Internet DRAFT - draft-fujiwara-dnsop-unclear

draft-fujiwara-dnsop-unclear






DNS Operations(dnsop)                                        K. Fujiwara
Internet-Draft                                                      JPRS
Intended status: Informational                              Oct 27, 2014
Expires: April 30, 2015


                    Unclear points of DNS protocols
                  draft-fujiwara-dnsop-unclear-00.txt

Abstract

   DNS protocols have some unclear points.  DNSSEC clarified some
   points.  However, there are still some unclear points.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
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   This Internet-Draft will expire on April 30, 2015.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
   2.  Unclear terminology . . . . . . . . . . . . . . . . . . . . . . 3
     2.1.  Full-resolver . . . . . . . . . . . . . . . . . . . . . . . 3
     2.2.  Referrals . . . . . . . . . . . . . . . . . . . . . . . . . 3
   3.  Unclear definitions . . . . . . . . . . . . . . . . . . . . . . 3
     3.1.  Ranking Data  . . . . . . . . . . . . . . . . . . . . . . . 4
   4.  Security considerations . . . . . . . . . . . . . . . . . . . . 4
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4
   6.  Normative References  . . . . . . . . . . . . . . . . . . . . . 4








































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1.  Introduction

   RFCs prior to RFC 2639 may contain unclear terminologies and unclear
   definitions.  Especially, RFC 1034, 1035, 1123, 2181 that described
   the main part of DNS protocols contain some unclear points and
   unclear terminologies.  This note tries to describe them.  Some parts
   may depend on implementations of those days.  For example, full-
   resolvers have one cache and mix authoritative data and non-
   authoritative data.

2.  Unclear terminology

2.1.  Full-resolver

   The 'full-resolver' definition is unclear.  [RFC1034] defines
   "Resolvers".  [RFC1035] uses "full resolver", "Recursive Server" and
   "Resolver".  [RFC1123] uses "full-service resolvers".  [RFC4033] uses
   "Security-Aware Recursive Name Server".  However, many textbooks and
   users use "cache server" or "caching server" as the full-resolver.

   Both authoritative server and stub resolver are clearly defined.

2.2.  Referrals

   The terminology 'referrals' is unclear.  Responses of authoritative
   servers are categorized into the following categories.

   Authoritative:  Name Error, No DATA or authoritative data (AA=1)

   Referrals:  Delegations under the zone.  (AA=0, non-authoritative)

   Others:  Other errors, or unnecessary data

   Referrals are important because they specify that there are
   delegations to children.  A clear definition of 'referrals' is
   necessary.  [RFC2181] seems to use "Data from the authority section
   of a non-authoritative answer" as "Referrals".

   RFC 1035 section 2.1 defines "authoritative" data.  However,
   referrals at zone cuts are not authoritative.

   Referrals may be a zone cut NS resource records and their glue.

3.  Unclear definitions







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3.1.  Ranking Data

   [RFC2181] section 5.4.1 Ranking Data defines the Ranking of received
   data.  The definition seems to be a mix of a rule to answer to stub
   resolvers, a rule to resolve domain names and cache update mechanism.

   Recent full-resolvers do not send referrals to stub resolvers.  For
   example, "Full-resolvers should not send non-authoritative data to
   stub resolvers" is one simple rule.

   The Ranking Data specifies that Referrals "Data from the authority
   section of a non-authoritative answer" is the lowest trustworthiness.
   Authoritative servers sometimes respond both the demanded response
   and "the authority section of an authoritative answer".  Then, the
   full-resolver chooses authoritative NS resource records.  As a
   result, the name resolution will be done by the added authority
   section data instead of previously received referrals.  This
   mechanism caused the ghost domain name problem and may increase
   queries to root.

   The name resolution is possible even if the Ranking is changed and
   the name resolution uses only Referrals and out-of-bailiwick name
   resolution.

4.  Security considerations

5.  IANA Considerations

6.  Normative References

   [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.

   [RFC1123]  Braden, R., "Requirements for Internet Hosts - Application
              and Support", STD 3, RFC 1123, October 1989.

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

   [RFC4033]  Arends, R., Austein, R., Larson, M., Massey, D., and S.
              Rose, "DNS Security Introduction and Requirements",
              RFC 4033, March 2005.






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Author's Address

   Kazunori Fujiwara
   Japan Registry Services Co., Ltd.
   Chiyoda First Bldg. East 13F, 3-8-1 Nishi-Kanda
   Chiyoda-ku, Tokyo  101-0065
   Japan

   Phone: +81 3 5215 8451
   EMail: fujiwara@jprs.co.jp









































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