Selecting a server from among many replicas

Document Type Expired Internet-Draft (asid WG)
Author Paul Leach 
Last updated 1997-02-24
Stream Internet Engineering Task Force (IETF)
Intended RFC status (None)
Expired & archived
pdf htmlized (tools) htmlized bibtex
Stream WG state WG Document
Document shepherd No shepherd assigned
IESG IESG state Expired
Consensus Boilerplate Unknown
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Responsible AD (None)
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


Many organizations today have Web servers for their organization, which supply information published by their organization to the Internet and to internal users via the HTTP protocol [6]. It is anticipated that many organizations will in the not-to-distant future have directory servers, which supply information about their organization to the Internet and to internal users via the LDAP protocol [7]. These servers all have DNS [1, 2] names, and they often are (or, in the future, will be likely to be) replicated for reliability or greater capacity. This leads to the problem of selecting among the replicas. We briefly survey current practice, for both centralized and geographically distributed replicas. Then we discuss emerging practice, represented by SRV and LOC RRs [3, 4]. We propose a way to use both of these together to select among geographically distributed replicas which, while not perfect, automates current practice. We propose a convention to handle the case of an organization that has a large number of sites, each of which needs a small number of replicas for availability in case of loss of external connectivity.


Paul Leach (

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)