Domain names: Concepts and facilities
RFC 882
Document | Type |
RFC - Unknown
(November 1983; Errata)
Updated by RFC 973
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Last updated | 2019-11-19 | ||
Stream | Legacy | ||
Formats | plain text html pdf htmlized bibtex | ||
Stream | Legacy state | (None) | |
Consensus Boilerplate | Unknown | ||
RFC Editor Note | (None) | ||
IESG | IESG state | RFC 882 (Unknown) | |
Telechat date | |||
Responsible AD | (None) | ||
Send notices to | (None) |
Network Working Group P. Mockapetris Request for Comments: 882 ISI November 1983 DOMAIN NAMES - CONCEPTS and FACILITIES +-----------------------------------------------------+ | | | This RFC introduces domain style names, their use | | for ARPA Internet mail and host address support, | | and the protocols and servers used to implement | | domain name facilities. | | | | This memo describes the conceptual framework of the | | domain system and some uses, but it omits many | | uses, fields, and implementation details. A | | complete specification of formats, timeouts, etc. | | is presented in RFC 883, "Domain Names - | | Implementation and Specification". That RFC | | assumes that the reader is familiar with the | | concepts discussed in this memo. | | | +-----------------------------------------------------+ INTRODUCTION The need for domain names As applications grow to span multiple hosts, then networks, and finally internets, these applications must also span multiple administrative boundaries and related methods of operation (protocols, data formats, etc). The number of resources (for example mailboxes), the number of locations for resources, and the diversity of such an environment cause formidable problems when we wish to create consistent methods for referencing particular resources that are similar but scattered throughout the environment. The ARPA Internet illustrates the size-related problems; it is a large system and is likely to grow much larger. The need to have a mapping between host names (e.g., USC-ISIF) and ARPA Internet addresses (e.g., 10.2.0.52) is beginning to stress the existing mechanisms. Currently hosts in the ARPA Internet are registered with the Network Information Center (NIC) and listed in a global table (available as the file <NETINFO>HOSTS.TXT on the SRI-NIC host) [1]. The size of this table, and especially the frequency of updates to the table are near the limit of manageability. What is needed is a distributed database that performs the same function, and hence avoids the problems caused by a centralized database. The problem for computer mail is more severe. While mail system implementers long ago recognized the impossibility of centralizing Mockapetris [Page 1] RFC 882 November 1983 Domain Names - Concepts and Facilities mailbox names, they have also created an increasingly large and irregular set of methods for identifying the location of a mailbox. Some of these methods involve the use of routes and forwarding hosts as part of the mail destination address, and consequently force the mail user to know multiple address formats, the capabilities of various forwarders, and ad hoc tricks for passing address specifications through intermediaries. These problems have common characteristics that suggest the nature of any solution: The basic need is for a consistent name space which will be used for referring to resources. In order to avoid the problems caused by ad hoc encodings, names should not contain addresses, routes, or similar information as part of the name. The sheer size of the database and frequency of updates suggest that it must be maintained in a distributed manner, with local caching to improve performance. Approaches that attempt to collect a consistent copy of the entire database will become more and more expensive and difficult, and hence should be avoided. The same principle holds for the structure of the name space, and in particular mechanisms for creating and deleting names; these should also be distributed. The costs of implementing such a facility dictate that it be generally useful, and not restricted to a single application. We should be able to use names to retrieve host addresses, mailbox data, and other as yet undetermined information. Because we want the name space to be useful in dissimilar networks, it is unlikely that all users of domain names will be able to agree on the set of resources or resource informationShow full document text