Network Working Group                                     P. Mockapetris
Request for Comments: 1034                                           ISI
Obsoletes: RFCs 882, 883, 973                              November 1987


                 DOMAIN NAMES - CONCEPTS AND FACILITIES



1. STATUS OF THIS MEMO

This RFC is an introduction to the Domain Name System (DNS), and omits
many details which can be found in a companion RFC, "Domain Names -
Implementation and Specification" [RFC-1035].  That RFC assumes that the
reader is familiar with the concepts discussed in this memo.

A subset of DNS functions and data types constitute an official
protocol.  The official protocol includes standard queries and their
responses and most of the Internet class data formats (e.g., host
addresses).

However, the domain system is intentionally extensible.  Researchers are
continuously proposing, implementing and experimenting with new data
types, query types, classes, functions, etc.  Thus while the components
of the official protocol are expected to stay essentially unchanged and
operate as a production service, experimental behavior should always be
expected in extensions beyond the official protocol.  Experimental or
obsolete features are clearly marked in these RFCs, and such information
should be used with caution.

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.

2. INTRODUCTION

(以下，略)