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