ソスソスソスフ包ソスソスソスソスソスRFC1035ソスフ難ソスソス{ソスソスソスiソスaソスソスjソスナゑソスソスB ソスソスソスフ包ソスソスソスソスフ翻ソスソスソスソスeソスフ撰ソスソスmソスソスソスヘ保擾ソスナゑソスソスネゑソスソスソスソス゚、 ソスソスソスmソスネ知ソスソスソスソスソスソスソス゚ゑソスソスソスヘ鯉ソスソスソスソスソスソスQソスニゑソスソストゑソスソスソスソスソスソスソスソスB ソス|ソスソスメはゑソスソスフ包ソスソスソスソスノゑソスソスソスト読者ゑソスソスソス闢セソスソス@ソスソスソスネる損ソスQソスフ責任ソスソスソスソスソスソスソスソスソスワゑソスソスソスB ソスソスソスフ翻ソスソスソスソスeソスノ鯉ソス閧ェソスソスソスソス鼾ソスAソスソスソスソスソスナの鯉ソスソスJソスソスA ソスソスソスフ指ソスEソスヘ適ソスリでゑソスソスB ソスソスソスフ包ソスソスソスソスフ配ソスzソスヘ鯉ソスソスフRソスeソスbソスソスソスlソスノ厄ソスソスソスソスソスソスナゑソスソスB


Network Working Group                                     P. Mockapetris
Request for Comments: 1035                                           ISI
                                                           November 1987
Obsoletes: RFCs 882, 883, 973

            DOMAIN NAMES - IMPLEMENTATION AND SPECIFICATION
                     ソスhソスソスソスCソスソスソスソス ソス| ソスソスソスソスソスニ仕ソスlソスソス

1. STATUS OF THIS MEMO
1. ソスソスソスフソスソスソスソスフ擾ソスソス

This RFC describes the details of the domain system and protocol, and
assumes that the reader is familiar with the concepts discussed in a
companion RFC, "Domain Names - Concepts and Facilities" [RFC-1034].
ソスソスソスソスRFCソスヘドソスソスソスCソスソスソスVソスXソスeソスソスソスニプソスソスソスgソスRソスソスソスフ細包ソスソスソスソスLソスqソスソスソスAソスヌ者ゑソスソスヨ連ソスソスソスソスRFC
ソスuソスhソスソスソスCソスソスソスソス ソス| ソスRソスソスソスZソスvソスgソスニ機ソス\ソスv[RFC-1034]ソスナ論ソスソスソスソスソスRソスソスソスZソスvソスgソスノ撰ソスソスハゑソスソスソス
ソスソスソスソスニ想ソス閧オソスワゑソスソスB

The domain system is a mixture of functions and data types which are an
official protocol and functions and data types which are still
experimental.  Since the domain system is intentionally extensible, new
data types and experimental behavior should always be expected in parts
of the system beyond the official protocol.  The official protocol parts
include standard queries, responses and the Internet class RR data
formats (e.g., host addresses).  Since the previous RFC set, several
definitions have changed, so some previous definitions are obsolete.
ソスhソスソスソスCソスソスソスVソスXソスeソスソスソスヘ鯉ソスソスソスソスフプソスソスソスgソスRソスソスソスニ機ソス\ソスニまゑソスソスソスソスソスソスIソスネデソス[ソス^ソス^ソスCソスvソスフ搾ソスソスソス
ソスナゑソスソスBソスhソスソスソスCソスソスソスVソスXソスeソスソスソスソスソスモ図ソスIソスノ拡ソスソスツ能ソスナゑソスソスソスフで、ソスVソスソスソスソスソスfソス[ソス^ソス^ソスCソスvソスソス
ソスソスソスソスソスIソスネ行ソスソスソスソスソスソスノ鯉ソスソスソスソスフプソスソスソスgソスRソスソスソスフ範囲外ソスナ行ソスソストゑソスニ予ソスzソスソスソスソスソスラゑソスソスナゑソスソスB
ソスソスソスソスソスフプソスソスソスgソスRソスソスソスフ包ソスソスソスソスヘ標ソスソスソスIソスネ問合ソスソスソスAソス答とイソスソスソス^ソス[ソスlソスbソスgソスNソスソスソスXソスソスソスソスソスソス
ソスRソス[ソスhソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスgソスiソス痰ヲソスホ、ソスzソスXソスgソスAソスhソスソスソスXソスjソスソスソスワみまゑソスソスBソスOソスソスRFCソスQ
ソスソスソスソスAソスソスソスソスソスツゑソスソスフ抵ソス`ソスソスソスマ会ソスソスソスソスソスソスフで、ソスソスソスソスソスツゑソスソスフ前ソスフ抵ソス`ソスソスソスソスソスソスxソスソスナゑソスソスB

Experimental or obsolete features are clearly marked in these RFCs, and
such information should be used with caution.
ソスソスソスソスソスソスRFCソスフ趣ソスソスソスソスIソスソスソスソスソスソスxソスソスフ機ソス\ソスヘ厄ソスソスmソスノマソス[ソスNソスソスtソスソスソスソスソスフで、ソスソスソスフよう
ソスネ擾ソスソスノ抵ソスソスモゑソスソスラゑソスソスナゑソスソスB

The reader is especially cautioned not to depend on the values which
appear in examples to be current or complete, since their purpose is
primarily pedagogical.  Distribution of this memo is unlimited.
ソスソスナ趣ソスソスソスソストゑソスソスソスlソスソスソスソスソスソスIソスネ目的ソスフ値ソスネので、ソスヌ者はゑソスソスフ値ソスソスソスソスソスンの値ソスソスソスソスソスソスソスソス
ソスソスソスソスソスソスソスlソスニ思ソスソスネゑソスソス謔、ソスノ抵ソスソスモゑソスソストゑソスソスソスソスソスソスソスソスBソスソスソスフソスソスソスソスフ配ソスzソスヘ厄ソスソスソスソスソスソスナゑソスソスB

                           Table of Contents
                                 ソスレ趣ソス

  1. STATUS OF THIS MEMO
     ソスソスソスフソスソスソスソスフ擾ソスソス
  2. INTRODUCTION
     ソスヘゑソスソス゚ゑソス
      2.1. Overview
           ソスTソスv
      2.2. Common configurations
           ソスソスソスハの設抵ソス
      2.3. Conventions
           ソスソス闌茨ソスソス
          2.3.1. Preferred name syntax
                 ソス]ソスワゑソスソスソスソスソスソスOソスソスソス@
          2.3.2. Data Transmission Order
                 ソスfソス[ソス^ソス]ソスソスソスソスソスソス
          2.3.3. Character Case
                 ソスソスソスソス
          2.3.4. Size limits
                 ソスTソスCソスYソスフ擾ソスソス
  3. DOMAIN NAME SPACE AND RR DEFINITIONS
     ソスhソスソスソスCソスソスソスソスソスソスヤとRソスqソスソス`
      3.1. Name space definitions
           ソスソスソスOソスソスヤ抵ソス`
      3.2. RR definitions
           ソスソスソスソスソスソスソスRソス[ソスhソスソス`
          3.2.1. Format
                 ソスtソスHソス[ソス}ソスbソスg
          3.2.2. TYPE values
                 ソスソスハ値
          3.2.3. QTYPE values
                 ソス竝ソスソスソスソスソス
          3.2.4. CLASS values
                 ソスNソスソスソスXソスl
          3.2.5. QCLASS values
                 ソス竝ソスソスソスNソスソスソスXソスl
      3.3. Standard RRs
            ソスWソスソスソスソスソスソスソスソスソスRソス[ソスh
          3.3.1. CNAME RDATA format
                 ソスWソスソスソスソスソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスg
          3.3.2. HINFO RDATA format
                 ソスzソスXソスgソスソス資鯉ソスソスソスソスRソス[ソスhソスtソスHソス[ソス}ソスbソスg
          3.3.3. MB RDATA format (EXPERIMENTAL)
                 ソスソスソス[ソスソスソス{ソスbソスNソスXソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスgソスiソスソスソスソスソスIソスj
          3.3.4. MD RDATA format (Obsolete)
                 MDソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスgソスiソスソスソスソスxソスソスj
          3.3.5. MF RDATA format (Obsolete)
                 MFソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスgソスiソスソスソスソスxソスソスj
          3.3.6. MG RDATA format (EXPERIMENTAL)
                 ソスソスソス[ソスソスソスOソスソスソス[ソスvソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスgソスiソスソスソスソスソスIソスj
          3.3.7. MINFO RDATA format (EXPERIMENTAL)
                 ソスソスソス[ソスソスソスソス資鯉ソスソスソスソスRソス[ソスhソスtソスHソス[ソス}ソスbソスgソスiソスソスソスソスソスIソスj
          3.3.8. MR RDATA format (EXPERIMENTAL)
                 ソスソスソス[ソスソスソスソスソスソスソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスgソスiソスソスソスソスソスIソスj
          3.3.9. MX RDATA format
                 ソスソスソス[ソスソスソスソスソスソスソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスg
          3.3.10. NULL RDATA format (EXPERIMENTAL)
                 ソスkソスソスソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスgソスiソスソスソスソスソスIソスj
          3.3.11. NS RDATA format
                 ソスlソス[ソスソスソスTソス[ソスoソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスg
          3.3.12. PTR RDATA format
                 ソス|ソスCソスソスソス^ソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスg
          3.3.13. SOA RDATA format
                 SOAソスソスソスソスソスfソス[ソス^
          3.3.14. TXT RDATA format
                 ソスeソスLソスXソスgソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスg
      3.4. ARPA Internet specific RRs
           ソスCソスソスソス^ソス[ソスlソスbソスgソスソスソスLソスソスソスソスソスソスソスRソス[ソスh
          3.4.1. A RDATA format
                 ソスAソスhソスソスソスXソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスg
          3.4.2. WKS RDATA format
                 ソスdソスソスソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスg
      3.5. IN-ADDR.ARPA domain
           IN-ADDR.ARPAソスhソスソスソスCソスソス
      3.6. Defining new types, classes, and special namespaces
           ソスVソスソスソスソスソス^ソスCソスvソスAソスNソスソスソスXソスニ難ソスソスハな厄ソスソスOソスソスヤの抵ソス`
  4. MESSAGES
     ソスソスソスbソスZソス[ソスW
      4.1. Format
           ソスtソスHソス[ソス}ソスbソスg
          4.1.1. Header section format
                 ソスwソスbソス_ソスソスソスtソスHソス[ソス}ソスbソスg
          4.1.2. Question section format
                 ソスソスソス笊費ソスtソスHソス[ソス}ソスbソスg
          4.1.3. Resource record format
                 ソスソスソスソスソスソスソスRソス[ソスhソスtソスHソス[ソス}ソスbソスg
          4.1.4. Message compression
                 ソスソスソスbソスZソス[ソスWソスソスソスk
      4.2. Transport
           ソス]ソスソス
          4.2.1. UDP usage
                 ソスtソスcソスoソスgソスpソス@
          4.2.2. TCP usage
                 ソスsソスbソスoソスgソスpソス@
  5. MASTER FILES
     ソス}ソスXソス^ソス[ソスtソス@ソスCソスソス
      5.1. Format
           ソスtソスHソス[ソス}ソスbソスg
      5.2. Use of master files to define zones
           ソス]ソス[ソスソスソスソスソス`ソスソスソス驍スソス゚のマソスXソス^ソス[ソスtソス@ソスCソスソスソスフ使ソスp
      5.3. Master file example
           ソス}ソスXソス^ソス[ソスtソス@ソスCソスソスソスフ暦ソス
  6. NAME SERVER IMPLEMENTATION
     ソスlソス[ソスソスソスTソス[ソスoソス[ソスソスソス
      6.1. Architecture
           ソス\ソスソス
          6.1.1. Control
                 ソスソスソスソス
          6.1.2. Database
                 ソスfソス[ソス^ソスxソス[ソスX
          6.1.3. Time
                 ソスソスソスソス
      6.2. Standard query processing
           ソスWソスソスソス竝ソスソスソスソスソスソス
      6.3. Zone refresh and reload processing
           ソス]ソス[ソスソスソスXソスVソスニ読み抵ソスソスソスソスソスソスソス
      6.4. Inverse queries (Optional)
           ソスtソス竝ソスソスソスiソスCソスソス)
          6.4.1. The contents of inverse queries and responses
                 ソスtソスフ趣ソスソスソスニ回答の抵ソスソスg
          6.4.2. Inverse query and response example
                 ソスtソス竝ソスソスソスニ回答暦ソス
          6.4.3. Inverse query processing
                 ソスtソス竝ソスソスソスソスソスソス
      6.5. Completion queries and responses
             ソスソスソスソスソス竝ソスソスソスニ会ソス
  7. RESOLVER IMPLEMENTATION
     ソスソスソス]ソスソスソスoソスフ趣ソスソスソス
      7.1. Transforming a user request into a query
           ソスソスソス[ソスUソスvソスソスソスフ趣ソスソスソスヨの変奇ソス
      7.2. Sending the queries
           ソス竝ソスソスソスフ托ソスソスM
      7.3. Processing responses
           ソスソスソスソスソスソス
      7.4. Using the cache
           ソスLソスソスソスbソスVソスソスソスフ使ソスp
  8. MAIL SUPPORT
     ソスソスソス[ソスソスソスTソス|ソス[ソスg
      8.1. Mail exchange binding
           ソスソスソス[ソスソスソスソスソスソスソスソスソスt
      8.2. Mailbox binding (Experimental)
           ソスソスソス[ソスソスソス{ソスbソスNソスXソスソスソスt(ソスソスソスソスソスIソスj
  9. REFERENCES and BIBLIOGRAPHY
     ソスQソスlソスソスソスソスソスニ包ソスソスソスソスレ録
  Index
  ソスソスソスソス

2. INTRODUCTION
2. ソスヘゑソスソス゚ゑソス

2.1. Overview
2.1. ソスTソスv

The goal of domain names is to provide a mechanism for naming resources
in such a way that the names are usable in different hosts, networks,
protocol families, internets, and administrative organizations.
ソスhソスソスソスCソスソスソスソスソスフゴソス[ソスソスソスヘ異なゑソスソスソスソスzソスXソスgソスニネソスbソスgソスソスソス[ソスNソスニプソスソスソスgソスRソスソスソスtソス@ソス~ソスソスソス[ソスソス
ソスCソスソスソス^ソス[ソスlソスbソスgソスニ管暦ソスソスgソスDソスナ厄ソスソスOソスソスソスソスソスpソスナゑソスソスソスソスソス@ソスニ厄ソスソスOソスソスソスソスソスフソスソスJソスjソスYソスソスソスソスソスソス
ソスソスソスソスソス驍アソスニでゑソスソスB

From the user's point of view, domain names are useful as arguments to a
local agent, called a resolver, which retrieves information associated
with the domain name.  Thus a user might ask for the host address or
mail information associated with a particular domain name.  To enable
the user to request a particular type of information, an appropriate
query type is passed to the resolver with the domain name.  To the user,
the domain tree is a single information space; the resolver is
responsible for hiding the distribution of data among name servers from
the user.
ソスソスソス[ソスUソス[ソスフ鯉ソスソスnソスソスソスソスAソスhソスソスソスCソスソスソスソスソスヘソスソス]ソスソスソスoソスニ呼ばゑソス驛搾ソス[ソスJソスソスソスネエソス[ソスWソスFソスソスソスg
ソスフ茨ソスソスソスソスノ暦ソスソスpソスナゑソスソスAソスソスソス]ソスソスソスoソスヘドソスソスソスCソスソスソスソスソスニ関連ソスソスソスソスソスソスソスソスヤゑソスソスワゑソスソスBソスソスソス[ソスUソス[
ソスソスソスソスソスソスフドソスソスソスCソスソスソスソスソスニ関連ソスソスソスソスソスzソスXソスgソスAソスhソスソスソスXソスソスソス驍「ソスヘソスソス[ソスソスソスソスソスソスソスソスソス゚るかソスソス
ソスソスソスソスワゑソスソスソスBソスソスソス[ソスUソス[ソスノ難ソスソスソスフタソスCソスvソスフ擾ソスソスソスソスソスソス゚るこソスニゑソスソスナゑソスソスソス謔、ソスノ、ソスhソスソス
ソスCソスソスソスソスソスニ具ソスソスノ適ソスリな問合ソスソスソス^ソスCソスvソスソスソスナソスソス]ソスソスソスoソスノ渡ソスソスソスソスワゑソスソスBソスソスソス[ソスUソス[ソスニゑソスソストド
ソスソスソスCソスソスソスcソスソスソス[ソスヘひとつの擾ソスソスソスヤでゑソスソスGソスソスソス]ソスソスソスoソスヘソスソス[ソスUソス[ソスソスソスソスlソス[ソスソスソスTソス[ソスoソス[
ソスヤのデソス[ソス^ソスソスソスUソスソスソスBソスソスソスモ任ソスソスソスソスソスソスワゑソスソスB

From the resolver's point of view, the database that makes up the domain
space is distributed among various name servers.  Different parts of the
domain space are stored in different name servers, although a particular
data item will be stored redundantly in two or more name servers.  The
resolver starts with knowledge of at least one name server.  When the
resolver processes a user query it asks a known name server for the
information; in return, the resolver either receives the desired
information or a referral to another name server.  Using these
referrals, resolvers learn the identities and contents of other name
servers.  Resolvers are responsible for dealing with the distribution of
the domain space and dealing with the effects of name server failure by
consulting redundant databases in other servers.
ソスソスソス]ソスソスソスoソスソスソス迪ゥソスソスニ、ソスhソスソスソスCソスソスソスソスヤゑソスソス\ソスソスソスソスソスソスfソス[ソス^ソスxソス[ソスXソスヘ様ソスXソスネネソス[ソスソスソスTソス[
ソスoソス[ソスノ包ソスソスzソスソスソスソスワゑソスソスBソスhソスソスソスCソスソスソスソスヤの異なる部ソスソスソスソスソスルなゑソスlソス[ソスソスソスTソス[ソスoソス[ソスノ登ソス^
ソスソスソスソスワゑソスソスAソスソスソスソスフデソス[ソス^ソスソスソスレは重ソスソスソスソスソスト2ソスソスソス驍「ソスヘゑソスソスソスネ擾ソスフネソス[ソスソスソスTソス[ソスoソス[ソスソス
ソスoソス^ソスソスソスソスワゑソスソスBソスソスソス]ソスソスソスoソスヘ擾ソスソスネゑソスソスニゑソスソスPソスツのネソス[ソスソスソスTソス[ソスoソス[ソスフ知ソスソスソスソスソスソスソスソスソスト起ソスソス
ソスソスソスワゑソスソスBソスソスソス]ソスソスソスoソスソスソスソスソス[ソスUソス[ソスフ問合ソスソスソスソスソスソスソスソスソスソスソス骼橸ソスAソスソスソスmソスフネソス[ソスソスソスTソス[ソスoソス[ソスノ擾ソス
ソスソスソスソスソスソスソスソス゚まゑソスソスGソス答で、ソスソスソス]ソスソスソスoソスヘ望ソスワゑソスソスソスソスソスか托ソスソスフネソス[ソスソスソスTソス[ソスoソスフ紹会ソスソス
ソスけまゑソスソスBソスソスソスソスソスフ紹会ソスソスソスgソスソスソスト、ソスソスソス]ソスソスソスoソスヘ托ソスソスフネソス[ソスソスソスTソス[ソスoソス[ソスニネソス[ソスソスソスTソス[
ソスoソス[ソスフ難ソスソスeソスソスソスwソスKソスソスソスワゑソスソスBソスソスソス]ソスソスソスoソスヘドソスソスソスCソスソスソスソスヤの包ソスソスUソスソスソスソスソスソスソスAソスソスソスフサソス[ソスoソス[
ソスフ重ソスソスソスソスソスソスfソス[ソス^ソスxソス[ソスXソス調べるこソスニで、ソスlソス[ソスソスソスTソス[ソスoソス[ソスフ擾ソスQソスノ影ソスソスソスソスソスソスソスソスソス
ソスモ任ソスソスソスソスソスソスワゑソスソスB

Name servers manage two kinds of data.  The first kind of data held in
sets called zones; each zone is the complete database for a particular
"pruned" subtree of the domain space.  This data is called
authoritative.  A name server periodically checks to make sure that its
zones are up to date, and if not, obtains a new copy of updated zones
from master files stored locally or in another name server.  The second
kind of data is cached data which was acquired by a local resolver.
This data may be incomplete, but improves the performance of the
retrieval process when non-local data is repeatedly accessed.  Cached
data is eventually discarded by a timeout mechanism.
ソスlソス[ソスソスソスTソス[ソスoソス[ソスソスソスQソスソズのデソス[ソス^ソスソスソスソスソスソスソスソスソスワゑソスソスBソスfソス[ソス^ソスフ最擾ソスソスフ趣ソズはゾソス[ソスソスソスソス
ソストばゑソスワゑソスソスGソスeソス]ソス[ソスソスソスソスソスhソスソスソスCソスソスソスソスヤの難ソスソスソスフ「ソスリゑソスソスソスソスソスソスvソスソスソスソスソスリの奇ソスソスSソスネデソス[
ソス^ソスxソス[ソスXソスナゑソスソスBソスソスソスフデソス[ソス^ソスヘ撰ソスソスソスソスニ呼ばゑソスワゑソスソスBソスlソス[ソスソスソスTソス[ソスoソス[ソスソスソスソスソスフゾソス[ソスソスソスソス
ソスナ新ソスソスソスmソスFソスソスソス驍スソス゚趣ソスソスソスソスIソスノ抵ソスソスソスソスソスソスsソスソスソスAソスソスソスソスソスナ新ソスナなゑソスソスソスホソスソス[ソスJソスソスソスノ厄ソスソスヘ托ソス
ソスフネソス[ソスソスソスTソス[ソスoソスノ登ソス^ソスソスソス黷スソスナ新ソスフゾソス[ソスソスソスRソスsソス[ソス得まゑソスソスBソスQソスヤ目の趣ソズのデソス[
ソス^ソスヘソスソス[ソスJソスソスソスソスソス]ソスソスソスoソスノゑソスソスソスト難ソスソスソス黷スソスLソスソスソスbソスVソスソスソスfソス[ソス^ソスナゑソスソスBソスソスソスフデソス[ソス^ソスヘ不
ソスソスソスSソスソスソスソスソスソスソスソスワゑソスソスが、ソスソスソス[ソスJソスソスソスナなゑソスソスfソス[ソス^ソスノ繰ソスソスヤゑソスソスAソスNソスZソスXソスソスソスソスロに、ソスソス
ソスソスソスvソスソスソスZソスXソスフ鯉ソスソスソスソスソスソスソスソスPソスソスソスワゑソスソスBソスLソスソスソスbソスVソスソスソスfソス[ソス^ソスソスソス^ソスCソスソスソスAソスEソスgソスソスソスJソスjソスYソスソスソスソス
ソスソスソスソスト捨てゑソスソスワゑソスソスB

This functional structure isolates the problems of user interface,
failure recovery, and distribution in the resolvers and isolates the
database update and refresh problems in the name servers.
ソスソスソスフ機ソス\ソス\ソスソスソスヘソスソス[ソスUソスEソスCソスソスソス^ソスtソスFソス[ソスXソスニ擾ソスQソス復とソスソス]ソスソスソスoソスフ包ソスソスUソスフ厄ソスソスソス
ソスソスソスソスソスAソスlソス[ソスソスソスTソス[ソスoソス[ソスフデソス[ソス^ソスxソス[ソスXソスXソスVソスニソスソスtソスソスソスbソスVソスソスソスソスソス離ゑソスソスワゑソスソスB

2.2. Common configurations
2.2. ソスソスソスハの設抵ソス

A host can participate in the domain name system in a number of ways,
depending on whether the host runs programs that retrieve information
from the domain system, name servers that answer queries from other
hosts, or various combinations of both functions.  The simplest, and
perhaps most typical, configuration is shown below:
ソスzソスXソスgソスソスソスAソスhソスソスソスCソスソスソスVソスXソスeソスソスソスソスソスソスソスソスソスソスソスソスソスソスソスソスソスvソスソスソスOソスソスソスソスソスソスソスソスソスsソスソスソスソスソスソスAソスソスソスソス
ソスzソスXソスgソスヨ問合ソスソスソスフ会ソスソスソスソスソスソスソスソスソスlソス[ソスソスソスTソス[ソスoソス走らせソスソスソスソスAソスソスソス@ソス\ソスソスlソスXソスノ組ソスン搾ソス
ソスせソスソスネど、ソスソスソスソスソスフ包ソスソス@ソスナドソスソスソスCソスソスソスlソス[ソスソスソスVソスXソスeソスソスソスノ参ソスソスソスソスソス驍アソスニゑソスソスナゑソスソスワゑソスソスB
ソスナゑソスソスPソスソスソスネ、ソスソスソスソスソスト托ソスソスソスソスナゑソスソスTソス^ソスIソスネ設抵ソスヘ以会ソスソスフとゑソスソスソスナゑソスソスF

                 Local Host ソスソスソス[ソスJソスソスソスzソスXソスg         |  Foreign ソスソスソスソス
                                                   |
    +---------+ ソスソスソス[ソスUソス竝ソスソス  +----------+ソス竝ソスソス   |  +--------+
    |         | user queries  |          |queries  |  |Foreign |
    |  User   |-------------->|          |---------|->|  Name  |
    | Program |               | Resolver |         |  | Server |
    | ソスソスソス[ソスUソスv|<--------------| ソスソスソス]ソスソスソスo |<--------|--|ソスソスソスソスソスlソス[|
    | ソスソスソスOソスソスソスソス| user responses|          |responses|  |ソスソスソスTソス[ソスo|
    +---------+ ソスソスソス[ソスUソスソス    +----------+ソスソス     |  +--------+
                                |     A            |
                cache additions |     | references |
                ソスLソスソスソスbソスVソスソスソスヌ会ソス  V     | ソスQソスソス       |
                              +----------+         |
                              |  cache   |         |
                              |ソスLソスソスソスbソスVソスソス|         |
                              +----------+         |

User programs interact with the domain name space through resolvers; the
format of user queries and user responses is specific to the host and
its operating system.  User queries will typically be operating system
calls, and the resolver and its cache will be part of the host operating
system.  Less capable hosts may choose to implement the resolver as a
subroutine to be linked in with every program that needs its services.
Resolvers answer user queries with information they acquire via queries
to foreign name servers and the local cache.
ソスソスソス[ソスUソス[ソスvソスソスソスOソスソスソスソスソスソスソスソスソス]ソスソスソスoソスソスハゑソスソストドソスソスソスCソスソスソスソスソスXソスyソス[ソスXソスニ托ソスソスン搾ソスpソスソスソスワゑソスソスG
ソスソスソス[ソスUソス[ソス竝ソスソスソスニソスソス[ソスUソス[ソス答のフソスHソス[ソス}ソスbソスgソスヘホソスXソスgソスニオソスyソスソスソス[ソスeソスBソスソスソスOソスEソスV
ソスXソスeソスソスソスノ固有ソスナゑソスソスBソスソスソス[ソスUソス[ソス竝ソスソスソスヘ典ソス^ソスIソスノオソスyソスソスソス[ソスeソスBソスソスソスOソスVソスXソスeソスソスソスRソス[ソスソス
ソスdソスbソスナ、ソスソスソス]ソスソスソスoソスニキソスソスソスbソスVソスソスソスヘホソスXソスgソスIソスyソスソスソス[ソスeソスBソスソスソスOソスVソスXソスeソスソスソスフ一部ソスナゑソスソスソス
ソスソスソスBソス\ソスヘの低いソスzソスXソスgソスソスソスソスソス]ソスソスソスoソスソスソスソスソスフサソス[ソスrソスXソスソスKソスvソスニゑソスソス驍キソスラてのプソスソスソスOソスソス
ソスソスソスナソスソスソスソスNソスソスソスソスソスTソスuソスソスソス[ソス`ソスソスソスニゑソスソスト趣ソスソスソスソスソスソス驍ゥソスソスソスソスソスソスワゑソスソスソスBソスソスソスソスソスフネソス[ソスソスソスTソス[
ソスoソス[ソスヨの問合ソスソスソスニソスソス[ソスJソスソスソスネキソスソスソスbソスVソスソスソスナ難ソスソスソスソスソスソスナ、ソスソスソス]ソスソスソスoソスソスソスソスソス[ソスUソス[ソスフ厄ソス
ソスソスソスソスソスノ難ソスソスソスソスワゑソスソスB

Note that the resolver may have to make several queries to several
different foreign name servers to answer a particular user query, and
hence the resolution of a user query may involve several network
accesses and an arbitrary amount of time.  The queries to foreign name
servers and the corresponding responses have a standard format described
in this memo, and may be datagrams.
ソスソスソス]ソスソスソスoソスソスソスソスソス驛ソス[ソスUソス[ソス竝ソスソスソスノ難ソスソスソスソス驍スソス゚にゑソスソスソスソスツゑソスソスフ異なゑソスlソス[ソスソスソスTソス[ソスoソス[
ソスノ問合ソスソスソスソスソスソスソスネゑソスソスソスホなゑソスネゑソスソスソスソスソスソスソスソスソスネゑソスソスAソスソスソス[ソスUソス[ソス竝ソスソスソスフ会ソスソスソスソスソスソスソスソスソスソスツゑソス
ソスフネソスbソスgソスソスソス[ソスNソスAソスNソスZソスXソスニゑソスソスソスソスソスxソスフ趣ソスソスヤゑソスソスKソスvソスネゑソスソスニに抵ソスソスモゑソスソストゑソスソスソスソスソスソスソスソスBソスソス
ソスフネソス[ソスソスソスTソス[ソスoソス[ソスヨの問合ソスソスソスニ対会ソスソスソスソスソス答は標ソスソスソスtソスHソス[ソス}ソスbソスgソスソスソスソスソスフソスソスソスソスナ記
ソスqソスソスソスソスAソスfソス[ソス^ソスOソスソスソスソスソスノなゑソスナゑソスソス蛯、ソスB

Depending on its capabilities, a name server could be a stand alone
program on a dedicated machine or a process or processes on a large
timeshared host.  A simple configuration might be:
ソスソスソスフ能ソスヘにゑソスソスソスト、ソスlソス[ソスソスソスTソス[ソスoソス[ソスヘ撰ソスpソス}ソスVソスソスソスソスフ単ソスフプソスソスソスOソスソスソスソスソスソスソスソスソスソスソスソスA
ソス蛯ォソスネタソスCソスソスソスVソスFソスAソスソスソスソスソスOソスzソスXソスgソスソスフプソスソスソスZソスXソスフ1ソスツゑソスソスソスソスソスソス閧オソスワゑソスソスBソスPソスソスソスネ撰ソス
ソス閧ェソスネ会ソスソスフとゑソスソスソスナゑソスソスF

                 Local Host ソスソスソス[ソスJソスソスソスzソスXソスg         |  Foreign ソスソスソスソス
                                                   |
      +---------+                                  |
     /         /|                                  |
    +---------+ |             +----------+ソスソス     |  +--------+
    |         | |             |          |responses|  |Foreign |
    |  Master | |             |   Name   |---------|->|Resolver|
    |  files  |-------------->|  Server  |         |  |  ソスソスソスソス  |
    | ソス}ソスXソス^ソス[| |             |  ソスlソス[ソスソス  |<--------|--|ソスソスソス]ソスソスソスo|
    | ソスtソス@ソスCソスソス|/              |  ソスTソス[ソスoソス[| queries |  +--------+
    +---------+               +----------+ ソス竝ソスソス  |

Here a primary name server acquires information about one or more zones
by reading master files from its local file system, and answers queries
about those zones that arrive from foreign resolvers.
ソスソスソスソスソスナプソスソスソスCソス}ソスソスソスlソス[ソスソスソスTソス[ソスoソス[ソスソスソスソスソス[ソスJソスソスソスtソス@ソスCソスソスソスVソスXソスeソスソスソスソスソスソス}ソスXソス^ソス[ソスtソス@
ソスCソスソスソスソスヌ搾ソスソスソスナ1ソスツ以擾ソスフゾソス[ソスソスソスフ擾ソスソス得て、ソスソスソスソスソスフソスソス]ソスソスソスoソスソスソス逞茨ソスソス]ソス[ソスソス
ソスノ関ゑソスソスソス竝ソスソスソスノ難ソスソスソスソスワゑソスソスB

The DNS requires that all zones be redundantly supported by more than
one name server.  Designated secondary servers can acquire zones and
check for updates from the primary server using the zone transfer
protocol of the DNS.  This configuration is shown below:
ソスcソスmソスrソスヘゑソスソスラてのゾソス[ソスソスソスソスソスPソスツ以擾ソスフネソス[ソスソスソスTソス[ソスoソス[ソスナ維趣ソスソスソスソス驍アソスニゑソスvソスソスソスソスソスソス
ソスソスソスBソスIソス閧ウソス黷スソスZソスJソスソスソス_ソスソスソスTソス[ソスoソス[ソスソスソスcソスmソスrソスフゾソス[ソスソスソス]ソスソスソスvソスソスソスgソスRソスソスソスソスソスgソスソスソスAソスソス
ソスvソスネサソス[ソスoソス[ソスソスソスソス]ソス[ソスソスソス得て更ソスVソスソスソスソスソスソスソスソスソスラるこソスニゑソスソスナゑソスソスワゑソスソスBソスソスソスフ設抵ソスヘ茨ソス
ソスソスソスフとゑソスソスソスナゑソスソスF

                 Local Host ソスソスソス[ソスJソスソスソスzソスXソスg         |  Foreign ソスソスソスソス
                                                   |
      +---------+                                  |
     /         /|                                  |
    +---------+ |        +----------+  ソスソス        |  +--------+
    |         | |        |          |  responses   |  |Foreign |
    |  Master | |        |   Name   |--------------|->|Resolver|
    |  files  |--------->|  Server  |              |  |ソスソスソスソス    |
    | ソス}ソスXソス^ソス[| |        |  ソスlソス[ソスソス  |<-------------|--|ソスソスソス]ソスソスソスo|
    | ソスtソス@ソスCソスソス|/         |  ソスTソス[ソスoソス[|   queries    |  +--------+
    +---------+          +----------+   ソス竝ソスソス     |
                          A   |ソスソスソスソスソスeソスiソスソスソスXソス竝ソスソス  |  +--------+
                          |   |maintenance queries |  |Foreign |
                          |   +--------------------|->|  Name  |
                          |                        |  | Server |
                          +------------------------|--|ソスソスソスソスソスlソス[|
                             maintenance responses |  |ソスソスソスTソス[ソスo|
                             ソスソスソスソスソスeソスiソスソスソスXソスソス      |  +--------+

In this configuration, the name server periodically establishes a
virtual circuit to a foreign name server to acquire a copy of a zone or
to check that an existing copy has not changed.  The messages sent for
these maintenance activities follow the same form as queries and
responses, but the message sequences are somewhat different.
ソスソスソスフ設抵ソスナネソス[ソスソスソスTソス[ソスoソス[ソスヘゾソス[ソスソスソスフコソスsソス[ソス得るかソスAソスソスソス驍「ソスヘ奇ソスソスソスソスフコソスsソス[ソスソス
ソスマ更ソスソスソスネゑソスソスソスソスニを調べるたソス゚会ソスソスソスソスフネソス[ソスソスソスTソス[ソスoソス[ソスノ趣ソスソスソスソスIソスノ会ソスソスzソスソスHソスソスソスmソスソスソスソス
ソスワゑソスソスBソスソスソスソスソスフ維趣ソスソスソスソスソスソスフゑソスソス゚に托ソスソス驛ソスbソスZソス[ソスWソスフ問合ソスソスソスニ回答は以会ソスソスニ難ソスソスソスソス`
ソスナゑソスソスソスソスAソスソスソスbソスZソス[ソスWソスフシソス[ソスPソスソスソスXソスヘ奇ソスソスソスソスルなゑソスソストゑソスソスワゑソスソスB

The information flow in a host that supports all aspects of the domain
name system is shown below:
ソスソスソスラてのドソスソスソスCソスソスソスlソス[ソスソスソスVソスXソスeソスソスソスソスソスTソス|ソス[ソスgソスソスソスソスzソスXソスgソスナの擾ソスソスtソスソスソス[ソスヘ以会ソスソスソス
ソスソスソスソスソスソスワゑソスソスF

                 Local Host ソスソスソス[ソスJソスソスソスzソスXソスg         |  Foreign ソスソスソスソス
                                                   |
    +---------+ ソスソスソス[ソスUソス竝ソスソス  +----------+ソス竝ソスソス   |  +--------+
    |         | user queries  |          |queries  |  |Foreign |
    |  User   |-------------->|          |---------|->|  Name  |
    | Program |               | Resolver |         |  | Server |
    | ソスソスソス[ソスUソスv|<--------------| ソスソスソス]ソスソスソスo |<--------|--|ソスソスソスソスソスlソス[|
    | ソスソスソスOソスソスソスソス| user responses|          |responses|  |ソスソスソスTソス[ソスo|
    +---------+ ソスソスソス[ソスUソスソス    +----------+ソスソス     |  +--------+
                                |     A            |
                cache additions |     | references |
                ソスLソスソスソスbソスVソスソスソスヌ会ソス  V     | ソスQソスソス       |
                          +-----------------+      |
                          | Shared database |      |
                          | ソスソスソスLソスfソス[ソス^ソスxソス[ソスX|      |
                          +-----------------+      |
                    ソスXソスV      A   | ソスQソスソス           |
      +---------+   refreshes |   | references     |
     /         /|             |   V                |
    +---------+ |        +----------+  ソスソス        |  +--------+
    |         | |        |          |  responses   |  |Foreign |
    |  Master | |        |   Name   |--------------|->|Resolver|
    |  files  |--------->|  Server  |              |  |ソスソスソスソス    |
    | ソス}ソスXソス^ソス[| |        |  ソスlソス[ソスソス  |<-------------|--|ソスソスソス]ソスソスソスo|
    | ソスtソス@ソスCソスソス|/         |  ソスTソス[ソスoソス[|   queries    |  +--------+
    +---------+          +----------+   ソス竝ソスソス     |
                          A   |ソスソスソスソスソスeソスiソスソスソスXソス竝ソスソス  |  +--------+
                          |   |maintenance queries |  |Foreign |
                          |   +--------------------|->|  Name  |
                          |                        |  | Server |
                          +------------------------|--|ソスソスソスソスソスlソス[|
                             maintenance responses |  |ソスソスソスTソス[ソスo|
                             ソスソスソスソスソスeソスiソスソスソスXソスソス      |  +--------+

The shared database holds domain space data for the local name server
and resolver.  The contents of the shared database will typically be a
mixture of authoritative data maintained by the periodic refresh
operations of the name server and cached data from previous resolver
requests.  The structure of the domain data and the necessity for
synchronization between name servers and resolvers imply the general
characteristics of this database, but the actual format is up to the
local implementor.
ソスソスソスLソスfソス[ソス^ソスxソス[ソスXソスヘソスソス[ソスJソスソスソスlソス[ソスソスソスTソス[ソスoソスニソスソス]ソスソスソスoソスフドソスソスソスCソスソスソスソスヤデソス[ソス^ソスソスソスソス
ソスソスソスワゑソスソスBソスソスソスLソスfソス[ソス^ソスxソス[ソスXソスフ抵ソスソスgソスヘ茨ソスハ的ソスノはネソス[ソスソスソスTソス[ソスoソスフ趣ソスソスソスソスIソスネ更ソスVソスソスソスソス
ソスナ維趣ソスソスソスソスソス髏ウソスソスソスネデソス[ソス^ソスニ、ソスOソスフソスソス]ソスソスソスoソスフ問合ソスソスソスフデソス[ソス^ソスLソスソスソスbソスVソスソスソスフ搾ソスソスソス
ソスナゑソスソスBソスhソスソスソスCソスソスソスfソス[ソス^ソスフ構ソスソスソスニネソス[ソスソスソスTソス[ソスoソスニソスソス]ソスソスソスoソスフ間の難ソスソスソスソスフ必ソスvソスソスソスヘゑソス
ソスフデソス[ソス^ソスxソス[ソスXソスフ茨ソスハ的ソスネ難ソスソスソスソスソスソステ趣ソスソスソスソスワゑソスソスAソスソスソスソスソスソスソスソスソスロのフソスHソス[ソス}ソスbソスgソスヘソスソス[
ソスJソスソスソスネ趣ソスソスソスソスメ趣ソスソスソスナゑソスソスB

Information flow can also be tailored so that a group of hosts act
together to optimize activities.  Sometimes this is done to offload less
capable hosts so that they do not have to implement a full resolver.
This can be appropriate for PCs or hosts which want to minimize the
amount of new network code which is required.  This scheme can also
allow a group of hosts can share a small number of caches rather than
maintaining a large number of separate caches, on the premise that the
centralized caches will have a higher hit ratio.  In either case,
resolvers are replaced with stub resolvers which act as front ends to
resolvers located in a recursive server in one or more name servers
known to perform that service:
ソスソスソスtソスソスソス[ソスソスソスソスソスソスソスナ難ソスソスすソスソスzソスXソスgソスフ奇ソスソスソスソスソスソスナ適ソスソスソスソスソスソス謔、ソスdソスソスソスト抵ソスソスソスソスナゑソスソスワゑソスソスB
ソスソスソスノは、ソス\ソスヘの低いソスzソスXソスgソスソスソスソスソスSソスネソスソス]ソスソスソスoソスソスソスソスソスソスソスソスソスネゑソスソストゑソスソスソスソスソスソス謔、ソスノ変更ソスソス
ソスソスソスワゑソスソスBソスソスソスソスヘPソスbソスソスKソスvソスネ新ソスソスソスソスソスlソスbソスgソスソスソス[ソスNソスRソス[ソスhソスフ量ゑソスソスナ擾ソスソスノゑソスソス驍アソスニゑソス
ソス]ソズホソスXソスgソスノ適ソスリでゑソスソス闢セソスワゑソスソスBソスソスソスフ変更ソスヘ難ソスソスソスソスソスソスzソスXソスgソスOソスソスソス[ソスvソスソスソスAソスWソスソスソス`ソスソス
ソスLソスソスソスbソスVソスソスソスソスソスソス闕ゑソスソスソスqソスbソスgソスソスソスソスソスソスソスツゑソスソスうソスニゑソスソスソスソスOソスソスナ、ソスソスソスソスソスフ個別のキソスソスソスb
ソスVソスソスソスソスソスソスソスフではなゑソスソスソスソスソスソスフキソスソスソスbソスVソスソスソスソスソスソスソスLソスソスソス驍スソス゚に使ソスソスソスソスソスニゑソスソスナゑソスソスワゑソスソスB
ソスソスソスソスソスソスフ場合ソスナゑソスソスAソスソスソス]ソスソスソスoソスソスソスXソス^ソスuソスソスソス]ソスソスソスoソスナ置ソスソスソスソスソスソスソスソスソスAソスXソス^ソスuソスソスソス]ソスソスソスo
ソスヘ切り株ソスソスソス]ソスソスソスoソスソスソスPソスツ以擾ソスフサソス[ソスrソスXソスソスソスsソスソスソスlソス[ソスソスソスTソス[ソスoソス[ソスフ難ソスソスフ再帰ソス竝ソスソス
ソスTソス[ソスoソス[ソスフフソスソスソスソスソスgソスGソスソスソスhソスフ厄ソスソス務めまゑソスソスF

                   Local Hosts ソスソスソス[ソスJソスソスソスzソスXソスg      |  Foreign ソスソスソスソス
                                                   |
    +---------+ ソスソス                               |
    | Stub    | responses                          |
    | Resolver|<--------------------+              |
    | ソスXソス^ソスu  |                     |              |
    | ソスソスソス]ソスソスソスo|----------------+    |              |
    +---------+ recursive      |    |              |
                queries        |    |              |
                ソスト帰ソス竝ソスソス     V    |              |
    +---------+ recursive +--------------+ソス竝ソスソス   |  +--------+
    | Stub    | queries   |              |queries  |  |Foreign |
    | Resolver|---------->|   Recursive  |---------|->|  Name  |
    | ソスXソス^ソスu  |           |   Server     |         |  | Server |
    | ソスソスソス]ソスソスソスo|<----------|   ソスト帰       |<--------|--|ソスソスソスuソスlソス[|
    +---------+ responses |   ソスTソス[ソスoソス[   |responses|  |ソスソスソスTソス[ソスo|
                ソスソス      +--------------+ソスソス     |  +--------+
                          |Central  cache|         |
                          |ソスWソスソスソスLソスソスソスbソスVソスソス|         |
                          +--------------+         |

In any case, note that domain components are always replicated for
reliability whenever possible.
ソスヌゑソスネケソス[ソスXソスナでゑソスソスAソスhソスソスソスCソスソスソス\ソスソスソスvソスfソスソスソスAソスツ能ソスナゑソスソス骼橸ソスヘゑソスソスツでゑソスソスAソスソスノ信ソスソス
ソスソスソスフゑソスソス゚に包ソスソスソスソスソスソスソス驍アソスニを注意を払ゑソスソストゑソスソスソスソスソスソスソスソスB

2.3. Conventions
2.3. ソスソス闌茨ソスソス

The domain system has several conventions dealing with low-level, but
fundamental, issues.  While the implementor is free to violate these
conventions WITHIN HIS OWN SYSTEM, he must observe these conventions in
ALL behavior observed from other hosts.
ソスhソスソスソスCソスソスソスVソスXソスeソスソスソスヘ低レソスxソスソスソスナゑソスソス驍ェソスAソスソス{ソスIソスネ、ソスソスソスソスソスソスソスソスソストゑソスソス驍「ソスソスソスツゑソスソスソス
ソスソス闌茨ソス゚ゑソスソスソスソスソスソスワゑソスソスBソスソスソスソスソスメゑソスソスAソスソスソスソスソスソスソスgソスフシソスXソスeソスソスソスソスソスナゑソスソスソスソスフ趣ソス闌茨ソス゚に破
ソス驍アソスニゑソスソスソスソスRソスナゑソスソスソスソスAソスソスソスソスソスフゑソスソスラての行ソスソスソスナの趣ソス闌茨ソス゚ゑソスソスソスソスフホソスXソスgソスソスソスソスマ察
ソスソスソスソスソスフに気ソスtソスソスソスネゑソスソストはなゑソスワゑソスソスソスB

2.3.1. Preferred name syntax
2.3.1. ソス]ソスワゑソスソスソスソスソスソスOソスソスソス@

The DNS specifications attempt to be as general as possible in the rules
for constructing domain names.  The idea is that the name of any
existing object can be expressed as a domain name with minimal changes.
ソスcソスmソスrソスdソスlソスヘドソスソスソスCソスソスソスソスソスソスgソスン暦ソスソストゑソスKソスソスソスノつゑソスソスト可能ソスネ鯉ソスソスソスソスハ的ソスナゑソスソスソス謔、
ソスノ趣ソスソスンまゑソスソスBソスlソスソスソスソスソスヘどゑソスネ奇ソスソスソスソスフオソスuソスWソスFソスNソスgソスソスソスソスソスナ擾ソスソスフ変更ソスナドソスソスソスCソスソスソスソスソスソス
ソスソスソスト表ソスソスソスソスソスニゑソスソスナゑソスソスソスニゑソスソスソスソスソスソスニでゑソスソスB

However, when assigning a domain name for an object, the prudent user
will select a name which satisfies both the rules of the domain system
and any existing rules for the object, whether these rules are published
or implied by existing programs.
ソスソスソスソスソスソスソスネゑソスソスソスAソスIソスuソスWソスFソスNソスgソスフドソスソスソスCソスソスソスソスソスソスソスソスソス闢厄ソストる時ソスAソスTソスdソスネソスソス[ソスUソス[ソスヘ、
ソスhソスソスソスCソスソスソスVソスXソスeソスソスソスフ規ソスソスソスニ、ソスソスソスソスソスフ厄ソスソスソスソスIソスソスソスソスソスソスソスヘ暗黙の計ソスソスノゑソスソスKソスソスソスフ、ソスソス
ソスソスソスフ規ソスソスソス満ゑソスソスソスソス謔、ソスノオソスuソスWソスFソスNソスgソスフ厄ソスソスOソスソスIソスヤでゑソスソス蛯、ソスB

For example, when naming a mail domain, the user should satisfy both the
rules of this memo and those in RFC-822.  When creating a new host name,
the old rules for HOSTS.TXT should be followed.  This avoids problems
when old software is converted to use domain names.
ソス痰ヲソスホ、ソスソスソス[ソスソスソスhソスソスソスCソスソスソス名づゑソスソスソスニゑソスソスノ、ソスソスソス[ソスUソス[ソスソスRFC-822ソスニゑソスソスフソスソスソスソスフ暦ソス
ソスソスソスフ規ソスソスソス満ゑソスソスソスソスラゑソスソスナゑソスソスBソスVソスソスソスソスソスzソスXソスgソスソスソスソスソスソス骼曰OSTS.TXTソスナの古ゑソスソスKソスソスソスソス
ソス]ソスソスソスラゑソスソスナゑソスソスBソスソスソスソスヘ、ソステゑソスソス\ソスtソスgソスEソスFソスAソスソスソスhソスソスソスCソスソスソスソスソスソスソスgソスソスソス謔、ソスノ変更ソスソスソスソスロ、
ソスgソスソスソスuソスソスソスソスソスソスソスソスワゑソスソスB

The following syntax will result in fewer problems with many
applications that use domain names (e.g., mail, TELNET).
ソスソスソスフ包ソスソス@ソスヘドソスソスソスCソスソスソスソスソスソスソスgソスソスソスソスソスソスソスフアソスvソスソスソスPソス[ソスVソスソスソスソスソスナの厄ソスソスソスソスソスソスネゑソスソスソスソスソスナゑソスソスソス
ソスソスソスiソス痰ヲソスホ、ソスソスソス[ソスソスソスATELNETソスjソスB

<domain> ::= <subdomain> | " "
<domain> ::= ソスhソスbソスgソスナ具ソスリゑソスソスソス<label>ソスフ列か、ソス文趣ソスソスソス

<subdomain> ::= <label> | <subdomain> "." <label>
<subdomain> ::= ソスhソスbソスgソスナ具ソスリゑソスソスソス<label>ソスフ暦ソス

<label> ::= <letter> [ [ <ldh-str> ] <let-dig> ]
<label> ::= ソスAソスソスソスtソス@ソスxソスbソスgソスナ始ソスワゑソスAソスAソスソスソスtソス@ソスxソスbソスgソスソスソスソスソスソスソスソスソスnソスCソスtソスソスソスソスソスソスソスソスソスA
            ソスAソスソスソスtソス@ソスxソスbソスgソスソスソスソスソスソスソスナ終ソスソス髟カソスソスソスソス

<ldh-str> ::= <let-dig-hyp> | <let-dig-hyp> <ldh-str>
<ldh-str> ::= ソスAソスソスソスtソス@ソスxソスbソスgソスソスソスソスソスソスソスソスソスnソスCソスtソスソスソスソスソスソスネる文ソスソスソスソス

<let-dig-hyp> ::= <let-dig> | "-"
<let-dig-hyp> ::= ソスAソスソスソスtソス@ソスxソスbソスgソスソスソスソスソスソスソスソスソスnソスCソスtソスソス

<let-dig> ::= <letter> | <digit>
<let-dig> ::= ソスAソスソスソスtソス@ソスxソスbソスgソスソスソスソスソスソス

<letter> ::= any one of the 52 alphabetic characters A through Z in
             upper case and a through z in lower case
<letter> ::= ソス蝠カソスソスソスソスAソスソスソスソスZソスニ擾ソスソスソスソスソスソスソスaソスソスソスソスzソスソス52ソスツの包ソスソスソスソスフどれか

<digit> ::= any one of the ten digits 0 through 9
<digit> ::= 0ソスソスソスソス9ソスソス10ソスツの撰ソスソスソスソスフどれか

Note that while upper and lower case letters are allowed in domain
names, no significance is attached to the case.  That is, two names with
the same spelling but different case are to be treated as if identical.
ソスhソスソスソスCソスソスソスソスソスナ大文ソスソスソスニ擾ソスソスソスソスソスソスソスソスソスソスソスソスソスワゑソスソスソスソスAソス蝠カソスソスソスソスソスソスソスソスソスノ具ソスハゑソスソスネゑソスソスソスソスニゑソス
ソスソスソスモゑソスソストゑソスソスソスソスソスソスソスソスBソスソスソスソスソスツづゑソスナ大文ソスソスソスソスソスソスソスソスソスソスソスルなゑソスQソスツの厄ソスソスOソスヘ難ソスソスソスソスソスソスOソスソス
ソスソスソスソスソスソスヘゑソスソスナゑソスソスB

The labels must follow the rules for ARPANET host names.  They must
start with a letter, end with a letter or digit, and have as interior
characters only letters, digits, and hyphen.  There are also some
restrictions on the length.  Labels must be 63 characters or less.
ソスソスソスxソスソスソスソスARPANET ソスzソスXソスgソスソスソスフ規ソスソスソスノ従ソスソスネゑソスソスソスホなゑソスワゑソスソスソスBソスソスソスソスソスヘ包ソスソスソスソスソスソスソス
ソスnソスワゑソスAソスソスソスソスソスソスソスソスソスソスソスナ終ソスソスソスAソスrソスソスソスヘ包ソスソスソスソスニ撰ソスソスソスソスニハソスCソスtソスソスソスソスソスソスネゑソスワゑソスソスBソスソスソスソス
ソスノつゑソスソストゑソスソスソスソスソスソスソスソスソスソスソスソス轤ゥソスフ撰ソスソスソスソスソスソスソスソスソスワゑソスソスBソスソスソスxソスソスソスヘ6ソスRソスフ包ソスソスソスソスネ会ソスソスノ違いソスソス
ソスソスワゑソスソスソスB

For example, the following strings identify hosts in the Internet:
ソス痰ヲソスホ、ソスソスソスフ包ソスソスソスソスソスヘイソスソスソス^ソス[ソスlソスbソスgソスナホソスXソスgソスソスソスソスソスハゑソスソスワゑソスソスF

A.ISI.EDU XX.LCS.MIT.EDU SRI-NIC.ARPA

2.3.2. Data Transmission Order
2.3.2. ソスfソス[ソス^ソス]ソスソスソスソスソスソス

The order of transmission of the header and data described in this
document is resolved to the octet level.  Whenever a diagram shows a
group of octets, the order of transmission of those octets is the normal
order in which they are read in English.  For example, in the following
diagram, the octets are transmitted in the order they are numbered.
ソスソスソスフ包ソスソスソスソスナ記ソスqソスソスソス黷スソスwソスbソス_ソスニデソス[ソス^ソスフ転ソスソスソスソスソスソスソスヘオソスNソスeソスbソスgソスソスソスxソスソスソスノ会ソスソスソスソスソスソスソス
ソスワゑソスソスBソス}ソスナオソスNソスeソスbソスgソスOソスソスソス[ソスvソスソスソスソスソスソスソスソスソスヘ、ソスソスソスソスソスフオソスNソスeソスbソスgソスフ転ソスソスソスソスソスソスソスヘゑソス
ソスソス轤ェソスpソスソスナ読まゑソスソスWソスソスソスIソスネ擾ソスソスソスソスナゑソスソスBソス痰ヲソスホ趣ソスソスフ図ソスナ、ソスeソスIソスNソスeソスbソスgソスヘ番搾ソス
ソスtソスソスソスソス黷スソスソスソスヤで転ソスソスソスソスソスソスワゑソスソスB

     0                   1
     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |       1       |       2       |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |       3       |       4       |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |       5       |       6       |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Whenever an octet represents a numeric quantity, the left most bit in
the diagram is the high order or most significant bit.  That is, the bit
labeled 0 is the most significant bit.  For example, the following
diagram represents the value 170 (decimal).
ソスIソスNソスeソスbソスgソスソスソスソスソスlソスソスソスソスソスソスソスニゑソスソスヘ図ソスフ最ゑソスソスソスソスフビソスbソスgソスソスソスナ擾ソスハビソスbソスgソスナゑソスソスBソスツまゑソス
ソスOソスニ趣ソスソスソスソスソスソスrソスbソスgソスソスソスナ擾ソスハビソスbソスgソスナゑソスソスBソス痰ヲソスホ、ソスソスソスフ図ソスヘ撰ソスソスlソスPソスVソスOソスi10ソスiソスソスソスj
ソスソス\ソスソスソスワゑソスソスB

     0 1 2 3 4 5 6 7
    +-+-+-+-+-+-+-+-+
    |1 0 1 0 1 0 1 0|
    +-+-+-+-+-+-+-+-+

Similarly, whenever a multi-octet field represents a numeric quantity
the left most bit of the whole field is the most significant bit.  When
a multi-octet quantity is transmitted the most significant octet is
transmitted first.
ソスソスソスlソスノ、ソス}ソスソスソス`ソスIソスNソスeソスbソスgソスフフソスBソス[ソスソスソスhソスソスソスソスソスlソスソスソスソスソスソスソスニゑソスソスヘ、ソスrソスbソスgソスtソスBソス[ソスソスソスh
ソスSソスフの最ゑソスソスソスソスソスソスナ擾ソスハビソスbソスgソスナゑソスソスBソスソスソスソスソスIソスNソスeソスbソスgソスフ撰ソスソスlソスソスソス]ソスソスソスソスソスソスソスニゑソスソスAソスソス
ソスソスハオソスNソスeソスbソスgソスソスソスナ擾ソスソスノ転ソスソスソスソスソスソスワゑソスソスB

2.3.3. Character Case
2.3.3. ソスソスソスソス

For all parts of the DNS that are part of the official protocol, all
comparisons between character strings (e.g., labels, domain names, etc.)
are done in a case-insensitive manner.  At present, this rule is in
force throughout the domain system without exception.  However, future
additions beyond current usage may need to use the full binary octet
capabilities in names, so attempts to store domain names in 7-bit ASCII
or use of special bytes to terminate labels, etc., should be avoided.
ソスソスソスソスソスフプソスソスソスgソスRソスソスソスフ一部ソスナゑソスソスソスcソスmソスrソスフゑソスソスラての包ソスソスソスソスナ、ソスソスソスラての包ソスソスソスソスソスiソス痰ヲ
ソスホ、ソスソスソスxソスソスソスAソスhソスソスソスCソスソスソスソスソスネど)ソスフ費ソスrソスヘ大文ソスソスソスソスソスソスソスソスソスフ違いソス無趣ソスソスソスソスソスソスソス@ソスナゑソス
ソスソスワゑソスソスBソスレ会ソスソスAソスソスソスフ規ソスソスソスヘ暦ソスOソスネゑソスソスhソスソスソスCソスソスソスVソスXソスeソスソスソスナ鯉ソスソスハゑソスソスソスソスソスソストゑソスソスワゑソスソスBソスソス
ソスソスソスソスソスAソスソスソスソスソスソスソスSソスネ2ソスiソスソスソスフオソスNソスeソスbソスgソス\ソスヘゑソスソスgソスソスソスKソスvソスソスソスソスソス驍ゥソスソスソスソスソスソスワゑソスソスソスAソスソス
ソスフゑソスソス゚ドソスソスソスCソスソスソスソスソスソスソスVソスrソスbソスgソスソスASCIIソスソス[ソスソスソスソスソスxソスソスソスネどの難ソスソスソスネバソスCソスgソスノゑソスソス驍ア
ソスニは費ソスソスソスソスソスソスソスラゑソスソスナゑソスソスB

When data enters the domain system, its original case should be
preserved whenever possible.  In certain circumstances this cannot be
done.  For example, if two RRs are stored in a database, one at x.y and
one at X.Y, they are actually stored at the same place in the database,
and hence only one casing would be preserved.  The basic rule is that
case can be discarded only when data is used to define structure in a
database, and two names are identical when compared in a case
insensitive manner.
ソスfソス[ソス^ソスソスソスhソスソスソスCソスソスソスVソスXソスeソスソスソスノ参ソスソスソスソスソス骼橸ソスAソスソスソスフ鯉ソスソスフ大文ソスソスソスソスソスソスソスソスソスヘ、ソスツ能ソスネ鯉ソスソスソスA
ソスロ趣ソスソスソスソスソスソスラゑソスソスナゑソスソスBソスソスソスソスソスソスソスフ状況でゑソスソスソスヘでゑソスソスワゑソスソスソスBソス痰ヲソスホ、ソスソスソスソスソスQソスツゑソス
ソスqソスqソスiソスソスソスソスソスソスソスRソス[ソスhソスjソスソスソスfソス[ソス^ソスxソス[ソスXソスノ登ソス^ソスソスソスソスAソスソスソスソスソスx.yソスナ、ソスソスソスソスソスソスX.Yソスナゑソス
ソスソスホ、ソスソスソスフ2ソスツはデソス[ソス^ソスxソス[ソスXソスフ難ソスソスソスソス齒奇ソスノ置ソスソスソスソスAソスソスソスソスソスソスソスソスソスソスロ托ソスソスソスソスソスソスナゑソスソスソス
ソスソスソスBソスソス{ソスIソスネ規ソスソスソスナ大文ソスソスソスソスソスソスソスソスソスヘデソス[ソス^ソスソスソスfソス[ソス^ソスxソス[ソスXソスナ構ソスソスソスソスソス`ソスソスソス骼橸ソスソス
ソスフみ厄ソスソスソスソスソスソスソスAソスQソスツの厄ソスソスOソスソスソス蝠カソスソスソスソスソスソスソスソスソスフ違いソス無趣ソスソスソスソスソスソスソス@ソスナ費ソスrソスソスソスソス骼
ソスソスソスソスソスニみなゑソスソスソスワゑソスソスB

Loss of case sensitive data must be minimized.  Thus while data for x.y
and X.Y may both be stored under a single location x.y or X.Y, data for
a.x and B.X would never be stored under A.x, A.X, b.x, or b.X.  In
general, this preserves the case of the first label of a domain name,
but forces standardization of interior node labels.
ソス蝠カソスソスソスソスソスソスソスソスソスフ違いソスソスソスソスソスハゑソスソスソスfソス[ソス^ソスフ托ソスソスソスソスヘ最擾ソスソスノゑソスソスネゑソスソスソスホなゑソスワゑソスソスソスBソスソス
ソスフゑソスソス゚、x.yソスソスX.Yソスフデソス[ソス^ソスソスソスソスソスノひとつの場所x.yソスソスソス驍「ソスソスX.Yソスノ保管ゑソスソスソストゑソスソスA
a.xソスソスB.Xソスフデソス[ソス^ソスソスソスソスソスソスソスソスA.xソスソスA.Xソスソスb.xソスソスb.Xソスノ保管ゑソスソスソスネゑソスソスナゑソスソス蛯、ソスBソスソスハに、
ソスソスソスソスヘドソスソスソスCソスソスソスソスソスフ最擾ソスソスフソスソスxソスソスソスフ大文ソスソスソスソスソスソスソスソスソスヘ維趣ソスソスソスソスワゑソスソスソスソスAソスソスソスソスソスmソス[ソスhソスソス
ソスxソスソスソスフ標ソスソスソスソスソスソスソスソスソスソスソスソスソスワゑソスソスB

Systems administrators who enter data into the domain database should
take care to represent the data they supply to the domain system in a
case-consistent manner if their system is case-sensitive.  The data
distribution system in the domain system will ensure that consistent
representations are preserved.
ソスfソス[ソス^ソスソスソスhソスソスソスCソスソスソスfソス[ソス^ソスxソス[ソスXソスフ抵ソスソスノ難ソスソスヘゑソスソスソスVソスXソスeソスソスソスヌ暦ソスソスメゑソスソスAソスソスソスソスソズゑソスフシ
ソスXソスeソスソスソスソスソス蝠カソスソスソスソスソスソスソスソスソスフ違いソスソスソスソスソスハゑソスソスソスネゑソスAソス蝠カソスソスソスソスソスソスソスソスソスソスソスソスムゑソスソスソスソスソスソス@ソスナド
ソスソスソスCソスソスソスVソスXソスeソスソスソスノ具ソスソスソスソスソスソスソスfソス[ソス^ソス\ソスソスソス注意ゑソスソスラゑソスソスナゑソスソスBソスhソスソスソスCソスソスソスVソスXソスeソスソスソスナゑソス
ソスfソス[ソス^ソスソスソスzソスVソスXソスeソスソスソスヘ茨ソスムゑソスソスソスソス\ソスソスソスソスソスロ趣ソスソスソスソスソス驍アソスニゑソスロ証ゑソスソスソスナゑソスソス蛯、ソスB

2.3.4. Size limits
2.3.4. ソスTソスCソスYソスフ擾ソスソス

Various objects and parameters in the DNS have size limits.  They are
listed below.  Some could be easily changed, others are more
fundamental.
ソスcソスmソスrソスフ趣ソスXソスネオソスuソスWソスFソスNソスgソスソスソスpソスソスソスソスソス[ソス^ソスTソスCソスYソスフ鯉ソスソスEソスソスソスソスソスソスソストゑソスソスワゑソスソスBソスソスソスソスソス
ソスヘ以会ソスソスノソスソスXソスgソスAソスbソスvソスソスソスソスワゑソスソスBソスソスソスソスソス轤ゥソスソスソスeソスユに変ゑソスソスソスソスワゑソスソスソスソスAソスソスソスフゑソスソスフゑソス
ソスソスソスソス{ソスIソスナゑソスソスB

labels          63 octets or less
ソスソスソスxソスソス          ソスUソスRソスIソスNソスeソスbソスgソスネ会ソス

names           255 octets or less
ソスソスソスO            ソスQソスTソスTソスIソスNソスeソスbソスgソスネ会ソス

TTL             positive values of a signed 32 bit number.
ソスソスソスソスソスソスソスソス        ソスソスソスソスソスtソスRソスQソスrソスbソスgソスソスソスソスソスフ撰ソスソスフ値

UDP messages    512 octets or less
ソスtソスcソスoソスソスソスbソスZソス[ソスW ソスTソスPソスQソスIソスNソスeソスbソスgソスネ会ソス

3. DOMAIN NAME SPACE AND RR DEFINITIONS
3. ソスhソスソスソスCソスソスソスソスソスソスヤとRソスqソスソス`

3.1. Name space definitions
3.1. ソスソスソスOソスソスヤ抵ソス`

Domain names in messages are expressed in terms of a sequence of labels.
Each label is represented as a one octet length field followed by that
number of octets.  Since every domain name ends with the null label of
the root, a domain name is terminated by a length byte of zero.  The
high order two bits of every length octet must be zero, and the
remaining six bits of the length field limit the label to 63 octets or
less.
ソスソスソスbソスZソス[ソスWソスナのドソスソスソスCソスソスソスソスソスソスソスソスソスxソスソスソスフ連ソスソスソスニゑソスソスト表ソスソスソスソスソスソスワゑソスソスBソスeソスソスソスxソスソスソスソスソスPソスI
ソスNソスeソスbソスgソスフ抵ソスソスソスソスtソスBソス[ソスソスソスhソスニ、ソスソスソスソスノ托ソスソスソスソスソスソスソスソスフ撰ソスソスソスソスソスソスフオソスNソスeソスbソスgソスナ表ソスソスソスソスソス
ソスソスソスBソスソスソスラてのドソスソスソスCソスソスソスソスソスソスソスソスソス[ソスgソスフゼソスソスソスフソスソスxソスソスソスナ終ソスソスソスフで、ソスhソスソスソスCソスソスソスソスソスソスソス[
ソスソスソスフ抵ソスソスソスソスoソスCソスgソスナ終ソスソスソスワゑソスソスBソスソスソスラての抵ソスソスソスソスIソスNソスeソスbソスgソスフ擾ソスハ2ソスrソスbソスgソスヘゼソスソスソスソス
ソスソスソスソスソスAソスソスソスソスソスト抵ソスソスソスソスtソスBソス[ソスソスソスhソスフ残ソスソスUソスrソスbソスgソスソスソスソスソスxソスソスソスフ抵ソスソスソスソスソスソスUソスRソスIソスNソスeソスbソスg
ソスネ会ソスソスノ撰ソスソスソスソスソスソスワゑソスソスB

To simplify implementations, the total length of a domain name (i.e.,
label octets and label length octets) is restricted to 255 octets or
less.
ソスソスソスソスソスソスPソスソスソスソスソスソスソス驍スソス゚に、ソスhソスソスソスCソスソスソスソスソスiソスソスソスネわちソスAソスソスソスxソスソスソスIソスNソスeソスbソスgソスニソスソスxソスソスソスソス
ソスIソスNソスeソスbソスgソスjソスフ全ソスフの抵ソスソスソスソスヘ2ソスTソスTソスIソスNソスeソスbソスgソスネ会ソスソスノ撰ソスソスソスソスソスソスソスワゑソスソスB

Although labels can contain any 8 bit values in octets that make up a
label, it is strongly recommended that labels follow the preferred
syntax described elsewhere in this memo, which is compatible with
existing host naming conventions.  Name servers and resolvers must
compare labels in a case-insensitive manner (i.e., A=a), assuming ASCII
with zero parity.  Non-alphabetic codes must match exactly.
ソスソスソスxソスソスソスヘソスソスxソスソスソスフ各ソスIソスNソスeソスbソスgソスノどゑソスネ8ソスrソスbソスgソスlソスソスソスワむゑソスソスニゑソスソスナゑソスソス驍ェソスAソスソスソスソス
ソスソスソスソスソスナ托ソスソスフとゑソスソスソスノ記ソスqソスソスソスソストゑソスソスソス]ソスワゑソスソスソスソスソスソス@ソス]ソスソスソスソスソスニゑソスソスソスソスソスソスソスソスEソスソスソスソスAソス]ソスソス
ソスソスソスソスソスソスソス@ソスヘ奇ソスソスソスソスフホソスXソスgソスlソス[ソス~ソスソスソスOソスKソスソスニ暦ソスソスソスソスナゑソスソスワゑソスソスBソスlソス[ソスソスソスTソス[ソスoソスニソスソス]ソスソス
ソスoソスソスソス蝠カソスソスソスソスソスソスソスソスソスフ違いソス無趣ソスソスソスソスソスソスソス@ソスナソスソスxソスソスソスソスソスrソスソスソスネゑソスソストはなゑソスネらいソスi
ソスソスソスネわちソスAA=a)ソスAソス[ソスソスソスpソスソスソスeソスBソスソスASCIIソスソスzソス閧オソスワゑソスソスBソスAソスソスソスtソス@ソスxソスbソスgソスナなゑソスソスRソス[
ソスhソスソスソスソスソスmソスノ茨ソスvソスソスソスネゑソスソストはなゑソスワゑソスソスソスB

3.2. RR definitions
3.2. ソスqソスqソスソス`

3.2.1. Format
3.2.1. ソスtソスHソス[ソス}ソスbソスg

All RRs have the same top level format shown below:
ソスソスソスラてのRソスqソスヘ以会ソスソスフ難ソスソスソスソスソスハフソスHソス[ソス}ソスbソスgソスナゑソスソスF

                                    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                     /
    /                                               /
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

where:

NAME            an owner name, i.e., the name of the node to which this
                resource record pertains.
ソスソスソスO            ソスソスソスLソスメ厄ソスソスAソスソスソスネわちソスAソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスノ関係ソスソスソスソスmソス[ソスhソスソス
                ソスソスソスOソスB

TYPE            two octets containing one of the RR TYPE codes.
ソスソスソス            ソスqソスqソス^ソスCソスvソスRソス[ソスhソスソスソスワむ2ソスIソスNソスeソスbソスgソスB

CLASS           two octets containing one of the RR CLASS codes.
ソスNソスソスソスX          ソスqソスqソスNソスソスソスXソスRソス[ソスhソスソスソスワむ2ソスIソスNソスeソスbソスgソスB

TTL             a 32 bit signed integer that specifies the time interval
                that the resource record may be cached before the source
                of the information should again be consulted.  Zero
                values are interpreted to mean that the RR can only be
                used for the transaction in progress, and should not be
                cached.  For example, SOA records are always distributed
                with a zero TTL to prohibit caching.  Zero values can
                also be used for extremely volatile data.
ソスソスソスソスソスソスソスソス        ソスRソスQソスrソスbソスgソスソスソスソスソスtソスソスソスソスソスナゑソスソスBソスソスソスソスソスソスソスRソス[ソスhソスフ擾ソス源ゑソスソストび抵ソスソスソス
                ソスソスソスソスワで、ソスLソスソスソスbソスVソスソスソスナゑソスソス骼橸ソスヤ隔ソスソスソスwソス閧オソスワゑソスソスBソス[ソスソスソスフ値
                ソスソスソスqソスqソスソスソスソスソスン進ソスsソスソスソスフ擾ソスソスソスソスノゑソスソスソスソスgソスpソスナゑソスソスAソスLソスソスソスbソスVソスソスソスソスソスラゑソス
                ソスナはなゑソスソスソスソスニゑソスソスモ厄ソスソスソスソスワゑソスソスBソス痰ヲソスソスSOAソスソスソスRソス[ソスhソスソスソスLソスソスソスbソスVソスソス
                ソスソスソスヨ止ソスソスソス驍スソス゚に擾ソスノゼソスソスTTLソスナ配ソスzソスソスソスソスワゑソスソスBソス[ソスソスソスlソスソスソスソスソスソス
                ソスソスソスソスソスノ奇ソスソスソスソスソスソス竄キソスソスソスfソス[ソス^ソスナ使ソスソスソスソスソスニゑソスソスナゑソスソスワゑソスソスB

ソス注:RFC2181ソスナSソスnソス`ソスフTソスsソスkソスヘゼソスソスソスナなゑソスソスソスホなゑソスネゑソスソスニ規ソス閧オソストゑソスソスワゑソスソスB
ソスワゑソスソスAソスsソスsソスkソスフ値ソスヘ0ソスネ擾ソスQソスPソスSソスVソスSソスWソスRソスUソスSソスVソスネ会ソスソスナ、ソスLソスソスソスソスソスソスソスRソスPソスrソスbソスg
ソスニ規ソス閧オソストゑソスソスワゑソスソスB

RDLENGTH        an unsigned 16 bit integer that specifies the length in
                octets of the RDATA field.
ソスソスソスソスソスfソス[ソス^ソスソス    ソスソスソスソスソスfソス[ソス^ソスtソスBソス[ソスソスソスhソスフオソスNソスeソスbソスgソスPソスハの抵ソスソスソスソスソスソスwソス閧キソス髟ソスソス
                ソスネゑソスソスPソスUソスrソスbソスgソスソスソスソスソスB

RDATA           a variable length string of octets that describes the
                resource.  The format of this information varies
                according to the TYPE and CLASS of the resource record.
ソスソスソスソスソスfソス[ソス^      ソスソスソス\ソス[ソスXソスソスソスLソスqソスソスソスソスIソスNソスeソスbソスgソスPソスハの可変抵ソスソスXソスgソスソスソスソスソスOソスBソスソスソスソス
                ソスソスソスフフソスHソス[ソス}ソスbソスgソスヘ趣ソスソスソスソスソスソスRソス[ソスhソスフタソスCソスvソスニクソスソスソスXソスノ従ソスソスソスソス
                ソスマ会ソスソスソスソスワゑソスソスB

3.2.2. TYPE values
3.2.2. ソスソスハ値

TYPE fields are used in resource records.  Note that these types are a
subset of QTYPEs.
ソスソスハフソスBソス[ソスソスソスhソスソスソスソスソスソスソスソスソスRソス[ソスhソスナ使ソスソスソスワゑソスソスBソスソスソスソスソスフ趣ソスハゑソスソスソスソスソスソスハの一部ソスソス
ソスソスソス驍アソスニを注意を払ゑソスソストゑソスソスソスソスソスソスソスソスB

TYPE            value and meaning
ソスソスソス            ソスlソスニ意厄ソス

A               1 a host address
A               1 ソスzソスXソスgソスAソスhソスソスソスX

NS              2 an authoritative name server
NS              2 ソスソスソスソスソスネネソス[ソスソスソスTソス[ソスo

MD              3 a mail destination (Obsolete - use MX)
MD              3 ソスソスソス[ソスソスソスソスソスソスiソスソスソスソスxソスソスAMXソスソスソスgソスソスソスソスソスニ)

MF              4 a mail forwarder (Obsolete - use MX)
MF              4 ソスソスソス[ソスソスソス]ソスソスソスiソスソスソスソスxソスソスAMXソスソスソスgソスソスソスソスソスニ)

CNAME           5 the canonical name for an alias
CNAME           5 ソスハ厄ソスソスノ対ゑソスソスソスWソスソスソスソス

SOA             6 marks the start of a zone of authority
SOA             6 ソスソスソスソスソス]ソス[ソスソスソスフ開ソスnソス\ソスソス

MB              7 a mailbox domain name (EXPERIMENTAL)
MB              7 ソスソスソス[ソスソスソス{ソスbソスNソスXソスhソスソスソスCソスソスソスソスソスiソスソスソスソスソスIソスj

MG              8 a mail group member (EXPERIMENTAL)
MG              8 ソスソスソス[ソスソスソスOソスソスソス[ソスvソスソスソスソスソスoソス[ソスiソスソスソスソスソスIソスj

MR              9 a mail rename domain name (EXPERIMENTAL)
MR              9 ソスソスソス[ソスソスソスソスソスソスソスhソスソスソスCソスソスソスソスソスiソスソスソスソスソスIソスj

NULL            10 a null RR (EXPERIMENTAL)
NULL            10 ソスkソスソスソスソスソスソスソスソスソスRソス[ソスhソスiソスソスソスソスソスIソスj

WKS             11 a well known service description
WKS             11 ソスソスソスmソスフサソス[ソスrソスXソスLソスq

PTR             12 a domain name pointer
PTR             12 ソスhソスソスソスCソスソスソスソスソス|ソスCソスソスソス^

HINFO           13 host information
HINFO           13 ソスzソスXソスgソスソスソス

MINFO           14 mailbox or mail list information
MINFO           14 ソスソスソス[ソスソスソス{ソスbソスNソスXソスソスソス驍「ソスヘソスソス[ソスソスソスソスソスXソスgソスソスソス

MX              15 mail exchange
MX              15 ソスソスソス[ソスソスソスソスソスソス

TXT             16 text strings
TXT             16 ソスeソスLソスXソスgソスソスソスソスソスソス

3.2.3. QTYPE values
3.2.3. ソス竝ソスソスソスソスソス

QTYPE fields appear in the question part of a query.  QTYPES are a
superset of TYPEs, hence all TYPEs are valid QTYPEs.  In addition, the
following QTYPEs are defined:
ソス竝ソスソスソスソスハフソスBソス[ソスソスソスhソスソスソス竝ソスソスソスフ趣ソスソス笊費ソスソスソスノ鯉ソスソスソスソスワゑソスソスBソス竝ソスソスソスソスハは趣ソスハ値ソスソス
ソスSソストゑソスソスワむ集ソスソスソスナ、ソスソスソスソスフゑソスソスラての趣ソスハゑソスソスソスソスソスソスソスソスソスソス竝ソスソスソスソスハでゑソスソスBソスソスソスソスノ趣ソスソスソス
ソス竝ソスソスソスソスハゑソスソスソス`ソスソスソスソスワゑソスソスF

AXFR            252 A request for a transfer of an entire zone
AXFR            252 ソスSソスソスソスフゾソス[ソスソスソスフ転ソスソスソスフ要ソスソス

MAILB           253 A request for mailbox-related records (MB, MG or MR)
MAILB           253 ソスソスソス[ソスソスソス{ソスbソスNソスXソスヨ連ソスフソスソスRソス[ソスhソスiMBソスソスMGソスソスMRソスjソスフ要ソスソス

MAILA           254 A request for mail agent RRs (Obsolete - see MX)
MAILA           254 ソスソスソス[ソスソスソス纓晢ソスlソスソスソスソスソスソスソスRソス[ソスhソスフ要ソスソスソスiソスソスソスソスxソスソスAMXソスQソスニ)

*               255 A request for all records
*               255 ソスソスソスラてのソスソスRソス[ソスhソスフ要ソスソス

3.2.4. CLASS values
3.2.4. ソスNソスソスソスXソスl

CLASS fields appear in resource records.  The following CLASS mnemonics
and values are defined:
ソスNソスソスソスXソスtソスBソス[ソスソスソスhソスソスソスソスソスソスソスソスソスRソス[ソスhソスノ鯉ソスソスソスソスワゑソスソスBソスソスソスフクソスソスソスXソスソスソスフと値ソスソスソスソス`ソスソスソスソス
ソスワゑソスソスF

IN              1 the Internet
IN              1 ソスCソスソスソス^ソス[ソスlソスbソスg

CS              2 the CSNET class (Obsolete - used only for examples in
                some obsolete RFCs)
CS              2 CSNET ソスNソスソスソスXソスiソスソスソスソスxソスソス|ソスソスソス骼橸ソスソスxソスソスソスRFCソスナ暦ソスノゑソスソスソスソスg
                ソスソス黷スソスj

CH              3 the CHAOS class
CH              3 ソスJソスIソスXソスNソスソスソスX

HS              4 Hesiod [Dyer 87]
HS              4 ソスwソスVソスIソスh[Dyer 87]

3.2.5. QCLASS values
3.2.5. ソス竝ソスソスソスNソスソスソスXソスl

QCLASS fields appear in the question section of a query.  QCLASS values
are a superset of CLASS values; every CLASS is a valid QCLASS.  In
addition to CLASS values, the following QCLASSes are defined:
ソス竝ソスソスソスNソスソスソスXソスtソスBソス[ソスソスソスhソスソスソス竝ソスソスソスフ趣ソスソス笊費ソスノ鯉ソスソスソスソスワゑソスソスBソス竝ソスソスソスNソスソスソスXソスlソスヘクソスソス
ソスXソスlソスフ全ソストの値ソスソスソスワむ集ソスソスソスナゑソスソスGソスソスソスラてのクソスソスソスXソスソスソスソスソスソスソスネ問合ソスソスソスNソスソスソスXソスナゑソスソスBソスN
ソスソスソスXソスlソスフほゑソスソスノ、ソスソスソスフ問合ソスソスソスNソスソスソスXソスlソスソスソスソス`ソスソスソスソスワゑソスソスF

*               255 any class
*               255 ソスSソストのクソスソスソスX

3.3. Standard RRs
3.3. ソスWソスソスソスソスソスソスソスソスソスRソス[ソスh

The following RR definitions are expected to occur, at least
potentially, in all classes.  In particular, NS, SOA, CNAME, and PTR
will be used in all classes, and have the same format in all classes.
Because their RDATA format is known, all domain names in the RDATA
section of these RRs may be compressed.
ソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスソス`ソスヘ、ソスソスソスネゑソスソスニゑソスソスソスソスン的ソスノ、ソスソスソスラてのクソスソスソスXソスナ托ソスソスンゑソスソス驍アソスソス
ソスソスソスソスソスメゑソスソスソスワゑソスソスBソスソスソスソスNSソスソスSOAソスソスCNAMEソスソスPTRソスヘゑソスソスラてのクソスソスソスXソスナ使ソスソスソスAソスソスソスラゑソス
ソスフクソスソスソスXソスナ難ソスソスソスソスtソスHソス[ソス}ソスbソスgソスソスソスソスソスツでゑソスソス蛯、ソスBソスソスソスソスソスフ趣ソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスg
ソスソスソスmソスソスソストゑソスソス驍ゥソスソスAソスソスソスラてのゑソスソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスフ趣ソスソスソスソスfソス[ソス^ソスソスソスナドソスソスソスCソスソス
ソスソスソスヘ茨ソスソスkソスソスソスソスソスナゑソスソス蛯、ソスB

<domain-name> is a domain name represented as a series of labels, and
terminated by a label with zero length.  <character-string> is a single
length octet followed by that number of characters.  <character-string>
is treated as binary information, and can be up to 256 characters in
length (including the length octet).
<domain-name>ソスソスソスxソスソスソスソスソスAソスソスソスソスソスソスソスソスソス[ソスソスソスフソスソスxソスソスソスナ終ソスソスソスソスソスソス`ソスソスソスフドソスソスソスCソスソスソスソスソスソス
ソスソスソスB<character-string>ソスPソスIソスNソスeソスbソスgソスフ抵ソスソスソスソスニ、ソスソスソスフ抵ソスソスソスソスフ撰ソスソスフ包ソスソスソスソスソスソスソスネゑソスソス
ソスソスソスB<character-string>ソスソスソスoソスCソスiソスソスソスソスソスニ茨ソスソスソスソスト、ソスiソスソスソスソスソスIソスNソスeソスbソスgソスソスソスワめて)
ソスナ托ソスQソスTソスUソスフ包ソスソスソスソスナゑソスソスB

3.3.1. CNAME RDATA format
3.3.1. ソスWソスソスソスソスソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスg

    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    /                     CNAME                     /
    /                                               /
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

where:

CNAME           A <domain-name> which specifies the canonical or primary
                name for the owner.  The owner name is an alias.
ソスWソスソスソスソス          ソスソスソスLソスメの標ソスソスソスソスソスワゑソスソスヘ托ソスPソスソスソスソスソスwソス閧キソスソス<domain-name>ソスBソスソスソスLソスソス
                ソスソスソスヘ別厄ソスソスナゑソスソスB

CNAME RRs cause no additional section processing, but name servers may
choose to restart the query at the canonical name in certain cases.  See
the description of name server logic in [RFC-1034] for details.
ソスWソスソスソスソスソスソスソスソスソスソスソスRソス[ソスhソスソスソスヌ会ソスソスソスソスフ擾ソスソスソスソスソスソスNソスソスソスソスソスワゑソスソスが、ソスlソス[ソスソスソスTソス[ソスoソス[ソスソスソスソスソスソス
ソスソスソスソスフ場合ソスノ標ソスソスソスソスソスナ問合ソスソスソスソスソスト開ソスソスソストゑソスソス謔「ソスナゑソスソスBソスlソス[ソスソスソスTソス[ソスoソス[ソスフソスソスWソスb
ソスNソスソス[RFC-1034]ソスフ記ソスqソスソスソスソスソストゑソスソスソスソスソスソスソスソスB

3.3.2. HINFO RDATA format
3.3.2. ソスzソスXソスgソスソス資鯉ソスソスソスソスRソス[ソスhソスtソスHソス[ソス}ソスbソスg

    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    /                      CPU                      /
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    /                       OS                      /
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

where:

CPU             A <character-string> which specifies the CPU type.
CPU             ソスbソスoソスtソスソスハゑソスソスwソス閧キソスソス<character-string>ソスB

OS              A <character-string> which specifies the operating
                system type.
OS              ソスIソスyソスソスソス[ソスeソスBソスソスソスOソスVソスXソスeソスソスソスソスハゑソスソスwソス閧キソスソス<character-string>ソスB

Standard values for CPU and OS can be found in [RFC-1010].
ソスbソスoソスtソスソスOSソスフ標ソスソスソスlソスソス[RFC-1010]ソスノゑソスソスソスワゑソスソスB

HINFO records are used to acquire general information about a host.  The
main use is for protocols such as FTP that can use special procedures
when talking between machines or operating systems of the same type.
HINFOソスソスソスRソス[ソスhソスソスソスzソスXソスgソスフ茨ソスハ的ソスネ擾ソスソス得ゑソスノに使ソスソスソスワゑソスソスBソスソスネ使ソスpソスヘ、ソスソス
ソスソスソスソズのマソスVソスソスソスフ間ゑソスIソスyソスソスソス[ソスeソスBソスソスソスOソスVソスXソスeソスソスソスヤで難ソスソスハな手順ソスソスソスgソスpソスナゑソスソスソス
FTPソスフようソスネプソスソスソスgソスRソスソスソスフゑソスソス゚でゑソスソスB

3.3.3. MB RDATA format (EXPERIMENTAL)
3.3.3. ソスソスソス[ソスソスソス{ソスbソスNソスXソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスgソスiソスソスソスソスソスIソスj

    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    /                   MADNAME                     /
    /                                               /
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

where:

MADNAME         A <domain-name> which specifies a host which has the
                specified mailbox.
MADNAME         ソスwソス閧ウソス黷スソスソスソス[ソスソスソス{ソスbソスNソスXソスソスソスソスソスツホソスXソスgソスソスソスwソス閧キソスソス
                <domain-name>ソスB

MB records cause additional section processing which looks up an A type
RRs corresponding to MADNAME.
MBソスソスソスRソス[ソスhソスソスMADNAMEソスノ対会ソスソスソスソスソスソスAソスhソスソスソスXソスソスハ趣ソスソスソスソスソスソスRソス[ソスhソスフ追会ソスソスソスソスフ擾ソスソスソスソスソスソスソス
ソスワゑソスソスB

3.3.4. MD RDATA format (Obsolete)
3.3.4. MDソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスgソスiソスソスソスソスxソスソスj

    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    /                   MADNAME                     /
    /                                               /
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

where:

MADNAME         A <domain-name> which specifies a host which has a mail
                agent for the domain which should be able to deliver
                mail for the domain.
MADNAME         ソスソスソスフドソスソスソスCソスソスソスノソスソス[ソスソスソスソスzソスBソスナゑソスソスソスGソス[ソスWソスFソスソスソスgソスフ趣ソスソスツホソスXソスg
                ソスソスソスwソス閧キソスソス<domain-name>ソスB

MD records cause additional section processing which looks up an A type
record corresponding to MADNAME.
MDソスソスソスRソス[ソスhソスソスMADNAMEソスノ対会ソスソスソスソスソスソスAソスhソスソスソスXソスソスハ趣ソスソスソスソスソスソスRソス[ソスhソスフ追会ソスソスソスソスフ擾ソスソスソスソスソスソスソス
ソスワゑソスソスB

MD is obsolete.  See the definition of MX and [RFC-974] for details of
the new scheme.  The recommended policy for dealing with MD RRs found in
a master file is to reject them, or to convert them to MX RRs with a
preference of 0.
MDソスヘ趣ソスソスソスxソスソスナゑソスソスBソスVソスソスソスソスソストの詳細ゑソスMXソスフ抵ソス`ソスソス[RFC-974]ソスソスソスソスソストゑソスソスソスソスソスソスソスソスBソス}
ソスXソス^ソス[ソスtソス@ソスCソスソスソスノゑソスソスソスMDソスソスソスソスソスソスソスRソス[ソスhソスノ対ゑソスソス髏ソスEソスソスソスソスソスソスiソスヘ、ソスソスソスソスソスソスソスソス竄キ
ソス驍ゥソスAソスDソスソスxソスOソスソスMXソスソスソスソスソスソスソスRソス[ソスhソス生撰ソスソスソスソス驍ゥソスナゑソスソスB

3.3.5. MF RDATA format (Obsolete)
3.3.5. MFソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスgソスiソスソスソスソスxソスソスj

    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    /                   MADNAME                     /
    /                                               /
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

where:

MADNAME         A <domain-name> which specifies a host which has a mail
                agent for the domain which will accept mail for
                forwarding to the domain.
MADNAME         ソスソスソスフドソスソスソスCソスソスソスノソスソス[ソスソスソスソス]ソスソスソスナゑソスソスソスGソス[ソスWソスFソスソスソスgソスフ趣ソスソスツホソスXソスg
                ソスソスソスwソス閧キソスソス<domain-name>ソスB

MF records cause additional section processing which looks up an A type
record corresponding to MADNAME.
MFソスソスソスRソス[ソスhソスソスMADNAMEソスノ対会ソスソスソスソスソスソスAソスhソスソスソスXソスソスハ趣ソスソスソスソスソスソスRソス[ソスhソスフ追会ソスソスソスソスフ擾ソスソスソスソスソスソスソス
ソスワゑソスソスB

MF is obsolete.  See the definition of MX and [RFC-974] for details ofw
the new scheme.  The recommended policy for dealing with MD RRs found in
a master file is to reject them, or to convert them to MX RRs with a
preference of 10.
MDソスヘ趣ソスソスソスxソスソスナゑソスソスBソスVソスソスソスソスソストの詳細ゑソスMXソスフ抵ソス`ソスソス[RFC-974]ソスソスソスソスソストゑソスソスソスソスソスソスソスソスBソス}
ソスXソス^ソス[ソスtソス@ソスCソスソスソスノゑソスソスソスMDソスソスソスソスソスソスソスRソス[ソスhソスノ対ゑソスソス髏ソスEソスソスソスソスソスソスiソスヘ、ソスソスソスソスソスソスソスソス竄キ
ソス驍ゥソスAソスDソスソスxソスPソスOソスソスMXソスソスソスソスソスソスソスRソス[ソスhソス生撰ソスソスソスソス驍ゥソスナゑソスソスB

3.3.6. MG RDATA format (EXPERIMENTAL)
3.3.6. ソスソスソス[ソスソスソスOソスソスソス[ソスvソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスgソスiソスソスソスソスソスIソスj

    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    /                   MGMNAME                     /
    /                                               /
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

where:

MGMNAME         A <domain-name> which specifies a mailbox which is a
                member of the mail group specified by the domain name.
ソスソスソス[ソスソスソスOソスソスソス[ソスvソスソスソスソスソスoソス[ソスソス ソスhソスソスソスCソスソスソスソスソスナ指ソス閧ウソスソス驛ソス[ソスソスソスOソスソスソス[ソスvソスフソスソスソスソスoソス[
                ソスフソスソス[ソスソスソス{ソスbソスNソスXソスソスソスwソス閧キソスソス<domain-name>ソスB

MG records cause no additional section processing.
ソスソスソス[ソスソスソスOソスソスソス[ソスvソスソスソスRソス[ソスhソスソスソスヌ会ソスソスソスソスフ擾ソスソスソスソスソスソスNソスソスソスソスソスワゑソスソスソスB

3.3.7. MINFO RDATA format (EXPERIMENTAL)
3.3.7. ソスソスソス[ソスソスソスソス資鯉ソスソスソスソスRソス[ソスhソスtソスHソス[ソス}ソスbソスgソスiソスソスソスソスソスIソスj

    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    /                    RMAILBX                    /
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    /                    EMAILBX                    /
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

where:

RMAILBX         A <domain-name> which specifies a mailbox which is
                responsible for the mailing list or mailbox.  If this
                domain name names the root, the owner of the MINFO RR is
                responsible for itself.  Note that many existing mailing
                lists use a mailbox X-request for the RMAILBX field of
                mailing list X, e.g., Msgroup-request for Msgroup.  This
                field provides a more general mechanism.
ソスモ任ソスメソスソス[ソスソスソス{ソスbソスNソスX ソスソスソス[ソスソスソスソスソスOソスソスソスXソスgソスソスソス驍「ソスヘソスソス[ソスソスソス{ソスbソスNソスXソスフ責任ソスメゑソスソスw
                ソス閧キソスソス<domain-name>ソスBソスソスソスソスソスソスソスフドソスソスソスCソスソスソスソスソスソスソスソスソス[ソスgソスソスソスソスソスソスソスソス
                ソスソスAMINFOソスソスソスソスソスソスソスRソス[ソスhソスフ擾ソスソスLソスメは趣ソスソスソスソスソスソスgソスソスソスモ任ソスメでゑソスソスBソスソス
                ソスソスソスフ奇ソスソスソスソスフソスソス[ソスソスソスソスソスOソスソスソスXソスgソスナソスソス[ソスソスソスソスソスOソスソスソスXソスgXソスフ責任ソスメゑソス
                X-requestソスソスソスgソスソスソスAソス痰ヲソスソスMsgroupソスフ責任ソスメゑソスMsgroup-request
                ソスソスソスgソスソスソスソスソスニに抵ソスソスモゑソスソストゑソスソスソスソスソスソスソスソスBソスソスソスフフソスBソス[ソスソスソスhソスヘゑソスソスソスハ的
                ソスネソスソスJソスjソスYソスソスソスソスソスソスソスソスソスソスソスワゑソスソスB

EMAILBX         A <domain-name> which specifies a mailbox which is to
                receive error messages related to the mailing list or
                mailbox specified by the owner of the MINFO RR (similar
                to the ERRORS-TO: field which has been proposed).  If
                this domain name names the root, errors should be
                returned to the sender of the message.
ソスGソスソスソス[ソスソスソス[ソスソスソス{ソスbソスNソスX MINFOソスソスソスソスソスソスソスRソス[ソスhソスフ擾ソスソスLソスメに指ソス閧ウソス黷スソスソスソス[ソスソスソスソスソスOソスソスソスX
                ソスgソス窿ソス[ソスソスソス{ソスbソスNソスXソスノ関ゑソスソスソスGソスソスソス[ソスソスソスbソスZソス[ソスWソスソスソスけ趣ソス驛ソス[
                ソスソスソス{ソスbソスNソスXソスソスソスwソスソス<domain-name>ソスiソスソスソスEソスソスソスソストゑソスソスソスERRORS-TO:
                ソスtソスBソス[ソスソスソスhソスノ類趣ソスソスソスソストゑソスソスワゑソスソスjソスBソスソスソスソスソスソスソスフドソスソスソスCソスソスソスソスソスソスソスソスソス[ソスg
                ソスソスソスソスソスソスソスネゑソスAソスGソスソスソス[ソスソスソスソスソスbソスZソス[ソスWソスフ托ソスソスMソスメに返ゑソスソスソスソスラゑソスソスナゑソスソスB

MINFO records cause no additional section processing.  Although these
records can be associated with a simple mailbox, they are usually used
with a mailing list.
MINFOソスソスソスRソス[ソスhソスソスソスヌ会ソスソスソスソスフ擾ソスソスソスソスソスソスNソスソスソスソスソスワゑソスソスソスBソスソスソスフソスソスRソス[ソスhソスソスPソスソスソスネソスソス[ソスソスソス{ソスb
ソスNソスXソスニ関連ソステゑソスソス驍アソスニゑソスソスナゑソスソス驍ェソスAソスソスソスソスソスヘ通常メソス[ソスソスソスソスソスOソスソスソスXソスgソスナ使ソスソスソスワゑソスソスB

3.3.8. MR RDATA format (EXPERIMENTAL)
3.3.8. ソスソスソス[ソスソスソスソスソスソスソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスg

    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    /                   NEWNAME                     /
    /                                               /
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

where:

NEWNAME         A <domain-name> which specifies a mailbox which is the
                proper rename of the specified mailbox.
ソスVソスソスソスソスソスソスソスO      ソスwソス閧オソスソスソスソスソス[ソスソスソス{ソスbソスNソスXソスフ適ソスリな会ソスソスソスソスフソスソス[ソスソスソス{ソスbソスNソスXソスソスソスwソスソス
                ソスソスソスソス<domain-name>ソスB

MR records cause no additional section processing.  The main use for MR
is as a forwarding entry for a user who has moved to a different
mailbox.
MRソスソスソスRソス[ソスhソスソスソスヌ会ソスソスフ包ソスソスソスソスソスソスソスソスNソスソスソスソスソスワゑソスソスソスBMRソスフ趣ソスネ用ソスrソスヘ異なるメソス[ソスソスソス{ソスbソスN
ソスXソスノ移転ソスソスソスソスソスソスソス[ソスUソス[ソスフ転ソスソスソスソスソスレとゑソスソストでゑソスソスB

3.3.9. MX RDATA format
3.3.9. ソスソスソス[ソスソスソスソスソスソスソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスg

    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    |                  PREFERENCE                   |
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    /                   EXCHANGE                    /
    /                                               /
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

where:

PREFERENCE      A 16 bit integer which specifies the preference given to
                this RR among others at the same owner.  Lower values
                are preferred.
ソスDソスソスx          ソスソスソスソスソスソスソスLソスメの趣ソスソスソスソスソスソスRソス[ソスhソスフ抵ソスソスナ、ソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスノ与ソスソスソスソス
                ソス黷スソスDソスソスxソスソスソスソスソスソスソスPソスUソスrソスbソスgソスフ撰ソスソスソスソスBソスソスソス痰「ソスlソスソスソスDソス謔ウソスソスソス
                ソスソスソスB

EXCHANGE        A <domain-name> which specifies a host willing to act as
                a mail exchange for the owner name.
ソスソスソスソス            ソスソスソスLソスメ厄ソスソスフゑソスソス゚にソスソス[ソスソスソスソスソスソスソスソスソスソスソスソスzソスXソスgソスソスソスソスソスソス<domain-name>ソスB

MX records cause type A additional section processing for the host
specified by EXCHANGE.  The use of MX RRs is explained in detail in
[RFC-974].
ソスソスソス[ソスソスソスソスソスソスソスソスソスRソス[ソスhソスソスソスソスソスソスソスナ指ソス閧ウソス黷スソスzソスXソスgソスフアソスhソスソスソスXソスソスハの追会ソスソスソスソスフ擾ソスソスソスソスソス
ソスソスソスソスソス轤オソスワゑソスソスBMXソスソスソスソスソスソスソスRソス[ソスhソスフ使ソスソスソスソスソスソス[RFC-974]ソスナ詳細で撰ソスソスソスソスソスソスソスワゑソスソスB

3.3.10. NULL RDATA format (EXPERIMENTAL)
3.3.10. ソスkソスソスソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスgソスiソスソスソスソスソスIソスj

    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    /                  <anything>                   /
    /                                               /
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

Anything at all may be in the RDATA field so long as it is 65535 octets
or less.
ソスUソスTソスTソスRソスTソスIソスNソスeソスbソスgソスネ会ソスソスフなゑソスナゑソスソスソスソス閧ヲソスワゑソスソスB

NULL records cause no additional section processing.  NULL RRs are not
allowed in master files.  NULLs are used as placeholders in some
experimental extensions of the DNS.
ソスkソスソスソスソスソスRソス[ソスhソスソスソスヌ会ソスソスソスソスフ擾ソスソスソスソスソスソスNソスソスソスソスソスワゑソスソスソスBソスkソスソスソスソスソスソスソスソスソスRソス[ソスhソスソスソス}ソスXソス^ソス[ソスtソス@
ソスCソスソスソスナ具ソスソスソスソスソスワゑソスソスソスBソスkソスソスソスヘゑソスソスソスcソスmソスrソスフ趣ソスソスソスソスIソスネ拡ソスソスソスナ場所ソスmソスロに用ソスソスソスソスソスソス
ソスソスソスB

3.3.11. NS RDATA format
3.3.11. ソスlソス[ソスソスソスTソス[ソスoソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスg

    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    /                   NSDNAME                     /
    /                                               /
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

where:

NSDNAME         A <domain-name> which specifies a host which should be
                authoritative for the specified class and domain.
ソスlソス[ソスソスソスTソス[ソスoソス[ソスhソスソスソスCソスソスソスソス ソスwソス閧ウソス黷スソスNソスソスソスXソスニドソスソスソスCソスソスソスフ撰ソスソスソスソスネホソスXソスgソスソスソスwソスソス
                ソスソスソスソス<domain-name>ソスB

NS records cause both the usual additional section processing to locate
a type A record, and, when used in a referral, a special search of the
zone in which they reside for glue information.
ソスlソス[ソスソスソスTソス[ソスoソスソスソスRソス[ソスhソスソスソスハ擾ソスフアソスhソスソスソスXソスソスハソスソスRソス[ソスhソスフ追会ソスソスソスソスフ擾ソスソスソスソスニ、ソスQソスニゑソス
ソスgソスソスソスソスニゑソスソスヘ、ソスレ抵ソスソスワ擾ソスソスノ托ソスソスンゑソスソスソス]ソス[ソスソスソスソスソスソスソスソスソスAソスソスソスソスソスソスソスソスソスワゑソスソスB

The NS RR states that the named host should be expected to have a zone
starting at owner name of the specified class.  Note that the class may
not indicate the protocol family which should be used to communicate
with the host, although it is typically a strong hint.  For example,
hosts which are name servers for either Internet (IN) or Hesiod (HS)
class information are normally queried using IN class protocols.
ソスlソス[ソスソスソスTソス[ソスoソスソスソスソスソスソスソスRソス[ソスhソスヘ指ソス閧オソスソスソスzソスXソスgソスソスソスAソスwソスソスNソスソスソスXソスフ擾ソスソスLソスメ厄ソスソスナ始ソスワゑソス
ソス]ソス[ソスソスソスソスソスソスソスツゑソスソスニゑソスソスソスソスメゑソスソスソスソスAソスニ厄ソスソスソスソスソスソスワゑソスソスBソスNソスソスソスXソスヘ茨ソスハに具ソスソスソスソスqソスソスソスgソスノゑソス
ソス驍ェソスAソスzソスXソスgソスニ通信ソスノ使ソスソスソスソスラゑソスソスvソスソスソスgソスRソスソスソスtソス@ソス~ソスソスソス[ソスソスソスソスソスソスソスネゑソスソスソスソスニに抵ソスソスソス
ソスソスソストゑソスソスソスソスソスソスソスソスBソス痰ヲソスホ、ソスCソスソスソス^ソス[ソスlソスbソスgソスiINソスjソスソスwソスVソスIソスhソスiHSソスjソスNソスソスソスXソスソスソスフネソス[
ソスソスソスTソス[ソスoソスナゑソスソスソスzソスXソスgソスソスソスハ擾ソスCソスソスソス^ソス[ソスlソスbソスgソスNソスソスソスXソスvソスソスソスgソスRソスソスソスナ趣ソスソス竄ウソスソスワゑソスソスB

3.3.12. PTR RDATA format
3.3.12. ソス|ソスCソスソスソス^ソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスg

    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    /                   PTRDNAME                    /
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

where:

PTRDNAME        A <domain-name> which points to some location in the
                domain name space.
ソス|ソスCソスソスソス^ソスhソスソスソスCソスソスソスソス ソスhソスソスソスCソスソスソスソスソスソスヤでゑソスソスソス齒奇ソスソスソスwソスソスソスソスソスソス<domain-name>ソスB

PTR records cause no additional section processing.  These RRs are used
in special domains to point to some other location in the domain space.
These records are simple data, and don't imply any special processing
similar to that performed by CNAME, which identifies aliases.  See the
description of the IN-ADDR.ARPA domain for an example.
PTRソスソスソスRソス[ソスhソスソスソスヌ会ソスソスフ包ソスソスソスソスソスソスソスソスNソスソスソスソスソスワゑソスソスソスBソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスヘドソスソスソスCソスソスソスソスソス
ソスフゑソスソス髑シソスフ場所ソスソスソスソスソスソスソスフに使ソスソスソスワゑソスソスBソスソスソスソスソスフソスソスRソス[ソスhソスヘ単ソスソスソスネデソス[ソス^ソスナ、
CNAMEソスフ行ソスソスソス謔、ソスネ難ソスソスハな擾ソスソスソスソスソスソステ趣ソスソスソスソスソスソスAソスハ厄ソスソスソスソスソスソスハゑソスソスワゑソスソスBソスソスニゑソスソスソス
IN-ADDR.ARPAソスhソスソスソスCソスソスソスフ記ソスqソスソスソスQソスニゑソスソストゑソスソスソスソスソスソスソスソスB

3.3.13. SOA RDATA format
3.3.13. SOAソスソスソスソスソスfソス[ソス^

    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    /                     MNAME                     /
    /                                               /
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    /                     RNAME                     /
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    |                    SERIAL                     |
    |                                               |
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    |                    REFRESH                    |
    |                                               |
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    |                     RETRY                     |
    |                                               |
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    |                    EXPIRE                     |
    |                                               |
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    |                    MINIMUM                    |
    |                                               |
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

where:

MNAME           The <domain-name> of the name server that was the
                original or primary source of data for this zone.
ソス}ソスXソス^ソス[ソスソス      ソスソスソスフゾソス[ソスソスソスfソス[ソス^ソスフ起ソスソスソスワゑソスソスヘ托ソスPソスフ擾ソス源でゑソスソスソスlソス[ソスソスソスTソス[
                ソスoソスソス<domain-name>ソスB

RNAME           A <domain-name> which specifies the mailbox of the
                person responsible for this zone.
ソスモ任ソスメ厄ソス        ソスソスソスフゾソス[ソスソスソスフ担ソスソスソスメのソスソス[ソスソスソス{ソスbソスNソスXソスソスソスwソス閧キソスソス<domain-name>ソスB

SERIAL          The unsigned 32 bit version number of the original copy
                of the zone.  Zone transfers preserve this value.  This
                value wraps and should be compared using sequence space
                arithmetic.
ソスVソスソスソスAソスソスソスヤ搾ソス    ソスソスソスソスソスネゑソスソスRソスQソスrソスbソスgソスフゾソス[ソスソスソスフ鯉ソスソス{ソスフバソス[ソスWソスソスソスソスソスヤ搾ソスソスBソス]ソス[ソスソス
                ソス]ソスソスソスソスソスソスソスフ値ソスソスソスロ趣ソスソスソスソスワゑソスソスBソスソスソスフ値ソスヘ擾ソスソスしてゑソスソスト、ソスAソスソスソスソスソス
                ソスソスソスZソスソスソスgソスソスソスト費ソスrソスソスソスソスソスラゑソスソスナゑソスソスB

REFRESH         A 32 bit time interval before the zone should be
                refreshed.
ソスソスソスtソスソスソスbソスVソスソス    ソスRソスQソスrソスbソスgソスフゾソス[ソスソスソスソスソスtソスソスソスbソスVソスソスソスフ間隔ソスB

RETRY           A 32 bit time interval that should elapse before a
                failed refresh should be retried.
ソストトソスソスソスC        ソスソスソスtソスソスソスbソスVソスソスソスノ趣ソスソスsソスソスノ再トソスソスソスCソスソスソスソスワでの、ソスRソスQソスrソスbソスgソスフ趣ソス
                ソスヤ間隔ソスB

EXPIRE          A 32 bit time value that specifies the upper limit on
                the time interval that can elapse before the zone is no
                longer authoritative.
ソスソスソスソスソスリゑソス        ソスRソスQソスrソスbソスgソスフゾソス[ソスソスソスソスソスソスソスソスソスナなゑソスソスネゑソスソスソスソスソスソスヤ。

MINIMUM         The unsigned 32 bit minimum TTL field that should be
                exported with any RR from this zone.
ソスナ擾ソスソスl          ソスソスソスフゾソス[ソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソス送信ソスソスソスソス鼾ソスノ指ソス閧ウソスソスソスナ擾ソスソスソス
                ソスソスソスソスソスソスソスヤゑソスソスソスソスソスソスRソスQソスrソスbソスgソスソスソスソスソスネゑソスソスソスソスB

SOA records cause no additional section processing.
SOAソスソスソスRソス[ソスhソスソスソスヌ会ソスソスソスソスフ擾ソスソスソスソスソスソスNソスソスソスソスソスワゑソスソスソスB

All times are in units of seconds.
ソスソスソスラての趣ソスソスヤは秒ソスPソスハでゑソスソスB

Most of these fields are pertinent only for name server maintenance
operations.  However, MINIMUM is used in all query operations that
retrieve RRs from a zone.  Whenever a RR is sent in a response to a
query, the TTL field is set to the maximum of the TTL field from the RR
and the MINIMUM field in the appropriate SOA.  Thus MINIMUM is a lower
bound on the TTL field for all RRs in a zone.  Note that this use of
MINIMUM should occur when the RRs are copied into the response and not
when the zone is loaded from a master file or via a zone transfer.  The
reason for this provison is to allow future dynamic update facilities to
change the SOA RR with known semantics.
ソスソスソスソスソスフフソスBソス[ソスソスソスhソスフ大部ソスソスソスソスソスlソス[ソスソスソスTソス[ソスoソスロ趣ソス^ソスpソスノゑソスソスソスソスヨ係ソスソスソスソスソスソスワゑソスソスBソスソス
ソスソスソスソスソスAソスナ擾ソスソスソスソスヘゾソス[ソスソスソスソスソス邇托ソスソスソスソスソスRソス[ソスhソスソスヤゑソスソスSソストの問合ソスソスソスソスソスソスナ使ソスソスソスワゑソスソスB
ソスソスソスソスソスソスソスRソス[ソスhソスソスソス竝ソスソスソスフ回答で托ソスソスソスソス骼橸ソスノ擾ソスノ撰ソスソスソスソスソスソスヤフソスBソス[ソスソスソスhソスノ趣ソスソスソスソスソスソスRソス[
ソスhソスフ最托ソスlソスニ適ソスリゑソスSOAソスフ最擾ソスソスlソスソスソスン定さソスソスワゑソスソスBソスツまゑソスナ擾ソスソスlソスヘゾソス[ソスソスソスソスソスフ全
ソストの趣ソスソスソスソスソスソスRソス[ソスhソスフ撰ソスソスソスソスソスソスヤフソスBソス[ソスソスソスhソスフ会ソスソスソスソスナゑソスソスBソスソスソスフ最擾ソスソスlソスヘ趣ソスソスソスソスソスソスRソス[ソスh
ソスソスソス答に設定さソスソス骼橸ソスノ使ソスpソスソスソスソスAソス}ソスXソス^ソス[ソスtソス@ソスCソスソスソスソスソスソス]ソス[ソスソスソスソスヌみ搾ソスソスだゑソスA
ソス]ソス[ソスソスソス]ソスソスソスソスソスソスソスソスロに使ソスpソスソスソスソスネゑソスソスソスソスニに抵ソスソスモゑソスソストゑソスソスソスソスソスソスソスソスBソスソスソスフ擾ソスソスソスソスフ暦ソスソスRソスソス
ソスソスソスソスソスフダソスCソスiソス~ソスbソスNソスXソスVソス@ソス\ソスナ奇ソスソスソスソスソスSOAソスソスソスソスソスソスソスRソス[ソスhソスフ意厄ソスソスソスマゑソスソスソスソス謔、ソスソス
ソスナゑソスソスB

3.3.14. TXT RDATA format
3.3.14. ソスeソスLソスXソスgソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスg

    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    /                   TXT-DATA                    /
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

where:

TXT-DATA        One or more <character-string>s.
ソスeソスLソスXソスgソスfソス[ソス^  ソスPソスツ以擾ソスソス<character-string>

TXT RRs are used to hold descriptive text.  The semantics of the text
depends on the domain where it is found.
ソスeソスLソスXソスgソスソスソスソスソスソスソスRソス[ソスhソスヘゑソスソスLソスqソスソスソスソスソスeソスLソスXソスgソスソスソスソスソスツゑソスソス゚に使ソスソスソスワゑソスソスBソスeソスLソスXソスg
ソスフ意厄ソスソスヘゑソスソス黷ェソスソスソスンゑソスソスソスhソスソスソスCソスソスソスノ暦ソスソスソスワゑソスソスB

3.4. Internet specific RRs
3.4. ソスCソスソスソス^ソス[ソスlソスbソスgソスソスソスLソスソスソスソスソスソスソスRソス[ソスh

3.4.1. A RDATA format
3.4.1. ソスAソスhソスソスソスXソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスg

    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    |                    ADDRESS                    |
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

where:

ADDRESS         A 32 bit Internet address.
ソスAソスhソスソスソスX        ソスRソスQソスrソスbソスgソスCソスソスソス^ソス[ソスlソスbソスgソスAソスhソスソスソスX

Hosts that have multiple Internet addresses will have multiple A
records.
ソスソスソスソスソスフイソスソスソス^ソス[ソスlソスbソスgソスAソスhソスソスソスXソスソスソスソスソスツホソスXソスgソスソスソスソスソスソスソスフAソスソスソスRソス[ソスhソスソスソスソスソスツでゑソスソス蛯、ソスB

A records cause no additional section processing.  The RDATA section of
an A line in a master file is an Internet address expressed as four
decimal numbers separated by dots without any imbedded spaces (e.g.,
"10.2.0.52" or "192.0.5.6").
ソス`ソスソスソスRソス[ソスhソスソスソスヌ会ソスソスソスソスフ擾ソスソスソスソスソスソスNソスソスソスソスソスワゑソスソスソスBソス}ソスXソス^ソス[ソスtソス@ソスCソスソスソスソスソスフアソスhソスソスソスXソスsソスソス
ソスソスソスソスソスfソス[ソス^ソスヘ包ソスソスヘ、ソスXソスyソス[ソスXソスソスソスソスソスhソスbソスgソスナ包ソスソスソスソスソスソス黷スソスSソスツの1ソスOソスiソスソスソスナ表ソスソスソスソスソス
ソスCソスソスソス^ソス[ソスlソスbソスgソスAソスhソスソスソスXソスナゑソスソスiソス痰ヲソスソス"10.2.0.52"ソスソス"192.0.5.6"ソスjソスB

3.4.2. WKS RDATA format
3.4.2. ソスdソスソスソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスg

    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    |                    ADDRESS                    |
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    |       PROTOCOL        |                       |
    +--+--+--+--+--+--+--+--+                       |
    |                                               |
    /                   <BIT MAP>                   /
    /                                               /
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

where:

ADDRESS         An 32 bit Internet address
ソスAソスhソスソスソスX        ソスRソスQソスrソスbソスgソスCソスソスソス^ソス[ソスlソスbソスgソスAソスhソスソスソスX

PROTOCOL        An 8 bit IP protocol number
ソスvソスソスソスgソスRソスソス      ソスWソスrソスbソスgソスhソスoソスvソスソスソスgソスRソスソスソスヤ搾ソス

<BIT MAP>       A variable length bit map.  The bit map must be a
                multiple of 8 bits long.
ソスrソスbソスgソス}ソスbソスv    ソスツ変抵ソスソスrソスbソスgソス}ソスbソスvソスBソスrソスbソスgソス}ソスbソスvソスヘ8ソスrソスbソスgソスフ倍ソスソスソスナゑソスソスB

The WKS record is used to describe the well known services supported by
a particular protocol on a particular internet address.  The PROTOCOL
field specifies an IP protocol number, and the bit map has one bit per
port of the specified protocol.  The first bit corresponds to port 0,
the second to port 1, etc.  If the bit map does not include a bit for a
protocol of interest, that bit is assumed zero.  The appropriate values
and mnemonics for ports and protocols are specified in [RFC-1010].
ソスdソスソスソスソスソスRソス[ソスhソスヘ難ソスソスソスフイソスソスソス^ソス[ソスlソスbソスgソスAソスhソスソスソスXソスソスナ難ソスソスソスフプソスソスソスgソスRソスソスソスフサソス|ソス[ソスg
ソスソスソスソスソスソスmソスTソス[ソスrソスXソスソスソスLソスqソスソスソス驍スソス゚に使ソスソスソスワゑソスソスBソスvソスソスソスgソスRソスソスソスtソスBソス[ソスソスソスhソスヘIソスoソスvソスソス
ソスgソスRソスソスソスヤ搾ソスソスソスソスwソス閧オソスワゑソスソスAソスrソスbソスgソス}ソスbソスvソスヘ指ソス閧ウソス黷スソスvソスソスソスgソスRソスソスソスフポソス[ソスgソスソスソスノ1
ソスrソスbソスgソスソスソスソスソスソスソスワゑソスソスBソスナ擾ソスソスフビソスbソスgソスヘポソス[ソスgソスOソスAソスQソスヤ目はポソス[ソスgソスPソスネどと対会ソスソスソスソスソス
ソスソスソスB ソスソスソスソスソスrソスbソスgソス}ソスbソスvソスソスソスmソス閧スソスソスソスvソスソスソスgソスRソスソスソスフビソスbソスgソスソスソスワまなゑソスソスネゑソスAソスソスソスソス
ソスrソスbソスgソスヘゼソスソスソスナゑソスソスソスニ思ソスソスソスワゑソスソスBソスKソスリな値ソスニポソス[ソスgソスフ厄ソスソスフとプソスソスソスgソスRソスソスソスソス
[RFC-1010]ソスナ指ソス閧ウソスソスワゑソスソスB

For example, if PROTOCOL=TCP (6), the 26th bit corresponds to TCP port
25 (SMTP).  If this bit is set, a SMTP server should be listening on TCP
port 25; if zero, SMTP service is not supported on the specified
address.
ソス痰ヲソスホ、ソスソスソスソスソスvソスソスソスgソスRソスソスソスソスソスsソスbソスoソスiソスUソスjソスネゑソスAソスソスQソスUソスヤ目のビソスbソスgソスヘTソスbソスoソス|ソス[
ソスgソスQソスTソスiソスrソスlソスsソスoソスjソスノ対会ソスソスソスソスワゑソスソスBソスソスソスソスソスソスソスフビソスbソスgソスソスソスZソスbソスgソスソスソスソスソスネゑソスAソスrソスlソスs
ソスoソスTソス[ソスoソス[ソスソスソスsソスbソスoソス|ソス[ソスgソスQソスTソスソスナ待ゑソスソストゑソスソスソスラゑソスソスナゑソスソスGソスソスソスソスソス[ソスソスソスネゑソスrソスlソスsソスo
ソスTソス[ソスrソスXソスソスソスwソス閧ウソス黷スソスAソスhソスソスソスXソスソスナサソス|ソス[ソスgソスソスソスソスワゑソスソスソスB

The purpose of WKS RRs is to provide availability information for
servers for TCP and UDP.  If a server supports both TCP and UDP, or has
multiple Internet addresses, then multiple WKS RRs are used.
ソスdソスソスソスソスソスソスソスソスソスRソス[ソスhソスフ目的ソスヘサソス[ソスoソス[ソスフTソスbソスoソスニUソスcソスoソスフ有ソスソスソスソスソスフ擾ソスソスソスpソスモゑソスソスソス
ソスソスソスニでゑソスソスBソスソスソスソスソスTソス[ソスoソス[ソスソスソスsソスbソスoソスニUソスcソスoソスフ暦ソスソスソスソスソスソスTソス|ソス[ソスgソスソスソスAソスソスソスソスソスフイソスソスソス^ソス[
ソスlソスbソスgソスAソスhソスソスソスXソスソスソスソスソスツなゑソスAソスソスソスソスソスフ仕ソスソスソスソスソスソスソスソスソスRソス[ソスhソスソスソスgソスソスソスワゑソスソスB

WKS RRs cause no additional section processing.
ソスdソスソスソスソスソスソスソスソスソスRソス[ソスhソスソスソスヌ会ソスソスソスソスフ擾ソスソスソスソスソスソスNソスソスソスソスソスワゑソスソスソスB

In master files, both ports and protocols are expressed using mnemonics
or decimal numbers.
ソス}ソスXソス^ソス[ソスtソス@ソスCソスソスソスナ、ソス|ソス[ソスgソスニプソスソスソスgソスRソスソスソスソスソスソスソスソスソスソスソスフゑソスソスPソスOソスiソスソスソスナ表ソスソスソスソスソスソスワゑソスソスB

3.5. IN-ADDR.ARPA domain
3.5. IN-ADDR.ARPAソスhソスソスソスCソスソス

The Internet uses a special domain to support gateway location and
Internet address to host mapping.  Other classes may employ a similar
strategy in other domains.  The intent of this domain is to provide a
guaranteed method to perform host address to host name mapping, and to
facilitate queries to locate all gateways on a particular network in the
Internet.
ソスCソスソスソス^ソス[ソスlソスbソスgソスヘゲソス[ソスgソスEソスFソスCソスフ場所ソスニイソスソスソス^ソス[ソスlソスbソスgソスAソスhソスソスソスXソスソスソスソスzソスXソスgソスヨゑソス
ソスマ奇ソスソスノ難ソスソスハなドソスソスソスCソスソスソスソスソスgソスソスソスワゑソスソスBソスソスソスフクソスソスソスXソスソスソスソスソスフドソスソスソスCソスソスソスナ類趣ソスソスフ包ソスソス@ソスソスソスg
ソスソスソスソスソスソスソスソスソスソスワゑソスソスソスBソスソスソスフドソスソスソスCソスソスソスヘホソスXソスgソスAソスhソスソスソスXソスソスソスソスzソスXソスgソスソスソスヨ変奇ソスソスソスソスソスロ擾ソス
ソスソスソス黷スソスソスソス@ソスフ提供と、ソスCソスソスソス^ソス[ソスlソスbソスgソスフ難ソスソスソスフネソスbソスgソスソスソス[ソスNソスフ擾ソスフゑソスソスラてのゲソス[
ソスgソスEソスFソスCソスフ場所ソスソスヒゑソスソス~ソス゚ゑソス竝ソスソスソスソスeソスユにゑソスソス驍アソスニゑソスソスソスソスAソスソスソスモ図ソスソスソスワゑソスソスB

Note that both of these services are similar to functions that could be
performed by inverse queries; the difference is that this part of the
domain name space is structured according to address, and hence can
guarantee that the appropriate data can be located without an exhaustive
search of the domain space.
ソスソスソスソスソスフサソス[ソスrソスXソスフ暦ソスソスソスソスソスソスtソス竝ソスソスソスナ趣ソスソスsソスナゑソスソスソス@ソス\ソスノ類趣ソスソスソスソストゑソスソス驍アソスニに抵ソスソスソス
ソスソスソストゑソスソスソスソスソスソスソスソスGソスソスソスソスヘドソスソスソスCソスソスソスソスソスソスヤのゑソスソスフ包ソスソスソスソスソスソスAソスhソスソスソスXソスノ従ソスソスソスト構ソスソスソスソスソスソスソスソス
ソストゑソスソスト、ソスソスソスソスフドソスソスソスCソスソスソスソスヤの徹ソスソスIソスネ探ソスソスソスネゑソスソスナ適ソスリなデソス[ソス^ソスフ場所ソスソスロ証ゑソス
ソス驍アソスニゑソスソスナゑソスソスソスニゑソスソスソスソスソスソスニでゑソスソスB

The domain begins at IN-ADDR.ARPA and has a substructure which follows
the Internet addressing structure.
ソスhソスソスソスCソスソスソスソスIN-ADDR.ARPAソスソスソスソスnソスワゑソスAソスCソスソスソス^ソス[ソスlソスbソスgソスAソスhソスソスソスXソス\ソスソスソスノ従ソスソスソス\ソスソスソスソス
ソスソスソスソスソスワゑソスソスB

Domain names in the IN-ADDR.ARPA domain are defined to have up to four
labels in addition to the IN-ADDR.ARPA suffix.  Each label represents
one octet of an Internet address, and is expressed as a character string
for a decimal value in the range 0-255 (with leading zeros omitted
except in the case of a zero octet which is represented by a single
zero).
IN-ADDR.ARPAソスhソスソスソスCソスソスソスフドソスソスソスCソスソスソスソスソスソスIN-ADDR.ARPAソスネ外ソスノ4ソスツのソスソスxソスソスソスソスソスソスソスソスソスソス
ソスソスソスBソスeソスソスソスxソスソスソスソスソスCソスソスソス^ソス[ソスlソスbソスgソスAソスhソスソスソスXソスフ1ソスIソスNソスeソスbソスgソスソス\ソスソスソスAソスOソスソスソスソスQソスTソスTソスソス
ソスヘ囲の1ソスOソスiソスソスソスlソスフ包ソスソスソスソスソスナ表ソスソスソスソスワゑソスソスBソスiソスソスソスフゼソスソスソスヘ省暦ソスソスソスソスソスワゑソスソスAソス[ソスソスソスフ値
ソスフオソスNソスeソスbソスgソスヘ暦ソスOソスナ1ソスツのゼソスソスソスナ表ソスソスソスワゑソスソスjソスB

Host addresses are represented by domain names that have all four labels
specified.  Thus data for Internet address 10.2.0.52 is located at
domain name 52.0.2.10.IN-ADDR.ARPA.  The reversal, though awkward to
read, allows zones to be delegated which are exactly one network of
address space.  For example, 10.IN-ADDR.ARPA can be a zone containing
data for the ARPANET, while 26.IN-ADDR.ARPA can be a separate zone for
MILNET.  Address nodes are used to hold pointers to primary host names
in the normal domain space.
ソスzソスXソスgソスAソスhソスソスソスXソスソスソスSソスツのソスソスxソスソスソスソスソスラてゑソスソスwソス閧ウソス黷スソスhソスソスソスCソスソスソスソスソスナ表ソスソスソスソスワゑソスソスBソスソス
ソスソスソスホイソスソスソス^ソス[ソスlソスbソスgソスAソスhソスソスソスX10.2.0.52ソスフデソス[ソス^ソスヘドソスソスソスCソスソスソスソス52.0.2.10.IN-ADDR.ARPA
ソスノゑソスソスソスワゑソスソスBソスtソスソスソスヘ読みにゑソスソスソスソスナゑソスソスソスソスAソスソスソスmソスノアソスhソスソスソスXソスソスヤで1ソスツのネソスbソスgソスソスソス[
ソスNソスソスソスマ任ソスソスソスソスソス]ソス[ソスソスソスソスソスソスソスソスソスワゑソスソスBソス痰ヲソスホ、10.IN-ADDR.ARPAソスソスARPANETソスフデソス[ソス^
ソスソスソスワむゾソス[ソスソスソスナ、26.IN-ADDR.ARPAソスソスMILNETソスフゑソスソス゚の別のゾソス[ソスソスソスナゑソスソスBソスAソスhソスソスソスX
ソスmソス[ソスhソスソスソスWソスソスソスhソスソスソスCソスソスソスソスヤの奇ソス{ソスzソスXソスgソスソスソスヨのポソスCソスソスソス^ソスソスソスソスソスツゑソスソス゚に使ソスソスソスワゑソスソスB

Network numbers correspond to some non-terminal nodes at various depths
in the IN-ADDR.ARPA domain, since Internet network numbers are either 1,
2, or 3 octets.  Network nodes are used to hold pointers to the primary
host names of gateways attached to that network.  Since a gateway is, by
definition, on more than one network, it will typically have two or more
network nodes which point at it.  Gateways will also have host level
pointers at their fully qualified addresses.
ソスCソスソスソス^ソス[ソスlソスbソスgソスlソスbソスgソスソスソス[ソスNソスヤ搾ソスソスヘ1ソスソスソスQソスソスソスRソスIソスNソスeソスbソスgソスネので、ソスlソスbソスgソスソスソス[ソスN
ソスヤ搾ソスソスソスIN-ADDR.ARPAソスhソスソスソスCソスソスソスフ趣ソスXソスネ深ソスソスソスフゑソスソスソスIソスソスソスナなゑソスソスmソス[ソスhソスノ対会ソスソスソスソスソス
ソスソスソスBソスlソスbソスgソスソスソス[ソスNソスmソス[ソスhソスソスソスソスソスフネソスbソスgソスソスソス[ソスNソスフゲソス[ソスgソスEソスFソスCソスフ奇ソス{ソスzソスXソスgソスソスソスヨゑソス
ソス|ソスCソスソスソス^ソスソスソスソスソスツゑソスソス゚に使ソスソスソスワゑソスソスBソスQソス[ソスgソスEソスFソスCソスソスソスソス`ソスソスlソスbソスgソスソスソス[ソスNソスノ1ソスツ茨ソス
ソス繧ソスソスフで、ソスソスハに2ソスツ以擾ソスフネソスbソスgソスソスソス[ソスNソスmソス[ソスhソスソスソスソスソスソスソスノ位置ソスソスソスソスナゑソスソス蛯、ソスB
ソスQソス[ソスgソスEソスFソスCソスソスソスソスソスSソスノ指ソス閧ウソス黷スソスAソスhソスソスソスXソスノゑソスソスzソスXソスgソスソスソスxソスソスソス|ソスCソスソスソス^ソスソスソスソスソスツゑソス
ソスソスソス蛯、ソスB

Both the gateway pointers at network nodes and the normal host pointers
at full address nodes use the PTR RR to point back to the primary domain
names of the corresponding hosts.
ソスlソスbソスgソスソスソス[ソスNソスmソス[ソスhソスフゲソス[ソスgソスEソスFソスCソス|ソスCソスソスソス^ソスニ奇ソスソスSソスネアソスhソスソスソスXソスmソス[ソスhソスフ茨ソスハホソスX
ソスgソスフ暦ソスソスソスソスナ対会ソスソスソスソスソスzソスXソスgソスフ奇ソス{ソスhソスソスソスCソスソスソスソスソスソスソスソスソス|ソスCソスソスソス^ソスソスソスソスソスソスソスRソス[ソスhソスソスソスgソスソスソスソス
ソスソスソスB

For example, the IN-ADDR.ARPA domain will contain information about the
ISI gateway between net 10 and 26, an MIT gateway from net 10 to MIT's
net 18, and hosts A.ISI.EDU and MULTICS.MIT.EDU.  Assuming that ISI
gateway has addresses 10.2.0.22 and 26.0.0.103, and a name MILNET-
GW.ISI.EDU, and the MIT gateway has addresses 10.0.0.77 and 18.10.0.4
and a name GW.LCS.MIT.EDU, the domain database would contain:
ソス痰ヲソスホ、IN-ADDR.ARPAソスhソスソスソスCソスソスソスソスソスAソスlソスbソスgソスPソスOソスニネソスbソスgソスQソスUソスフ間のIソスrソスhソスQソス[ソスg
ソスEソスFソスCソスフ擾ソスソスニ、ソスlソスbソスgソスPソスOソスニMソスhソスsソスフネソスbソスgソスPソスWソスフ間のMソスhソスsソスフゲソス[ソスgソスEソスFソスC
ソスフ擾ソスソスニ、ソスニホソスXソスgA.ISI.EDUソスソスMULTICS.MIT.EDUソスフ擾ソスソスソスソスソスソスツとゑソスソスワゑソスソスBソスhソスrソスh
ソスQソス[ソスgソスEソスFソスCソスフアソスhソスソスソスXソスソス10.2.0.22ソスソス26.0.0.103ソスナ厄ソスソスOソスソスMILNET- GW.ISI.EDU
ソスナ、ソスlソスhソスsソスQソス[ソスgソスEソスFソスCソスソス10.0.0.77ソスソス18.10.0.4ソスナ厄ソスソスOソスソスGW.LCS.MIT.EDUソスニゑソスソスソス
ソスニ、ソスhソスソスソスCソスソスソスfソス[ソス^ソスxソス[ソスXソスソスソスネ会ソスソスフ厄ソスソスOソスソスソスワみまゑソスソスFソスB

    10.IN-ADDR.ARPA.           PTR MILNET-GW.ISI.EDU.
    10.IN-ADDR.ARPA.           PTR GW.LCS.MIT.EDU.
    18.IN-ADDR.ARPA.           PTR GW.LCS.MIT.EDU.
    26.IN-ADDR.ARPA.           PTR MILNET-GW.ISI.EDU.
    22.0.2.10.IN-ADDR.ARPA.    PTR MILNET-GW.ISI.EDU.
    103.0.0.26.IN-ADDR.ARPA.   PTR MILNET-GW.ISI.EDU.

    77.0.0.10.IN-ADDR.ARPA.    PTR GW.LCS.MIT.EDU.
    4.0.10.18.IN-ADDR.ARPA.    PTR GW.LCS.MIT.EDU.
    103.0.3.26.IN-ADDR.ARPA.   PTR A.ISI.EDU.
    6.0.0.10.IN-ADDR.ARPA.     PTR MULTICS.MIT.EDU.

Thus a program which wanted to locate gateways on net 10 would originate
a query of the form QTYPE=PTR, QCLASS=IN, QNAME=10.IN-ADDR.ARPA.  It
would receive two RRs in response:
ソスlソスbソスgソスPソスOソスフゲソス[ソスgソスEソスFソスCソスフ場所ソスソスmソス閧スソスソスソスvソスソスソスOソスソスソスソスソスソスソス竝ソスソスソスソスソス=ソス|ソスCソスソスソス^ソスA
ソス竝ソスソスソスNソスソスソスX=ソスCソスソスソス^ソス[ソスlソスbソスgソスAソス竝ソスソスソスソス=10.IN-ADDR.ARPA.ソスフ問合ソスソスソスソスソスソスソスソスナゑソスソスソス
ソスソスソスBソスソスソスソスヘ回答で2ソスツの趣ソスソスソスソスソスソスRソス[ソスhソスソスソスけ趣ソスソスナゑソスソス蛯、ソスF

    10.IN-ADDR.ARPA.           PTR MILNET-GW.ISI.EDU.
    10.IN-ADDR.ARPA.           PTR GW.LCS.MIT.EDU.

The program could then originate QTYPE=A, QCLASS=IN queries for MILNET-
GW.ISI.EDU. and GW.LCS.MIT.EDU. to discover the Internet addresses of
these gateways.
ソスvソスソスソスOソスソスソスソスソスヘゲソス[ソスgソスEソスFソスCMILNET-GW.ISI.EDU.ソスニゲソス[ソスgソスEソスFソスCGW.LCS.MIT.EDU.
ソスフイソスソスソス^ソス[ソスlソスbソスgソスAソスhソスソスソスXソス発鯉ソスソスソスソス驍スソス゚に、ソスソスソス黷ゥソスソス竝ソスソスソスソスソス=ソスAソスhソスソスソスXソスA
ソス竝ソスソスソス^ソスCソスv=ソスCソスソスソス^ソス[ソスlソスbソスgソスフ問合ソスソスソスソスソスナゑソスソスワゑソスソスB

A resolver which wanted to find the host name corresponding to Internet
host address 10.0.0.6 would pursue a query of the form QTYPE=PTR,
QCLASS=IN, QNAME=6.0.0.10.IN-ADDR.ARPA, and would receive:
ソスCソスソスソス^ソス[ソスlソスbソスgソスzソスXソスgソスAソスhソスソスソスX10.0.0.6ソスノ対会ソスソスソスソスソスzソスXソスgソスソスソスソス]ソズソスソス]ソスソスソスoソスソスソスソス
ソスソスソスソスソスソスソス=ソス|ソスCソスソスソス^ソスAソス竝ソスソスソスNソスソスソスX=ソスCソスソスソス^ソス[ソスlソスbソスgソスAソス竝ソスソスソスソス=6.0.0.10.IN-ADDR.ARPA
ソスフ問合ソスソスソスソスソスソスソスAソスネ会ソスソスソスソスソスMソスソスソスソスナゑソスソス蛯、ソスF

    6.0.0.10.IN-ADDR.ARPA.     PTR MULTICS.MIT.EDU.

Several cautions apply to the use of these services:
ソスソスソスソスソスツゑソスソスフ警ソスソスソスソスソスソスソスソスソスフサソス[ソスrソスXソスフ使ソスpソスノ難ソスソストはまゑソスワゑソスソスF

   - Since the IN-ADDR.ARPA special domain and the normal domain
     for a particular host or gateway will be in different zones,
     the possibility exists that that the data may be inconsistent.
   - ソスソスソスソスzソスXソスgソスソスQソス[ソスgソスEソスFソスCソスソスIN-ADDR.ARPAソスソスソスハドソスソスソスCソスソスソスニ通擾ソスフドソスソスソスCソスソス
     ソスソスソスルなゑソスソスソスソス]ソス[ソスソスソスノゑソスソスソスフで、ソスfソス[ソス^ソスソスソスソスソスソスソスソスソストゑソスソスソスツ能ソスソスソスソスソスソスソスソスワゑソスソスB

   - Gateways will often have two names in separate domains, only
     one of which can be primary.
   - ソスQソス[ソスgソスEソスFソスCソスソスソスソスソスホゑソスソスホ別のドソスソスソスCソスソスソスフ2ソスツの厄ソスソスOソスソスソスソスソスツゑソスソスPソスツゑソスソスソスソスソスソスソス
     ソス{ソスナゑソスソスB

   - Systems that use the domain database to initialize their
     routing tables must start with enough gateway information to
     guarantee that they can access the appropriate name server.
   - ソスソスソス[ソスeソスBソスソスソスOソスeソス[ソスuソスソスソスソスソスソスソスソスソスソスソスソスソストドソスソスソスCソスソスソスfソス[ソス^ソスxソス[ソスXソスソスソスgソスソスソスVソスXソスeソスソス
     ソスソスソスAソスKソスリなネソス[ソスソスソスTソス[ソスoソス[ソスノアソスNソスZソスXソスナゑソスソス驍アソスニゑソスロ証ゑソスソス驍スソス゚に十ソスソスソスソス
     ソスQソス[ソスgソスEソスFソスCソスソスソスソスソスソスソスソスソスネゑソスソスソスホなゑソスワゑソスソスソスB

   - The gateway data only reflects the existence of a gateway in a
     manner equivalent to the current HOSTS.TXT file.  It doesn't
     replace the dynamic availability information from GGP or EGP.
   - ソスQソス[ソスgソスEソスFソスCソスfソス[ソス^ソスヘ鯉ソスソスンゑソスHOSTS.TXTソスtソス@ソスCソスソスソスニ難ソスソスソスソスソスソス@ソスナゲソス[ソスgソスEソスFソスC
     ソスフ托ソスソスンを反映ソスソスソス驍セソスソスソスナゑソスソスBソスソスソスソスヘGソスfソスoソスソスdソスfソスoソスソスソスソス_ソスCソスiソス~ソスbソスNソスノ有
     ソスソスソスネ擾ソスソスソスソスソスソスワゑソスソスソスB

3.6. Defining new types, classes, and special namespaces
3.6. ソスVソスソスソスソスソス^ソスCソスvソスAソスNソスソスソスXソスニ難ソスソスハな厄ソスソスOソスソスヤの抵ソス`

The previously defined types and classes are the ones in use as of the
date of this memo.  New definitions should be expected.  This section
makes some recommendations to designers considering additions to the
existing facilities.  The mailing list [email protected] is the
forum where general discussion of design issues takes place.
ソスOソスノ抵ソス`ソスソスソス黷スソスソスハとクソスソスソスXソスヘゑソスソスフソスソスソスソスフ難ソスソスtソスフ趣ソスソス_ソスナ使ソスpソスソスソスフゑソスソスフでゑソスソスBソスVソスソス
ソスソスソスソス`ソスソスソス\ソスzソスソスソスソスソスラゑソスソスナゑソスソスBソスソスソスフ章は奇ソスソスソスソス@ソス\ソスノ追会ソスソスソスソスlソスソスソスソスfソスUソスCソスiソス[ソスノゑソス
ソス髏ソスEソスソスソスソスソスワゑソスソスBソスソスソス[ソスソスソスソスソスOソスソスソスXソス[email protected]ソスヘデソスUソスCソスソスソスソスソス
ソスフ茨ソスハ的ソスネ論ソスcソスソスソスNソスソスソスソスtソスHソス[ソスソスソスソスソスナゑソスソスB

In general, a new type is appropriate when new information is to be
added to the database about an existing object, or we need new data
formats for some totally new object.  Designers should attempt to define
types and their RDATA formats that are generally applicable to all
classes, and which avoid duplication of information.  New classes are
appropriate when the DNS is to be used for a new protocol, etc which
requires new class-specific data formats, or when a copy of the existing
name space is desired, but a separate management domain is necessary.
ソスソスハに、ソスソスソスソスソスフオソスuソスWソスFソスNソスgソスフ新ソスソスソスソスソスソスソスソスソスfソス[ソス^ソスxソス[ソスXソスノ追会ソスソスソスソスソスロゑソスAソスソスソスソス
ソス黷ゥソスフまゑソスソスソスソスソスソスVソスソスソスソスソスIソスuソスWソスFソスNソスgソスノ新ソスソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスgソスソスKソスvソスニゑソスソス骼橸ソスA
ソスKソスリでゑソスソスBソスfソスUソスCソスiソス[ソスソスソスAソスソスハにゑソスソスラてのクソスソスソスXソスノ適ソスpソスナゑソスソスAソスソスソスフ重ソスソスソスソスソスソスソス
ソスソス謔、ソスノ、ソスソスハと趣ソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスgソスソスソス`ソスソスソス謔、ソスニ趣ソスソスンゑソスラゑソスソスナゑソスソスBソスVソスソス
ソスソスソスNソスソスソスXソスソスソスAソスcソスmソスrソスソスソスVソスソスソスソスソスNソスソスソスXソスソスソスソスフデソス[ソス^ソスtソスHソス[ソス}ソスbソスgソスソスKソスvソスニゑソスソスソスVソスソス
ソスソスソスvソスソスソスgソスRソスソスソスネどで使ソスソス黷ゥソスAソスソスソスソスソスフ厄ソスソスOソスソスヤの包ソスソスソスソスソスソスKソスvソスナ別の管暦ソスソスhソスソスソスCソスソス
ソスソスソスKソスvソスネ趣ソスソスAソスVソスソスソスソスソスソスハゑソスソスKソスリでゑソスソスB

New types and classes need mnemonics for master files; the format of the
master files requires that the mnemonics for type and class be disjoint.
ソスVソスソスソスソスソスソスハとクソスソスソスXソスソスソス}ソスXソス^ソス[ソスtソス@ソスCソスソスソスフゑソスソス゚に覚ソスソスソスユゑソスソスソスソスフゑソスKソスvソスニゑソスソスワゑソスソスG
ソス}ソスXソス^ソス[ソスtソス@ソスCソスソスソスフフソスHソス[ソス}ソスbソスgソスヘ趣ソスハとクソスソスソスXソスフ厄ソスソスフゑソスソスソスソスハ要ソスfソスソスソスソスソスソスソスネゑソスソスソス
ソスニゑソスvソスソスソスソスソスワゑソスソスB

TYPE and CLASS values must be a proper subset of QTYPEs and QCLASSes
respectively.
ソスソスハとクソスソスソスXソスlソスヘゑソスソス黷シソスソス竝ソスソスソスソスハと問合ソスソスソスNソスソスソスXソスフ適ソスリな包ソスソスソスソスWソスソスソスノ違いソスソス
ソスソスワゑソスソスソスB

The present system uses multiple RRs to represent multiple values of a
type rather than storing multiple values in the RDATA section of a
single RR.  This is less efficient for most applications, but does keep
RRs shorter.  The multiple RRs assumption is incorporated in some
experimental work on dynamic update methods.
ソスソスソスンのシソスXソスeソスソスソスヘ托ソスソスソスソスフ値ソスソスソスミとつの趣ソスソスソスソスソスソスRソス[ソスhソスフ趣ソスソスソスソスfソス[ソス^ソスノゑソスソスワゑソスソスソスソスA
ソズゑソスソス多ソスソスソスフ趣ソスハの値ソスソス\ソスソスソスソスソス゚に托ソスソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスソスソスgソスソスソスワゑソスソスBソスソスソスソスヘゑソスソスソス
ソストゑソスソスフアソスvソスソスソスPソス[ソスVソスソスソスソスソスナ鯉ソスソスソスソスソスソス痰「ソスナゑソスソスソスソスAソスソスソスソスソスソスソスRソス[ソスhソスソスソスソスソスZソスソスソスソスヤに包ソス
ソスソスソスワゑソスソスBソスソスソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスフ会ソスソスソスヘゑソスソスソスソスソス_ソスCソスiソス~ソスbソスNソスXソスVソスソスソス@ソスフ趣ソスソスソスソスIソスネ仕
ソスソスソスノ趣ソスソスソスソスソスソスソスワゑソスソスB

The present system attempts to minimize the duplication of data in the
database in order to insure consistency.  Thus, in order to find the
address of the host for a mail exchange, you map the mail domain name to
a host name, then the host name to addresses, rather than a direct
mapping to host address.  This approach is preferred because it avoids
the opportunity for inconsistency.
ソスソスソスンのシソスXソスeソスソスソスヘ茨ソスム撰ソスソスソスロ障すソス驍スソス゚デソス[ソス^ソスxソス[ソスXソスナデソス[ソス^ソスフ包ソスソスソスソスソスソスナ擾ソスソスノゑソス
ソス謔、ソスニ趣ソスソスンまゑソスソスBソスソスソスフゑソスソス゚ソスソス[ソスソスソスソスソスソスソスフゑソスソス゚のホソスXソスgソスAソスhソスソスソスXソスソスソスソスソスツゑソスソス驍スソス゚に、
ソスソスソス[ソスソスソスhソスソスソスCソスソスソスソスソスソスソスAソスhソスソスソスXソスノ抵ソスソスレ変奇ソスソスソスソスソスフではなゑソスソスAソスソスソス[ソスソスソスhソスソスソスCソスソスソスソスソスソスソスz
ソスXソスgソスソスソスノ、ソスzソスXソスgソスソスソスソスソスzソスXソスgソスAソスhソスソスソスXソスノ変奇ソスソスソスソスワゑソスソスBソスソスソスフ包ソスソス@ソスヘ不ソスソスソスソスソスフ可能ソスソス
ソスソスソスソスソスソスソスフで好ソスワゑソスワゑソスソスB

In defining a new type of data, multiple RR types should not be used to
create an ordering between entries or express different formats for
equivalent bindings, instead this information should be carried in the
body of the RR and a single type used.  This policy avoids problems with
caching multiple types and defining QTYPEs to match multiple types.
ソスVソスソスソスソスソス^ソスCソスvソスフデソス[ソス^ソスソスソス`ソスソスソスソスロに、ソスソスソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスソスハゑソスソスソスソスレ間に擾ソスソスソス
ソスソスソスツゑソスソスソスソスソスAソスソスソスソスソスソスソスム付ソスソスソスフ異なゑソスtソスHソス[ソス}ソスbソスgソスソス\ソスソスソスソスソス驍スソス゚に使ソスソスソスソスラゑソス
ソスナはゑソスソスソスワゑソスソスソスBソスソスソスフ擾ソスソスヘ趣ソスソスソスソスソスソスRソス[ソスhソス{ソスフで運ソスホゑソスAソスPソスツの趣ソスハゑソスソスgソスソスソスソス
ソスラゑソスソスナゑソスソスBソスソスソスフ包ソスソスjソスヘ托ソスソスソスソスフ趣ソスハのキソスソスソスbソスVソスソスソスニ托ソスソスソスソスフ趣ソスハに対会ソスソスソスソス髑ソス竝ソスソス
ソスソスハゑソスソス`ソスソスソスソスソスソスソスソスソスソスソスワゑソスソスB

For example, the original form of mail exchange binding used two RR
types one to represent a "closer" exchange (MD) and one to represent a
"less close" exchange (MF).  The difficulty is that the presence of one
RR type in a cache doesn't convey any information about the other
because the query which acquired the cached information might have used
a QTYPE of MF, MD, or MAILA (which matched both).  The redesigned
service used a single type (MX) with a "preference" value in the RDATA
section which can order different RRs.  However, if any MX RRs are found
in the cache, then all should be there.
ソス痰ヲソスホ、ソスソスソス[ソスソスソスソスソスソスソスフ鯉ソスソスXソスフ擾ソスソスソスソスヘ2ソスツの趣ソスソスソスソスソスソスRソス[ソスhソスソスソスgソスpソスソスソスAソスPソスツゑソスソスuソス゚ゑソスソスv
(MD)ソスソス\ソスソスソスAソスソスソスソスソスPソスツゑソスソスuソス゚ゑソスソスネゑソスソスv(MF)ソスソス\ソスソスソストゑソスソスワゑソスソスソスソスBソスソスソスソスソスソスソスソスソスニは、
ソスLソスソスソスbソスVソスソスソスソスソス得ゑソスソス竝ソスソスソスソスMFソスソスMDソスソスMAILAソスiソスソスソスソスソスノ茨ソスvソスjソスフどゑソスソスソスソスソス閧ヲソスソス
ソスフで、ソスLソスソスソスbソスVソスソスソスソスフ1ソスツの趣ソスソスソスソスソスソスRソス[ソスhソスソスハの托ソスソスンゑソスソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスフ托ソスソスソス
ソスノ関ゑソスソスソスソスソスソスソスソスソスソスソスネゑソスソスソスソスニでゑソスソスBソスマ更ソスソスソス黷スソスfソスUソスCソスソスソスヘ、ソスルなる資ソスソスソスソスソスRソス[ソスh
ソスヤに擾ソスソスソスソスtソスソスソスソスソスナゑソスソスソス謔、ソスノ趣ソスソスソスソスfソス[ソス^ソスソスソスノ優ソスソスxソスソスソスソスソスツ、ソスPソスツの趣ソスソス(MX)ソスソスソスg
ソスソスソスソスソスソスソスニでゑソスソスBソスソスソスソスMXソスソスソスソスソスソスソスRソス[ソスhソスソスソスLソスソスソスbソスVソスソスソスノゑソスソスソスネゑソスAソスSソストの趣ソスソスソスソスソスソスRソス[
ソスhソスソスソスLソスソスソスbソスVソスソスソスノゑソスソスソスナゑソスソス蛯、ソスB

4. MESSAGES
4. ソスソスソスbソスZソス[ソスW

4.1. Format
4.1. ソスtソスHソス[ソス}ソスbソスg

All communications inside of the domain protocol are carried in a single
format called a message.  The top level format of message is divided
into 5 sections (some of which are empty in certain cases) shown below:
ソスソスソスラてのドソスソスソスCソスソスソスvソスソスソスgソスRソスソスソスフ難ソスソスソスソスフ通信ソスヘソスソスbソスZソス[ソスWソスニ呼ばゑソスソスミとつのフソスHソス[
ソス}ソスbソスgソスナ運ソスホゑソスワゑソスソスBソスソスソスbソスZソス[ソスWソスフ最擾ソスハフソスHソス[ソス}ソスbソスgソスヘ以会ソスソスフ5ソスツの包ソスソスソスソスノ包ソスソスソス
ソスソスソスワゑソスソスiソスソスソス髟費ソスソスソスヘゑソスソスソス鼾ソスヘ具ソスナゑソスソスjソスF

    +---------------------+
    |     Header ソスwソスbソス_   |
    +---------------------+
    |     Question ソスソスソスソス   | the question for the name server
    +---------------------+ ソスlソス[ソスソスソスTソス[ソスoソスヨの問合ソスソス
    |     Answer  ソスソス    | RRs answering the question
    +---------------------+ ソス竝ソスソスソスフ回答の趣ソスソスソスソスソスソスRソス[ソスh
    |    Authority ソスソスソスソス   | RRs pointing toward an authority
    +---------------------+ ソスソスソスソスソスネネソス[ソスソスソスTソス[ソスoソスソスソスソスソスソスソスソスソスソスソスソスソスRソス[ソスh
    |    Additional ソスヌ会ソス  | RRs holding additional information
    +---------------------+ ソスヌ会ソスソスソスソスソスソスソスソスツ趣ソスソスソスソスソスソスRソス[ソスh

The header section is always present.  The header includes fields that
specify which of the remaining sections are present, and also specify
whether the message is a query or a response, a standard query or some
other opcode, etc.
ソスwソスbソス_ソスソスソスヘ擾ソスノ托ソスソスンゑソスソストゑソスソスワゑソスソスBソスwソスbソス_ソス[ソスヘどの包ソスソスソスソスソスソスソスソスンゑソスソス驍ゥソスAソスソスソスbソスZソス[ソスW
ソスソスソス竝ソスソスソスソスソス答ゑソスソスAソスWソスソスソスIソスネ問合ソスソスソスソスソスソスソスフ擾ソスソスソスソスソスソス明趣ソスソスソスソスソスtソスBソス[ソスソスソスhソスソスソスワみゑソス
ソスソスソスB

The names of the sections after the header are derived from their use in
standard queries.  The question section contains fields that describe a
question to a name server.  These fields are a query type (QTYPE), a
query class (QCLASS), and a query domain name (QNAME).  The last three
sections have the same format: a possibly empty list of concatenated
resource records (RRs).  The answer section contains RRs that answer the
question; the authority section contains RRs that point toward an
authoritative name server; the additional records section contains RRs
which relate to the query, but are not strictly answers for the
question.
ソスwソスbソス_ソス[ソスフ鯉ソスフ包ソスソスソスソスフ厄ソスソスOソスヘ標ソスソスソスIソスネ趣ソスソスソスナの使ソスソスソスソスソスソスソス逍スソスソスソスソスソスソスワゑソスソスソスソスBソスソスソスソス
ソスソスソスヘネソス[ソスソスソスTソス[ソスoソスヨの趣ソスソスソスソスソスLソスqソスソスソスソスtソスBソス[ソスソスソスhソスソスソスワゑソスナゑソスソスワゑソスソスBソスソスソスソスソスフフソスBソス[
ソスソスソスhソスヘ問合ソスソスソスソスハ(QTYPEソスjソスAソス竝ソスソスソスNソスソスソスXソスiQCLASSソスjソスニ問合ソスソスソスhソスソスソスCソスソスソスソス
ソスiQNAMEソスjソスナゑソスソスBソスソスフ3ソスツの包ソスソスソスソスヘ難ソスソスソスソスtソスHソス[ソス}ソスbソスgソスソスソスソスソスソスソスワゑソスソスFソスソスソスソスソスソスソスRソス[ソスh
ソスフソスソスXソスgソスナ具ソスフ趣ソスソスソスソスソスソスソスワゑソスソスBソス答包ソスソスヘ問合ソスソスソスノ難ソスソスソスソス骼托ソスソスソスソスソスRソス[ソスhソスソスソスワみまゑソスソスG
ソスソスソスソスソスソスソスヘ撰ソスソスソスソスネネソス[ソスソスソスTソス[ソスoソス[ソスソスソスソスソスソスソス|ソスCソスソスソスgソスフ趣ソスソスソスソスソスソスRソス[ソスhソスソスソスワみまゑソスソスAソスヌ会ソス
ソスソスソスRソス[ソスhソスソスソスヘ問合ソスソスソスノ関連ソスソスソストゑソスソス驍ェソスAソス竝ソスソスソスフ鯉ソスソスソスソスネ難ソスソスソスソスナはなゑソスソスソスソスソスソスソスソスRソス[
ソスhソスソスソスワみまゑソスソスB

4.1.1. Header section format
4.1.1. ソスwソスbソス_ソスソスソスtソスHソス[ソス}ソスbソスg

The header contains the following fields:
ソスwソスbソス_ソス[ソスヘ趣ソスソスフフソスBソス[ソスソスソスhソスソスソスワゑソスナゑソスソスワゑソスソスF

                                    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    |   RCODE   |
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    |                    QDCOUNT                    |
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    |                    ANCOUNT                    |
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    |                    NSCOUNT                    |
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    |                    ARCOUNT                    |
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

where:

ID              A 16 bit identifier assigned by the program that
                generates any kind of query.  This identifier is copied
                the corresponding reply and can be used by the requester
                to match up replies to outstanding queries.
ソスソスソスハ子          ソス竝ソスソスソス生撰ソスソスソスソスソスvソスソスソスOソスソスソスソスソスノゑソスソスソスト奇ソスソスソスソストゑソス黷スソスPソスUソスrソスbソスg
                ソスソスソスハ子ソスBソスソスソスフ趣ソスソスハ子ソスヘ対会ソスソスソスソス驩橸ソスソスソスノコソスsソス[ソスソスソスソスAソスソスソスソスソス未会ソス
                ソスソスソスフ趣ソスソスソスノ対会ソスソスソスソスソスソスソスフに使ソスpソスナゑソスソスワゑソスソスB

QR              A one bit field that specifies whether this message is a
                query (0), or a response (1).
ソスソスソスソス^ソスソス      ソスソスソスフソスソスbソスZソス[ソスWソスソスソスソスソスソスiソスOソスjソスソスソス答(ソスPソスjソスソスソスソスソスソスソスソスソスPソスrソスbソスg
                ソスtソスBソス[ソスソスソスhソスB

OPCODE          A four bit field that specifies kind of query in this
                message.  This value is set by the originator of a query
                and copied into the response.  The values are:
ソスIソスyソスソスソス[ソスVソスソスソスソスソスRソス[ソスh ソスソスソスフソスソスbソスZソス[ソスWソスフ趣ソスソスソスフ趣ソズゑソスソスソスソスソスソスSソスrソスbソスgソスtソスBソス[ソスソスソスhソスB
                ソスソスソスフ値ソスヘ趣ソスソスソスフ作成ソスメにつゑソスソスソスソスAソス答にコソスsソス[ソスソスソスソスワゑソスソスBソスl
                ソスヘ以会ソスソスナゑソスソスF

                0               a standard query (QUERY)
                0               ソスWソスソスソスIソスネ趣ソスソスソスiソスソスソスソスj

                1               an inverse query (IQUERY)
                1               ソスtソス竝ソスソスソスiソスtソスソスソスソスj

                2               a server status request (STATUS)
                2               ソスTソス[ソスoソスソスヤ要ソスソスソスiソスソスヤ)

                3-15            reserved for future use
                3-15            ソスソスソスソスソスフ使ソスpソスフゑソスソス゚に予ソスソスB

AA              Authoritative Answer - this bit is valid in responses,
                and specifies that the responding name server is an
                authority for the domain name in question section.
AA              ソスソスソスソスソスネ解答−ソスソスソスフビソスbソスgソスヘ回答で鯉ソスソスヘゑソスソスソスソスソスAソスソスソスソスソスソスソスソスソスlソス[ソスソス
                ソスTソス[ソスoソスソスソスソスソス笊費ソスフドソスソスソスCソスソスソスソスソスフ撰ソスソスソスソスネネソス[ソスソスソスTソス[ソスoソスソスソスソスソスソスソスソスソスソス
                ソスソスソスB

                Note that the contents of the answer section may have
                multiple owner names because of aliases.  The AA bit
                corresponds to the name which matches the query name, or
                the first owner name in the answer section.
                ソス答包ソスソスフ抵ソスソスgソスソスソスハ厄ソスソスフゑソスソス゚に托ソスソスソスソスフ擾ソスソスLソスメ厄ソスソスソスソスソスソスツゑソスソスソスソスソスソスソスソス
                ソスソスソスソスソスニに抵ソスソスモゑソスソストゑソスソスソスソスソスソスソスソスBソス`ソス`ソスrソスbソスgソスヘ趣ソスソスソスフ厄ソスソスOソスソスソスAソスソス
                ソスソスソスフ最擾ソスソスフ擾ソスソスLソスメ厄ソスソスノ対会ソスソスソスソスワゑソスソスB

TC              TrunCation - specifies that this message was truncated
                due to length greater than that permitted on the
                transmission channel.
TC              ソスリり落ソスソスソス|ソス`ソスソスソス`ソスソスソスソスソスlソスソスソスソスノ最大長ソスソス閭ソスbソスZソス[ソスWソスソスソスソスソスソスソスネゑソス
                ソスソスソスソスソス゚ゑソスソスフソスソスbソスZソス[ソスWソスソスソスリり落ソスニゑソスソス黷スソスソスソスニゑソスソスソスソスソスソスワゑソスソスB

RD              Recursion Desired - this bit may be set in a query and
                is copied into the response.  If RD is set, it directs
                the name server to pursue the query recursively.
                Recursive query support is optional.
RD              ソスト帰ソスvソス]ソス|ソスソスソスフビソスbソスgソスヘ問合ソスソスソスナ設定さソスソスAソス答にコソスsソス[ソスソスソスソス
                ソスワゑソスソスBソスソスソスソスソスト帰ソスvソス]ソスソスソスン定さソスソスソスネゑソスAソスlソス[ソスソスソスTソス[ソスoソスノ再帰ソスソス
                ソスソスソスソスソスソスvソス]ソスソスソスワゑソスソスBソスト帰ソス答のサソス|ソス[ソスgソスヘ任ソスモでゑソスソスB

RA              Recursion Available - this be is set or cleared in a
                response, and denotes whether recursive query support is
                available in the name server.
RA              ソスト帰ソスツ能ソス|ソスソスソスソスヘ回答で設定かソスNソスソスソスAソスソスソスソスAソスlソス[ソスソスソスTソス[ソスoソスソスソスソス
                ソスAソスIソス竝ソスソスソスソスソスTソス|ソス[ソスgソスソスソス驍ゥソスヌゑソスソスソスソスソスソスソスソスソスソスワゑソスソスB

Z               Reserved for future use.  Must be zero in all queries
                and responses.
Z               ソスソスソスソスソスフ使ソスpソスフゑソスソス゚に予ソスさゑソスワゑソスソスソスソスBソスソスソスラての趣ソスソスソスニ回答でゼ
                ソスソスソスナゑソスソスソスノ違いソスソスソスソスワゑソスソスソスB

RCODE           Response code - this 4 bit field is set as part of
                responses.  The values have the following
                interpretation:
ソス答コソス[ソスh      ソス答コソス[ソスhソス|ソスソスソスフ4ソスrソスbソスgソスtソスBソス[ソスソスソスhソスヘ回答の一部ソスニゑソスソスト設抵ソス
                ソスソスソスソスワゑソスソスBソスlソスフ会ソスソス゚は趣ソスソスフ通ゑソスナゑソスソスFソスB

                0               No error condition
                0               ソスGソスソスソス[ソスヘゑソスソス閧ソスワゑソスソスソス

                1               Format error - The name server was
                                unable to interpret the query.
                1               ソスtソスHソス[ソス}ソスbソスgソスGソスソスソス[ソス|ソスBソスlソス[ソスソスソスTソス[ソスoソス[ソスヘ厄ソス
                                ソスソスソスソスソスフ翻ソスがでゑソスソスワゑソスソスソスナゑソスソスソスソスB

                2               Server failure - The name server was
                                unable to process this query due to a
                                problem with the name server.
                2               ソスTソス[ソスoソス[ソスソスソスsソス|ソスソスソスOソスTソス[ソスoソス[ソスヘネソス[ソスソスソスTソス[ソスoソス[
                                ソスノゑソスソスソスソスソスソスソスフゑソスソス゚にゑソスソスフ問合ソスソスソスソスソスソスソスソスソスソスソスソス
                                ソスソスソスニゑソスソスナゑソスソスワゑソスソスソスナゑソスソスソスソスB

                3               Name Error - Meaningful only for
                                responses from an authoritative name
                                server, this code signifies that the
                                domain name referenced in the query does
                                not exist.
                3               ソスソスソスOソスGソスソスソス[ソス|ソス答の撰ソスソスソスソスネネソス[ソスソスソスTソス[ソスoソス[ソスソス
                                ソスソスソスモ厄ソスソスソスソスソスソスソスワゑソスソスAソスソスソスフコソス[ソスhソスヘ問合ソスソスソスナ参
                                ソスニゑソスソス黷スソスhソスソスソスCソスソスソスソスソスソスソスソスソスンゑソスソスネゑソスソスソスソスニゑソスソスソスソスソス
                                ソスワゑソスソスB

                4               Not Implemented - The name server does
                                not support the requested kind of query.
                4               ソスソスソスソスソスソスソスソストゑソスソスネゑソスソス|ソスlソス[ソスソスソスTソス[ソスoソスヘ具ソスソス゚ゑソスソス
                                ソスソスソスソズの問合ソスソスソスソスソスTソス|ソス[ソスgソスソスソスワゑソスソスソスB

                5               Refused - The name server refuses to
                                perform the specified operation for
                                policy reasons.  For example, a name
                                server may not wish to provide the
                                information to the particular requester,
                                or a name server may not wish to perform
                                a particular operation (e.g., zone
                                transfer) for particular data.
                5               ソスソスソスロ−ソスlソス[ソスソスソスTソス[ソスoソス[ソスヘポソスソスソスVソス[ソスIソスネ暦ソスソスRソスソス
                                ソスwソス閧ウソス黷スソスIソスyソスソスソス[ソスVソスソスソスソスソスフ趣ソスソスsソスソスソスソスソスロゑソスソスソス
                                ソスソスソスBソス痰ヲソスホ、ソスlソス[ソスソスソスTソス[ソスoソス[ソスソスソスソスソスソスフ問合ソスソス
                                ソスメに擾ソスソスフ具ソスソスソスソスソス]ソスワなゑソスソスソスソスソスソスソスAソスlソス[ソスソスソスTソス[
                                ソスoソス[ソスソスソスソスソスソスフデソス[ソス^ソスフ難ソスソスソスフオソスyソスソスソス[ソスVソスソスソスソス
                                ソスiソス痰ヲソスホゾソス[ソスソスソス]ソスソスソスjソスソス]ソスワなゑソスソスソスソスソスソスソスソスソスソス
                                ソスソスソスソスB

                6-15            Reserved for future use.
                6-15            ソスソスソスソスソスフ使ソスpソスフゑソスソス゚に予ソスソス

QDCOUNT         an unsigned 16 bit integer specifying the number of
                entries in the question section.
QDCOUNT         ソスソスソス笊費ソスフ搾ソスソスレ撰ソスソスソスソスソスソスソスソスソスソスソスソスネゑソスソスPソスUソスrソスbソスgソスフ撰ソスソスソス

ANCOUNT         an unsigned 16 bit integer specifying the number of
                resource records in the answer section.
ANCOUNT         ソス答包ソスソスフ搾ソスソスレ撰ソスソスソスソスソスソスソスソスソスソスソスソスネゑソスソスPソスUソスrソスbソスgソスフ撰ソスソスソス

NSCOUNT         an unsigned 16 bit integer specifying the number of name
                server resource records in the authority records
                section.
NSCOUNT         ソスソスソスソスソスソスソスフネソス[ソスソスソスTソス[ソスoソスソスソスソスソスソスソスRソス[ソスhソスフ撰ソスソスソスソスソスソスソスソスソスソスソスソスネゑソスソスPソスU
                ソスrソスbソスgソスフ撰ソスソスソス

ARCOUNT         an unsigned 16 bit integer specifying the number of
                resource records in the additional records section.
ARCOUNT         ソスヌ会ソスソスソスソスフ搾ソスソスレ撰ソスソスソスソスソスソスソスソスソスソスソスソスネゑソスソスPソスUソスrソスbソスgソスフ撰ソスソスソス

4.1.2. Question section format
4.1.2. ソスソスソス笊費ソスtソスHソス[ソス}ソスbソスg

The question section is used to carry the "question" in most queries,
i.e., the parameters that define what is being asked.  The section
contains QDCOUNT (usually 1) entries, each of the following format:
ソスソスソス笊費ソスヘゑソスソスソスソストゑソスソスフ問合ソスソスソスナ「ソスソスソスソスvソスソスソス^ソスヤゑソスソス゚に使ソスソスソスAソスソスソスソスソスqソスヒゑソスソストゑソスソスソス
ソスソスソスソスソス`ソスソスソスワゑソスソスBソスソスソスフ包ソスソスソスソスソスQDCOUNTソスツ(ソスハ擾ソスPソスツ)ソスフ搾ソスソスレゑソスソスワみ、ソスソスソスフフソスHソス[
ソス}ソスbソスgソスナゑソスソスF

                                    1  1  1  1  1  1
      0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    |                                               |
    /                     QNAME ソスソスソス笆シ              /
    /                                               /
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    |                     QTYPE ソス竝ソスソスソスソスソス          |
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    |                     QCLASS ソス竝ソスソスソスNソスソスソスX       |
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

where:

QNAME           a domain name represented as a sequence of labels, where
                each label consists of a length octet followed by that
                number of octets.  The domain name terminates with the
                zero length octet for the null label of the root.  Note
                that this field may be an odd number of octets; no
                padding is used.
ソスソスソス笆シ          ソスソスソスxソスソスソスフ連ソスソスソスナゑソスソスソスhソスソスソスCソスソスソスソスソスAソスeソスソスソスxソスソスソスソスソスIソスNソスeソスbソスgソスソスソスニ、
                ソスソスソスフ撰ソスソスソスソスソスソスフオソスNソスeソスbソスgソスソスソス逅ャソス阯ァソスソスソスワゑソスソスBソスhソスソスソスCソスソスソスソスソスヘソスソス[
                ソスgソスソスソスモ厄ソスソスソスソスソス[ソスソスソスフ値ソスフ抵ソスソスソスソスIソスNソスeソスbソスgソスナ終ソスソスソスワゑソスソスBソスソスソスソス
                ソスtソスBソス[ソスソスソスhソスソスソス数ソスIソスNソスeソスbソスgソスソスソスソスソスソスソスソスネゑソスソスソスソスニに抵ソスソスモゑソスソストゑソスソスソス
                ソスソスソスソスソスGソスQソスIソスNソスeソスbソスgソスPソスハにゑソスソスソスネどの位置ソスソスソスソスソスソスソスソスソスソスワゑソスソスソスB

QTYPE           a two octet code which specifies the type of the query.
                The values for this field include all codes valid for a
                TYPE field, together with some more general codes which
                can match more than one type of RR.
ソス竝ソスソスソスソスソス      ソス竝ソスソスソスソスハゑソスソスwソス閧キソスソスQソスIソスNソスeソスbソスgソスRソス[ソスhソスBソスソスソスフフソスBソス[ソスソスソスhソスソス
                ソスSソストの撰ソスソスソスソスネ趣ソスハ値ソスソスソスAソスソスソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスノ茨ソスvソスソスソス驍ソスソスソス
                ソスハ的ソスネ趣ソスハ値ソスナゑソスソスB

QCLASS          a two octet code that specifies the class of the query.
                For example, the QCLASS field is IN for the Internet.
ソス竝ソスソスソスNソスソスソスX    ソスソスソスソスNソスソスソスXソスソスソスソスソスソスソスQソスIソスNソスeソスbソスgソスRソス[ソスhソスBソス痰ヲソスホイソスソスソス^ソス[ソスlソスbソスg
                ソスナは趣ソスソスソスNソスソスソスXソスtソスBソス[ソスソスソスhソスソスINソスソスソスン定さソスソスソスB

4.1.3. Resource record format
4.1.3. ソスソスソスソスソスソスソスRソス[ソスhソスtソスHソス[ソス}ソスbソスg

The answer, authority, and additional sections all share the same
format: a variable number of resource records, where the number of
records is specified in the corresponding count field in the header.
Each resource record has the following format:
ソス答包ソスソスニ撰ソスソスソスソスソスソスニ追会ソスソスソスソスヘゑソスソスラて難ソスソスソスソスtソスHソス[ソス}ソスbソスgソスソスソスソスソスLソスソスソスワゑソスソスFソスツ変個の趣ソスソスソス
ソスソスソスRソス[ソスhソスAソスソスソスRソス[ソスhソスソスソスソスソスwソスbソス_ソス[ソスフ対会ソスソスソスソスソスJソスEソスソスソスgソスtソスBソス[ソスソスソスhソスナ指ソス閧ウソスソスワゑソスソスB
ソスeソスソスソスソスソスソスソスRソス[ソスhソスソスソスソスソスフフソスHソス[ソス}ソスbソスgソスソスソスソスソスソスソスワゑソスソスFソスB

                                    1  1  1  1  1  1
      0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    |                                               |
    /                                               /
    /                      NAME ソスソスソスO                /
    |                                               |
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    |                      TYPE ソスソスソス                |
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    |                     CLASS ソスNソスソスソスX              |
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    |                      TTL ソスソスソスソスソスソスソスソス             |
    |                                               |
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    |                   RDLENGTH ソスソスソスソスソスfソス[ソス^ソスソス       |
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--|
    /                     RDATA ソスソスソスソスソスfソス[ソス^          /
    /                                               /
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

where:

NAME            a domain name to which this resource record pertains.
ソスソスソスO            ソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスノ関係ソスソスソスソスhソスソスソスCソスソスソスソスソスB

TYPE            two octets containing one of the RR type codes.  This
                field specifies the meaning of the data in the RDATA
                field.
ソスソスソス            ソスPソスツの趣ソスソスソスソスソスソスRソス[ソスhソスソスハゑソスソスワむ2ソスIソスNソスeソスbソスgソスBソスソスソスフフソスBソス[ソスソスソスh
                ソスヘ趣ソスソスソスソスfソス[ソス^ソスtソスBソス[ソスソスソスhソスフデソス[ソス^ソスフ意厄ソスソスソスソスwソス閧オソスワゑソスソスB

CLASS           two octets which specify the class of the data in the
                RDATA field.
ソスNソスソスソスX          ソスソスソスfソス[ソス^ソスtソスBソス[ソスソスソスhソスフデソス[ソス^ソスフクソスソスソスXソスソスソスwソス閧キソスソスQソスIソスNソスeソスbソスgソスB

TTL             a 32 bit unsigned integer that specifies the time
                interval (in seconds) that the resource record may be
                cached before it should be discarded.  Zero values are
                interpreted to mean that the RR can only be used for the
                transaction in progress, and should not be cached.
ソスソスソスソスソスソスソスソス        ソスソスソスソスソスソスソスRソス[ソスhソスソスソスLソスソスソスbソスVソスソスソスソスソストゑソスソスソスソストよいソスソスソスヤ(ソスbソスPソスハ)ソスソスソスソス
                ソスソスソスRソスQソスrソスbソスgソスソスソスソスソスネゑソスソスソスソスソスソスBソス[ソスソスソスフ値ソスソスソスソスソスソスソスソスソスRソス[ソスhソスソスソスソスソスワ進
                ソスsソスソスソスフ擾ソスソスソスソスナのみ使ソスソスソスト、ソスLソスソスソスbソスVソスソスソスソスソスラゑソスソスナはなゑソスソスソスソスニゑソスソスソス
                ソスソスソスソスソスワゑソスソスB

RDLENGTH        an unsigned 16 bit integer that specifies the length in
                octets of the RDATA field.
ソスソスソスソスソスfソス[ソス^ソスソス    ソスソスソスソスソスfソス[ソス^ソスtソスBソス[ソスソスソスhソスフオソスNソスeソスbソスgソスPソスハの抵ソスソスソスソスソスソスwソス閧キソス髟ソスソス
                ソスネゑソスソスフ1ソスUソスrソスbソスgソスフ撰ソスソスソスソスB

RDATA           a variable length string of octets that describes the
                resource.  The format of this information varies
                according to the TYPE and CLASS of the resource record.
                For example, the if the TYPE is A and the CLASS is IN,
                the RDATA field is a 4 octet ARPA Internet address.
ソスソスソスソスソスfソス[ソス^      ソスソスソスソスソスソスソスLソスqソスソスソスソスIソスNソスeソスbソスgソスPソスハの可変抵ソスソスソスソスソスソスソスBソスソスソスフ擾ソスソスソス
                ソスtソスHソス[ソス}ソスbソスgソスヘ趣ソスソスソスソスソスソスRソス[ソスhソスソスハとクソスソスソスXソスノ従ソスソスソスト変会ソスソスソスソスワゑソスソスB
                ソス痰ヲソスホ、ソスソスソスソスソスソスハゑソスソス`ソスナクソスソスソスXソスソスINソスネら資ソスソスソスfソス[ソス^ソスtソスBソス[ソスソスソスh
                ソスヘ4ソスIソスNソスeソスbソスgソスソスARPAソスCソスソスソス^ソス[ソスlソスbソスgソスAソスhソスソスソスXソスナゑソスソスソスB

4.1.4. Message compression
4.1.4. ソスソスソスbソスZソス[ソスWソスソスソスk

In order to reduce the size of messages, the domain system utilizes a
compression scheme which eliminates the repetition of domain names in a
message.  In this scheme, an entire domain name or a list of labels at
the end of a domain name is replaced with a pointer to a prior occurance
of the same name.
ソスソスソスbソスZソス[ソスWソスフ大きソスソスソスソスソスソスソス轤キソスソスソス゚に、ソスhソスソスソスCソスソスソスVソスXソスeソスソスソスヘソスソスbソスZソス[ソスWソスフドソスソスソスCソスソス
ソスソスソスフ費ソスソスソスソスソスソス除ソスソスソス驤ウソスkソストを利用ソスソスソスワゑソスソスBソスソスソスフ案で終ソスソス閧ェソスソスソスソスソスhソスソスソスCソスソスソスソスソス窿
ソスxソスソスソスフソスソスXソスgソスナ、ソスhソスソスソスCソスソスソスソスソスフ終ソスソス閧ェソスソスソスソスソスソスソスOソスフ対会ソスソスソスソス髟費ソスソスソスヨのポソスCソスソスソス^ソスソス
ソスuソスソスソスソスソスソスソスソスソスワゑソスソスB

The pointer takes the form of a two octet sequence:
ソス|ソスCソスソスソス^ソス[ソスヘ2ソスIソスNソスeソスbソスgソス`ソスソスソスソスソスニゑソスワゑソスソスF

    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    | 1  1|                OFFSET ソスIソスtソスZソスbソスg        |
    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

The first two bits are ones.  This allows a pointer to be distinguished
from a label, since the label must begin with two zero bits because
labels are restricted to 63 octets or less.  (The 10 and 01 combinations
are reserved for future use.)  The OFFSET field specifies an offset from
the start of the message (i.e., the first octet of the ID field in the
domain header).  A zero offset specifies the first byte of the ID field,
etc.
ソスナ擾ソスソスフ2ソスrソスbソスgソスヘ1ソスナゑソスソスBソスソスソスxソスソスソスソスソスUソスRソスIソスNソスeソスbソスgソスネ会ソスソスノ鯉ソスソス閧ウソスソスQソスフゼソスソスソスフビソスb
ソスgソスソスソスソスnソスワる事ソスソスソスソスAソスソスソスxソスソスソスニポソスCソスソスソス^ソスソスソスソスハでゑソスソスワゑソスソスBソスiソスPソスOソスニ0ソスPソスフ組ソスソスソスソス
ソスヘ厄ソスソスソスソスフ使ソスpソスフゑソスソス゚に予ソスさゑソスワゑソスソスBソスjソスIソスtソスZソスbソスgソスtソスBソス[ソスソスソスhソスヘソスソスbソスZソス[ソスWソスフ搾ソス
ソスソスソスiソスhソスソスソスCソスソスソスwソスbソス_ソスフ趣ソスソスハ子ソスtソスBソス[ソスソスソスhソスフ最擾ソスソスフオソスNソスeソスbソスgソスjソスソスソスソスフオソスtソスZソスbソスg
ソスソスソスソスソスソスソスワゑソスソスBソス[ソスソスソスIソスtソスZソスbソスgソスソスソスソスソスハ子ソスtソスBソス[ソスソスソスhソスフ最擾ソスソスフバソスCソスgソスソスソスwソス閧オソスワゑソスソスB

The compression scheme allows a domain name in a message to be
represented as either:
ソスソスソスkソストはソスソスbソスZソス[ソスWソスフドソスソスソスCソスソスソスソスソスソスソスネ会ソスソスフゑソスソスソスソス黷ゥソスナ表ソスソスソスソスソス驍アソスニゑソスソスソスソスソスソスワゑソスソスF

   - a sequence of labels ending in a zero octet
   - ソス[ソスソスソスフ値ソスフオソスNソスeソスbソスgソスナ終ソスソス驛会ソスxソスソスソスソスB

   - a pointer
   - ソス|ソスCソスソスソス^ソスB

   - a sequence of labels ending with a pointer
   - ソス|ソスCソスソスソス^ソスナ終ソスソス驛会ソスxソスソスソスソスB

Pointers can only be used for occurances of a domain name where the
format is not class specific.  If this were not the case, a name server
or resolver would be required to know the format of all RRs it handled.
As yet, there are no such cases, but they may occur in future RDATA
formats.
ソス|ソスCソスソスソス^ソスソスソスtソスHソス[ソス}ソスbソスgソスソスソスNソスソスソスXソスソスソスLソスナなゑソスソスhソスソスソスCソスソスソスソスソスナゑソスソスソスソスgソスソスソスワゑソスソスBソスソスソスソスソスソス
ソスネゑソスソスソスホ、ソスlソス[ソスソスソスTソス[ソスoソス[ソス窿奇ソス]ソスソスソスoソスソスソスソスソスソスソスソスソスソスソスソスソスラての趣ソスソスソスソスソスソスRソス[ソスhソスフフソスHソス[
ソス}ソスbソスgソスソスmソスソス謔、ソスノ要ソスソスソスソスソスソスソスナゑソスソス蛯、ソスBソスワゑソスソスAソスソスソスフようソスネケソス[ソスXソスヘゑソスソスソスワゑソスソスソス
ソスソスソスAソスソスソスソスソスソスソスソスソスソスソスフ趣ソスソスソスソスfソス[ソス^ソスtソスHソス[ソス}ソスbソスgソスナ起ソスソスソス驍ゥソスソスソスソスソスソスワゑソスソスソスB

If a domain name is contained in a part of the message subject to a
length field (such as the RDATA section of an RR), and compression is
used, the length of the compressed name is used in the length
calculation, rather than the length of the expanded name.
ソスソスソスソスソスhソスソスソスCソスソスソスソスソスソスソスiソスソスソスソスソスソスソスRソス[ソスhソスフ趣ソスソスソスソスfソス[ソス^ソスソスソスフようソスネ)ソスソスソスbソスZソス[ソスWソスソスソスフ抵ソスソスソス
ソスtソスBソス[ソスソスソスhソスフ適ソスpソスソスソスける部ソスソスソスノゑソスソスソスAソスソスソスkソスソスソスgソスソスソスソスネゑソスAソスソスソスソスソスvソスZソスナ茨ソスソスkソスソス
ソス黷スソスソスソスOソスソスソスgソスソスソスAソスWソスJソスソスソス黷スソスソスソスOソスフ抵ソスソスノはなゑソスワゑソスソスソスB

Programs are free to avoid using pointers in messages they generate,
although this will reduce datagram capacity, and may cause truncation.
However all programs are required to understand arriving messages that
contain pointers.
ソスvソスソスソスOソスソスソスソスソスヘ撰ソスソスソスソスソスソス驛ソスbソスZソス[ソスWソスナポソスCソスソスソス^ソスソスソスソスソスソスソスフは趣ソスソスRソスナゑソスソスソスソスBソスソスソスkソスヘデソス[
ソス^ソスOソスソスソスソスソスeソスハゑソスソスソスソス轤オソスAソスソスソスbソスZソス[ソスWソスフ鯉ソスソスフ切り落ソスソスソスソスソスソスソスソスソスナゑソスソス蛯、ソスBソスソスソスソスソスソスソスA
ソスソスソスラてのプソスソスソスOソスソスソスソスソスヘポソスCソスソスソス^ソスソスソスワむ難ソスソスソスソスソスソスbソスZソス[ソスWソス理会ソスソスソスソスソス謔、ソスノ要ソスソスソスソスソスソス
ソスワゑソスソスB

For example, a datagram might need to use the domain names F.ISI.ARPA,
FOO.F.ISI.ARPA, ARPA, and the root.  Ignoring the other fields of the
message, these domain names might be represented as:
ソス痰ヲソスホ、ソスfソス[ソス^ソスOソスソスソスソスソスソスソスhソスソスソスCソスソスソスソスF.ISI.ARPAソスソスFOO.F.ISI.ARPAソスソスARPAソスニソスソス[ソスg
ソスソスソスgソスソスソスKソスvソスソスソスソスソス驍ゥソスソスソスソスソスソスワゑソスソスソスBソスソスソスbソスZソス[ソスWソスフ托ソスソスフフソスBソス[ソスソスソスhソス無趣ソスソスソスソスソスニ、
ソスソスソスソスソスフドソスソスソスCソスソスソスソスソスフ以会ソスソスフようソスノ表ソスソスソスソスソスソス驍ゥソスソスソスソスソスソスワゑソスソスソスFソスB

       +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    20 |           1           |           F           |
       +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    22 |           3           |           I           |
       +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    24 |           S           |           I           |
       +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    26 |           4           |           A           |
       +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    28 |           R           |           P           |
       +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    30 |           A           |           0           |
       +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

       +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    40 |           3           |           F           |
       +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    42 |           O           |           O           |
       +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    44 | 1  1|                20                       |
       +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

       +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    64 | 1  1|                26                       |
       +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

       +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    92 |           0           |                       |
       +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

The domain name for F.ISI.ARPA is shown at offset 20.  The domain name
FOO.F.ISI.ARPA is shown at offset 40; this definition uses a pointer to
concatenate a label for FOO to the previously defined F.ISI.ARPA.  The
domain name ARPA is defined at offset 64 using a pointer to the ARPA
component of the name F.ISI.ARPA at 20; note that this pointer relies on
ARPA being the last label in the string at 20.  The root domain name is
defined by a single octet of zeros at 92; the root domain name has no
labels.
ソスhソスソスソスCソスソスソスソスF.ISI.ARPAソスソスソスIソスtソスZソスbソスgソスQソスOソスノゑソスソスソスワゑソスソスBソスhソスソスソスCソスソスソスソスFOO.F.ISI.ARPA
ソスソスソスIソスtソスZソスbソスgソスSソスOソスノゑソスソスソスワゑソスソスGソスソスソスフ抵ソス`ソスヘ前ソスノ抵ソス`ソスソスソス黷スF.ISI.ARPAソスソスFOOソスソスソスx
ソスソスソスソスAソスソスソスソスソスソス|ソスCソスソスソス^ソスソスソスgソスソスソスワゑソスソスBソスhソスソスソスCソスソスソスソスARPAソスソスソスIソスtソスZソスbソスgソスUソスSソスナ抵ソス`ソスソスソスソスA
ソスソスソスOF.ISI.ARPAソスソスARPAソスソスソスヨのポソスCソスソスソス^ソスソスソスgソスソスソスワゑソスソスGARPAソスノ関ゑソスソス驍アソスフポソスCソスソスソス^ソスソス
ソスQソスOソスフ包ソスソスソスソスソスフ最鯉ソスフソスソスxソスソスソスヨのポソスCソスソスソス^ソスナゑソスソス骼厄ソスノ抵ソスソスモゑソスソストゑソスソスソスソスソスソスソスソスBソスソスソス[ソスg
ソスhソスソスソスCソスソスソスソスソスヘオソスtソスZソスbソスgソスXソスQソスナゼソスソスソスフ値ソスフ1ソスIソスNソスeソスbソスgソスナ抵ソス`ソスソスソスソスワゑソスソスGソスソスソス[ソスg
ソスhソスソスソスCソスソスソスソスソスヘソスソスxソスソスソスソスソスソスソスソスソスワゑソスソスソスB

4.2. Transport
4.2. ソス]ソスソス

The DNS assumes that messages will be transmitted as datagrams or in a
byte stream carried by a virtual circuit.  While virtual circuits can be
used for any DNS activity, datagrams are preferred for queries due to
their lower overhead and better performance.  Zone refresh activities
must use virtual circuits because of the need for reliable transfer.
ソスcソスmソスrソスヘソスソスbソスZソス[ソスWソスソスソスfソス[ソス^ソスOソスソスソスソスソスソスソスソスソスzソスソスHソスフバソスCソスgソスソスソスナ運ソスホゑソス骼厄ソスソスzソス閧オ
ソスワゑソスソスBソスソスソスzソスソスHソスソスソスヌゑソスネDソスmソスrソスソスソスソスソスナゑソスソスgソスソスソスワゑソスソスソスソスAソスfソス[ソス^ソスOソスソスソスソスソスソスソスIソス[ソスoソスwソスb
ソスhソスヘ擾ソスソスソスソスソスソス謔「ソスソスソス\ソスソスソスoソスソスソスソスソス゚問合ソスソスソスナ好ソスワゑソスワゑソスソスBソス]ソス[ソスソスソスソスソスtソスソスソスbソスVソスソスソスソスソスソスソスソス
ソスヘ信ソスソスソスナゑソスソスソス]ソスソスソスソスソスKソスvソスネゑソスソス゚会ソスソスzソスソスHソスソスソスgソスソスネゑソスソストはなゑソスワゑソスソスソスB

The Internet supports name server access using TCP [RFC-793] on server
port 53 (decimal) as well as datagram access using UDP [RFC-768] on UDP
port 53 (decimal).
ソスCソスソスソス^ソス[ソスlソスbソスgソスヘネソス[ソスソスソスTソス[ソスoソスAソスNソスZソスXソスソスソスsソスbソスo[RFC-793]ソスフサソス[ソスoソス[ソス|ソス[ソスg53
ソスiソスPソスOソスiソスソスソスjソスニUソスcソスo[RFC-768]ソスフポソス[ソスg53ソスiソスPソスOソスiソスソスソスjソスナサソス|ソス[ソスgソスソスソスワゑソスソスB

4.2.1. UDP usage
4.2.1. ソスtソスcソスoソスgソスpソス@

Messages sent using UDP user server port 53 (decimal).
ソスソスソスbソスZソス[ソスWソスソスソスtソスcソスoソスフサソス[ソスoソス[ソス|ソス[ソスgソスTソスRソスiソスPソスOソスiソスソスソスjソスフソスソス[ソスUソスノ托ソスソスMソスソスソスワゑソスソスB

Messages carried by UDP are restricted to 512 bytes (not counting the IP
or UDP headers).  Longer messages are truncated and the TC bit is set in
the header.
ソスtソスcソスoソスナ運ソスホゑソス驛ソスbソスZソス[ソスWソスソスソスiソスhソスoソスソスtソスcソスoソスwソスbソス_ソス[ソスソスソスvソスZソスノ難ソスソスソスネゑソスソスナ)
ソスTソスPソスQソスoソスCソスgソスノ撰ソスソスソスソスソスソスソスワゑソスソスBソスソスソスソスソスソスソスbソスZソス[ソスWソスソスソスリり落ソスニゑソスソスソスAソスwソスbソス_ソスフTソスb
ソスrソスbソスgソスソスソスン定さソスソスワゑソスソスB

ソス注:RFC2181ソスナTソスbソスrソスbソスgソスヘ解答セソスNソスVソスソスソスソスソスニ鯉ソスソスミセソスNソスVソスソスソスソスソスソスソスソスソスノゑソスソスソスソスKソスp
ソスソスソスAソスヌ会ソスソスZソスNソスVソスソスソスソスソスソスソスソスソスノは適ソスpソスソスソスネゑソスソスニ規ソス閧オソストゑソスソスワゑソスソスBソスヌ会ソスソスZソスNソスVソスソスソスソスソスソス
ソスソスソスソスソスノ趣ソスソスソスソスソスソスRソス[ソスhソスWソスソスソスソスソスレゑソスソスソスXソスyソス[ソスXソスソスソスネゑソスソスネゑソスソスソスソス鼾ソスヘ、ソスソスソスソスソスソスソスRソス[ソスh
ソスWソスソスソスソスソス答に載ゑソスソスソスソスsソスbソスrソスbソスgソスソスソスン定しソスネゑソスソスニゑソスソスソスソスソスソスナゑソスソスB

UDP is not acceptable for zone transfers, but is the recommended method
for standard queries in the Internet.  Queries sent using UDP may be
lost, and hence a retransmission strategy is required.  Queries or their
responses may be reordered by the network, or by processing in name
servers, so resolvers should not depend on them being returned in order.
ソスtソスcソスoソスヘゾソス[ソスソスソス]ソスソスソスナ使ソスソスソスワゑソスソスが、ソスCソスソスソス^ソス[ソスlソスbソスgソスフ標ソスソスソスIソスネ問合ソスソスソスフ撰ソスソスEソスソス
ソス黷スソスソスソス@ソスナゑソスソスBソスtソスcソスoソスソスソスgソスソスソスソスソス竝ソスソスソスソスソスソスソスソスソス驍ゥソスソスソスソスソスソスネゑソスソスフで、ソスト托ソスソス略ソスソス
ソスKソスvソスナゑソスソスBソスlソスbソスgソスソスソス[ソスNソスソスlソス[ソスソスソスTソス[ソスoソスソスソスソスソスナ問合ソスソスソスソス答の擾ソスソスソスソスソスソスマゑソス驍ゥソスソス
ソスソスソスソスネゑソスソスフで、ソスソスソス]ソスソスソスoソスソスソスヤ托ソスソスソスソスソスソスノ依托ソスソスソスソスソスラゑソスソスナはゑソスソスソスワゑソスソスソスB

The optimal UDP retransmission policy will vary with performance of the
Internet and the needs of the client, but the following are recommended:
ソスナ適ソスネUソスcソスoソスト托ソスソスソスソスjソスヘイソスソスソス^ソス[ソスlソスbソスgソスフ撰ソスソス\ソスニクソスソスソスCソスAソスソスソスgソスフ必ソスvソスナ変会ソスソスソスソスソス
ソスナゑソスソス蛯、ソスソスソスAソスソスソスフゑソスソスニゑソスソスソスソス゚ゑソスソスワゑソスソスF

   - The client should try other servers and server addresses
     before repeating a query to a specific address of a server.
   - ソスNソスソスソスCソスAソスソスソスgソスヘサソス[ソスoソス[ソスフ難ソスソスソスフアソスhソスソスソスXソスノ問合ソスソスソスソスソスJソスソスヤゑソスソスOソスノ托ソスソスフサソス[
     ソスoソス[ソスニサソス[ソスoソス[ソスAソスhソスソスソスXソスソスソスソスソスンゑソスラゑソスソスナゑソスソスB

   - The retransmission interval should be based on prior
     statistics if possible.  Too aggressive retransmission can
     easily slow responses for the community at large.  Depending
     on how well connected the client is to its expected servers,
     the minimum retransmission interval should be 2-5 seconds.
   - ソスト托ソスソスヤ隔ソスヘ、ソスツ能ソスネゑソスAソスソスソスOソスフ難ソスソスvソスlソスノ奇ソステゑソスソスラゑソスソスナゑソスソスBソスソスソスワゑソスノゑソスソスUソスソス
     ソスIソスネ再托ソスソスソスソスソスハ的ソスネ具ソスソスソスソスフの費ソスソスソスソスソスeソスユに遅ソスソスソスナゑソスソスワゑソスソスBソスNソスソスソスCソスAソスソスソスgソスソス
     ソスソスソスメゑソスソスソスソスTソス[ソスoソス[ソスノどれぐソス轤「ソスqソスソスソスソスソストるかソスノゑソスソスAソスナ擾ソスソスト托ソスソスヤ隔ソスヘ2ソス|ソスT
     ソスbソスナゑソスソスソスラゑソスソスナゑソスソスB

More suggestions on server selection and retransmission policy can be
found in the resolver section of this memo.
ソスTソス[ソスoソス[ソスIソスソスソスニ再托ソスソスソスソスjソスフゑソス闡スソスソスソスフ抵ソストゑソスソスソスソスフソスソスソスソスフソスソス]ソスソスソスoソスフ章で鯉ソスソスツゑソスソスソス
ソスワゑソスソスB

ソス注:RFC2181ソスナゑソスソスソスノ会ソスソスソスソスフUソスcソスoソスpソスPソスbソスgソスフソソス[ソスXソスAソスhソスソスソスXソスヘ、ソス竝ソスソスソスソス
ソスソスソスソスAソスhソスソスソスXソスナなゑソスソスソスホなゑソスネゑソスソスニ規ソス閧オソストゑソスソスワゑソスソスB

4.2.2. TCP usage
4.2.2. ソスsソスbソスoソスgソスpソス@

Messages sent over TCP connections use server port 53 (decimal).  The
message is prefixed with a two byte length field which gives the message
length, excluding the two byte length field.  This length field allows
the low-level processing to assemble a complete message before beginning
to parse it.
ソスsソスbソスoソスレ托ソスソスナ托ソスソスソスソス驛ソスbソスZソス[ソスWソスソスソスTソス[ソスoソス[ソス|ソス[ソスgソスTソスRソスiソスPソスOソスiソスソスソスjソスソスソスgソスソスソスワゑソスソスB
ソスソスソスbソスZソス[ソスWソスフ前ソスノは2ソスoソスCソスgソスフソスソスbソスZソス[ソスWソスフ抵ソスソスソスソスtソスBソス[ソスソスソスhソスソスソスtソスソスソスワゑソスソスAソスソスソスソスソスソス
ソスヘ2ソスoソスCソスgソスフ抵ソスソスソスソスtソスBソス[ソスソスソスhソスソスソスgソスソスソスワみまゑソスソスソスBソスソスソスフ抵ソスソスソスソスtソスBソス[ソスソスソスhソスヘソスソスbソスZソス[
ソスWソスソスソスソスヘゑソスソスソスOソスノ低レソスxソスソスソスフ擾ソスソスソスソスナ奇ソスソスSソスネソスソスbソスZソス[ソスWソスノ組ソスン暦ソスソストるこソスニゑソスソスソスソスソスソスソス
ソスソスソスB

Several connection management policies are recommended:
ソスソスソスソスソスツゑソスソスフ接托ソスソスヌ暦ソスソスソスソスjソスソスソスソスソス゚ゑソスソスワゑソスソスF

   - The server should not block other activities waiting for TCP
     data.
   - ソスTソス[ソスoソス[ソスヘTソスbソスoソスfソス[ソス^ソスソスメつ間に托ソスソスフ奇ソスソスソスソスソスソス~ソス゚ゑソスラゑソスソスナはゑソスソスソスワゑソスソスソスB

   - The server should support multiple connections.
   - ソスTソス[ソスoソス[ソスヘ托ソスソスソスソスフ接托ソスソスソスソスTソス|ソス[ソスgソスソスソスソスラゑソスソスナゑソスソスB

   - The server should assume that the client will initiate
     connection closing, and should delay closing its end of the
     connection until all outstanding client requests have been
     satisfied.
   - ソスTソス[ソスoソス[ソスヘクソスソスソスCソスAソスソスソスgソスソスソスソスレ托ソスソスソスソスIソスソスソスソスソスソスニ想ソス閧キソスソスラゑソスソスナ、ソスソスソスラてゑソス
     ソスソスソスソスソスソスソスフクソスソスソスCソスAソスソスソスgソスvソスソスソスソスソスソスソスソスソスソスソスソスワで接托ソスソスソスツゑソスソス驍アソスニゑソスソスソスソスホゑソスソスラゑソス
     ソスナゑソスソスB

   - If the server needs to close a dormant connection to reclaim
     resources, it should wait until the connection has been idle
     for a period on the order of two minutes.  In particular, the
     server should allow the SOA and AXFR request sequence (which
     begins a refresh operation) to be made on a single connection.
     Since the server would be unable to answer queries anyway, a
     unilateral close or reset may be used instead of a graceful
     close.
   - ソスソスソスソスソスTソス[ソスoソス[ソスソスソスソスソス\ソス[ソスXソスヤ還ゑソスvソスソスソスソスソス驍スソス゚に休ソスソスソスソスソスレ托ソスソスソスツゑソスソスソスKソスvソスソス
     ソスソスソスソスネゑソスAソスレ托ソスソスソスソスQソスソスソスヤの会ソスソスソスソスソスソスソスソスネゑソスソスソスソスメつべゑソスソスナゑソスソスBソスソスソスノ、ソスTソス[ソスoソス[
     ソスヘ1ソスツの接托ソスソスナ(ソスソスソスtソスソスソスbソスVソスソスソスIソスyソスソスソス[ソスVソスソスソスソスソスソスソスnソス゚ゑソスjSOAソスソスAXFRソスフ問合
     ソスソスソスフ連ソスソスソスソスソスソスソスソスソスラゑソスソスナゑソスソスBソスTソス[ソスoソス[ソスソスソス竝ソスソスソスノ難ソスソスソスソス驍アソスニゑソスソスsソスツ能ソスナゑソスソスソス
     ソスソスソスソスソスソスAソスソスソスJソスネ終ソスソスソスナはなゑソスソスソスソスソスIソスネ終ソスソスソス窿奇ソスZソスbソスgソスソスソスgソスソスソス驍ゥソスソスソスソスソスソス
     ソスソスソスソスB

5. MASTER FILES
5. ソス}ソスXソス^ソス[ソスtソス@ソスCソスソス

Master files are text files that contain RRs in text form.  Since the
contents of a zone can be expressed in the form of a list of RRs a
master file is most often used to define a zone, though it can be used
to list a cache's contents.  Hence, this section first discusses the
format of RRs in a master file, and then the special considerations when
a master file is used to create a zone in some name server.
ソス}ソスXソス^ソス[ソスtソス@ソスCソスソスソスヘテソスLソスXソスgソス`ソスソスソスナ趣ソスソスソスソスソスソスRソス[ソスhソスソスソスワゑソスナゑソスソスソスeソスLソスXソスgソスtソス@ソスCソスソス
ソスナゑソスソスBソス]ソス[ソスソスソスフ難ソスソスeソスソスソスソスソスソスソスソスソスRソス[ソスhソスソスソスXソスgソスフゑソスソスソスソスソスソスナ表ソスソスソスナゑソスソスソスフで、ソス}ソスXソス^ソス[
ソスtソス@ソスCソスソスソスナゾソス[ソスソスソスソスソス`ソスソスソスソスノに使ソスソスソスAソスLソスソスソスbソスVソスソスソスソスソスeソスフソスソスXソスgソスAソスbソスvソスナ使ソスソス
ソスソスワゑソスソスBソスソスソスソスフゑソスソスフ章は最擾ソスソスノマソスXソス^ソス[ソスtソス@ソスCソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスフフソスHソス[ソス}ソスbソスg
ソスソス_ソスソスソスAソスソスソスノマソスXソス^ソス[ソスtソス@ソスCソスソスソスソスソスソスソスソスlソス[ソスソスソスTソス[ソスoソスナゾソス[ソスソスソスソスソスソス驍スソス゚に使ソスソスソスソス
ソスソスソスソスハな考ソスソスソスソス_ソスソスソスワゑソスソスB

5.1. Format
5.1. ソスtソスHソス[ソス}ソスbソスg

The format of these files is a sequence of entries.  Entries are
predominantly line-oriented, though parentheses can be used to continue
a list of items across a line boundary, and text literals can contain
CRLF within the text.  Any combination of tabs and spaces act as a
delimiter between the separate items that make up an entry.  The end of
any line in the master file can end with a comment.  The comment starts
with a ";" (semicolon).
ソスtソス@ソスCソスソスソスフフソスHソス[ソス}ソスbソスgソスヘ搾ソスソスレの連ソスソスソスナゑソスソスBソスソスソスレは奇ソス{ソスIソスノ行ソスPソスハでゑソスソスソスソスAソスJソスb
ソスRソスソスソスgソスソスソスニ行ソスフ具ソスソスEソスソスソスzソスソスソスト搾ソスソスレを続ゑソスソスAソスeソスLソスXソスgソスソスソスソスソスソスCRLFソスソスソスワむゑソスソスニゑソスソスソス
ソスソスソスワゑソスソスBソス^ソスuソスニ空白の組ソスソスソスソスソスソスソスソスソスレゑソスソスソスソス繧ーソスソスvソスfソスヤの具ソスリゑソスノなゑソスワゑソスソスBソス}
ソスXソス^ソス[ソスtソス@ソスCソスソスソスフどの行ソスソスソスRソスソスソスソスソスgソスナ終ソスソスソスナゑソスソスワゑソスソスBソスRソスソスソスソスソスgソスソス";"ソスZソス~ソスRソスソスソスソス
ソスナ始ソスワゑソスワゑソスソスB

The following entries are defined:
ソスネ会ソスソスフ搾ソスソスレゑソスソスソス`ソスソスソスソスワゑソスソスF

    <blank>[<comment>]

    $ORIGIN <domain-name> [<comment>]

    $INCLUDE <file-name> [<domain-name>] [<comment>]

    <domain-name><rr> [<comment>]

    <blank><rr> [<comment>]

Blank lines, with or without comments, are allowed anywhere in the file.
ソスRソスソスソスソスソスgソスフ有ソスソスソスノ関ゑソス轤クソスAソスtソス@ソスCソスソスソスソスソスナ空白行ソスソスソスソスソスソスソスソスワゑソスソスB

Two control entries are defined: $ORIGIN and $INCLUDE.  $ORIGIN is
followed by a domain name, and resets the current origin for relative
domain names to the stated name.  $INCLUDE inserts the named file into
the current file, and may optionally specify a domain name that sets the
relative domain name origin for the included file.  $INCLUDE may also
have a comment.  Note that a $INCLUDE entry never changes the relative
origin of the parent file, regardless of changes to the relative origin
made within the included file.
ソスQソスツの撰ソスソス苟包ソスuソスソスソスレゑソスソスソス`ソスソスソスソスワゑソスソスF$ORIGINソスソス$INCLUDEソスB$ORIGINソスフ鯉ソスノはドソスソス
ソスCソスソスソスソスソスソスソスソスソスソスソスAソスソスソスホ的ソスネドソスソスソスCソスソスソスソスソスフ起ソス_ソスhソスソスソスCソスソスソスソスソスソスン定しソスワゑソスソスB$INCLUDEソスソス
ソスwソス閧ウソス黷スソスtソス@ソスCソスソスソスソスソスソスソスンのフソス@ソスCソスソスソスノ挿ソスソスソスソスソスAソスIソスvソスVソスソスソスソスソスナ挿ソスソスソスtソス@ソスCソスソスソスソスソスソス
ソスソスソスホ的ソスネドソスソスソスCソスソスソスソスソスフ起ソス_ソスhソスソスソスCソスソスソスソスソスソスソスwソス閧オソストゑソスソス謔「ソスナゑソスソスB$INCLUDEソスソスソスRソスソスソスソス
ソスgソスソスソスソスソスソスソストゑソスソス驍ゥソスソスソスソスソスソスワゑソスソスソスB$INCLUDEソスソスソスレゑソスソスAソス}ソスソスソスtソス@ソスCソスソスソスソスソスナ托ソスソスホ的ソスネ起
ソス_ソスソスマ更ソスソスソストゑソスソスAソスソスソスソスソスト親ソスtソス@ソスCソスソスソスフ托ソスソスホ的ソスネドソスソスソスCソスソスソスフ起ソス_ソスソスマゑソスソスネゑソスソスソスソスニゑソス
ソスwソスEソスソスソスワゑソスソスB

The last two forms represent RRs.  If an entry for an RR begins with a
blank, then the RR is assumed to be owned by the last stated owner.  If
an RR entry begins with a <domain-name>, then the owner name is reset.
ソスナ鯉ソスフ2ソスツの擾ソスソスソスソスヘ趣ソスソスソスソスソスソスRソス[ソスhソスフ代理ソス務めまゑソスソスBソスソスソスソスソスソスソスソスソスソスソスRソス[ソスhソスソスソスレゑソスソスソス
ソスソスソスナ始ソスワゑソスネゑソスAソスソスソスソスソスソスソスRソス[ソスhソスヘ最鯉ソスノ出ソストゑソスソスソスソスソスソスLソスメに擾ソスソスLソスソスソスソスソスニ考ソスソスソスソスソス
ソスワゑソスソスBソスソスソスソスソスソスソスソスソスソスソスRソス[ソスhソスソスソスレゑソス<domain-name>ソスソスソスソスnソスワゑソスネゑソスAソスソスソスLソスメ厄ソスソスヘソスソスZソスb
ソスgソスソスソスソスワゑソスソスB

<rr> contents take one of the following forms:
<rr>ソスソスソスeソスソスソスソスソスフ擾ソスソスソスソスフ1ソスツゑソスソスニゑソスワゑソスソスF

    [<TTL>] [<class>] <type> <RDATA>

    [<class>] [<TTL>] <type> <RDATA>

The RR begins with optional TTL and class fields, followed by a type and
RDATA field appropriate to the type and class.  Class and type use the
standard mnemonics, TTL is a decimal integer.  Omitted class and TTL
values are default to the last explicitly stated values.  Since type and
class mnemonics are disjoint, the parse is unique.  (Note that this
order is different from the order used in examples and the order used in
the actual RRs; the given order allows easier parsing and defaulting.)
ソスソスソスソスソスソスソスRソス[ソスhソスヘ任ソスモ指ソスソスソスTTLソスニクソスソスソスXソスtソスBソス[ソスソスソスhソスニ趣ソスハと、ソスソスハとクソスソスソスXソスノ適
ソスリな趣ソスソスソスソスfソス[ソス^ソスtソスBソス[ソスソスソスhソスソスソスソスnソスワゑソスワゑソスソスBソスNソスソスソスXソスニタソスCソスvソスヘ標ソスソスソスソスソスフゑソスソスgソスソス
TTLソスヘ1ソスOソスiソス@ソスフ撰ソスソスソスソスナゑソスソスBソスネ暦ソスソスソスソス黷スソスNソスソスソスXソスソスTTLソスlソスヘ最鯉ソスフ厄ソスソスソスソスIソスノ述ソスラゑソスソス
ソスソスソスlソスソスソスfソスtソスHソスソスソスgソスナゑソスソスBソス^ソスCソスvソスニクソスソスソスXソスソスソスフゑソスソスソスソスハ要ソスfソスソスソスソスソスソスソスネゑソスソスフで、ソスiソスソスソスソス
ソスソスソスヘソスソスjソス[ソスNソスナゑソスソスBソスiソスソスソスフ暦ソスナ使ソスソスソスソスソスソスソスソスソスソスソスソスソスロに使ソスソストる資ソスソスソスソスソスRソス[ソスhソスナの擾ソス
ソスソスソスニ異なるこソスニに抵ソスソスモゑソスソストゑソスソスソスソスソスソスソスソスGソスソスソスソスフ擾ソスソスソスソスヘ包ソスソスフ会ソスヘゑソスeソスユにゑソスソスAソスfソスtソスH
ソスソスソスgソスソスソスソスソスソスソスワゑソスソスBソスj

<domain-name>s make up a large share of the data in the master file.
The labels in the domain name are expressed as character strings and
separated by dots.  Quoting conventions allow arbitrary characters to be
stored in domain names.  Domain names that end in a dot are called
absolute, and are taken as complete.  Domain names which do not end in a
dot are called relative; the actual domain name is the concatenation of
the relative part with an origin specified in a $ORIGIN, $INCLUDE, or as
an argument to the master file loading routine.  A relative name is an
error when no origin is available.
<domain-name>ソスヘマソスXソス^ソス[ソスtソス@ソスCソスソスソスナデソス[ソス^ソスフ大きソスネ具ソスソスLソスソスソスソスソスワゑソスソスBソスhソスソスソスCソスソスソスソス
ソスフソスソスxソスソスソスヘ点ソスナ具ソスリゑソス黷スソスソスソスソスソスソスナ表ソスソスソスソスワゑソスソスBソスNソスHソス[ソスgソスフ規ソスソスソスソスソスCソスモの包ソスソスソスソスソス
ソスhソスソスソスCソスソスソスソスソスノ設定すソス驍アソスニゑソスソスソスソスソスソスワゑソスソスBソス_ソスノ終ソスソスソスhソスソスソスCソスソスソスソスソスソスソスソスホと呼ばゑソスト、
ソスソスソスSソスニ思ソスソスソスワゑソスソスBソス_ソスノ終ソスソスソスネゑソスソスhソスソスソスCソスソスソスソスソスソスソスソスソスホ的ソスナ呼ばゑソスワゑソスソスGソスソスソスロのド
ソスソスソスCソスソスソスソスソスヘ、$ORIGINソスソス$INCLUDEソスソス}ソスXソス^ソス[ソスtソス@ソスCソスソスソスソスソスソスソス[ソスhソスソスソス驛具ソス[ソス`ソスソスソスフ茨ソス
ソスソスソスノ指ソス閧ウソスソスNソス_ソスニ托ソスソスホ的ソスソスソスソスソスフ鯉ソスソスソスソスナゑソスソスBソスソスソスホ的ソスネ厄ソスソスOソスソスソスAソスNソス_ソスソスソスソスソスpソスツ能ソスソス
ソスヘなゑソスソスソスソスGソスソスソス[ソスナゑソスソスB

<character-string> is expressed in one or two ways: as a contiguous set
of characters without interior spaces, or as a string beginning with a "
and ending with a ".  Inside a " delimited string any character can
occur, except for a " itself, which must be quoted using \ (back slash).
<character-string>ソスヘ2ソスソズの包ソスソス@ソスナ表ソスソスソスソスソスソスワゑソスソスFソスソスソスソスソスフスソスyソス[ソスXソスソスソスネゑソスソスAソスソス
ソスソスソスソスソスAソスソスソス驍「ソスソス"ソスナ始ソスワゑソス"ソスナ終ソスソス髟カソスソスソスソスB"ソスナ具ソスリゑソス黷スソスソスソスソスソスソスフ難ソスソスソスソスソス"ソスネ外
ソスフどゑソスネ包ソスソスソスソスソスソスン抵ソスナゑソスソスA"ソスソスソスgソスソス\ソスiソスoソスbソスNソスXソスソスソスbソスVソスソスソスjソスナ茨ソスソスpソスナゑソスソスワゑソスソスB

Because these files are text files several special encodings are
necessary to allow arbitrary data to be loaded.  In particular:
ソスソスソスソスソスフフソス@ソスCソスソスソスソスソスeソスLソスXソスgソスtソス@ソスCソスソスソスナゑソスソス驍ゥソスソスAソスソスソスソスソスツゑソスソスフ難ソスソスハなコソス[ソスhソスソスソスソス
ソスCソスモのデソス[ソス^ソスノソスソス[ソスhソスソスソスソス驍アソスニゑソスソスソスソスソスソスソスソス゚に必ソスvソスナゑソスソスBソスソスソスノ:

                of the root.
                ソスソスソス[ソスgソスノつゑソスソスソス

@               A free standing @ is used to denote the current origin.
@               ソスPソスニゑソス@ソスソスソスソスソスンの起ソス_ソスソスソスモ厄ソスソスソスソス驍スソス゚に使ソスソスソスワゑソスソスB

\X              where X is any character other than a digit (0-9), is
                used to quote that character so that its special meaning
                does not apply.  For example, "\." can be used to place
                a dot character in a label.
\X              ソスPソスOソスソスソスソスソスiソスO-ソスXソスjソスネ外ソスフキソスソスソスソスソスNソス^ソスナ、ソスソスソスハな意厄ソスソスソスKソスpソスソス
                ソスソスソスノ、ソスソスソスフ包ソスソスソスソスソスソスソスソスpソスソスソス驍スソス゚に使ソスソスソスワゑソスソスBソス痰ヲソスホ、"\."ソスソス
                ソスソスソスxソスソスソスソスソスノドソスbソスgソスソスソスソスソスソスuソスソスソスソスソス゚に使ソスソスソスワゑソスソスB

\DDD            where each D is a digit is the octet corresponding to
                the decimal number described by DDD.  The resulting
                octet is assumed to be text and is not checked for
                special meaning.
\DDD            ソスeソスcソスソスソスソスソスソスソスナDソスcソスcソスフ1ソスOソスiソスソスソスナ趣ソスソスソスソスソスソスIソスNソスeソスbソスgソスナゑソスソスBソスソス
                ソスハとゑソスソスト撰ソスソスソスソスソスIソスNソスeソスbソスgソスヘテソスLソスXソスgソスニ考ソスソスソスソスソスAソスソスソスソスソスト難ソスソスソス
                ソスネ意厄ソスソスソスソス`ソスFソスbソスNソスソスソスソスワゑソスソスソスB

( )             Parentheses are used to group data that crosses a line
                boundary.  In effect, line terminations are not
                recognized within parentheses.
( )             ソスソスソスハゑソスソスsソスソスソスワゑソスソスソスソスOソスソスソス[ソスvソスfソス[ソス^ソスノ使ソスソスソスワゑソスソスBソスソスソスロ、ソスソスソスハ難ソス
                ソスナ行ソスソスソスソスソスFソスソスソスソスソスソスワゑソスソスソスB

;               Semicolon is used to start a comment; the remainder of
                the line is ignored.
;               ソスZソス~ソスRソスソスソスソスソスソスソスRソスソスソスソスソスgソスソスソスnソス゚るたソス゚に使ソスソスソスワゑソスソスGソスソスソスCソスソスソスフ残
                ソス閧ェソスソスソスソスソスソスソスソスワゑソスソスB

5.2. Use of master files to define zones
5.2. ソス]ソス[ソスソスソスソスソス`ソスソスソス驍スソス゚のマソスXソス^ソス[ソスtソス@ソスCソスソスソスフ使ソスp

When a master file is used to load a zone, the operation should be
suppressed if any errors are encountered in the master file.  The
rationale for this is that a single error can have widespread
consequences.  For example, suppose that the RRs defining a delegation
have syntax errors; then the server will return authoritative name
errors for all names in the subzone (except in the case where the
subzone is also present on the server).
ソス}ソスXソス^ソス[ソスtソス@ソスCソスソスソスソスソス]ソス[ソスソスソスソスヌみ搾ソスソズのに使ソスソスソス骼橸ソスAソス}ソスXソス^ソス[ソスtソス@ソスCソスソスソスノエソスソスソス[
ソスソスソスソスソスソスネゑソスホ、ソスソスソスソスヘ抵ソスソス~ソスソスソスソスソスラゑソスソスナゑソスソスBソスソスソス~ソスソスソス髣晢ソスRソスヘひとつのエソスソスソス[ソスソスソスL
ソスヘ囲に影ソスソスソスソスソスソスソスソスソスソスソス驍アソスニゑソスソスソスソス驍ゥソスソスナゑソスソスBソス痰ヲソスホ、ソスマ任ソスソスソス`ソスソスソストゑソスソス骼托ソスソスソスソス
ソスRソス[ソスhソスソスソスソスソス@ソスGソスソスソス[ソスノなゑソスソストゑソスニ考ソスソスソストゑソスソスソスソスソスソスソスソスGソスソスソスソスニサソス[ソスoソス[ソスヘ委任ソスソスフゾソス[
ソスソスソスフゑソスソスラての厄ソスソスOソスノつゑソスソスト撰ソスソスソスソスソスソスGソスソスソス[ソスソスヤゑソスソスワゑソスソスiソスTソスuソス]ソス[ソスソスソスソスソスソスソスソスソスTソス[ソスoソス[
ソスソスノゑソスソスソス鼾ソスソスソスソスソスソスソスワゑソスソスjソスB

Several other validity checks that should be performed in addition to
insuring that the file is syntactically correct:
ソスtソス@ソスCソスソスソス\ソスソスソスソスソスソスソスソスソスソスソスソスソスニゑソスロ証ゑソスソス驍スソス゚、ソスソスソスフ追会ソスソスフ撰ソスソスソスソスソスソス`ソスFソスbソスNソスソスソスsソスソスソス
ソスソスラゑソスソスナゑソスソスF

   1. All RRs in the file should have the same class.
   1. ソスtソス@ソスCソスソスソスソスソスフ全ソストの趣ソスソスソスソスソスソスRソス[ソスhソスヘ難ソスソスソスソスNソスソスソスXソスソスソスソスソスツべゑソスソスナゑソスソスB

   2. Exactly one SOA RR should be present at the top of the zone.
   2. ソス]ソス[ソスソスソスフ最擾ソスソスノ撰ソスソスmソスノ1ソスツゑソスSOAソスソスソスソスソスソスソスRソス[ソスhソスソスソスソスソスソスラゑソスソスナゑソスソスB

   3. If delegations are present and glue information is required,
      it should be present.
   3. ソスソスソスソスソスマ任ソスソスソスソスソスソスAソスレ抵ソスソスワ擾ソスが必ソスvソスネゑソスAソスソスソスソスヘ托ソスソスンゑソスソスソスラゑソスソスナゑソスソスB

   4. Information present outside of the authoritative nodes in the
      zone should be glue information, rather than the result of an
      origin or similar error.
   4. ソスソスソスンゑソスソストゑソスソス驍ェソス]ソス[ソスソスソスフ撰ソスソスソスソスネノソス[ソスhソスナなゑソスソスソスソスヘ接抵ソスソスワ擾ソスソスナゑソスソスソスラゑソス
      ソスナ、ソスNソス_ソス笂ッソスlソスフエソスソスソス[ソスナはゑソスソスソスワゑソスソスソスB

5.3. Master file example
5.3. ソス}ソスXソス^ソス[ソスtソス@ソスCソスソスソスフ暦ソス

The following is an example file which might be used to define the
ISI.EDU zone.and is loaded with an origin of ISI.EDU:
ソスソスソスフゑソスソスフゑソスISI.EDUソス]ソス[ソスソスソスソスソス`ソスソスソスAISI.EDUソスoソスgソスソスソスソスソスソスソス[ソスhソスソスソスソスフに使ソスソスソスソス
ソスtソス@ソスCソスソスソスフ暦ソスナゑソスソスF

@   IN  SOA     VENERA      Action\.domains (
                                 20     ; SERIAL
                                 7200   ; REFRESH
                                 600    ; RETRY
                                 3600000; EXPIRE
                                 60)    ; MINIMUM

        NS      A.ISI.EDU.
        NS      VENERA
        NS      VAXA
        MX      10      VENERA
        MX      20      VAXA

A       A       26.3.0.103

VENERA  A       10.1.0.52
        A       128.9.0.32

VAXA    A       10.2.0.27
        A       128.9.0.33

$INCLUDE <SUBSYS>ISI-MAILBOXES.TXT

Where the file <SUBSYS>ISI-MAILBOXES.TXT is:
ソスtソス@ソスCソスソス<SUBSYS>ISI-MAILBOXES.TXTソスヘ趣ソスソスフとゑソスソスソスナゑソスソスF

    MOE     MB      A.ISI.EDU.
    LARRY   MB      A.ISI.EDU.
    CURLEY  MB      A.ISI.EDU.
    STOOGES MG      MOE
            MG      LARRY
            MG      CURLEY

Note the use of the \ character in the SOA RR to specify the responsible
person mailbox "[email protected]".
ソスモ任ソスメのゑソスソスソスソス[ソスソスソス{ソスbソスNソスXソス[email protected]ソスvソスソスソスwソス閧キソス驍スソス゚ゑソスSOA
ソスソスソスソスソスソスソスRソス[ソスhソスソス\ソスLソスソスソスソスソスNソス^ソスフ使ソスpソスノ抵ソスソスモゑソスソストゑソスソスソスソスソスソスソスソスB

6. NAME SERVER IMPLEMENTATION
6. ソスlソス[ソスソスソスTソス[ソスoソス[ソスソスソス

6.1. Architecture
6.1. ソス\ソスソス

The optimal structure for the name server will depend on the host
operating system and whether the name server is integrated with resolver
operations, either by supporting recursive service, or by sharing its
database with a resolver.  This section discusses implementation
considerations for a name server which shares a database with a
resolver, but most of these concerns are present in any name server.
ソスlソス[ソスソスソスTソス[ソスoソスフ最適ソスネ構ソスソスソスヘホソスXソスgソスIソスyソスソスソス[ソスeソスBソスソスソスOソスVソスXソスeソスソスソスノ依托ソスソスソスソスソスナゑソスソスソス
ソスソスソスAソスソスソスソスソストネソス[ソスソスソスTソス[ソスoソスナゑソスソス驍ゥソスロゑソスソスノゑソスソスソスソスソス轤クソスAソスト帰ソスIソスTソス[ソスrソスXソスソスソスTソス|ソス[ソスg
ソスソスソス驍アソスニで、ソスソスソス驍「ソスヘソスソス]ソスソスソスoソスニデソス[ソス^ソスxソス[ソスXソスソスソスソスソスLソスソスソス驍アソスニで、ソスソスソス]ソスソスソスoソスニ難ソス
ソスソスソスソスソスソスワゑソスソスBソスソスソスフ章はソスソス]ソスソスソスoソスニデソス[ソス^ソスxソス[ソスXソスソスソスソスソスLソスソスソスソスlソス[ソスソスソスTソス[ソスoソス[ソスノ対ゑソス
ソスソスソスソスソスソスフ考ソスソスソスソス_ソスソスソスワゑソスソスAソスソスソスソスソスソスソスソスソスソスソスフ趣ソスソスヘ大部ソスソスソスフネソス[ソスソスソスTソス[ソスoソスノゑソスソスソスソスソスソスソス
ソスソスソスB

6.1.1. Control
6.1.1. ソスソスソスソス

A name server must employ multiple concurrent activities, whether they
are implemented as separate tasks in the host's OS or multiplexing
inside a single name server program.  It is simply not acceptable for a
name server to block the service of UDP requests while it waits for TCP
data for refreshing or query activities.  Similarly, a name server
should not attempt to provide recursive service without processing such
requests in parallel, though it may choose to serialize requests from a
single client, or to regard identical requests from the same client as
duplicates.  A name server should not substantially delay requests while
it reloads a zone from master files or while it incorporates a newly
refreshed zone into its database.
ソスlソス[ソスソスソスTソス[ソスoソス[ソスヘ、ソスzソスXソスgソスnソスrソスソスフ包ソスソスソスソスフタソスXソスNソスニゑソスソスト趣ソスソスソスソスソスソスソス驍ゥソスAソスソスソスソスソスフ擾ソス
ソスソスソスソスソスソスソスソスPソスツのタソスXソスNソスニゑソスソスト趣ソスソスソスソスソスソスソス驍ゥソスナ、ソスソスソスソスソスフ難ソスソスソスソスフ擾ソスソスソスソスソスソスsソスソスソスネゑソスソスソスソス
ソスネゑソスワゑソスソスソスBソスlソス[ソスソスソスTソス[ソスoソスソスソスAソスソスソスtソスソスソスbソスVソスソスソスsソスbソスoソスfソス[ソス^ソスソス竝ソスソスソスソスメつ間に、
ソスtソスcソスoソス竝ソスソスソスTソス[ソスrソスXソスソスソス~ソス゚ゑソスラゑソスソスナゑソスソスソスワゑソスソスソスBソスソスソスlソスノ、ソスlソス[ソスソスソスTソス[ソスoソス[ソスソスソスソス
ソスソスノ問合ソスソスソスソスソスソスソスソスソスソスソスネゑソスソスナ再帰ソスIソスネサソス[ソスrソスXソスソス供ゑソスソスソスソスソスAソスPソスツのクソスソスソスCソスAソスソスソスg
ソスソスソスソスフ連ソスソスソスソスソスソス竝ソスソスソスソスAソスソスソスソスソスNソスソスソスCソスAソスソスソスgソスソスソスソスフ難ソスソスソスソス竝ソスソスソスソスソスdソスソスソスソスソスソスソス竝ソスソス
ソスニみなゑソスソスラゑソスソスナはゑソスソスソスワゑソスソスソスBソスlソス[ソスソスソスTソス[ソスoソス[ソスソスソスAソス}ソスXソス^ソス[ソスtソス@ソスCソスソスソスソスソスソス]ソス[ソスソス
ソスソスソストソスソス[ソスhソスソスソスソスヤゑソスAソスfソス[ソス^ソスxソス[ソスXソスノソスソスtソスソスソスbソスVソスソスソス]ソス[ソスソスソスソスソスソス闕橸ソズ際に、ソス竝
ソスソスソスソスxソス轤キソスラゑソスソスナはゑソスソスソスワゑソスソスソスB

6.1.2. Database
6.1.2. ソスfソス[ソス^ソスxソス[ソスX

While name server implementations are free to use any internal data
structures they choose, the suggested structure consists of three major
parts:
ソスlソス[ソスソスソスTソス[ソスoソスソスソスソスソスメはどゑソスネ難ソスソスソスソスfソス[ソス^ソス\ソスソスソスソスIソスソスソスソスソストゑソスソスソスソスソスソスソスソスAソスソストゑソスソス黷スソス\
ソスソスソスヘ3ソスツの趣ソスvソスネパソス[ソスcソスソスソス逅ャソス阯ァソスソスソスワゑソスソスF

   - A "catalog" data structure which lists the zones available to
     this server, and a "pointer" to the zone data structure.  The
     main purpose of this structure is to find the nearest ancestor
     zone, if any, for arriving standard queries.
   - ソスソスソスフサソス[ソスoソス[ソスフ茨ソスソスソスソス]ソス[ソスソスソスソスソスソスソスXソスgソスAソスbソスvソスソスソスソスuソスJソス^ソスソスソスOソスvソスfソス[ソス^ソス\ソスソスソスソス
     ソス]ソス[ソスソスソスfソス[ソス^ソス\ソスソスソスヨの「ソス|ソスCソスソスソス^ソスvソスBソスソスソスフ構ソスソスソスフ趣ソスネ目的ソスヘ、ソスソスソスソスソスWソスソスソスソス
     ソスソスソスソスソスソスソスソスソスソスソスニゑソスソスノ、ソスナゑソスソス゚ゑソスソスソスcソス]ソス[ソスソスソスソスソスソスソスツゑソスソス驍アソスニでゑソスソスB

   - Separate data structures for each of the zones held by the
     name server.
   - ソスlソス[ソスソスソスTソス[ソスoソス[ソスフ趣ソスソスツゾソス[ソスソスソスソスソス黷シソスソスフ包ソスソスソスfソス[ソス^ソス\ソスソスソスB

   - A data structure for cached data. (or perhaps separate caches
     for different classes)
   - ソスLソスソスソスbソスVソスソスソスfソス[ソス^ソスフデソス[ソス^ソス\ソスソスソスBソスiソスソスソスソスソスNソスソスソスXソスハに異なゑソスLソスソスソスbソスVソスソスソスjソスB

All of these data structures can be implemented an identical tree
structure format, with different data chained off the nodes in different
parts: in the catalog the data is pointers to zones, while in the zone
and cache data structures, the data will be RRs.  In designing the tree
framework the designer should recognize that query processing will need
to traverse the tree using case-insensitive label comparisons; and that
in real data, a few nodes have a very high branching factor (100-1000 or
more), but the vast majority have a very low branching factor (0-1).
ソスソスソスラてデソス[ソス^ソス\ソスソスソスナ、ソスmソス[ソスhソスフ異る部ソスソスソスナ異なゑソスfソス[ソス^ソスソスソスqソスソスソスソスAソスソスソスソスフツソスソスソス[
ソス\ソスソスソスtソスHソス[ソス}ソスbソスgソスソスソスソスソスソスソスソスソスワゑソスソスFソスJソス^ソスソスソスOソスナデソス[ソス^ソスヘゾソス[ソスソスソスヨのポソスCソスソスソス^ソスナ、ソス]ソス[
ソスソスソスニとキソスソスソスbソスVソスソスソスfソス[ソス^ソス\ソスソスソスナ、ソスfソス[ソス^ソスヘ趣ソスソスソスソスソスソスRソス[ソスhソスナゑソスソス蛯、ソスBソスfソスUソスCソスiソス[ソスソス
ソスリ機ソス\ソスソスン計ソスソスソスソスロに以会ソスソスソスFソスソスソスソスソスソスラゑソスソスナゑソスソスソスAソス竝ソスソスソスソスソスソスソスヘ大文ソスソスソスソスソスソスソスソスソスソス
ソス痰「ソス無趣ソスソスソスソス驛会ソスxソスソスソスソスrソスソスソスgソスソスソスcソスソスソス[ソスソスソスソスソスワなゑソスソスnソスソスソスソスソスソスKソスvソスソスソスソスソスソスナゑソスソス蛯、ソスG
ソスソスソスfソス[ソス^ソスナ、ソスソスソスソスソスフノソス[ソスhソスソスソスソスソスノ托ソスソスソスソスフ包ソスソスソスtソス@ソスNソス^ソス[ソスiソスPソスOソスOソス|ソスPソスOソスOソスOソスソス
ソス驍「ソスヘゑソスソスソスネ擾ソスjソスソスソスソスソスツでゑソスソス蛯、ソスAソスソスソスソスヌゑソスソスルとゑソスヌは擾ソスソスネゑソスソスソスソスフ包ソスソスソスtソス@ソスNソス^ソス[
ソスiソスOソス|ソスPソスjソスソスソスソスソスソスソスワゑソスソスB

One way to solve the case problem is to store the labels for each node
in two pieces: a standardized-case representation of the label where all
ASCII characters are in a single case, together with a bit mask that
denotes which characters are actually of a different case.  The
branching factor diversity can be handled using a simple linked list for
a node until the branching factor exceeds some threshold, and
transitioning to a hash structure after the threshold is exceeded.  In
any case, hash structures used to store tree sections must insure that
hash functions and procedures preserve the casing conventions of the
DNS.
ソス蝠カソスソスソスソスソスソスソスソスソスフ厄ソスソスソスソスソスソスソスソスソスツの包ソスソス@ソスヘノソス[ソスhソスフソスソスxソスソスソスソスソスQソスツの包ソスソスソスソスナ登ソス^ソスソスソスソス
ソスソスソスニでゑソスソスFソスAソスXソスLソス[ソスソスソスソスソスフ大文ソスソスソスソスソスソスソスソスソスソスソスヌゑソスソス轤ゥソスノなゑソスソストゑソスソスソスWソスソスソスソスソスソスソスソスソス蝠カ
ソスソスソスソスソスソスソスソスソスフソスソスxソスソスソスニ、ソスeソスソスソスソスソスフ大文ソスソスソスソスソスソスソスソスソスソスソスルなゑソスソストゑソスソスソスrソスbソスgソスソスBソスソスソスソスtソス@
ソスNソス^ソス[ソスフ托ソスソスlソスソスソスヘ、ソスソスソスしてゑソスソスソスvソスfソスソスソスソスソスソス閾値ソス超ゑソスソスソスワで、ソスmソス[ソスhソスフ単ソスソスソスソス
ソスソスソスソスソスNソスソスソスXソスgソスナ対擾ソスソスソスソスA閾値ソス超ゑソスソスソスソスソスnソスbソスVソスソスソス\ソスソスソスノ移行ソスナゑソスソスワゑソスソスBソスヌゑソスネ擾ソス
ソスソスソスナゑソスソスAソスLソスソスソスリ包ソスソスナ使ソスソスソスnソスbソスVソスソスソス\ソスソスソスソスソスAソスnソスbソスVソスソスソス@ソス\ソスニ手順ソスソスソスcソスmソスrソスフ約束ゑソス
ソスロ趣ソスソスソスソス驍アソスニゑソスロ証ゑソスソスネゑソスソストはなゑソスワゑソスソスソスB

The use of separate structures for the different parts of the database
is motivated by several factors:
ソスfソス[ソス^ソスxソス[ソスXソスフ異なる部ソスソスソスフ個々ソスフ構ソスソスソスフ用ソスrソスヘゑソスソスソスソスツゑソスソスフ要ソスfソスノゑソスソスソストゑソスソスワゑソス
ソスワゑソスソスF

   - The catalog structure can be an almost static structure that
     need change only when the system administrator changes the
     zones supported by the server.  This structure can also be
     used to store parameters used to control refreshing
     activities.
   - ソスJソス^ソスソスソスOソス\ソスソスソスヘ、ソスソスソスソスソスVソスXソスeソスソスソスヌ暦ソスソスメゑソスソスTソス[ソスoソス[ソスフ茨ソスソスソスソス]ソス[ソスソスソスソスマゑソスソス骼
     ソスソスソスソスソスマ会ソスソスソスソスソスソスソスルとゑソスヌ静的ソスネ構ソスソスソスナゑソスソスBソスソスソスフ構ソスソスソスヘソスソスtソスソスソスbソスVソスソスソスソスソスソスソスソス
     ソスRソスソスソスgソスソスソス[ソスソスソスソスソスソスpソスソスソスソスソス[ソス^ソスフ記ソスソスソスノ使ソスソスソスソスソスニゑソスソスナゑソスソスワゑソスソスB

   - The individual data structures for zones allow a zone to be
     replaced simply by changing a pointer in the catalog.  Zone
     refresh operations can build a new structure and, when
     complete, splice it into the database via a simple pointer
     replacement.  It is very important that when a zone is
     refreshed, queries should not use old and new data
     simultaneously.
   - ソス]ソス[ソスソスソスツ別のデソス[ソス^ソス\ソスソスソスヘ、ソスJソス^ソスソスソスOソスフポソスCソスソスソス^ソスソスマゑソスソス驍アソスニで変更ソスナゑソス
     ソスワゑソスソスBソス]ソス[ソスソスソスソスソスtソスソスソスbソスVソスソスソスソスソスがソスVソスソスソスソスソス\ソスソスソス生撰ソスソスソスソスソスソスソスソスソスソスソスソスニゑソスソスノ、ソスP
     ソスソスソスネポソスCソスソスソス^ソスマ更ソスナデソス[ソス^ソスxソス[ソスXソスフ変更ソスソスソスナゑソスソスワゑソスソスBソス]ソス[ソスソスソスソスソスtソスソスソスbソスVソスソス
     ソスフ趣ソスソスAソス竝ソスソスソスナ古ゑソスソスfソス[ソス^ソスニ新ソスソスソスソスソスfソス[ソス^ソスフ暦ソスソスソスソスソスソスgソスソスソストはなゑソスワゑソスソスソスB

   - With the proper search procedures, authoritative data in zones
     will always "hide", and hence take precedence over, cached
     data.
   - ソスソスソスmソスネ探ソスソスソス闖ソスナ、ソス]ソス[ソスソスソスフ撰ソスソスソスソスネデソス[ソス^ソスソスソスソスノキソスソスソスbソスVソスソスソスソスソス黷スソスfソス[ソス^
     ソスソスソスuソスBソスソスソスvソスAソスソスソスソスソスネデソス[ソス^ソスソスソスDソス謔ウソスソスソスナゑソスソス蛯、ソスB

   - Errors in zone definitions that cause overlapping zones, etc.,
     may cause erroneous responses to queries, but problem
     determination is simplified, and the contents of one "bad"
     zone can't corrupt another.
   - ソスdソスソスソス]ソス[ソスソスソス生ゑソスソスソス]ソス[ソスソスソスソス`ソスフエソスソスソス[ソスネどで問合ソスソスソスホゑソスソスソスソスソスソスソスソス答ゑソス
     ソスソスソス驍ゥソスソスソスソスソスソスワゑソスソスが、ソスソスソスソスソスソスソスヘ単ソスソスソスナ、ソスuソスソスソスソスソスvソス]ソス[ソスソスソスソスソスeソスヘよいソス]ソス[
     ソスソスソスソスソスソスソスソスソスソスソス驍アソスニゑソスソスナゑソスソスワゑソスソスソスB

   - Since the cache is most frequently updated, it is most
     vulnerable to corruption during system restarts.  It can also
     become full of expired RR data.  In either case, it can easily
     be discarded without disturbing zone data.
   - ソスLソスソスソスbソスVソスソスソスソスソスソスソスホゑソスソスホアソスbソスvソスfソス[ソスgソスソスソスソスソスフで、ソスVソスXソスeソスソスソスト開ソスナ会ソスソス竄キ
     ソスソスソスナゑソスソスBソスLソスソスソスbソスVソスソスソスソスソスソスソスソスソスリれ資ソスソスソスfソス[ソス^ソスナ厄ソスソスワるこソスニゑソスソスソスソスソスワゑソスソスBソスヌゑソス
     ソス鼾ソスソスソスAソス]ソス[ソスソスソスfソス[ソス^ソス乱ゑソスソスソスソスニなゑソスソスeソスユに削除ソスナゑソスソスワゑソスソスB

A major aspect of database design is selecting a structure which allows
the name server to deal with crashes of the name server's host.  State
information which a name server should save across system crashes
includes the catalog structure (including the state of refreshing for
each zone) and the zone data itself.
ソスfソス[ソス^ソスxソス[ソスXソスfソスUソスCソスソスソスフ趣ソスネ観点ソスヘ、ソスlソス[ソスソスソスTソス[ソスoソス[ソスソスソスlソス[ソスソスソスTソス[ソスoソスフホソスXソスgソスソス
ソスソスQソスノ対会ソスソスナゑソスソスソス\ソスソスソスソスIソスヤ趣ソスソスナゑソスソスBソスlソス[ソスソスソスTソス[ソスoソス[ソスソスソスVソスXソスeソスソスソスソスQソスノ費ソスソスソスソスト包ソス
ソスソスソスソスソスソスラゑソスソスソスヤ擾ソスソスヘ、ソスJソス^ソスソスソスOソス\ソスソスソスiソスeソス]ソス[ソスソスソスフソスソスtソスソスソスbソスVソスソスソスソスヤゑソスソスワめて)
ソスニゾソス[ソスソスソスfソス[ソス^ソスソスソス齊ゥソスgソスナゑソスソスB

6.1.3. Time
6.1.3. ソスソスソスソス

Both the TTL data for RRs and the timing data for refreshing activities
depends on 32 bit timers in units of seconds.  Inside the database,
refresh timers and TTLs for cached data conceptually "count down", while
data in the zone stays with constant TTLs.
ソスソスソスソスソスソスソスRソス[ソスhソスフ撰ソスソスソスソスソスソスヤデソス[ソス^ソスニソスソスtソスソスソスbソスVソスソスソスソスソスソスソスフタソスCソス~ソスソスソスOソスfソス[ソス^ソスヘ秒ソスPソスソス
ソスフ3ソスQソスフビソスbソスgソス^ソスCソス}ソス[ソスノ依托ソスソスソスソスワゑソスソスBソスfソス[ソス^ソスxソス[ソスXソスソスソスソスソスナ、ソスソスソスtソスソスソスbソスVソスソスソス^ソスC
ソス}ソス[ソスニキソスソスソスbソスVソスソスソスfソス[ソス^ソスフ撰ソスソスソスソスソスソスヤは概ソスOソスIソスノ「ソスJソスEソスソスソスgソス_ソスEソスソスソスvソスソスソスソスAソス]ソス[ソスソス
ソスフ撰ソスソスソスソスソスソスヤデソス[ソス^ソスソスソスソスソスlソスフままでゑソスソスB

A recommended implementation strategy is to store time in two ways:  as
a relative increment and as an absolute time.  One way to do this is to
use positive 32 bit numbers for one type and negative numbers for the
other.  The RRs in zones use relative times; the refresh timers and
cache data use absolute times.  Absolute numbers are taken with respect
to some known origin and converted to relative values when placed in the
response to a query.  When an absolute TTL is negative after conversion
to relative, then the data is expired and should be ignored.
ソスソスソスEソスソスソスソスソスソスソスソスソス略ソスヘ趣ソスソスヤゑソスソスQソスツの包ソスソス@ソスナ記ソスソスソスソスソスソスヘゑソスソスナゑソスソスFソスソスソスホ的ソスソスソスヤと撰ソスソス
ソスソスソスナ。ソスソスソスソスソスソスソスソスソスソスツの包ソスソス@ソスソスソスソスソスソスナ3ソスQソスrソスbソスgソスヤ搾ソスソスフ撰ソスソスフ値ソスソスソスgソスソスソスAソスソスソスソスソスナ包ソス
ソスフ値ソスソスソスgソスソスソスソスソスニでゑソスソスBソス]ソス[ソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスヘ托ソスソスホ趣ソスソスソスソスgソスソスソスワゑソスソスGソスソスソスtソスソスソスbソスVソスソス
ソス^ソスCソス}ソス[ソスニキソスソスソスbソスVソスソスソスfソス[ソス^ソスヘ撰ソスホ趣ソスソスソスソスgソスソスソスワゑソスソスBソスソスホ趣ソスソスソスソスソスソスソスソスソスmソスフ起ソス_ソスソスソスソス
ソスソスソスノ設定さソスソスAソス竝ソスソスソスノ対ゑソスソスソス答に設定すソスソスニゑソスソスAソスソスソスホ的ソスネ値ソスノ変奇ソスソスソスソスソスワゑソスソスB
ソスソスホ趣ソスソスヤの撰ソスソスソスソスソスソスヤを相対趣ソスソスノ変奇ソスソスソスソスソスソスロに値ソスソスソスソスソスノなゑソスソスソスソスソスfソス[ソス^ソスヘ奇ソスソスソスソスリゑソス
ソスナ厄ソスソスソスソスソスソスソスソスラゑソスソスナゑソスソスB

6.2. Standard query processing
6.2. ソスWソスソスソス竝ソスソスソスソスソスソス

The major algorithm for standard query processing is presented in
[RFC-1034].
ソスWソスソスソス竝ソスソスソスソスソスソスソスフゑソスソス゚の趣ソスvソスネアソスソスソスSソスソスソスYソスソスソスソス[RFC-1034]ソスノゑソスソスソスワゑソスソスB

When processing queries with QCLASS=*, or some other QCLASS which
matches multiple classes, the response should never be authoritative
unless the server can guarantee that the response covers all classes.
ソス竝ソスソスソスNソスソスソスX=*ソスワゑソスソスヘ包ソスソスソスソスフクソスソスソスXソスノ茨ソスvソスソスソスソス竝ソスソスソスソスソスソスソスソスソスソスソス骼橸ソスAソスTソス[ソスoソス[ソスソス
ソス答の全ソストのクソスソスソスXソスソスロ証でゑソスソスネゑソスソスソスソスソス答は撰ソスソスソスソスノなゑソスワゑソスソスソスB

When composing a response, RRs which are to be inserted in the
additional section, but duplicate RRs in the answer or authority
sections, may be omitted from the additional section.
ソス答ゑソスソスソスソスロに、ソスヌ会ソスソスソスソスノ趣ソスソスソスソスソスソスRソス[ソスhソスソスソスソスソス驍ゥソスソスソスソスソスソスワゑソスソスが、ソス答包ソスソス竦ウソスソス
ソスソスソスノゑソスソス骼托ソスソスソスソスソスRソス[ソスhソスニ重ソスソスソスソスソス骼托ソスソスソスソスソスRソス[ソスhソスヘ追会ソスソスソスソスソスソス迴懶ソスソスソスソス驍ゥソスソスソスソスソスソスソス
ソスソスソスソスB

When a response is so long that truncation is required, the truncation
should start at the end of the response and work forward in the
datagram.  Thus if there is any data for the authority section, the
answer section is guaranteed to be unique.
ソス答ゑソスソスリり落ソスニゑソスソスソスソスKソスvソスネほど抵ソスソスソスソスソスソスヘ、ソスリり落ソスニゑソスソスヘ回答の終ソスソス閧ゥソスソスnソス゚、
ソスfソス[ソス^ソスOソスソスソスソスソスナ前ソスソスソスソスソスソスソスヨ行ソスソスソスラゑソスソスナゑソスソスBソスソスソスソスソスト撰ソスソスソスソスソスソスフデソス[ソス^ソスソスソスソスソスソスネゑソスAソスソス
ソスソスソスソスソスヘ奇ソスソスSソスネゑソスソスニゑソスソスロ証ゑソスソスソスワゑソスソスB

The MINIMUM value in the SOA should be used to set a floor on the TTL of
data distributed from a zone.  This floor function should be done when
the data is copied into a response.  This will allow future dynamic
update protocols to change the SOA MINIMUM field without ambiguous
semantics.
SOAソスフ最擾ソスソスlソスヘゾソス[ソスソスソスソスソスソスzソスzソスソスソスソスソスfソス[ソス^ソスフ撰ソスソスソスソスソスソスヤの会ソスソスソスソスソスン定すソス驍スソス゚ゑソス
ソスgソスソスソスソスラゑソスソスナゑソスソスBソスソスソスフ会ソスソスソスソスヘ、ソスfソス[ソス^ソスソスソス答にコソスsソス[ソスソスソスソス骼橸ソスAソスソスソスソスソスラゑソス
ソスナゑソスソスBソスソスソスソスヘ厄ソスソスソスソスフダソスCソスiソス~ソスbソスNソスXソスVソスvソスソスソスgソスRソスソスソスナ意厄ソスソスソスソスsソスソスソストになるこソスニゑソス
ソスソスSOAソスナ擾ソスソスソスソスtソスBソス[ソスソスソスhソスフ変更ソスソスソスソスソスソスソスナゑソスソス蛯、ソスB

6.3. Zone refresh and reload processing
6.3. ソス]ソス[ソスソスソスXソスVソスニ読み抵ソスソスソスソスソスソスソス

In spite of a server's best efforts, it may be unable to load zone data
from a master file due to syntax errors, etc., or be unable to refresh a
zone within the its expiration parameter.  In this case, the name server
should answer queries as if it were not supposed to possess the zone.
ソスTソス[ソスoソス[ソスフ最善ソスフ努ソスヘにゑソスソスソスソスソスソスソス轤クソスAソス}ソスXソス^ソス[ソスtソス@ソスCソスソスソスフ構ソスソスソスソスソスソスAソスソスソスソスソス^
ソスCソス}ソス[ソスソスソスノゾソス[ソスソスソスソスソスtソスソスソスbソスVソスソスソスソスソスナゑソスソスネゑソスソスネど、ソス]ソス[ソスソスソスfソス[ソス^ソスソスヌめなゑソスソス鼾ソスソス
ソスソスソスソスワゑソスソスBソスソスソスフ場合ソスAソスlソス[ソスソスソスTソス[ソスoソス[ソスヘゑソスソスフゾソス[ソスソスソスソスソスソスソスLソスソスソストゑソスソスネゑソスソスソスソスフようソスノ、
ソス竝ソスソスソスノ難ソスソスソスソスソスラゑソスソスナゑソスソスB

If a master is sending a zone out via AXFR, and a new version is created
during the transfer, the master should continue to send the old version
if possible.  In any case, it should never send part of one version and
part of another.  If completion is not possible, the master should reset
the connection on which the zone transfer is taking place.
ソスソスソスソスソス}ソスXソス^ソス[ソスソスAXFRソスナゾソス[ソスソスソス送てゑソスナ抵ソスソスノ、ソスソスソスソスソスト新ソスソスソスソスソスナゑソスソスソスソスソスソスネゑソスA
ソス}ソスXソス^ソス[ソスヘ、ソスツ能ソスネゑソスAソステゑソスソスナを送り続ソスソスソスソスラゑソスソスナゑソスソスBソスヌゑソスネ場合ソスナゑソスソスAソスソスソス髟
ソスソスソスヘ新ソスソスソスソスソスナで、ソスソスソス髟費ソスソスソスヘ古ゑソスソスナでゑソスソスソス謔、ソスネゑソスソスフを送ゑソスラゑソスソスナはゑソスソスソスワゑソスソスソスB
ソスソスソスソスソス]ソス[ソスソスソス]ソスソスソス続ゑソスソスソスソスネゑソスソスネゑソスAソス}ソスXソス^ソス[ソスヘゾソス[ソスソスソス]ソスソスソスソスソスソスソストゑソスソスソスレ托ソスソスソスソスソス
ソスZソスbソスgソスソスソスソスラゑソスソスナゑソスソスB

6.4. Inverse queries (Optional)
6.4. ソスtソス竝ソスソスソスiソスCソスソス)

Inverse queries are an optional part of the DNS.  Name servers are not
required to support any form of inverse queries.  If a name server
receives an inverse query that it does not support, it returns an error
response with the "Not Implemented" error set in the header.  While
inverse query support is optional, all name servers must be at least
able to return the error response.
ソスtソス竝ソスソスソスヘDソスmソスrソスフ任ソスモの包ソスソスソスソスナゑソスソスBソスlソス[ソスソスソスTソス[ソスoソスソスソスtソス竝ソスソスソス`ソスソスソスフ趣ソスソスソスソスソスvソスソス
ソスソスソスソスワゑソスソスソスBソスソスソスソスソスlソス[ソスソスソスTソス[ソスoソスソスソスソスソスソスソスソスソストゑソスソスネゑソスソスtソス竝ソスソスソスソスソスけ趣ソスソスネゑソスAソスwソスb
ソス_ソス[ソスノ「ソスソスソスソスソスソスソスソストなゑソスソスvソスGソスソスソス[ソスソスン定しソスGソスソスソス[ソス答ゑソスヤゑソスソスワゑソスソスBソスtソス竝ソスソスソスフ趣ソス
ソスソスソスソスソスCソスモでゑソスソスソスソスAソスソスソスラてのネソス[ソスソスソスTソス[ソスoソス[ソスヘ擾ソスソスネゑソスソスニゑソスソスGソスソスソス[ソス答ゑソスヤゑソスソスネゑソスソスソス
ソスホなゑソスワゑソスソスソスB

6.4.1. The contents of inverse queries and responses
6.4.1. ソスtソスフ趣ソスソスソスニ回答の抵ソスソスg

Inverse queries reverse the mappings performed by standard query
operations; while a standard query maps a domain name to a resource,
an inverse query maps a resource to a domain name.  For example,
a standard query might bind a domain name to a host address;
the corresponding inverse query binds the host address to a domain name.
ソスtソス竝ソスソスソスソスソスWソスソスソス竝ソスソスソスソスソスソスナ行ソスソス黷スソスマ奇ソスソス反転ソスソスソスワゑソスソスGソスWソスソスソスIソスネ問合ソスソスソスソスソスhソスソス
ソスCソスソスソスソスソスソスソスソスソスソスソスソスソスRソス[ソスhソスノ変奇ソスソスソスソスソスフに対ゑソスソスAソスtソスフ問合ソスソスソスソスソスソスソスソスソスソスソスRソス[ソスhソスソスソスhソスソスソスC
ソスソスソスソスソスノ変奇ソスソスソスソスワゑソスソスBソス痰ヲソスホ、ソスWソスソスソス竝ソスソスソスソスソスhソスソスソスCソスソスソスソスソスzソスXソスgソスAソスhソスソスソスXソスノ変奇ソスソスソスソスソス
ソスソスソスソスソスソスソスソスワゑソスソスソスGソスホ会ソスソスソスソスソスtソス竝ソスソスソスヘホソスXソスgソスAソスhソスソスソスXソスノドソスソスソスCソスソスソスソスソスソスマ奇ソスソスソスソスワゑソスソスB

Inverse queries take the form of a single RR in the answer section of
the message, with an empty question section.  The owner name of the
query RR and its TTL are not significant.  The response carries
questions in the question section which identify all names possessing
the query RR WHICH THE NAME SERVER KNOWS.  Since no name server knows
about all of the domain name space, the response can never be assumed to
be complete.  Thus inverse queries are primarily useful for database
management and debugging activities.  Inverse queries are NOT an
acceptable method of mapping host addresses to host names; use the IN-
ADDR.ARPA domain instead.
ソスtソス竝ソスソスソスソスソスbソスZソス[ソスWソスフ回答包ソスソスフ1ソスツの趣ソスソスソスソスソスソスRソス[ソスhソスニ、ソスソスフ趣ソスソス笊費ソスソスソスソスネゑソスワゑソスソスB
ソス竝ソスソスソスソスソスソスソスソスソスRソス[ソスhソスフ擾ソスソスLソスメ厄ソスソスニ撰ソスソスソスソスソスソスヤは意厄ソスソスソスソスソスソスソスワゑソスソスソスBソス答はネソス[ソスソスソスTソス[
ソスoソス[ソスソスソスmソスソスソストゑソスソス驍キソスラての問合ソスソスソスソスソスソスソスソスソスRソス[ソスhソスソスソスソスソスLソスソスソストゑソスソス髢シソスOソスソスソスソスソス笊費ソスノ撰ソス
ソス閧オソスソスソスソスソスフでゑソスソスBソスlソス[ソスソスソスTソス[ソスoソス[ソスソスソスhソスソスソスCソスソスソスソスソスソスヤのゑソスソスラてゑソスmソスソスソストゑソスソスソスフでゑソス
ソスソスソスフで、ソス答は鯉ソスソスソスソスト奇ソスソスSソスネゑソスソスフと考ソスソスソスソスソスワゑソスソスソスBソスソスソスフゑソスソス゚逆ソス竝ソスソスソスヘ趣ソスノデソス[
ソス^ソスxソス[ソスXソスヌ暦ソスソスニデソスoソスbソスOソスソスソスソスソスノ役立ゑソスソスワゑソスソスBソスtソス竝ソスソスソスヘホソスXソスgソスAソスhソスソスソスXソスソスソスzソスXソスg
ソスソスソスノ変奇ソスソスソスソスソス謔「ソスソスソス@ソスナはゑソスソスソスワゑソスソスソスGソスソスソスフ托ソスソスソスIN-ADDR.ARPAソスhソスソスソスCソスソスソスソスソスgソスソス
ソスワゑソスソスB

Where possible, name servers should provide case-insensitive comparisons
for inverse queries.  Thus an inverse query asking for an MX RR of
"Venera.isi.edu" should get the same response as a query for
"VENERA.ISI.EDU"; an inverse query for HINFO RR "IBM-PC UNIX" should
produce the same result as an inverse query for "IBM-pc unix".  However,
this cannot be guaranteed because name servers may possess RRs that
contain character strings but the name server does not know that the
data is character.
ソスツ能ソスネ場合ソスAソスlソス[ソスソスソスTソス[ソスoソスソスソスtソス竝ソスソスソスノ大文ソスソスソスソスソスソスソスソスソスフ違いソス無趣ソスソスソスソスソスソスrソスソスソス
ソスソスソスソスソスソスラゑソスソスナゑソスソスBソスソスソスソスソスMXソスソスソスソスソスソスソスRソス[ソスh"Venera.isi.edu"ソスソスソスソスソス゚ゑソスtソス竝ソスソスソスソス
"VENERA.ISI.EDU"ソスフ逆ソスソスソスソスニ難ソスソスソスソス答ゑソスソスソスノ難ソスソスソスソスラゑソスソスナゑソスソスG"IBM-PC UNIX"ソスz
ソスXソスgソスソス資鯉ソスソスソスソスRソス[ソスhソスフ逆ソス竝ソスソスソスソス"IBM-pc unix"ソスフ逆ソス竝ソスソスソスニ難ソスソスソスソスソスソスハゑソスソスNソスソス
ソスソスソスラゑソスソスナゑソスソスBソスソスソスソスソスソスソスAソスlソス[ソスソスソスTソス[ソスoソスソスソスソスソスソスソスソスソスソスワむ趣ソスソスソスソスソスソスRソス[ソスhソスソスソスソスソスLソスソスソス驍ゥソスソス
ソスソスソスソスネゑソスソスソスソスAソスlソス[ソスソスソスTソス[ソスoソス[ソスソスソスfソス[ソス^ソスソスソスソスソスソスソスソスソスヌゑソスソスソスソスソスmソスソスネゑソスソスフで保証はでゑソス
ソスワゑソスソスソスB

When a name server processes an inverse query, it either returns:
ソスlソス[ソスソスソスTソス[ソスoソス[ソスソスソスtソス竝ソスソスソスソスソスソスソスソスソスソスソス骼橸ソスAソスネ会ソスソスソスヤゑソスソスソスソスソスソスソスソスソスワゑソスソスソスF

   1. zero, one, or multiple domain names for the specified
      resource as QNAMEs in the question section
   1. ソスOソスツ以擾ソスフ趣ソスソス笊費ソスフ問合ソスソスソスソスソスナ指ソス閧オソスソスソスソスソスソスソスフドソスソスソスCソスソスソスソスソスB

   2. an error code indicating that the name server doesn't support
      inverse mapping of the specified resource type.
   2. ソスlソス[ソスソスソスTソス[ソスoソスソスソスwソス閧ウソス黷スソスソスソスソスソスソスハの逆ソスマ奇ソスソスソスソスソスソスソスソスソスソストゑソスソスネゑソスソスソスソスニゑソス
      ソスソスソスソスソスGソスソスソス[ソスRソス[ソスhソスB

When the response to an inverse query contains one or more QNAMEs, the
owner name and TTL of the RR in the answer section which defines the
inverse query is modified to exactly match an RR found at the first
QNAME.
ソスtソスフ趣ソスソスソスノ対ゑソスソスソス答ゑソスソスPソスツ以擾ソスフ問合ソスソスソスソスソスソスソスワむ趣ソスソスAソスtソスフ趣ソスソスソスソスソス`ソスソスソスソスソス
ソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスフ擾ソスソスLソスメ厄ソスソスニ撰ソスソスソスソスソスソスヤは最擾ソスソスフ問合ソスソスソスソスソスナ鯉ソスソスツゑソスソス骼托ソスソスソスソスソスRソス[
ソスhソスフと撰ソスソスmソスノ茨ソスvソス謔、ソスノ修ソスソスソスソスソスソスワゑソスソスB

RRs returned in the inverse queries cannot be cached using the same
mechanism as is used for the replies to standard queries.  One reason
for this is that a name might have multiple RRs of the same type, and
only one would appear.  For example, an inverse query for a single
address of a multiply homed host might create the impression that only
one address existed.
ソスtソスフ趣ソスソスソスナ返ゑソスソス黷スソスソスソスソスソスソスソスRソス[ソスhソスソスソスWソスソスソスIソスネ趣ソスソスソスナ使ソスソスソストゑソスソスソスLソスソスソスbソスVソスソスソスソスソスJ
ソスjソスYソスソスソスナキソスソスソスbソスVソスソスソスナゑソスソスワゑソスソスソスBソスソスソスフ1ソスツの暦ソスソスRソスヘ厄ソスソスOソスソスソスソスソスソスソス^ソスCソスvソスフ托ソスソスソスソスフ趣ソス
ソスソスソスソスソスRソス[ソスhソスソスソスツゑソスソスソスソスソスソスソスネゑソスソスソスソスAソスソスソスソスソスPソスソスソスソスソスソスソスソスソスソスソス驍スソス゚でゑソスソスBソス痰ヲソスホ、ソス}ソスソス
ソス`ソスzソス[ソスソスソスzソスXソスgソスフひとつのアソスhソスソスソスXソスフ逆ソス竝ソスソスソスソスソスAソスzソスXソスgソスノアソスhソスソスソスXソスソスソスPソスツゑソスソスソス
ソスソスソスソス謔、ソスネ茨ソスロゑソス^ソスソスソス驍ゥソスソスソスソスソスソスワゑソスソスソスB

6.4.2. Inverse query and response example
6.4.2. ソスtソス竝ソスソスソスニ回答暦ソス

The overall structure of an inverse query for retrieving the domain
name that corresponds to Internet address 10.1.0.52 is shown below:
ソスCソスソスソス^ソス[ソスlソスbソスgソスAソスhソスソスソスX10.1.0.52ソスノ対会ソスソスソスソスソスhソスソスソスCソスソスソスソスソスソスヤゑソスソスtソス竝ソスソスソスフ全ソスソス
ソスIソスネ構ソスソスソスヘ会ソスソスノ鯉ソスソスソスソスソスソスワゑソスソスF

                         +-----------------------------------------+
           Header        |          OPCODE=IQUERY, ID=997          |
           ソスwソスbソス_        +-----------------------------------------+
          Question       |                 <empty>                 |
            ソスソスソスソス         +-----------------------------------------+
           Answer        |        <anyname> A IN 10.1.0.52         |
            ソスソス         +-----------------------------------------+
          Authority      |                 <empty>                 |
            ソスソスソスソス         +-----------------------------------------+
         Additional      |                 <empty>                 |
            ソスヌ会ソス         +-----------------------------------------+

This query asks for a question whose answer is the Internet style
address 10.1.0.52.  Since the owner name is not known, any domain name
can be used as a placeholder (and is ignored).  A single octet of zero,
signifying the root, is usually used because it minimizes the length of
the message.  The TTL of the RR is not significant.  The response to
this query might be:
ソスソスソスフ問合ソスソスソスヘ、ソスヌゑソスネ趣ソスソスソスフ難ソスソスソスソスソスソスCソスソスソス^ソス[ソスlソスbソスgソスXソス^ソスCソスソスソスAソスhソスソスソスX10.1.0.52
ソスナゑソスソス驍ゥソスqソスヒまゑソスソスBソスソスソスLソスメ厄ソスソスソスソスmソスソスソストなゑソスソスフ、ソスCソスモのドソスソスソスCソスソスソスソスソスソスソスソスソスソスソス゚に暦ソス
ソスpソスナゑソスソスワゑソスソスiソスソスソスソスソスト厄ソスソスソスソスソスソスソスワゑソスソスjソスBソス[ソスソスソスフ値ソスフ1ソスツのオソスNソスeソスbソスgソスソスソスソスソス[ソスgソスソスソスソス
ソスソスソスソスソスAソスソスソスbソスZソス[ソスWソスソスソスソスソスナ擾ソスソスノゑソスソス驍スソス゚通擾ソスgソスソスソスワゑソスソスBソスソスソスソスソスソスソスRソス[ソスhソスフ撰ソスソスソスソスソスソスソス
ソスヘ意厄ソスソスソスソスソスソスソスワゑソスソスソスBソスソスソスフ趣ソスソスソスノ対ゑソスソスソス答は以会ソスソスソスソスソスソスソスソスソスワゑソスソスソスF

                         +-----------------------------------------+
           Header        |         OPCODE=RESPONSE, ID=997         |
           ソスwソスbソス_        +-----------------------------------------+
          Question       |QTYPE=A, QCLASS=IN, QNAME=VENERA.ISI.EDU |
            ソスソスソスソス         +-----------------------------------------+
           Answer        |  VENERA.ISI.EDU  A IN 10.1.0.52         |
            ソスソス         +-----------------------------------------+
          Authority      |                 <empty>                 |
            ソスソスソスソス         +-----------------------------------------+
         Additional      |                 <empty>                 |
            ソスヌ会ソス         +-----------------------------------------+

ソス注:RFCソスソスAソスソスソスノゑソスソスソスOPCODEソスソスRESPONSEソスニゑソスソスソスソスlソスヘなゑソスソスフで、
ソスソスLソスフヘソスbソス_ソスフ記ソスレゑソス"OPCODE=IQUERY, ID=997, QR=1"ソスソスソスソスソスソスソスソスソスソスソスソスソスナゑソスソスB

Note that the QTYPE in a response to an inverse query is the same as the
TYPE field in the answer section of the inverse query.  Responses to
inverse queries may contain multiple questions when the inverse is not
unique.  If the question section in the response is not empty, then the
RR in the answer section is modified to correspond to be an exact copy
of an RR at the first QNAME.
ソスtソス竝ソスソスソスノ対ゑソスソスソス答で趣ソスソスソスソスハゑソスソスtソス竝ソスソスソスフ回答包ソスソスフ趣ソスハフソスBソス[ソスソスソスhソスニ難ソスソスソスソスソス
ソスニに抵ソスソスモゑソスソストゑソスソスソスソスソスソスソスソスBソスtソス竝ソスソスソスノ対ゑソスソスソス答ゑソスソスAソスtソスソスソスソスモではなゑソスソスソスソスAソスソスソスソスソスソス
ソスソスソスソスソスソスワむゑソスソスソスソスソスソスソスワゑソスソスソスBソスソスソスソスソス答ソスソスbソスZソス[ソスWソスフ趣ソスソス笊費ソスソスソスソスナはなゑソスソスネゑソスAソスソス
ソスソスソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスヘ最擾ソスソスフ問合ソスソスソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスフ撰ソスソスmソスネコソスsソス[ソスノ対会ソスソスソスソスソス
ソス謔、ソスノ修ソスソスソスソスソスソスワゑソスソスB

6.4.3. Inverse query processing
6.4.3. ソスtソス竝ソスソスソスソスソスソス

Name servers that support inverse queries can support these operations
through exhaustive searches of their databases, but this becomes
impractical as the size of the database increases.  An alternative
approach is to invert the database according to the search key.
ソスtソス竝ソスソスソスソスソスソスソスソスソスソスソスソスlソス[ソスソスソスTソス[ソスoソスソスソスfソス[ソス^ソスxソス[ソスXソスフ徹ソスソスIソスネ探ソスソスソスノゑソスソスソストゑソスソスフ托ソス
ソスソスソスソスソスソスソスソスナゑソスソスワゑソスソスソスソスAソスfソス[ソス^ソスxソス[ソスXソスフ大きソスソスソスソスソスソスソスソスソスソスソスソスニ費ソスソスソスpソスIソスノなゑソスワゑソスソスB
ソスソスソスソスフ包ソスソス@ソスヘ探ソスソスソスフキソス[ソスノ従ソスソスソストデソス[ソス^ソスxソス[ソスXソス裏返ゑソスソスソスソスニでゑソスソスB

For name servers that support multiple zones and a large amount of data,
the recommended approach is separate inversions for each zone.  When a
particular zone is changed during a refresh, only its inversions need to
be redone.
ソスソスソスソスソスフゾソス[ソスソスソスニ托ソスハのデソス[ソス^ソスソスソスTソス|ソス[ソスgソスソスソスソスlソス[ソスソスソスTソス[ソスoソスフ撰ソスソスEソスソスソス黷スソスソスiソスヘ各
ソス]ソス[ソスソスソスソスソスフ逆ソスソスソスソスソスナゑソスソスBソスソスソスソスフゾソス[ソスソスソスソスソスソスソスtソスソスソスbソスVソスソスソスナ変ゑソスソスソスソスソスソスソスAソスソスソスフゾソス[ソスソス
ソスフ暦ソスソスヤゑソスソスソスソスソスソスソスソスソス闥シソスソスソスホゑソスソスソスソスナゑソスソスB

Support for transfer of this type of inversion may be included in future
versions of the domain system, but is not supported in this version.
ソスソスソスフ暦ソスソスヤゑソスソスフ趣ソズのタソス]ソスソスソスフ趣ソスソスソスソスソスソスhソスソスソスCソスソスソスVソスXソスeソスソスソスフ厄ソスソスソスソスフ版に含めゑソスソス驍ゥ
ソスソスソスソスソスソスワゑソスソスが、ソスソスソスフ版には含めまゑソスソスソスB

6.5. Completion queries and responses
6.5. ソスソスソスソスソス竝ソスソスソスニ会ソス

The optional completion services described in RFC-882 and RFC-883 have
been deleted.  Redesigned services may become available in the future.
RFC-882ソスソスRFC-883ソスナ記ソスqソスソスソス黷スソスCソスモの奇ソスソスソスソスTソス[ソスrソスXソスヘ削除ソスソスソスソスワゑソスソスソスソスBソスfソスUソスCソスソス
ソスソスマ更ソスソスソスソスソスTソス[ソスrソスXソスソスソスソスソスソスソスソスソスpソスツ能ソスノなるかソスソスソスソスソスソスワゑソスソスソスB

7. RESOLVER IMPLEMENTATION
7. ソスソスソス]ソスソスソスoソスフ趣ソスソスソス

The top levels of the recommended resolver algorithm are discussed in
[RFC-1034].  This section discusses implementation details assuming the
database structure suggested in the name server implementation section
of this memo.
ソスソスソスEソスソスソス黷スソスソスソス]ソスソスソスoソスAソスソスソスSソスソスソスYソスソスソスフ概ソスOソスソス[RFC-1034]ソスナ論ソスソスソスソスソスワゑソスソスBソスソスソスフ章ゑソス
ソスソスソスフソスソスソスソスフネソス[ソスソスソスTソス[ソスoソスソスソスソスソスソスソスナ抵ソストゑソスソス黷スソスfソス[ソス^ソスxソス[ソスXソス\ソスソスソスソスzソス閧オソストゑソスソスソスソス
ソスソスソスフ詳細ゑソス_ソスソスソスワゑソスソスB

7.1. Transforming a user request into a query
7.1. ソスソスソス[ソスUソスvソスソスソスフ趣ソスソスソスヨの変奇ソス

The first step a resolver takes is to transform the client's request,
stated in a format suitable to the local OS, into a search specification
for RRs at a specific name which match a specific QTYPE and QCLASS.
Where possible, the QTYPE and QCLASS should correspond to a single type
and a single class, because this makes the use of cached data much
simpler.  The reason for this is that the presence of data of one type
in a cache doesn't confirm the existence or non-existence of data of
other types, hence the only way to be sure is to consult an
authoritative source.  If QCLASS=* is used, then authoritative answers
won't be available.
ソスソスソス]ソスソスソスoソスフ最擾ソスソスフ手順ソスヘ、ソスソスソス[ソスJソスソスソスnソスrソスノ適ソスソスソスソスソスtソスHソス[ソス}ソスbソスgソスナ記ソスqソスソスソス黷スソスNソスソス
ソスCソスAソスソスソスgソスvソスソスソスソスソスAソスwソス閧オソスソスソスソスソスOソスノ茨ソスvソスソスソス骼ソソスソスソスハと趣ソスソスソスNソスソスソスXソスソスソスソスソスソスソスRソス[ソスhソスソス
ソスソスソスソスソスdソスlソスヨ変奇ソスソスソスソス驍アソスニでゑソスソスBソスLソスソスソスbソスVソスソスソスfソス[ソス^ソスフ暦ソスソスpソスソスPソスソスソスノゑソスソスソスフで、ソスツ能
ソスネ場合ソスAソスソスソスソスソスハと趣ソスソスソスNソスソスソスXソスヘひとつの趣ソスハとひとつのクソスソスソスXソスノ対会ソスソスソスソスソスラゑソス
ソスナゑソスソスBソスソスソスフ暦ソスソスRソスヘキソスソスソスbソスVソスソスソスソスソスフゑソスソスソスソズのデソス[ソス^ソスフ托ソスソスンゑソスソスソスソスフ趣ソズのデソス[ソス^ソスソス
ソスソスソスンの有ソスソスソスフ確ソスFソスノ使ソスソスソスネゑソスソスニゑソスソスソスソスソスソスニで、ソスソスソスソスフ確ソスFソスソスソスソスBソスソスフ包ソスソス@ソスヘ撰ソスソスソスソスソス
ソスソス源を調べるこソスニでゑソスソスBソスソスソスソスQCLASS=*ソスネら正ソスソスソスネ難ソスソスソスソスヘ暦ソスソスpソスツ能ソスナなゑソスソスナゑソスソスソス
ソスソスソスB

Since a resolver must be able to multiplex multiple requests if it is to
perform its function efficiently, each pending request is usually
represented in some block of state information.  This state block will
typically contain:
ソスソスソス]ソスソスソスoソスソスソスAソスソスソスソスソスIソスノ機ソス\ソスソスソスソスソスsソスソスソスソスネゑソスAソスソスソスソスソスフ要ソスソスソス同趣ソスソスノ托ソスソスMソスナゑソスソスネゑソスソスソス
ソスホなゑソスネゑソスソスフで、ソスeソスソスソスソスソスソスフ問合ソスソスソスソスソスハ常あソスソスソスヤ擾ソスソスナ表ソスソスソスソスワゑソスソスBソスソスヤ擾ソスソス
ソスソスソスソスハに以会ソスソスソスソスワみまゑソスソスF

   - A timestamp indicating the time the request began.
     The timestamp is used to decide whether RRs in the database
     can be used or are out of date.  This timestamp uses the
     absolute time format previously discussed for RR storage in
     zones and caches.  Note that when an RRs TTL indicates a
     relative time, the RR must be timely, since it is part of a
     zone.  When the RR has an absolute time, it is part of a
     cache, and the TTL of the RR is compared against the timestamp
     for the start of the request.
   - ソスvソスソスソスソスソスnソス゚ゑソスソスソスソスヤゑソスソスソスソスソスソス^ソスCソスソスソスXソス^ソスソスソスvソスBソス^ソスCソスソスソスXソス^ソスソスソスvソスヘデソス[ソス^ソスxソス[ソスX
     ソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスナ使ソスソスソス驍ゥソスAソステゑソスソスソスソスソスソスソスソス゚るたソス゚に使ソスソスソスワゑソスソスBソスソスソスフタ
     ソスCソスソスソスXソス^ソスソスソスvソスヘ前ソスフゾソス[ソスソスソスニキソスソスソスbソスVソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスフ登ソス^ソスナ論ソスソスソスソスソスソス
     ソスホ趣ソスソスヤフソスHソス[ソス}ソスbソスgソスソスソスgソスソスソスワゑソスソスBソスソスソスソスソスソスソスRソス[ソスhソスソスソスソスソスソスソスヤゑソスソスソスソスホ的ソスネ趣ソスソスソスソスソス
     ソスソスソスソスソスAソスソスソスソスソスソスソスRソス[ソスhソスソスソス]ソス[ソスソスソスフ一部ソスネので、ソスナ新ソスノ違いソスネゑソスソスソスソスニに抵ソスソスモゑソス
     ソストゑソスソスソスソスソスソスソスソスBソスソスソスソスソスソスソスRソス[ソスhソスソスソスソスホ趣ソスソスヤゑソスソスソスソスツ趣ソスソスAソスソスソスソスヘキソスソスソスbソスVソスソスソスフ一部
     ソスナゑソスソスAソスソスソスソスソスト趣ソスソスソスソスソスソスRソス[ソスhソスフ撰ソスソスソスソスソスソスヤは要ソスソスソスソスソスsソスソスソスソスソス^ソスCソスソスソスXソス^ソスソスソスvソスソスソスソス
     ソスソスソスノゑソスソスト費ソスソスfソスソスソスソスワゑソスソスB

     Note that using the timestamp is superior to using a current
     time, since it allows RRs with TTLs of zero to be entered in
     the cache in the usual manner, but still used by the current
     request, even after intervals of many seconds due to system
     load, query retransmission timeouts, etc.
     ソスソスソスソスソスソスソスヤゑソスソス[ソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスソスソスハ擾ソスフ包ソスソス@ソスナキソスソスソスbソスVソスソスソスノ難ソスソスソス驍アソスニゑソス
     ソスナゑソスソス驍ェソスAソスVソスXソスeソスソスソスソスソスラゑソスト托ソスソス^ソスCソスソスソスAソスEソスgソスネどで撰ソスソスbソスヤ擾ソスソスソスソスソスソスxソスソス驍ゥ
     ソスソスソスソスソスソスネゑソスソスソスソスワ趣ソスソスsソスソスソスフ問合ソスソスソスナまゑソスソスソスソスソスソスソスソスRソス[ソスhソスソスソスgソスソスソスフで、ソスソスソスン趣ソスソスソス
     ソスナはなゑソスソス^ソスCソスソスソスXソス^ソスソスソスvソスソスソスgソスソスソスソスソスニに抵ソスソスモゑソスソストゑソスソスソスソスソスソスソスソスB

   - Some sort of parameters to limit the amount of work which will
     be performed for this request.
   - ソスvソスソスソスソスソスsソスソスソスdソスソスソスハを制鯉ソスソスソスソス驍ソスソスソスフパソスソスソスソスソス[ソス^

     The amount of work which a resolver will do in response to a
     client request must be limited to guard against errors in the
     database, such as circular CNAME references, and operational
     problems, such as network partition which prevents the
     resolver from accessing the name servers it needs.  While
     local limits on the number of times a resolver will retransmit
     a particular query to a particular name server address are
     essential, the resolver should have a global per-request
     counter to limit work on a single request.  The counter should
     be set to some initial value and decremented whenever the
     resolver performs any action (retransmission timeout,
     retransmission, etc.)  If the counter passes zero, the request
     is terminated with a temporary error.
     ソスソスソス]ソスソスソスoソスソスソスNソスソスソスCソスAソスソスソスgソスvソスソスソスノ会ソスソスソスソストゑソスソスソスナゑソスソスうソスdソスソスソスフ量は鯉ソスソス閧ウソスソスソス
     ソスソスソスソスノ違いソスソスソスソスワゑソスソスソスBソスソスソスしゑソスソスソス{ソスソスソスQソスニのようソスネデソス[ソス^ソスxソス[ソスXソスナエソスソスソス[
     ソスソスAソスソスソス]ソスソスソスoソスソスソスKソスvソスネネソス[ソスソスソスTソス[ソスoソス[ソスノアソスNソスZソスXソスソスソスソスフゑソスjソス~ソスソスソスソスlソスbソスg
     ソスソスソス[ソスNソスソスソスソスソスネどの運ソスpソスソスソスソスソスxソスソスソスソスソス驍スソス゚に。ソスソスソス]ソスソスソスoソスソスソスソスソスソスフネソス[ソスソスソスTソス[
     ソスoソスAソスhソスソスソスXソスノ難ソスソスソスフ問合ソスソスソスソスソスト托ソスソスソスソスソスニゑソスソスフ撰ソスソスフ局包ソスソスIソスソスソスソスソスソスソスsソスツ鯉ソスソスネゑソス
     ソスナ、ソスソスソス]ソスソスソスoソスヘ要ソスソスソスソスソスニの仕ソスソスソス制鯉ソスソスソスソス驍スソス゚にグソスソスソス[ソスoソスソスソスネカソスEソスソスソス^ソス[
     ソスソスソスソスソスツべゑソスソスナゑソスソスBソスJソスEソスソスソス^ソス[ソスヘゑソスソス髀会ソスソスソスlソスソスソスン定さソス黹奇ソス]ソスソスソスoソスソスソスネにゑソスソスソス
     ソスソスiソスト托ソスソス^ソスCソスソスソスAソスEソスgソスAソスト托ソスソスネど)ソスソスソス驍スソスムに鯉ソスソスZソスソスソスソスワゑソスソスBソスJソスEソスソスソス^ソス[
     ソスソスソス[ソスソスソスノなゑソスソスソスソスソスvソスソスソスヘ一時ソスIソスネエソスソスソス[ソスナ終ソスソスワゑソスソスB

     Note that if the resolver structure allows one request to
     start others in parallel, such as when the need to access a
     name server for one request causes a parallel resolve for the
     name server's addresses, the spawned request should be started
     with a lower counter.  This prevents circular references in
     the database from starting a chain reaction of resolver
     activity.
     ソスソスソスソスソスソスソス]ソスソスソスoソスフ構ソスソスソスソスソスソスソスソスソスフ要ソスソスソスソスソスソスソスノ行ソスソスソスソスフでゑソスソスソスホ、ソス痰ヲソスホゑソスソスソス
     ソスlソス[ソスソスソスTソス[ソスoソスヨの要ソスソスソスソスソスlソス[ソスソスソスTソス[ソスoソス[ソスフアソスhソスソスソスXソスフ会ソスソスソスソス生撰ソスソスソスソスソスソスロ、
     ソスソスソスsソスソスソスソスソスvソスソスソスソスソスソス闖ュソスネゑソスソスJソスEソスソスソス^ソス[ソスlソスナはゑソスソス゚ゑソスソスソスラゑソスソスソスソスノ抵ソスソスモゑソスソスソス
     ソスソスソスソスソスソスソスソスソスBソスソスソスソスヘデソス[ソス^ソスxソス[ソスXソスフ擾ソスソスソスQソスニゑソスソスソスソス]ソスソスソスoソスソスソスソスソスフ連ソスソスソスソスソスソスソスソスソスn
     ソス゚ゑソスフゑソスjソス~ソスソスソスワゑソスソスB

   - The SLIST data structure discussed in [RFC-1034].
   - ソスTソス[ソスoソスソスソスXソスgソスfソス[ソス^ソス\ソスソスソスソス[RFC-1034]ソスナ論ソスソスソスソスワゑソスソスB

     This structure keeps track of the state of a request if it
     must wait for answers from foreign name servers.
     ソスソスソスフ構ソスソスソスヘ、ソスソスソスソスソスOソスフネソス[ソスソスソスTソス[ソスoソスフ会ソスソスソスソスソスメゑソスソスネゑソスソスソスホなゑソスネゑソスソスネゑソスA
     ソスソスソスNソスGソスXソスgソスフ擾ソスヤゑソスソスLソス^ソスEソスヌ跡ゑソスソスワゑソスソスB

7.2. Sending the queries
7.2. ソス竝ソスソスソスフ托ソスソスM

As described in [RFC-1034], the basic task of the resolver is to
formulate a query which will answer the client's request and direct that
query to name servers which can provide the information.  The resolver
will usually only have very strong hints about which servers to ask, in
the form of NS RRs, and may have to revise the query, in response to
CNAMEs, or revise the set of name servers the resolver is asking, in
response to delegation responses which point the resolver to name
servers closer to the desired information.  In addition to the
information requested by the client, the resolver may have to call upon
its own services to determine the address of name servers it wishes to
contact.
[RFC-1034]ソスナ記ソスqソスソスソスソスソス謔、ソスノ、ソスソスソス]ソスソスソスoソスフ奇ソス{ソスIソスネ仕ソスソスソスヘクソスソスソスCソスAソスソスソスgソスフ要ソスソス
ソスノ難ソスソスソスソスソスナゑソスソスうソス竝ソスソスソス生撰ソスソスソスソスAソス竝ソスソスソスソスソスソスソスソスソスソスソスソスソスソスソスソスlソス[ソスソスソスTソス[ソスoソスノ鯉ソスソスソス
ソス骼厄ソスナゑソスソスBソス答者は通常たソスソスソスlソス[ソスソスソスTソス[ソスoソスソスソスソスソスソスソスRソス[ソスhソスフ形ソスソスソスナどのサソス[ソスoソス[ソスソス
ソスqソスヒゑソスラゑソスソスソスソスソスソスノ具ソスソスヘなヒソスソスソスgソスソスソスソスソスツゑソスソスソスソスナゑソスソス蛯、ソスAソスソスソスソスソスト奇ソス{ソスソスソスノ会ソスソスソスソスト厄ソス
ソスソスソスソスソスソスソスCソスソスソスソスソスソスソスソスAソスソスソス]ソスソスソスoソスノ望ソスワゑソスソスソスソスソスソスノゑソスソス゚ゑソスソスlソス[ソスソスソスTソス[ソスoソスソスソスソスソスソスソスマ任
ソスソスソスソスソスノ会ソスソスソスソストソスソス]ソスソスソスoソスソスソスqソスヒゑソスlソス[ソスソスソスTソス[ソスoソスフ集ソスソスソスソスソスCソスソスソスソスソスネゑソスソスソスホなゑソスネゑソスソスソス
ソスソスソスソスソスソスワゑソスソスソスBソスNソスソスソスCソスAソスソスソスgソスノゑソスソスソスト具ソスソス゚ゑソス黷スソスソスソスフほゑソスソスノ、ソスソスソス]ソスソスソスoソスヘ連ソスソス
ソスソスソスソス閧スソスソスソスlソス[ソスソスソスTソス[ソスoソスフアソスhソスソスソスXソスソスソスソスソス閧キソス驍スソス゚要ソスソスソスソスソスネゑソスソスソスホなゑソスネゑソスソスソスソスソス
ソスソスソスソスワゑソスソスソスB

In any case, the model used in this memo assumes that the resolver is
multiplexing attention between multiple requests, some from the client,
and some internally generated.  Each request is represented by some
state information, and the desired behavior is that the resolver
transmit queries to name servers in a way that maximizes the probability
that the request is answered, minimizes the time that the request takes,
and avoids excessive transmissions.  The key algorithm uses the state
information of the request to select the next name server address to
query, and also computes a timeout which will cause the next action
should a response not arrive.  The next action will usually be a
transmission to some other server, but may be a temporary error to the
client.
ソスヌゑソスネ場合ソスナゑソスソスAソスソスソスフソスソスソスソスナ使ソスソス黷スソスソスソスfソスソスソスヘゑソスソスソスソスソスソスソス閧オソスワゑソスソスBソスソスソス]ソスソスソスoソスヘク
ソスソスソスCソスAソスソスソスgソスソスソスソスvソスソスソスソスソス黷スソスvソスソスソスニ難ソスソスソスソスナ撰ソスソスソスソスソスソス黷スソスvソスソスソスフ、ソスソスソスdソスフ要ソスソスソスソスソスソスソスソスソスソス
ソスワゑソスソスBソスeソスvソスソスソスソスソスソスソスソスソスヤ擾ソスソスナ表ソスソスソスソスAソスソスソスソスソスト望ソスワゑソスソスソスソスsソスソスソスヘソスソスNソスGソスXソスgソスソスソスソスソスソス
ソスソスソスソスツ能ソスソスソスソスソスナ托ソスノゑソスソスソスソスソス@ソスナソスソス]ソスソスソスoソスソスソスlソス[ソスソスソスTソス[ソスoソスノ問合ソスソスソスソス`ソスBソスソスソス驍ア
ソスニで、ソスソスソスNソスGソスXソスgソスソスソスvソスソスソス骼橸ソスヤゑソスソスナ擾ソスソスノゑソスソスAソスノ端ソスネ托ソスソスMソスソスソスソスソスソスワゑソスソスBソスソスソスAソスソスソスSソスソス
ソスYソスソスソスヘ照会すソス骼滂ソスフネソス[ソスソスソスTソス[ソスoソスAソスhソスソスソスXソスソスIソスヤゑソスソス゚に要ソスソスソスソスヤ擾ソスソスソスソスgソスソスソスAソスソス
ソスソスソスト回答ゑソスソスソスソスソスソスソスソスネゑソスソスソスソスソスソスソスソスフ行ソスソスソスソスソスNソスソスソスソスソス^ソスCソスソスソスAソスEソスgソスソスソスvソスZソスソスソスワゑソスソスBソスソスソスフ行
ソスソスソスヘ通常何ソスソスソスソスソスフサソス[ソスoソス[ソスヨの転ソスソスソスナゑソスソスがソスAソスNソスソスソスCソスAソスソスソスgソスヨ一時ソスIソスGソスソスソス[ソスソス
ソス驍ゥソスソスソスソスソスソスワゑソスソスソスB

The resolver always starts with a list of server names to query (SLIST).
This list will be all NS RRs which correspond to the nearest ancestor
zone that the resolver knows about.  To avoid startup problems, the
resolver should have a set of default servers which it will ask should
it have no current NS RRs which are appropriate.  The resolver then adds
to SLIST all of the known addresses for the name servers, and may start
parallel requests to acquire the addresses of the servers when the
resolver has the name, but no addresses, for the name servers.
ソスソスソス]ソスソスソスoソスヘ擾ソスノ照会すソスソスラゑソスソスTソス[ソスoソス[ソスソスソスフソスソスXソスgソスiSLISTソスjソスソスソスソスnソス゚まゑソスソスBソスソスソスソス
ソスソスソスXソスgソスヘソスソス]ソスソスソスoソスソスソスmソスソスソストゑソスソスソスナゑソスソス゚ゑソスソスフ撰ソスcソス]ソス[ソスソスソスノ対会ソスソスソスソス驍キソスラてのネソス[ソスソス
ソスTソス[ソスoソスソスソスソスソスソスソスRソス[ソスhソスナゑソスソス蛯、ソスBソスNソスソスソスソスソスフ厄ソスソスソスソスソスソスソス驍スソス゚、ソスソスソスソスソスKソスリな鯉ソスソスンゑソス
ソスlソス[ソスソスソスTソス[ソスoソスソスソスソスソスソスソスRソス[ソスhソスソスソスソスソスソスソスネゑソスソスソスホ、ソスソスソス]ソスソスソスoソスヘゑソスソスソスソスqソスヒゑソスfソスtソスHソスソスソスg
ソスTソス[ソスoソス[ソスフセソスbソスgソスソスソスソスソスツべゑソスソスナゑソスソスBソスソスソス]ソスソスソスoソスヘサソス[ソスoソス[ソスソスソスXソスgソスノネソス[ソスソスソスTソス[ソスoソスソス
ソスソスソスmソスフ全ソストのアソスhソスソスソスXソスソスソスソスソスソスソスAソスソスソス]ソスソスソスoソスソスソスlソス[ソスソスソスTソス[ソスoソスフ厄ソスソスOソスネ外ソスAソスhソスソスソスXソスソスソスソス
ソスソスソスネゑソスソスネゑソスホ、ソスTソス[ソスoソス[ソスフアソスhソスソスソスXソスソスソスlソスソスソスソスソス髟スソスsソスソスソスソスソスvソスソスソスソスソスnソス゚てゑソスソス謔「ソスナゑソスソスB

To complete initialization of SLIST, the resolver attaches whatever
history information it has to the each address in SLIST.  This will
usually consist of some sort of weighted averages for the response time
of the address, and the batting average of the address (i.e., how often
the address responded at all to the request).  Note that this
information should be kept on a per address basis, rather than on a per
name server basis, because the response time and batting average of a
particular server may vary considerably from address to address.  Note
also that this information is actually specific to a resolver address /
server address pair, so a resolver with multiple addresses may wish to
keep separate histories for each of its addresses.  Part of this step
must deal with addresses which have no such history; in this case an
expected round trip time of 5-10 seconds should be the worst case, with
lower estimates for the same local network, etc.
ソスTソス[ソスoソス[ソスソスソスXソスgソスフ擾ソスソスソスソスソスソスソスソスソスソスソスソスソスソス驍スソス゚に、ソスソスソス]ソスソスソスoソスヘサソス[ソスoソスソスソスXソスgソスフ各ソスAソスhソスソス
ソスXソスノ暦ソスソスソスソスソスソスソスtソスソスソスソスソスワゑソスソスBソスソスソスソスヘ通擾ソスAソスhソスソスソスXソスフ会ソスソスソスソスソスソスヤとアソスhソスソスソスXソス答暦ソス
ソスiソスソスソスフアソスhソスソスソスXソスソスソスヌのゑソスソス轤「ソスvソスソスソスノ会ソスソスソスソスソスソスソスソスソスソスjソスフ擾ソスソスソスソスtソスソスソスソスソスソスソスソスソスナゑソスソス蛯、ソスB
ソスソスソスソスTソス[ソスoソスフ会ソスソスソスソスソスソスヤゑソス答暦ソスソスヘアソスhソスソスソスXソスソスソスノ搾ソスソスソスソスソスソスソスフで、ソスソスソスソスソスソスソスヤゑソス答暦ソス
ソスヘネソス[ソスソスソスTソス[ソスoソスソスソスナはなゑソスソスAソスhソスソスソスXソスソスソスノ保管ゑソスソスソスソスラゑソスソスナゑソスソスBソスワゑソスソスソスソスフ擾ソスがソス
ソス]ソスソスソスoソスAソスhソスソスソスXソスニサソス[ソスoソス[ソスAソスhソスソスソスXソスフ対厄ソスソスノ難ソスソスLソスネゑソスソスニに抵ソスソスモゑソスソストゑソスソスソスソスソスソスソスソスAソスソス
ソスソスソスフアソスhソスソスソスXソスソスソスソスソスツソスソス]ソスソスソスoソスソスソスeソスAソスhソスソスソスXソスソスソスフ暦ソスソスソスソスフ保趣ソスソスソス]ソズゑソスソスソスソスソスソスソスネゑソスソスB
ソスソスソスフスソスeソスbソスvソスナ暦ソスソスソスソスソスソスソスソスソスソスネゑソスソスAソスhソスソスソスXソスソスソスソスソスソスネゑソスソストはなゑソスワゑソスソスソスGソスソスソスフ場合
ソスTソス|ソスPソスOソスbソスフ会ソスソスソスソスソスソスヤゑソスソスナ茨ソスソスフ場合ソスナ、ソスソスソス[ソスJソスソスソスlソスbソスgソスソスソス[ソスNソスナはゑソスソス痰ュソスソスソスソス
ソスソスソスソスラゑソスソスナゑソスソスB

Note that whenever a delegation is followed, the resolver algorithm
reinitializes SLIST.
ソスマ任ソスソスソスsソスソスソス骼橸ソスヘゑソスソスツでゑソスソスAソスソスソス]ソスソスソスoソスAソスソスソスSソスソスソスYソスソスソスソスソスTソス[ソスoソス[ソスソスソスXソスgソスソスソスト擾ソスソスソス
ソスソスソスソスソス驍アソスニに抵ソスソスモゑソスソストゑソスソスソスソスソスソスソスソスB

The information establishes a partial ranking of the available name
server addresses.  Each time an address is chosen and the state should
be altered to prevent its selection again until all other addresses have
been tried.  The timeout for each transmission should be 50-100% greater
than the average predicted value to allow for variance in response.
ソスソスソスヘ暦ソスソスpソスツ能ソスネネソス[ソスソスソスTソス[ソスoソスAソスhソスソスソスXソスフ包ソスソスソスソスIソスネ擾ソスソスハゑソスソスmソスソスソスソスソスワゑソスソスBソスAソスhソスソスソスX
ソスソスソスIソスソスソスソスソスソスソスニ、ソスソスソスラての托ソスソスフアソスhソスソスソスXソスソスソスソスソスソスソスソスソスワで再び難ソスソスソスソスAソスhソスソスソスXソスソスIソスソス
ソスソスソスネゑソスソス謔、ソスノ、ソスソスヤゑソスマ会ソスソスソスソスソスソスワゑソスソスBソスeソス]ソスソスソスフタソスCソスソスソスAソスEソスgソスヘ包ソスソスUソスソスソスlソスソスソスソスソスト包ソス
ソスマ予ソスソスソスlソスソスソスTソスO-ソスPソスOソスOソスソスソス蛯ォソスソスソスソスソスソスラゑソスソスナゑソスソスB

Some fine points:
ソスソスソスソスソスソスソスソスネポソスCソスソスソスgソスF

   - The resolver may encounter a situation where no addresses are
     available for any of the name servers named in SLIST, and
     where the servers in the list are precisely those which would
     normally be used to look up their own addresses.  This
     situation typically occurs when the glue address RRs have a
     smaller TTL than the NS RRs marking delegation, or when the
     resolver caches the result of a NS search.  The resolver
     should detect this condition and restart the search at the
     next ancestor zone, or alternatively at the root.
   - ソスソスソス]ソスソスソスoソスヘサソス[ソスoソス[ソスソスソスXソスgソスナ指ソス閧ウソス黷スソスlソス[ソスソスソスTソス[ソスoソスフ全ソストゑソスソスソスソスpソスツ能ソスソス
     ソスネゑソスソスAソスソスソスXソスgソスソスソスフサソス[ソスoソス[ソスソスソスソスソスフサソス[ソスoソスソスソスgソスフアソスhソスソスソスXソスノ問いソスソスソスせソスネゑソス
     ソスニ鯉ソスソスソスソスナゑソスソスソスソスソスヤに托ソスソスソスソスソスソス驍ゥソスソスソスソスソスソスワゑソスソスソスBソスソスソスフ擾ソスヤは茨ソスハに、ソスレ抵ソスソスソス
     ソスAソスhソスソスソスXソスソスソスソスソスソスソスRソス[ソスhソスフ撰ソスソスソスソスソスソスヤゑソスソスマ任ソスソスソスソスソスlソス[ソスソスソスTソス[ソスoソスソスソスソスソスソスソスRソス[ソスh
     ソスフ撰ソスソスソスソスソスソスヤゑソス闖ャソスソスソスソスソスニゑソスソスソスAソスソスソスソスソスソス黷ェソスlソス[ソスソスソスTソス[ソスoソスソスソスソスソスソスソスLソスソスソスbソスVソスソス
     ソスソスソストゑソス鼾ソスノ、ソスソスソスンゑソスソスワゑソスソスBソスソスソス]ソスソスソスoソスヘゑソスソスフ擾ソスヤゑソスソスソスソスoソスソスソスAソスソスソスフ撰ソスcソス]ソス[
     ソスソスソスソスソスソスAソスソスソス驍「ソスヘソスソス[ソスgソスソスソスソス{ソスソスソスソスソスト開ソスソスソスソスラゑソスソスナゑソスソスB

   - If a resolver gets a server error or other bizarre response
     from a name server, it should remove it from SLIST, and may
     wish to schedule an immediate transmission to the next
     candidate server address.
   - ソスソスソスソスソスソスソス]ソスソスソスoソスソスソスlソス[ソスソスソスTソス[ソスoソス[ソスソスソスソスTソス[ソスoソス[ソスGソスソスソス[ソス竭シソスフ奇ソスルな費ソスソスソスソスソス
     ソスソスネゑソスAソスソスソスフネソス[ソスソスソスTソス[ソスoソスソスソスTソス[ソスoソスソスソスXソスgソスソスソス迴懶ソスソスソスAソスソスソスフ鯉ソスソスTソス[ソスoソス[ソスA
     ソスhソスソスソスXソスノ托ソスソスソスソスソスソスMソスソスソス驍アソスニゑソス]ソズゑソスソスソスソスソスソスソスワゑソスソスソスB

7.3. Processing responses
7.3. ソスソスソスソスソスソス

The first step in processing arriving response datagrams is to parse the
response.  This procedure should include:
ソスけ趣ソスソスソスソスソス答デソス[ソス^ソスOソスソスソスソスソスソスソスソスソスソスソスソスソスソスナ擾ソスソスフ手順ソスヘ回答ゑソスソスソスヘゑソスソス驍アソスニでゑソスソスB
ソスソスソスフ手順ソスソスソスネ会ソスソスソスソスワむべゑソスソスナゑソスソスF

   - Check the header for reasonableness.  Discard datagrams which
     are queries when responses are expected.
   - ソスwソスbソス_ソスソスソスソスソスソスソスIソスソスソス`ソスFソスbソスNソスソスソスワゑソスソスBソス答ゑソスソスソスソスメゑソスソスソスソスフに問合ソスソスソスナゑソスソスソスfソス[
     ソス^ソスOソスソスソスソスソスソスソスフててゑソスソスソスソスソスソスソスソスB

   - Parse the sections of the message, and insure that all RRs are
     correctly formatted.
   - ソスソスソスbソスZソス[ソスWソスフ各ソスソスソスソスソスソスヘゑソスソスAソスソスソスラての趣ソスソスソスソスソスソスRソス[ソスhソスソスソスソスソスmソスtソスHソス[ソス}ソスbソスgソスソス
     ソスソスソス驍アソスニゑソスロ証ゑソスソストゑソスソスソスソスソスソスソスソスB

   - As an optional step, check the TTLs of arriving data looking
     for RRs with excessively long TTLs.  If a RR has an
     excessively long TTL, say greater than 1 week, either discard
     the whole response, or limit all TTLs in the response to 1
     week.
   - ソスモの手順ソスニゑソスソスト、ソスソスソスソスソスソスソスヤゑソスソスソスソスソスソスソスソスソスソスソスソスソスソスソスソスソスソスRソス[ソスhソスソスソスネゑソスソスソスソスmソスFソスソスソストゑソス
     ソスソスソスソスソスソスソスBソスソスソスソスソスソスソスソスソスソスソスRソス[ソスhソスフ撰ソスソスソスソスソスソスヤゑソスソスソスソスソスソスソスソスソスソスソスソスネゑソスAソス痰ヲソスホ1ソスTソスヤ茨ソス
     ソスソスネゑソスAソス答全ソスフゑソスソスフてるかソスAソスソスソスラての回答の撰ソスソスソスソスソスソスヤゑソスソスPソスTソスヤに撰ソスソスソスソスソス
     ソストゑソスソスソスソスソスソスソスソスB

The next step is to match the response to a current resolver request.
The recommended strategy is to do a preliminary matching using the ID
field in the domain header, and then to verify that the question section
corresponds to the information currently desired.  This requires that
the transmission algorithm devote several bits of the domain ID field to
a request identifier of some sort.  This step has several fine points:
ソスソスソスフ手順ソスヘ鯉ソスソスンのソスソス]ソスソスソスoソスvソスソスソスノ対ゑソスソスソス答と茨ソスvソスソスソス驍アソスニでゑソスソスBソスソスソスEソスソスソス黷スソスソス
ソスソスソスヘドソスソスソスCソスソスソスwソスbソス_ソス[ソスナ趣ソスソスハ子ソスtソスBソス[ソスソスソスhソスソスソスgソスソスソスト茨ソスvソスソスソスソスソスソスフゑソスソスソスソスOソスソスソスソスソスソスソスA
ソスソスソスノ趣ソスソス笊費ソスソスソス]ソスワゑソスソスソスソスソスソスノ対会ソスソスソスソス驍アソスニゑソスソスmソスソスソス゚る事ソスナゑソスソスBソスソスソスソスヘ托ソスソスMソスAソスソスソスS
ソスソスソスYソスソスソスソスソスhソスソスソスCソスソスソスソスソスハ子ソスフ会ソスソスrソスbソスgソスソスソスソスソスソスソスbソスZソス[ソスWソスフ包ソスソズに使ソスソスソス驍アソスニゑソスvソスソスソスソス
ソスワゑソスソスBソスソスソスフ手順ソスノはゑソスソスソスソスツゑソスソスフ費ソスソスソスソスネポソスCソスソスソスgソスソスソスソスソスソスワゑソスソスF

   - Some name servers send their responses from different
     addresses than the one used to receive the query.  That is, a
     resolver cannot rely that a response will come from the same
     address which it sent the corresponding query to.  This name
     server bug is typically encountered in UNIX systems.
   - ソスソスソスソスlソス[ソスソスソスTソス[ソスoソス[ソスソスソス竝ソスソスソスソスソスソスMソスソスソスソスフに使ソスソスソスソスソスフと異なゑソスAソスhソスソスソスXソスソス
     ソスソス答を送ゑソスワゑソスソスBソスソスソスネわちソスAソスソスソスソスニ難ソスソスソスソスAソスhソスソスソスXソスナ回答ゑソスメつソスソス]ソスソスソスo
     ソスソスソスソスソスソスソスナゑソスソスワゑソスソスソスBソスソスソスフネソス[ソスソスソスTソス[ソスoソスoソスOソスヘUソスmソスhソスwソスVソスXソスeソスソスソスナ典ソス^ソスIソスソス
     ソスソスソスソスソスソスソスワゑソスソスB

   - If the resolver retransmits a particular request to a name
     server it should be able to use a response from any of the
     transmissions.  However, if it is using the response to sample
     the round trip time to access the name server, it must be able
     to determine which transmission matches the response (and keep
     transmission times for each outgoing message), or only
     calculate round trip times based on initial transmissions.
   - ソスソスソスソスソスソスソス]ソスソスソスoソスソスソスlソス[ソスソスソスTソス[ソスoソスノゑソスソス驛奇ソスNソスGソスXソスgソスソスソスト托ソスソスソスソスソスネゑソスAソスヌの会ソス
     ソスフゑソスソスgソスソスソスソス謔、ソスノゑソスソスラゑソスソスナゑソスソスBソスソスソスソスソスソスソスAソス答ゑソスソスソスソスソスソスlソス[ソスソスソスTソス[ソスoソス[ソスノアソスN
     ソスZソスXソスソスソス驩晢ソスソスソスソスソスヤを調べゑソスネゑソスAソスヌの托ソスソスMソスニどの回答ゑソスソスホ会ソスソスソスソス驍ゥソスソスソスソスソス
     ソスソスソスソス謔、ソスノゑソスソス驍ゥソスiソスソスソスソスソスト全ソストの托ソスソスMソスソスソスbソスZソス[ソスWソスフ托ソスソスMソスソスソスヤゑソスロ趣ソスソスソスソスソスjソスA
     ソスナ擾ソスソスフ托ソスソスMソスノ奇ソステゑソスソスト会ソスソスソスソスソスソスヤゑソスソスvソスZソスソスソスネゑソスソスソスホなゑソスワゑソスソスソスB

   - A name server will occasionally not have a current copy of a
     zone which it should have according to some NS RRs.  The
     resolver should simply remove the name server from the current
     SLIST, and continue.
   - ソスlソス[ソスソスソスTソス[ソスoソスソスソスソスソスワゑソスソスソスlソス[ソスソスソスTソス[ソスoソスソスソスソスソスソスソスRソス[ソスhソスノ関ゑソスソスソス]ソス[ソスソスソスフ最新
     ソスフコソスsソス[ソスソスソスソスソスソスソスネゑソスソスナゑソスソス蛯、ソスBソスソスソス]ソスソスソスoソスヘゑソスソスソスソスlソス[ソスソスソスTソス[ソスoソスソスソスソスソスンのサソス[
     ソスoソスソスソスXソスgソスソスソス迴懶ソスソスソスAソスpソスソスソスソスソスソスラゑソスソスナゑソスソスB

7.4. Using the cache
7.4. ソスLソスソスソスbソスVソスソスソスフ使ソスp

In general, we expect a resolver to cache all data which it receives in
responses since it may be useful in answering future client requests.
However, there are several types of data which should not be cached:
ソスソスハに、ソスソスソス]ソスソスソスoソスヘ厄ソスソスソスソスフクソスソスソスCソスAソスソスソスgソスvソスソスソスノ難ソスソスソスソスソスロに有ソスpソスソスソスソスソスソスソスソスネゑソスソスフで、
ソス答で受け趣ソス驍キソスラてのデソス[ソス^ソスソスソスLソスソスソスbソスVソスソスソスソスソス驍アソスニゑソスソスソスソスメゑソスソスワゑソスソスBソスソスソスソスソスソスソスネゑソス
ソスソスAソスLソスソスソスbソスVソスソスソスソスソスラゑソスソスナはなゑソスソスソスソスソスソスツゑソスソスフ趣ソズのデソス[ソス^ソスソスソスソスソスソスワゑソスソスF

   - When several RRs of the same type are available for a
     particular owner name, the resolver should either cache them
     all or none at all.  When a response is truncated, and a
     resolver doesn't know whether it has a complete set, it should
     not cache a possibly partial set of RRs.
   - ソスソスソス髀奇ソスLソスメ厄ソスソスフ難ソスソスソスソスソズのゑソスソスソスソスツゑソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスソスソスソスソスpソスツ能ソスネ趣ソスソスAソスソスソス]
     ソスソスソスoソスヘゑソスソスソスソスSソストゑソスソスLソスソスソスbソスVソスソスソスソスソス驍ゥソスAソスSソストキソスソスソスbソスVソスソスソスソスソスネゑソスソスソスソスニゑソスソスラゑソス
     ソスナゑソスソスBソス答ゑソスソスリり落ソスニゑソスソスソスAソスソスソス]ソスソスソスoソスソスソスソスソスSソスネ回答集ソスソスソスソスソスソスソスソスソストゑソスソス驍ゥソスm
     ソスソスネゑソスソスソスソスAソスソスソスソスソスIソスネ趣ソスソスソスソスソスソスRソス[ソスhソスWソスソスソスソスソスLソスソスソスbソスVソスソスソスソスソスラゑソスソスナはゑソスソスソスワゑソスソスソスB

   - Cached data should never be used in preference to
     authoritative data, so if caching would cause this to happen
     the data should not be cached.
   - ソスLソスソスソスbソスVソスソスソスソスソス黷スソスfソス[ソス^ソスソスソスソスソスソスソスト撰ソスソスソスソスネデソス[ソス^ソスノ対ゑソスソスト優ソスソスIソスノ使ソスソスソスソス
     ソスラゑソスソスナゑソスソスソスワゑソスソスソスAソスソスソスソスソスLソスソスソスbソスVソスソスソスナゑソスソス黷ェソスソスソスソスソスソスネゑソスAソスfソス[ソス^ソスヘキソスソスソスb
     ソスVソスソスソスソスソスラゑソスソスナはゑソスソスソスワゑソスソスソスB

   - The results of an inverse query should not be cached.
   - ソスtソス竝ソスソスソスフ鯉ソスソスハはキソスソスソスbソスVソスソスソスソスソスラゑソスソスナはゑソスソスソスワゑソスソスソスB

   - The results of standard queries where the QNAME contains "*"
     labels if the data might be used to construct wildcards.  The
     reason is that the cache does not necessarily contain existing
     RRs or zone boundary information which is necessary to
     restrict the application of the wildcard RRs.
   - ソスソスソスCソスソスソスhソスJソス[ソスhソスソスソスソスソスレ的ソスフ問合ソスソスソスソスソスソス"*"ソスソスソスxソスソスソスソスソスワむ標ソスソスソス竝ソスソスソスフ、ソスソス
     ソスハ。ソスソスソスRソスヘキソスソスソスbソスVソスソスソスソスソスソスソスCソスソスソスhソスJソス[ソスhソスソスソスソスソスソスソスRソス[ソスhソスフアソスvソスソスソスPソス[ソスVソスソスソスソス
     ソスソスソスソスソス閧キソス驍スソス゚に必ソスvソスネ奇ソスソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスソス]ソス[ソスソスソスソスソスEソスフ擾ソスソスソスソスワゑソスソス
     ソスソスソスネゑソスソスソスソスソスナゑソスソスB

   - RR data in responses of dubious reliability.  When a resolver
     receives unsolicited responses or RR data other than that
     requested, it should discard it without caching it.  The basic
     implication is that all sanity checks on a packet should be
     performed before any of it is cached.
   - ソスMソスソスソスソスソスフ疑ソスしソスソスソス答の趣ソスソスソスソスソスソスRソス[ソスhソスfソス[ソス^ソスBソスソスソス]ソスソスソスoソスソスソス]ソスワなゑソスソス答ゑソス
     ソスソスソス゚ゑソス黷スソスソスソスフ以外ソスフ趣ソスソスソスソスソスソスRソス[ソスhソスqソスqソスfソス[ソス^ソスソスソスけとる時ソスAソスソスソスソスソスソスLソスソスソスb
     ソスVソスソスソスソスソスネゑソスソスフてゑソスラゑソスソスナゑソスソスBソスソス{ソスIソスネ意厄ソスソスヘゑソスソスラてのパソスPソスbソスgソスフ茨ソスソスSソス_ソスソス
     ソスソスソスAソスソスソスソスソスソスLソスソスソスbソスVソスソスソスソスソスソスOソスノ行ソスソスソスラゑソスソスナゑソスソスソスニゑソスソスソスソスソスソスニでゑソスソスB

In a similar vein, when a resolver has a set of RRs for some name in a
response, and wants to cache the RRs, it should check its cache for
already existing RRs.  Depending on the circumstances, either the data
in the response or the cache is preferred, but the two should never be
combined.  If the data in the response is from authoritative data in the
answer section, it is always preferred.
ソズ趣ソスソスフ傾ソスソスソスナ、ソスソスソス]ソスソスソスoソスソスソスソスソス髢シソスOソスフ趣ソスソスソスソスソスソスRソス[ソスhソスフ回答難ソスソスト、ソスソスソスフ趣ソスソスソスソスソスソスRソス[
ソスhソスソスソスLソスソスソスbソスVソスソスソスソスソス驍アソスニゑソス]ソズ趣ソスソスAソスソスソスナに奇ソスソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスソスソスネゑソスソスソスソスLソスソスソスbソスVソスソス
ソスソスソス`ソスFソスbソスNソスソスソスソスラゑソスソスナゑソスソスBソス況にゑソスソスソスト、ソス答のデソス[ソス^ソスソスソスLソスソスソスbソスVソスソスソスフデソス[ソス^ソスソス
ソスDソス謔ウソスソスワゑソスソスAソスソスソスソスソスソスソスソスソスフ2ソスツは鯉ソスソスソスソスソスソスソスソスラゑソスソスナはゑソスソスソスワゑソスソスソスBソスソスソスソスソス答のデソス[
ソス^ソスソスソス答包ソスソスナ撰ソスソスソスソスネデソス[ソス^ソスネゑソスAソスソスノ優ソス謔ウソスソスワゑソスソスB

8. MAIL SUPPORT
8. ソスソスソス[ソスソスソスTソス|ソス[ソスg

The domain system defines a standard for mapping mailboxes into domain
names, and two methods for using the mailbox information to derive mail
routing information.  The first method is called mail exchange binding
and the other method is mailbox binding.  The mailbox encoding standard
and mail exchange binding are part of the DNS official protocol, and are
the recommended method for mail routing in the Internet.  Mailbox
binding is an experimental feature which is still under development and
subject to change.
ソスhソスソスソスCソスソスソスVソスXソスeソスソスソスヘドソスソスソスCソスソスソスソスソスフ抵ソスソスノソスソス[ソスソスソス{ソスbソスNソスXソスソスソス}ソスbソスvソスソスソスソスWソスソスソスニ、ソスソスソス[
ソスソスソスzソスMソスソスソス得るたソス゚のソスソス[ソスソスソス{ソスbソスNソスXソスソスソスソスソスgソスソスソスQソスツの包ソスソス@ソスソスソス`ソスソスソスワゑソスソスBソスソス
ソスソスソスフ包ソスソス@ソスヘソスソス[ソスソスソスソスソスソスソスソスソスtソスニ呼ばゑソスAソスソスソスフ包ソスソス@ソスヘソスソス[ソスソスソス{ソスbソスNソスXソスソスソスtソスナゑソスソスBソスソスソス[
ソスソスソス{ソスbソスNソスXソスRソス[ソスfソスBソスソスソスOソスWソスソスソスニソスソス[ソスソスソスソスソスソスソスソスソスtソスヘDソスmソスrソスソスソスソスソスvソスソスソスgソスRソスソスソスフ一部ソスソス
ソスソスソスソスAソスCソスソスソス^ソス[ソスlソスbソスgソスナソスソス[ソスソスソスzソスMソスフ撰ソスソスEソスソスソス黷スソスソスソス@ソスナゑソスソスBソスソスソス[ソスソスソス{ソスbソスNソスXソスソスソスt
ソスソスソスソスソスソスソスIソス@ソス\ソスナ開ソスソスソスソスソスナゑソスソスソスマ会ソスソスフ可能ソスソスソスソスソスソスソスソスワゑソスソスB

The mailbox encoding standard assumes a mailbox name of the form
"<local-part>@<mail-domain>".  While the syntax allowed in each of these
sections varies substantially between the various mail internets, the
preferred syntax for the ARPA Internet is given in [RFC-822].
ソスソスソス[ソスソスソス{ソスbソスNソスXソスRソス[ソスfソスBソスソスソスOソスWソスソスソスソス"<local-part>@<mail-domain>"ソス`ソスソスソスフソスソス[ソスソス
ソス{ソスbソスNソスXソスソスソスソスzソス閧オソスワゑソスソスBソスソスソスソスソスフ章の構ソスソスソスヘイソスソスソス^ソス[ソスlソスbソスgソスソスソス[ソスソスソスフ托ソスソスlソスソスソスソス
ソスソスソス゚十ソスソスソスソスソスlソスナゑソスソスソスソスAARPAソスCソスソスソス^ソス[ソスlソスbソスgソスフ望ソスワゑソスソスソスソス\ソスソスソスソス[RFC-822]ソスノゑソスソスソスワゑソスソスB

The DNS encodes the <local-part> as a single label, and encodes the
<mail-domain> as a domain name.  The single label from the <local-part>
is prefaced to the domain name from <mail-domain> to form the domain
name corresponding to the mailbox.  Thus the mailbox HOSTMASTER@SRI-
NIC.ARPA is mapped into the domain name HOSTMASTER.SRI-NIC.ARPA.  If the
<local-part> contains dots or other special characters, its
representation in a master file will require the use of backslash
quoting to ensure that the domain name is properly encoded.  For
example, the mailbox [email protected] would be represented as
Action\.domains.ISI.EDU.
ソスcソスmソスrソスヘひとつのソスソスxソスソスソスニゑソスソスソス<local-part>ソスソスソスRソス[ソスhソスソスソスソスソスAソスhソスソスソスCソスソスソスソスソスニゑソスソスソス
<mail-domain>ソスソスソスRソス[ソスhソスソスソスソスソスワゑソスソスBソスソスソス[ソスソスソス{ソスbソスNソスXソスノ対会ソスソスソスソストゑソスソスソスhソスソスソスCソスソスソスソスソスソス
ソス\ソスソスソスソスソス驍スソス゚に、<mail-domain>ソスフ前ソスソス<local-part>ソスソスソスtソスソスソスワゑソスソスBソスソスソスソスナソスソス[ソスソス
ソス{ソスbソスNソスXHOSTMASTER@SRI- NIC.ARPAソスヘドソスソスソスCソスソスソスソスHOSTMASTER.SRI-NIC.ARPA.ソスノ包ソス
ソスソスソスソスソスソスワゑソスソスBソスソスソスソス<local-part>ソスソスソスhソスbソスgソス竭シソスフ難ソスソスハな包ソスソスソスソスソスソスワむなゑソスAソス}ソスXソス^ソス[
ソスtソス@ソスCソスソスソスソスソスナバソスbソスNソスXソスソスソスbソスVソスソスソスナ茨ソスソスpソスソスソスト表ソスソスソスソスソス驍アソスニでドソスソスソスCソスソスソスソスソスソスソスソスソスmソスノコソス[
ソスhソスソスソスソスソスソス驍アソスニゑソスロ証ゑソスソスソス謔、ソスノ要ソスソスソスソスソスソスワゑソスソスBソス痰ヲソスホ、ソスソスソス[ソスソスソス{ソスbソスNソスX
[email protected]ソスソスAction\.domains.ISI.EDUソスニ表ソスソスソスソスソスソスワゑソスソスB

8.1. Mail exchange binding
8.1. ソスソスソス[ソスソスソスソスソスソスソスソスソスt

Mail exchange binding uses the <mail-domain> part of a mailbox
specification to determine where mail should be sent.  The <local-part>
is not even consulted.  [RFC-974] specifies this method in detail, and
should be consulted before attempting to use mail exchange support.
ソスソスソス[ソスソスソスソスソスソスソスソスソスソスソスナソスソス[ソスソスソス{ソスbソスNソスXソスdソスlソスソスソスソス<mail-domain>ソスソスソスソスソスソスソスソスソス[ソスソスソスフ托ソスソスソスソス
ソスソスソスソスソス閧キソスソスフに使ソスソスソスワゑソスソスB<local-part>ソスヘ抵ソスソスラゑソスソスワゑソスソスソスB[RFC-974]ソスソスソスソスソスフ包ソス
ソス@ソスフ詳細ゑソスソスwソス閧オソスAソスソスソス[ソスソスソスソスソスソスソスソスソスgソスソスソスOソスノ抵ソスソスラゑソスソスソスラゑソスソスナゑソスソスB

One of the advantages of this method is that it decouples mail
destination naming from the hosts used to support mail service, at the
cost of another layer of indirection in the lookup function.  However,
the addition layer should eliminate the need for complicated "%", "!",
etc encodings in <local-part>.
ソスソスソスフ包ソスソス@ソスフ暦ソスソス_ソスフ1ソスツゑソスソスAソスソスソス[ソスソスソスTソス[ソスrソスXソスノ使ソスソスソスzソスXソスgソスニソスソス[ソスソスソスフ茨ソスソス譁シソスソスリゑソス
ソスソスソスソスソスソスソスAソスソスソスソスソス@ソス\ソスナ会ソスソスワわしソスwソスソスソスgソスソスソスRソスXソスgソスナゑソスソスBソスソスソスソスソスソスソスヌ会ソスソスwソスソス<local-part>
ソスフコソス[ソスfソスBソスソスソスOソスナ包ソスソスGソスソス"%"ソスソス"!"ソスフ必ソスvソスソスソスソスrソスソスソスソスソスソスラゑソスソスナゑソスソスソスB

The essence of the method is that the <mail-domain> is used as a domain
name to locate type MX RRs which list hosts willing to accept mail for
<mail-domain>, together with preference values which rank the hosts
according to an order specified by the administrators for <mail-domain>.
ソスソスソス@ソスフ本ソスソスソスヘ、<mail-domain>ソスヘソスソス[ソスソスソスソスソスソスソスソスソスソスソスソスソスRソス[ソスhソスソスソスノでドソスソスソスCソスソスソスソスソスニゑソス
ソスト用ソスソスソスソスソスAソスソスソスソスソスソスソスRソス[ソスhソスソス<mail-domain>ソスフソスソス[ソスソスソスソスソスソスソスソスソスzソスXソスgソスソスソスソスソスXソスgソスAソスb
ソスvソスソスソスA<mail-domain>ソスヌ暦ソスソスメの指ソス閧オソスソスソスソスソスソスソスソスソスソスソスソスソスDソスソスlソスナホソスXソスgソスソスソスソスラるこソスソス
ソスナゑソスソスB

In this memo, the <mail-domain> ISI.EDU is used in examples, together
with the hosts VENERA.ISI.EDU and VAXA.ISI.EDU as mail exchanges for
ISI.EDU.  If a mailer had a message for [email protected], it would
route it by looking up MX RRs for ISI.EDU.  The MX RRs at ISI.EDU name
VENERA.ISI.EDU and VAXA.ISI.EDU, and type A queries can find the host
addresses.
ソスソスソスフソスソスソスソスソス<mail-domain>ISI.EDUソスソスソスソスノ使ソスソスソスAソスzソスXソスgVENERA.ISI.EDUソスソス
VAXA.ISI.EDUソスソスISI.EDUソスフソスソス[ソスソスソスソスソスソスソスソスソスソスソスワゑソスソスBソスソスソスソスソスソスソス[ソスソスソスソスソスMソスメゑソス
[email protected]ソスヨのソスソスbソスZソス[ソスWソスソスソスソスソスソスソストゑソスソスソスソスソスAISI.EDUソスフソスソス[ソスソスソスソスソスソスソスソスソスソス
ソスソスソスRソス[ソスhソス調べて配ソスMソスoソスHソスソスソスソスソス゚ゑソスナゑソスソス蛯、ソスBISI.EDUソスフソスソス[ソスソスソスソスソスソスソスソスソスソスソスソスソスRソス[
ソスhソスソスVENERA.ISI.EDUソスソスVAXA.ISI.EDUソスフ厄ソスソスOソスソスソスソスソスソスソスAソスAソスhソスソスソスXソスソスハの趣ソスソスソスナホソスXソスg
ソスAソスhソスソスソスXソスソスソスソスソスツゑソスソスソスソスソスソスソスソスニゑソスソスナゑソスソスワゑソスソスB

8.2. Mailbox binding (Experimental)
8.2. ソスソスソス[ソスソスソス{ソスbソスNソスXソスソスソスt(ソスソスソスソスソスIソスj

In mailbox binding, the mailer uses the entire mail destination
specification to construct a domain name.  The encoded domain name for
the mailbox is used as the QNAME field in a QTYPE=MAILB query.
ソスソスソス[ソスソスソス{ソスbソスNソスXソスソスソスtソスナ、ソスソスソス[ソスソスソスソスソスMソスメはドソスソスソスCソスソスソスソスソスソスgソスン暦ソスソストるたソス゚に全ソスソスソスフソスソス[
ソスソスソスソスソスソスdソスlソスソスソスgソスソスソスワゑソスソスBソスソスソス[ソスソスソス{ソスbソスNソスXソスフゑソスソス゚のコソス[ソスhソスソスソスソスソス黷スソスhソスソスソスCソスソスソスソスソスヘ厄ソス
ソスソスソスソスソスソスハソスMAILBソスフ問合ソスソスソスソスハフソスBソス[ソスソスソスhソスソスpソスソスソスワゑソスソスB

Several outcomes are possible for this query:
ソスソスソスソスソスツゑソスソスフ鯉ソスソスハはゑソスソスフ趣ソスソスソスフゑソスソス゚に可能ソスナゑソスソスF

   1. The query can return a name error indicating that the mailbox
      does not exist as a domain name.
   1. ソス竝ソスソスソスヘソスソス[ソスソスソス{ソスbソスNソスXソスソスソスhソスソスソスCソスソスソスソスソスニゑソスソスト托ソスソスンゑソスソスネゑソスソスソスソスニゑソスソスソスソスソスソスソスソスOソスG
      ソスソスソス[ソスソスヤゑソスソスソスソスニゑソスソスナゑソスソスワゑソスソスB

      In the long term, this would indicate that the specified
      mailbox doesn't exist.  However, until the use of mailbox
      binding is universal, this error condition should be
      interpreted to mean that the organization identified by the
      global part does not support mailbox binding.  The
      appropriate procedure is to revert to exchange binding at
      this point.
      ソスソスソスソスソスヤ、ソスソスソスソスヘ指ソス閧ウソス黷スソスソスソス[ソスソスソス{ソスbソスNソスXソスソスソスソスソスンゑソスソスネゑソスソスソスソスニゑソスソスソスソスソスソスナゑソスソスソス
      ソスソスソスBソスソスソスソスソスソスソスAソスソスソス[ソスソスソス{ソスbソスNソスXソスソスソスtソスフ使ソスpソスソスソスソスハ的ソスノなゑソスワで、ソスソスソスフエソスソスソス[
      ソスソスソスソスソスヘソスソス[ソスソスソスAソスhソスソスソスXソスフグソスソスソス[ソスoソスソスソスネ包ソスソスソスソスノ趣ソスソスソスソスソスソスgソスDソスソスソスソスソス[ソスソスソス{ソスbソスN
      ソスXソスソスソスソスソスソスソスgソスpソスソスソストゑソスソスネゑソスソスソスソスニゑソスソスモ厄ソスソスソスソスソスニ会ソスソス゚ゑソスソスソスソスラゑソスソスナゑソスソスBソスKソスリな趣ソス
      ソスソスソスソスソスソスソスフ趣ソスソス_ソスナ鯉ソスソスソスソスソスソスtソスノ逆ソス゚りすソスソスヘゑソスソスナゑソスソスB

   2. The query can return a Mail Rename (MR) RR.
   2. ソス竝ソスソスソスヘソスソス[ソスソスソスソスソスソスソスiMRソスjソスソスソスソスソスソスソスRソス[ソスhソスソスヤゑソスソスソスソスニゑソスソスナゑソスソスワゑソスソスB

      The MR RR carries new mailbox specification in its RDATA
      field.  The mailer should replace the old mailbox with the
      new one and retry the operation.
      ソスソスソス[ソスソスソスソスソスソスソスソスソスソスソスソスソスRソス[ソスhソスヘゑソスソスフ趣ソスソスソスソスfソス[ソス^ソスtソスBソス[ソスソスソスhソスノ新ソスソスソスソスソスソスソス[ソスソスソス{ソスb
      ソスNソスXソスdソスlソスソスソスレゑソスソスワゑソスソスBソスソスソスCソスソスソス[ソスヘ古ゑソスソスソスソス[ソスソスソス{ソスbソスNソスXソスソスVソスソスソスソスソスナ置ソスソスソスソスソスソス
      ソスト、ソスソスソスソスソス続行ソスソスソスラゑソスソスナゑソスソスB

   3. The query can return a MB RR.
   3. ソス竝ソスソスソスヘソスソス[ソスソスソス{ソスbソスNソスXソスソスソスソスソスソスソスRソス[ソスhソスソスヤゑソスソスソスソスニゑソスソスナゑソスソスワゑソスソスB

      The MB RR carries a domain name for a host in its RDATA
      field.  The mailer should deliver the message to that host
      via whatever protocol is applicable, e.g., b,SMTP.
      ソスソスソス[ソスソスソス{ソスbソスNソスXソスソスソスソスソスソスソスRソス[ソスhソスソスソスソスソスソスソスfソス[ソス^ソスtソスBソス[ソスソスソスhソスナホソスXソスgソスフドソスソスソスCソスソス
      ソスソスソスソスソス^ソスムまゑソスソスBソスソスソス[ソスソスソスソスソスMソスメは、ソスKソスpソスツ能ソスネプソスソスソスgソスRソスソスソスナ、ソス痰ヲソスホSソスlソスs
      ソスoソスナ、ソスzソスXソスgソスヨソスソスbソスZソス[ソスWソスソスヘゑソスソスソスラゑソスソスナゑソスソスB

   4. The query can return one or more Mail Group (MG) RRs.
   4. ソス竝ソスソスソスヘ1ソスツ以擾ソスフソスソス[ソスソスソスOソスソスソス[ソスvソスソスソスソスソスソスソスRソス[ソスhソスソスヤゑソスソスソスソスニゑソスソスナゑソスソスワゑソスソスB

      This condition means that the mailbox was actually a mailing
      list or mail group, rather than a single mailbox.  Each MG RR
      has a RDATA field that identifies a mailbox that is a member
      of the group.  The mailer should deliver a copy of the
      message to each member.
      ソスソスソスフ擾ソスソスソスソスヘソスソス[ソスソスソス{ソスbソスNソスXソスソスソスAソスミとつのソスソス[ソスソスソス{ソスbソスNソスXソスナなゑソスソスAソスソスソスロはソスソス[
      ソスソスソスソスソスOソスソスソスXソスgソスソスソスソスソス[ソスソスソスOソスソスソス[ソスvソスナゑソスソスソスソスソスソスソスソスニゑソスソスモ厄ソスソスソスソスワゑソスソスBソスeソスソスソス[ソスソスソスOソスソスソス[
      ソスvソスソスソスソスソスソスソスRソス[ソスhソスソスソスOソスソスソス[ソスvソスフソスソスソスソスoソス[ソスナゑソスソス驛ソス[ソスソスソス{ソスbソスNソスXソスソスソスソスソスハゑソスソス骼
      ソスソスソスfソス[ソス^ソスtソスBソス[ソスソスソスhソスソスソスソスソスソスソストゑソスソスワゑソスソスBソスソスソス[ソスソスソスソスソスMソスメは各ソスソスソスソスソスoソス[ソスヨのソスソスb
      ソスZソス[ソスWソスフコソスsソス[ソスソスヘゑソスソスソスラゑソスソスナゑソスソスB

   5. The query can return a MB RR as well as one or more MG RRs.
   5. ソス竝ソスソスソスヘソスソス[ソスソスソス{ソスbソスNソスXソスソスソスソスソスソスソスRソス[ソスhソスニ1ソスツ以擾ソスフソスソス[ソスソスソスOソスソスソス[ソスvソスソスソスソスソスソス
      ソスRソス[ソスhソスソスヤゑソスソスソスソスニゑソスソスナゑソスソスワゑソスソスB

      This condition means the the mailbox was actually a mailing
      list.  The mailer can either deliver the message to the host
      specified by the MB RR, which will in turn do the delivery to
      all members, or the mailer can use the MG RRs to do the
      expansion itself.
      ソスソスソスフ擾ソスヤはソスソス[ソスソスソス{ソスbソスNソスXソスソスソスソスソスロはソスソス[ソスソスソスソスソスOソスソスソスXソスgソスナゑソスソス驍アソスニゑソスソスモ厄ソスソスソス
      ソスワゑソスソスBソスソスソス[ソスソスソスソスソスMソスメはソスソス[ソスソスソス{ソスbソスNソスXソスソスソスソスソスソスソスRソス[ソスhソスナ指ソス閧ウソスソスソスzソスXソスgソスソス
      ソスソスソスbソスZソス[ソスWソスソスヘゑソスソスAソスzソスXソスgソスソスソスソスソスラてのソスソスソスソスoソス[ソスノソスソス[ソスソスソスソスzソスBソスソスソス驍ゥソスAソスソスソス[
      ソスソスソスソスソスMソスメゑソスソスソスソス[ソスソスソスOソスソスソス[ソスvソスソスソスソスソスソスソスRソス[ソスhソスソスソスgソスソスソスト趣ソスソスソスソスナ配ソスBソスソスソス驍アソスニゑソスソスソス
      ソスソスソスワゑソスソスB

In any of these cases, the response may include a Mail Information
(MINFO) RR.  This RR is usually associated with a mail group, but is
legal with a MB.  The MINFO RR identifies two mailboxes.  One of these
identifies a responsible person for the original mailbox name.  This
mailbox should be used for requests to be added to a mail group, etc.
The second mailbox name in the MINFO RR identifies a mailbox that should
receive error messages for mail failures.  This is particularly
appropriate for mailing lists when errors in member names should be
reported to a person other than the one who sends a message to the list.
ソスソスソスソスソスフ場合ソスフゑソスソスソスソスソスソスソス答にソスソス[ソスソスソスソスソスiMINFOソスjソスソスソスソスソスソスソスRソス[ソスhソスソスソスワむゑソスソスソスソスソス
ソスソスワゑソスソスソスBソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスヘ通常メソス[ソスソスソスOソスソスソス[ソスvソスニ鯉ソスソスム付ソスソスソスワゑソスソスソスソスAソスソスソス[ソスソスソス{ソスb
ソスNソスXソスナゑソスソスソスソスソスソスソスソスナゑソスソスBソスソスソス[ソスソスソスソス資鯉ソスソスソスソスRソス[ソスhソスヘ2ソスツのソスソス[ソスソスソス{ソスbソスNソスXソスソスソスソスソスハゑソス
ソスワゑソスソスBソスPソスツゑソスソスIソスソスソスWソスiソスソスソスフソスソス[ソスソスソス{ソスbソスNソスXソスソスソスフ責任ソスメゑソスソスwソス閧オソスワゑソスソスBソスソスソスフソスソス[ソスソス
ソス{ソスbソスNソスXソスヘソスソス[ソスソスソスOソスソスソス[ソスvソスノ会ソスソスソスソスソスvソスソスソスソスソスソスネどに使ソスソスソスソスラゑソスソスナゑソスソスBソスソスソス[ソスソスソスソス
ソス資鯉ソスソスソスソスRソス[ソスhソスフ2ソスヤ目のソスソス[ソスソスソス{ソスbソスNソスXソスソスソスヘソスソス[ソスソスソスソスQソスフエソスソスソス[ソスソスソスbソスZソス[ソスWソスソス
ソスけ趣ソスソスラゑソスソスソスソス[ソスソスソス{ソスbソスNソスXソスソスソスwソス閧オソスワゑソスソスBソスソスソスソスヘ難ソスソスノソスソス[ソスソスソスソスソスOソスソスソスXソスgソスナ、ソスソス
ソスソスソスoソス[ソスソスソスフエソスソスソス[ソスソスソスAソスソスソスXソスgソスノソスソスbソスZソス[ソスWソス送ゑソスネ外ソスフ、ソスソスソスソスlソスノ托ソスソス骼橸ソスノ適ソスソス
ソスナゑソスソスB

New fields may be added to this RR in the future.
ソスVソスソスソスソスソスtソスBソス[ソスソスソスhソスソスソスソスソスソスソスソスソスフ趣ソスソスソスソスソスソスRソス[ソスhソスノ会ソスソスソスソスソスソス驍ゥソスソスソスソスソスソスワゑソスソスソスB

9. REFERENCES and BIBLIOGRAPHY
9. ソスQソスlソスソスソスソスソスニ包ソスソスソスソスレ録

[Dyer 87]       S. Dyer, F. Hsu, "Hesiod", Project Athena
                Technical Plan - Name Service, April 1987, version 1.9.

                Describes the fundamentals of the Hesiod name service.
                ソスwソスVソスIソスhソスlソス[ソスソスソスTソス[ソスrソスXソスフ奇ソス{ソスソスソスLソスqソスソスソスワゑソスソスB

[IEN-116]       J. Postel, "Internet Name Server", IEN-116,
                USC/Information Sciences Institute, August 1979.

                A name service obsoleted by the Domain Name System, but
                still in use.
                ソスhソスソスソスCソスソスソスlソス[ソスソスソスVソスXソスeソスソスソスナ趣ソスソスソスxソスソスノなるがソスAソスワゑソスソスgソスpソスソスソスフネソス[
                ソスソスソスTソス[ソスrソスXソスB

[Quarterman 86] J. Quarterman, and J. Hoskins, "Notable Computer Networks",
                Communications of the ACM, October 1986, volume 29, number
                10.

[RFC-742]       K. Harrenstien, "NAME/FINGER", RFC-742, Network
                Information Center, SRI International, December 1977.

[RFC-768]       J. Postel, "User Datagram Protocol", RFC-768,
                USC/Information Sciences Institute, August 1980.

[RFC-793]       J. Postel, "Transmission Control Protocol", RFC-793,
                USC/Information Sciences Institute, September 1981.

[RFC-799]       D. Mills, "Internet Name Domains", RFC-799, COMSAT,
                September 1981.

                Suggests introduction of a hierarchy in place of a flat
                name space for the Internet.
                ソスCソスソスソス^ソス[ソスlソスbソスgソスノフソスソスソスbソスgソスネ厄ソスソスOソスソスヤの托ソスソスソスノ階ソスwソスフ難ソスソスソスソスソス
                ソスソスソス゚まゑソスソスB

[RFC-805]       J. Postel, "Computer Mail Meeting Notes", RFC-805,
                USC/Information Sciences Institute, February 1982.

[RFC-810]       E. Feinler, K. Harrenstien, Z. Su, and V. White, "DOD
                Internet Host Table Specification", RFC-810, Network
                Information Center, SRI International, March 1982.

                Obsolete.  See RFC-952.
                ソスソスソスソスxソスソスBRFC-952ソスQソスニ。

[RFC-811]       K. Harrenstien, V. White, and E. Feinler, "Hostnames
                Server", RFC-811, Network Information Center, SRI
                International, March 1982.

                Obsolete.  See RFC-953.
                ソスソスソスソスxソスソスBRFC-953ソスQソスニ。

[RFC-812]       K. Harrenstien, and V. White, "NICNAME/WHOIS", RFC-812,
                Network Information Center, SRI International, March
                1982.

[RFC-819]       Z. Su, and J. Postel, "The Domain Naming Convention for
                Internet User Applications", RFC-819, Network
                Information Center, SRI International, August 1982.

                Early thoughts on the design of the domain system.
                Current implementation is completely different.
                ソスhソスソスソスCソスソスソスVソスXソスeソスソスソスフデソスUソスCソスソスソスノつゑソスソストの擾ソスソスソスソスフ考ソスソスソスBソスソスソスンの趣ソス
                ソスソスソスヘ奇ソスソスSソスノ異なゑソスソストゑソスソスワゑソスソスB

[RFC-821]       J. Postel, "Simple Mail Transfer Protocol", RFC-821,
                USC/Information Sciences Institute, August 1980.

[RFC-830]       Z. Su, "A Distributed System for Internet Name Service",
                RFC-830, Network Information Center, SRI International,
                October 1982.

                Early thoughts on the design of the domain system.
                Current implementation is completely different.
                ソスhソスソスソスCソスソスソスVソスXソスeソスソスソスフデソスUソスCソスソスソスノつゑソスソストの擾ソスソスソスソスフ考ソスソスソスBソスソスソスンの趣ソス
                ソスソスソスヘ奇ソスソスSソスノ異なゑソスソストゑソスソスワゑソスソスB

[RFC-882]       P. Mockapetris, "Domain names - Concepts and
                Facilities," RFC-882, USC/Information Sciences
                Institute, November 1983.

                Superceeded by this memo.
                ソスソスソスフソスソスソスソスノ趣ソスソスソスト変ゑソスソスソスワゑソスソスソスソスB

[RFC-883]       P. Mockapetris, "Domain names - Implementation and
                Specification," RFC-883, USC/Information Sciences
                Institute, November 1983.

                Superceeded by this memo.
                ソスソスソスフソスソスソスソスノ趣ソスソスソスト変ゑソスソスソスワゑソスソスソスソスB

[RFC-920]       J. Postel and J. Reynolds, "Domain Requirements",
                RFC-920, USC/Information Sciences Institute,
                October 1984.

                Explains the naming scheme for top level domains.
                ソスナ擾ソスハドソスソスソスCソスソスソスフ厄ソスソスソスソストゑソスソスソスソスソスソスソスワゑソスソスB

[RFC-952]       K. Harrenstien, M. Stahl, E. Feinler, "DoD Internet Host
                Table Specification", RFC-952, SRI, October 1985.

                Specifies the format of HOSTS.TXT, the host/address
                table replaced by the DNS.
                HOSTS.TXT ソスフフソスHソス[ソス}ソスbソスgソスソスソスwソス閧オソスワゑソスソスAソスzソスXソスgソス^ソスAソスhソスソスソスXソスeソス[
                ソスuソスソスソスヘDソスmソスrソスナ置ソスソスソスソスソスソスソスソスワゑソスソスB

[RFC-953]       K. Harrenstien, M. Stahl, E. Feinler, "HOSTNAME Server",
                RFC-953, SRI, October 1985.

                This RFC contains the official specification of the
                hostname server protocol, which is obsoleted by the DNS.
                This TCP based protocol accesses information stored in
                the RFC-952 format, and is used to obtain copies of the
                host table.
                ソスソスソスフRソスeソスbソスヘホソスXソスgソスソスソスTソス[ソスoソス[ソスvソスソスソスgソスRソスソスソスフ鯉ソスソスソスソスdソスlソスソスソスソスソスワみ、
                ソスcソスmソスrソスナ趣ソスソスソスxソスソスノゑソスソスソスワゑソスソスBソスソスソスフTソスbソスoソスxソス[ソスXソスvソスソスソスgソスRソスソスソスソス
                RFC-952ソスtソスHソス[ソス}ソスbソスgソスナ記ソスソスソスソスソス黷スソスソスソスヨのアソスNソスZソスXソスソスソスソスソスAソスzソスX
                ソスgソスeソス[ソスuソスソスソスフコソスsソス[ソス得るたソス゚に使ソスソスソスワゑソスソスB

[RFC-973]       P. Mockapetris, "Domain System Changes and
                Observations", RFC-973, USC/Information Sciences
                Institute, January 1986.

                Describes changes to RFC-882 and RFC-883 and reasons for
                them.
                RFC-882ソスソスRFC-883ソスヨの変更ソスニゑソスソスフ暦ソスソスRソスソスソスLソスqソスソスソスワゑソスソスB

[RFC-974]       C. Partridge, "Mail routing and the domain system",
                RFC-974, CSNET CIC BBN Labs, January 1986.

                Describes the transition from HOSTS.TXT based mail
                addressing to the more powerful MX system used with the
                domain system.
                HOSTS.TXTソスxソス[ソスXソスフソスソス[ソスソスソスソスソスソスソス闍ュソスヘなドソスソスソスCソスソスソスVソスXソスeソスソスソスソス
                ソスgソスソスソスソスMXソスソスソスVソスXソスeソスソスソスヨの移行ソスソスソスLソスqソスソスソスワゑソスソスB

[RFC-1001]      NetBIOS Working Group, "Protocol standard for a NetBIOS
                service on a TCP/UDP transport: Concepts and Methods",
                RFC-1001, March 1987.

                This RFC and RFC-1002 are a preliminary design for
                NETBIOS on top of TCP/IP which proposes to base NetBIOS
                name service on top of the DNS.
                ソスソスソスソスRFCソスソスRFC-1002ソスソスTCP/IPソスソスソスNETBIOSソスフ予ソスソスソスfソスUソスCソスソスソスナ、
                DNSソスソスナゑソスNetBIOSソスソスソスOソスTソス[ソスrソスXソスソスソストゑソスソスワゑソスソスB

[RFC-1002]      NetBIOS Working Group, "Protocol standard for a NetBIOS
                service on a TCP/UDP transport: Detailed
                Specifications", RFC-1002, March 1987.

[RFC-1010]      J. Reynolds, and J. Postel, "Assigned Numbers", RFC-1010,
                USC/Information Sciences Institute, May 1987.

                Contains socket numbers and mnemonics for host names,
                operating systems, etc.
                ソスzソスXソスgソスソスソスAソスIソスyソスソスソス[ソスeソスBソスソスソスOソスVソスXソスeソスソスソスフゑソスソス゚のソソスPソスbソスgソスヤ搾ソスソスソス
                ソスソスソスフゑソスソスワゑソスナゑソスソスワゑソスソスB

[RFC-1031]      W. Lazear, "MILNET Name Domain Transition", RFC-1031,
                November 1987.

                Describes a plan for converting the MILNET to the DNS.
                MILNETソスソスソスcソスmソスrソスノ変奇ソスソスソスソスソスvソスソスソスソスLソスqソスソスソスワゑソスソスB

[RFC-1032]      M. Stahl, "Establishing a Domain - Guidelines for
                Administrators", RFC-1032, November 1987.

                Describes the registration policies used by the NIC to
                administer the top level domains and delegate subzones.
                ソスナ擾ソスハドソスソスソスCソスソスソスフ管暦ソスソスニサソスuソスhソスソスソスCソスソスソスマ任ソスソスソスソスソス驍スソス゚にNソスhソスb
                ソスノゑソスソスソスト使ソスソス黷スソスoソス^ソスソスソスjソスソスソスLソスqソスソスソスワゑソスソスB

[RFC-1033]      M. Lottor, "Domain Administrators Operations Guide",
                RFC-1033, November 1987.

                A cookbook for domain administrators.
                ソスhソスソスソスCソスソスソスヌ暦ソスソスメのゑソスソス゚の暦ソスソスソスソスフ本

[Solomon 82]    M. Solomon, L. Landweber, and D. Neuhengen, "The CSNET
                Name Server", Computer Networks, vol 6, nr 3, July 1982.

                Describes a name service for CSNET which is independent
                from the DNS and DNS use in the CSNET.
                ソスcソスmソスrソスノ依托ソスソスソスソスネゑソスCSNETソスフネソス[ソスソスソスTソス[ソスrソスXソスソスCSNETソスナのDソスmソスr
                ソスgソスpソスソスソスLソスqソスソスソスワゑソスソスB

Index
ソスソスソスソス


          *

          ;  

          <character-string>
          <domain-name>

          @

          \

          A

          Byte order

          CH
          Character case
          CLASS
          CNAME
          Completion
          CS

          Hesiod
          HINFO
          HS

          IN
 
          IN-ADDR.ARPA domain
          Inverse queries

          Mailbox names
          MB
          MD
          MF
          MG
          MINFO
          MINIMUM
          MR
          MX

          NS
          NULL

          Port numbers
          Primary server
          PTR    

          QCLASS
          QTYPE

          RDATA
          RDLENGTH

          Secondary server
          SOA
          Stub resolvers

          TCP
          TXT
          TYPE

          UDP

          WKS

[]Japanese translation by Ishida So