CIDR (Classless Inter-Domain Routing)

Method of abbreviated recording of IP addresses and address space management in IPv4 networks. Instead of using traditional classful addressing such as Class A, B, C, and so on, CIDR provides a more flexible ability to split and distribute IP addresses. This method makes more efficient use of available resources, allowing you to more accurately determine the size of subnets and their boundaries. CIDR records IP addresses in address/prefix format, where the prefix indicates the number of bits used for the network portion of the address. This reduces the amount of address space that needs to be managed and facilitates routing across networks.