing by emailing the template to dns-rrtype-

   A. Submission Date:

   B.1 Submission Type:  [ ] New RRTYPE  [ ] Modification to RRTYPE
   B.2 Kind of RR:  [ ] Data RR  [ ] Meta-RR

   C. Contact Information for submitter (will be publicly posted):
         Email Address:
         International telephone number:
         Other contact handles:

   D. Motivation for the new RRTYPE application.
      Please keep this part at a high level to inform the Expert and
      reviewers about uses of the RRTYPE. Most reviewers will be DNS
      experts that may have limited knowledge of your application space.

   E. Description of the proposed RR type.
      This description can be provided in-line in the template, as an
      attachment, or with a publicly available URL.

   F. What existing RRTYPE or RRTYPEs come closest to filling that need
      and why are they unsatisfactory?

   G. What mnemonic is requested for the new RRTYPE (optional)?
      Note: this can be left blank and the mnemonic decided after the
      template is accepted.

   H. Does the requested RRTYPE make use of any existing IANA registry
      or require the creation of a new IANA sub-registry in DNS
      Parameters?  If so, please indicate which registry is to be used
      or created. If a new sub-registry is needed, specify the
      allocation policy for it and its initial contents. Also include
      what the modification procedures will be.

   I. Does the proposal require/expect any changes in DNS
      servers/resolvers that prevent the new type from being processed
      as an unknown RRTYPE (see [RFC3597])?

   J. Comments:

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Appendix B: Changes From RFC 6195

   Drop description of changes from RFC 5395 to RFC 6195 since those
   changes have already happened and we don't need to do them again. Add
   description of changes from RFC 6195.

   Cut back RRTYPE Expert review period to two weeks and eliminate the
   mandatory comment period. Change workflow description
   for RRTYPE review and allocation to correspond more closely to actual

   Close AFSDB sub-type registry.

   Update references for revised versions and change ASCII reference to

   Clarify IANA archiving of referenced documentation as well as
   approved RRTYPE application template.

   In the RRTYPE application template, change the label of question "B"
   to "B.1" and add "B.2" to ask about the kind of RR.

   A number of editorial changes and typo fixes.

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Normative References

   [RFC20] - Cerf, V., "ASCII format for network interchange", RFC 20,
   October 1969.

   [RFC1034] - Mockapetris, P., "Domain names - concepts and
   facilities", STD 13, RFC 1034, November 1987.

   [RFC1035] - Mockapetris, P., "Domain names - implementation and
   specification", STD 13, RFC 1035, November 1987.

   [RFC1996] - Vixie, P., "A Mechanism for Prompt Notification of Zone
   Changes (DNS NOTIFY)", RFC 1996, August 1996.

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

   [RFC2181] - Elz, R. and R. Bush, "Clarifications to the DNS
   Specification", RFC 2181, July 1997.

   [RFC2845] - Vixie, P., Gudmundsson, O., Eastlake 3rd, D., and B.
   Wellington, "Secret Key Transaction Authentication for DNS (TSIG)",
   RFC 2845, May 2000.

   [RFC2930] - Eastlake 3rd, D., "Secret Key Establishment for DNS (TKEY
   RR)", RFC 2930, September 2000.

   [RFC3425] - Lawrence, D., "Obsoleting IQUERY", RFC 3425, November

   [RFC3597] - Gustafsson, A., "Handling of Unknown DNS Resource Record
   (RR) Types", RFC 3597, September 2003.

   [RFC4020] - Kompella, K. and A. Zinin, "Early IANA Allocation of
   Standards Track Code Points", BCP 100, RFC 4020, February 2005.

   [RFC4033] - Arends, R., Austein, R., Larson, M., Massey, D., and S.
   Rose, "DNS Security Introduction and Requirements", RFC 4033, March

   [RFC4034] - Arends, R., Austein, R., Larson, M., Massey, D., and S.
   Rose, "Resource Records for the DNS Security Extensions", RFC 4034,
   March 2005.

   [RFC4035] - Arends, R., Austein, R., Larson, M., Massey, D., and S.
   Rose, "Protocol Modifications for the DNS Security Extensions", RFC
   4035, March 2005.

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   [RFC4635] - Eastlake 3rd, D., "HMAC SHA (Hashed Message
   Authentication Code, Secure Hash Algorithm) TSIG Algorithm
   Identifiers", RFC 4635, August 2006.

   [RFC5226] - Narten, T. and H. Alvestrand, "Guidelines for Writing an
   IANA Considerations Section in RFCs", BCP 26, RFC 5226, May 2008.

   [RFC2671bis] - Damas, J., Graff, M., and Vixie, P., "Extension
   Mechanisms for DNS (EDNS0)", draft-ietf-dnsext-rfc2671bis-edns0, work
   in progress.

Informative References

   [Dyer1987] - Dyer, S., and F. Hsu, "Hesiod", Project Athena Technical
   Plan - Name Service, April 1987.

   [Moon1981] - Moon, D., "Chaosnet", A.I. Memo 628, Massachusetts
   Institute of Technology Artificial Intelligence Laboratory, June

   [RFC1183] - Everhart, C., Mamakos, L., Ullmann, R., and P.
   Mockapetris, "New DNS RR Definitions", RFC 1183, October 1990.

   [RFC1591] - Postel, J., "Domain Name System Structure and
   Delegation", RFC 1591, March 1994.

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

   [RFC2673] - Crawford, M., "Binary Labels in the Domain Name System",
   RFC 2673, August 1999.

   [RFC2931] - Eastlake 3rd, D., "DNS Request and Transaction Signatures
   ( SIG(0)s )", RFC 2931, September 2000.

   [RFC4343] - Eastlake 3rd, D., "Domain Name System (DNS) Case
   Insensitivity Clarification", RFC 4343, January 2006.

   [RFC6195] - Eastlake 3rd, D., "Domain Name System (DNS) IANA
   Considerations", RFC 6195, March 2011.

D. Eastlake 3rd                                                [Page 18]
INTERNET-DRAFT                                   DNS IANA Considerations

Author's Address

   Donald E. Eastlake 3rd
   Huawei R&D USA
   155 Beaver Street
   Milford, MA 01757 USA

   Telephone:   +1-508-333-2270

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D. Eastlake 3rd                                                [Page 19]