RFC 1034 (rfc1034) - Page 1 of 55


Domain names - concepts and facilities



Alternative Format: Original Text Document



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

This RFC introduces domain style names, their use for Internet mail and
host address support, and the protocols and servers used to implement
domain name facilities.

2.1. The history of domain names

The impetus for the development of the domain system was growth in the
Internet:

   - Host name to address mappings were maintained by the Network
     Information Center (NIC) in a single file (HOSTS.TXT) which
     was FTPed by all hosts [RFC-952, RFC-953].  The total network



Mockapetris