RFC 2219 (rfc2219) - Page 1 of 8
Use of DNS Aliases for Network Services
Alternative Format: Original Text Document
Network Working Group M. Hamilton
Request for Comments: 2219 Loughborough University
BCP: 17 R. Wright
Category: Best Current Practice Lawrence Berkeley Laboratory
October 1997
Use of DNS Aliases for Network Services
Status of this Memo
This document specifies an Internet Best Current Practices for the
Internet Community, and requests discussion and suggestions for
improvements. Distribution of this memo is unlimited.
Abstract
It has become a common practice to use symbolic names (usually
CNAMEs) in the Domain Name Service (DNS - [RFC-1034, RFC-1035]) to
refer to network services such as anonymous FTP [RFC-959] servers,
Gopher [RFC-1436] servers, and most notably World-Wide Web HTTP
[RFC-1945] servers. This is desirable for a number of reasons. It
provides a way of moving services from one machine to another
transparently, and a mechanism by which people or agents may
programmatically discover that an organization runs, say, a World-
Wide Web server.
Although this approach has been almost universally adopted, there is
no standards document or similar specification for these commonly
used names. This document seeks to rectify this situation by
gathering together the extant 'folklore' on naming conventions, and
proposes a mechanism for accommodating new protocols.
It is important to note that these naming conventions do not provide
a complete long term solution to the problem of finding a particular
network service for a site. There are efforts in other IETF working
groups to address the long term solution to this problem, such as the
Server Location Resource Records (DNS SRV) [RFC-2052] work.
1. Rationale
In order to locate the network services offered at a particular
Internet domain one is faced with the choice of selecting from a
growing number of centralized databases - typically Web or Usenet
News "wanderers", or attempting to infer the existence of network
services from whatever DNS information may be available. The former
approach is not practical in some cases, notably when the entity
seeking service information is a program.
Hamilton & Wright Best Current Practice