Deprecating obsolete DNS Resource Records Types
draft-sury-deprecate-obsolete-resource-records-01

Versions: 00 01                                                         
dnsop                                                            O. Sury
Internet-Draft                                                   E. Hunt
Updates: 1035,3597,4035 (if approved)        Internet Systems Consortium
Intended status: Standards Track                            May 13, 2019
Expires: November 14, 2019


            Deprecating obsolete DNS Resource Records Types
           draft-sury-deprecate-obsolete-resource-records-01

Abstract

   This document deprecates Resource Records (RR) Types that are either
   not being used for anything meaningful or were been already made
   obsolete by other RFCs.  This document updates [RFC1035], [RFC1035],
   [RFC4034].

Status of This Memo

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

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   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."

   This Internet-Draft will expire on November 14, 2019.

Copyright Notice

   Copyright (c) 2019 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.



Sury & Hunt             Expires November 14, 2019               [Page 1]


Internet-Draft        Deprecating old mail RRTYPES              May 2019


Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Deprecating MD, MF, MB, MG, MR, MINFO, MAILA, and MAILBRR
       Types . . . . . . . . . . . . . . . . . . . . . . . . . . . .   2
   3.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   2
   4.  Implementation Considerations . . . . . . . . . . . . . . . .   3
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   3
   6.  Operational Considerations  . . . . . . . . . . . . . . . . .   4
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   4
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   4
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   4
     8.2.  Informative References  . . . . . . . . . . . . . . . . .   4
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   4

1.  Introduction

   [RFC1035] and other documents have defined some Resource Record (RR)
   Types that are no longer in common use, some of which have been
   rendered obsolete by subsequent standards, but have never been
   clearly deprecated in the context of the DNS.  In some cases there
   have been interoperability problems between DNS implementations that
   support these types and those that do not - for example, because of
   DNS name compression in the wire format.  Continued support for these
   RR Types imposes a complexity cost on new implementations for little
   benefit.

   This document formally deprecates such RR Types, allowing
   implementations to drop specific support for them.

2.  Deprecating MD, MF, MB, MG, MR, MINFO, MAILA, and MAILBRR Types

   The MD, MF, MB, MG, MR, MINFO, MAILA, and MAILB RR Types aren't used
   in any existing standards, and this documents deprecates their usage.
   The MD, MF, MB, MG, MR, and MINFO RR Types RDATA contain a domain
   name that could be compressed in the RDATA section.

   As an update to [RFC3597] and [RFC4034] this document specifies that
   for MD, MF, MB, MG, MR, and MINFO RR types, the canonical form is
   such that no downcasing of embedded domain names takes place, and is
   otherwise identical to the canonical form specified in [RFC4034]
   section 6.2.

3.  IANA Considerations

   This documents updates the IANA registry "Domain Name System (DNS)
   Parameters" ([DNS-IANA]).




Sury & Hunt             Expires November 14, 2019               [Page 2]


Internet-Draft        Deprecating old mail RRTYPES              May 2019


              +-------+-------+------------+---------------+
              | TYPE  | Value | Meaning    | Reference     |
              +-------+-------+------------+---------------+
              | MD    | 3     | DEPRECATED | This document |
              | MF    | 4     | DEPRECATED | This document |
              | MB    | 7     | DEPRECATED | This document |
              | MG    | 8     | DEPRECATED | This document |
              | MR    | 9     | DEPRECATED | This document |
              | MINFO | 14    | DEPRECATED | This document |
              +-------+-------+------------+---------------+

4.  Implementation Considerations

   Types will be flagged as obsolete/deprecated in the IANA registry,
   and the following guidance is given to DNS implementors in the
   handling of obsolete/deprecated RR types:

   1.  Authoritative DNS Servers SHOULD issue a warning when loading
       zones that contain DEPRECATED RR Types;

   2.  DNS Servers MUST NOT compress RDATA when rendering DEPRECATED RR
       Types to wire format;

   3.  Recursive DNS Servers MAY support legacy compression in
       DEPRECATED RR Types for received data for backward compatibility
       if desired, but SHOULD warn if such information is received.
       Compressed RDATA in DEPRECATED RR Types MUST be uncompressed
       before sending and they MUST NOT be re-transmitted;

   4.  DNS Clients which receive DEPRECATED RR Types MAY interpret them
       as unknown RR types ([RFC3597]), and MUST NOT interfere with
       their transmission;

   5.  DNSSEC Validators and Signers SHOULD treat RDATA for DEPRECATED
       RR Types as opaque with respect to canonical RR ordering and
       deduplication;

   6.  DEPRECATED RR Types MUST never be treated as a known-type with
       respect to the wire protocol.

5.  Security Considerations

   This document has no security considerations.








Sury & Hunt             Expires November 14, 2019               [Page 3]


Internet-Draft        Deprecating old mail RRTYPES              May 2019


6.  Operational Considerations

   The varying states of implementation of MD, MF, MB, MG, MR, and MINFO
   RR Types has already caused operational problems between DNS
   implementations that do implement the aforementioned types and those
   that don't because of DNS compression on the wire.  This document
   aims to rectify the situation by encouraging removal of support for
   all these RR types in DNS implementations.  This should not cause
   signficant operational problems because these records are not in wide
   use on the Internet.  [COMMENT: Some data?]

7.  Acknowledgements

   Peter van Dijk for poking me to write the draft.  Daniel Salzman for
   reviewing the document.  Evan Hunt and Michael Casadevall to write
   Implementation Considerations section.

8.  References

8.1.  Normative References

   [RFC1035]  Mockapetris, P., "Domain names - implementation and
              specification", STD 13, RFC 1035, DOI 10.17487/RFC1035,
              November 1987, <https://www.rfc-editor.org/info/rfc1035>.

   [RFC3597]  Gustafsson, A., "Handling of Unknown DNS Resource Record
              (RR) Types", RFC 3597, DOI 10.17487/RFC3597, September
              2003, <https://www.rfc-editor.org/info/rfc3597>.

   [RFC4034]  Arends, R., Austein, R., Larson, M., Massey, D., and S.
              Rose, "Resource Records for the DNS Security Extensions",
              RFC 4034, DOI 10.17487/RFC4034, March 2005,
              <https://www.rfc-editor.org/info/rfc4034>.

8.2.  Informative References

   [DNS-IANA]
              "Domain Name System (DNS) Parameters",
              <https://www.iana.org/assignments/dns-parameters/
              dns-parameters.xhtml>.

Authors' Addresses

   Ondrej Sury
   Internet Systems Consortium
   CZ

   EMail: ondrej@isc.org



Sury & Hunt             Expires November 14, 2019               [Page 4]


Internet-Draft        Deprecating old mail RRTYPES              May 2019


   Evan Hunt
   Internet Systems Consortium
   US

   EMail: each@isc.org














































Sury & Hunt             Expires November 14, 2019               [Page 5]