Classless Inter-Domain Routing


Classless Inter-Domain Routing (CIDR, pronunciation: /ˈsaɪ.dr/ or /ˈsi.dr/) is a method for allocating IP addresses and routing Internet Protocol packets. The Internet Engineering Task Force introduced CIDR in 1993 to replace the previous addressing architecture of classful network design in the Internet. Its goal was to slow the growth of routing tables on routers across the Internet, and to help slow the rapid exhaustion of IPv4 addresses.