draft-ietf-dnsext-2929bis-01.txt

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INTERNET-DRAFT           DNS IANA Considerations             August 2005


3.1.2 Special Note on the OPT RR

   The OPT (OPTion) RR, number 41, is specified in [RFC 2671].  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.



3.1.3 The AFSDB RR Subtype Field

   The AFSDB RR [RFC 1183] is a CLASS insensitive RR that has the same
   RDATA field structure as the MX RR but the 16 bit unsigned integer
   field at the beginning of the RDATA is interpreted as a subtype as
   follows:

     Decimal
   Hexadecimal

     0
   0x0000 -  Allocation requires IETF Standards Action.

     1
   0x0001 - Andrews File Service v3.0 Location Service [RFC 1183].

     2
   0x0002 - DCE/NCA root cell directory node [RFC 1183].

     3 - 65,279
   0x0003 - 0xFEFF - Allocation by IETF Consensus.

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

     65,535
   0xFFFF - Reserved, allocation requires IETF Standards Action.



3.2 RR CLASS IANA Considerations

   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 CLASS and
   those for another CLASS.  The same name can have completely different
   meanings in different CLASSes; however, the label types are the same
   and the null label is usable only as root in every CLASS.  However,
   as global networking and DNS have evolved, the IN, or Internet, CLASS
   has dominated DNS use.


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

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

     Decimal
   Hexadecimal

     0
   0x0000 - Reserved, assignment requires an IETF Standards Action.

     1
   0x0001 - Internet (IN).

     2
   0x0002 - Available for assignment by IETF Consensus as a data CLASS.

     3
   0x0003 - Chaos (CH) [Moon 1981].

     4
   0x0004 - Hesiod (HS) [Dyer 1987].

     5 - 127
   0x0005 - 0x007F - available for assignment by IETF Consensus for data
          CLASSes only.

     128 - 253
   0x0080 - 0x00FD - available for assignment by IETF Consensus for
          QCLASSes only.

     254
   0x00FE - QCLASS None [RFC 2136].

     255
   0x00FF - QCLASS Any [RFC 1035].

     256 - 32,767
   0x0100 - 0x7FFF - Assigned by IETF Consensus.

     32,768 - 65,279
   0x8000 - 0xFEFF - Assigned based on Specification Required as defined
          in [RFC 2434].

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

     65,535
   0xFFFF - Reserved, can only be assigned by an IETF Standards Action.


D. Eastlake 3rd                                                [Page 10]


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3.3 RR NAME Considerations

   DNS NAMEs are sequences of labels [RFC 1035].  The last label in each
   NAME is "ROOT" which is the zero length label.  By definition, the
   null or ROOT label can not be used for any other NAME purpose.

   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 most
   current uses involve only [US-ASCII].  For retrieval, Text labels are
   defined to treat ASCII upper and lower case letter codes as matching
   [insensitive].  Binary labels are bit sequences [RFC 2673]. The
   Binary label type is Experimental [RFC 3363].

   IANA considerations for label types are given in [RFC 2671].

   NAMEs are local to a CLASS.  The Hesiod [Dyer 1987] and Chaos [Moon
   1981] CLASSes are essentially for 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 [RFC 1591].  Some information on reserved top level
   domain names is in BCP 32 [RFC 2606].



4. Security Considerations

   This document addresses IANA considerations in the allocation of
   general DNS parameters, not security.  See [RFC 4033, 4034, 4035] for
   secure DNS considerations.

















D. Eastlake 3rd                                                [Page 11]


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Appendix: Changes from RFC 2929

   RFC Editor: This Appendix should be deleted for publication.

   Changes from RFC 2929 to this draft:

   1. Changed many "IETF Consensus" for RR TYPEs to be "DNS TYPE
   Allocation Policy" and add the specification of that policy. Change
   some remaining "IETF Standards Action" allocation requirements to say
   "as modified by [RFC 4020]".

   2. Updated various RFC references.

   3. Mentioned that the Binary label type is now Experimental and
   IQuery is Obsolete.

   4. Changed allocation status of RR Type 0xFFFF and RCODE 0xFFFF to be
   IETF Standards Action required.

   5. Add an IANA allocation policy for the AFSDB RR Subtype field.

   6. Addition of reference to case insensitive draft.






























D. Eastlake 3rd                                                [Page 12]


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Copyright and Disclaimer

   Copyright (C) The Internet Society (2005).  This document is subject to
   the rights, licenses and restrictions contained in BCP 78, and except
   as set forth therein, the authors retain all their rights.


   This document and the information contained herein are provided on an
   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
   ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
   INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
   INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.



Normative References

   [RFC 1034] - Mockapetris, P., "Domain Names - Concepts and
   Facilities", STD 13, RFC 1034, November 1987.

   [RFC 1035] - Mockapetris, P., "Domain Names - Implementation and
   Specifications", STD 13, RFC 1035, November 1987.

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

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

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

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

   [RFC 2434] - Narten, T. and H. Alvestrand, "Guidelines for Writing an
   IANA Considerations Section in RFCs", BCP 26, RFC 2434, October 1998.

   [RFC 2671] - Vixie, P., "Extension mechanisms for DNS (EDNS0)", RFC
   2671, August 1999.

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

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


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

   [RFC 3363] - Bush, R., Durand, A., Fink, B., Gudmundsson, O., and T.
   Hain, "Representing Internet Protocol version 6 (IPv6) Addresses in
   the Domain Name System (DNS)", RFC 3363, August 2002.

   [RFC 3425] - Lawrence, D., "Obsoleting IQUERY", RFC 3425, November
   2002.

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

   [RFC 4033] - Arends, R., Austein, R., Larson, M., Massey, D., and S.
   Rose, "DNS Security Introduction and Requirements", RFC 4033, March
   2005.

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

   [RFC 4044] - Arends, R., Austein, R., Larson, M., Massey, D., and S.
   Rose, "Protocol Modifications for the DNS Security Extensions", RFC
   4035, March 2005.

   [US-ASCII] - ANSI, "USA Standard Code for Information Interchange",
   X3.4, American National Standards Institute: New York, 1968.



Informative References

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

   [Moon 1981] - D. Moon, "Chaosnet", A.I. Memo 628, Massachusetts
   Institute of Technology Artificial Intelligence Laboratory, June
   1981.

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

   [RFC 2929] - Eastlake 3rd, D., Brunner-Williams, E., and B. Manning,
   "Domain Name System (DNS) IANA Considerations", BCP 42, RFC 2929,
   September 2000.

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

   [insensitive] - Eastlake, D., "Domain Name System (DNS) Case


D. Eastlake 3rd                                                [Page 14]


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   Insensitivity Clarification", draft-ietf-dnsext-insensitive-*.txt,
   work in progress.


















































D. Eastlake 3rd                                                [Page 15]


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Authors Addresses

   Donald E. Eastlake 3rd
   Motorola Laboratories
   155 Beaver Street
   Milford, MA 01757 USA

   Telephone:   [phone] (w)
   email:       [e-mail]



Expiration and File Name

   This draft expires February 2006.

   Its file name is draft-ietf-dnsext-2929bis-01.txt.



































D. Eastlake 3rd                                                [Page 16]