classless inter-domain routing

Computing Dictionary

Classless Inter-Domain Routing definition

networking
(CIDR) /sid*r/ A technique that summarises a block of Internet addresses in a routing table as an address in dotted decimal notation followed by a forward slash and a two-digit decimal number giving the number of leading one bits in the subnet mask. For example, 123.123.123.0/24 specifies a subnet mask of 11111111.11111111.11111111.00000000 (binary), implying the block of addresses 123.123.123.0 through 123.123.123.255.
CIDR is "classless" because it is not limited to the subnet masks specified by Internet address classes A, B and C.
According to RFC 1519, CIDR was implemented to distribute Internet address space more efficiently and to provide a mechanism for IP route aggregation. This in turn reduces the number of entries in IP routing tables, enabling faster, more efficient routing, e.g. using routing protocols such as OSPF. CIDR is supported by BGP4.
See also RFC 1467, RFC 1518, RFC 1520.
(2006-01-26)
The Free On-line Dictionary of Computing, © Denis Howe 2010 http://foldoc.org
Cite This Source
Explore Dictionary.com
Previous Definition: classless
Next Definition: classless society
More from Thesaurus.com
Synonyms and Antonyms for classless inter-domain routing
More from Reference.com
Search for articles containing classless inter-domain routing
Dictionary.com Word FAQs

Dictionary.com presents 366 FAQs, incorporating some of the frequently asked questions from the past with newer queries.

Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature