classless inter-domain routing

1 definition found

classless inter-domain routing - Free On-line Dictionary of Computing (26 May 2007) :

  Classless Inter-Domain Routing
  CIDR
  
     <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)