RFC - 2308
Negative Caching of DNS Queries (DNS NCACHE)
| Original: | ftp://ftp.isi.edu/in-notes/rfc2308.txt |
|---|---|
| Authors: | M. Andrews [CSIRO] |
| Date: | March 1998 |
| Category: | Proposed Standard |
| Updates: | |
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| RFC-1035std13 [STD 13] |
Domain names - implementation and specification (Updated by RFC-1876exp, RFC-1348, RFC-4033prop, RFC-4035prop, RFC-4034prop, RFC-2308prop, RFC-2065, RFC-2845prop, RFC-2181prop, RFC-1995prop, RFC-1996prop, RFC-2535, RFC-4343prop, RFC-3658, RFC-1982prop, RFC-2136prop, RFC-3425prop, RFC-1101, RFC-1183exp, RFC-2137) |
| RFC-1034std13 [STD 13] |
Domain names - concepts and facilities (Updated by RFC-1876exp, RFC-1348, RFC-4033prop, RFC-4035prop, RFC-4034prop, RFC-2308prop, RFC-2065, RFC-2181prop, RFC-2535, RFC-4343prop, RFC-1982prop, RFC-4592prop, RFC-1101, RFC-1183exp) |
| Updated by: | |
|---|---|
| RFC-4035prop | Protocol Modifications for the DNS Security Extensions (Updated by RFC-4470prop) |
| RFC-4034prop | Resource Records for the DNS Security Extensions (Updated by RFC-4470prop) |
| RFC-4033prop | DNS Security Introduction and Requirements |
| Referred by: | 21 RFC |
| Refers to: | 6 RFC |
Status
This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (1998). All Rights Reserved.
Abstract
[RFC1034] provided a description of how to cache negative responses. It however had a fundamental flaw in that it did not allow a name server to hand out those cached responses to other resolvers, thereby greatly reducing the effect of the caching. This document addresses issues raise in the light of experience and replaces [RFC1034 Section 4.3.4].
Negative caching was an optional part of the DNS specification and deals with the caching of the non-existence of an RRset [RFC2181] or domain name.
Negative caching is useful as it reduces the response time for negative answers. It also reduces the number of messages that have to be sent between resolvers and name servers hence overall network traffic. A large proportion of DNS traffic on the Internet could be eliminated if all resolvers implemented negative caching. With this in mind negative caching should no longer be seen as an optional part of a DNS resolver.
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prepared by Miloslav Nic
- the founder of Zvon.org and Law-Ref.org
- the head of B.Sc. program Informatics and chemistry [in Czech]
- the founder of Lidem.org - Volby 2006 - parliamentary elections in the Czech Republic [in Czech]
- the chief consultant of the publishing house ICT Press
- and Pavel Srb, a student of B.Sc. program Informatics and chemistry