It allows networks to be subdivided regardless of their traditional class
Class Network Subnet Mask Broadcast A 17.0.0.0 255.0.0.0 17.255.255.255 B 183.194.0.0 255.255.0.0 183.194.255.255 C 199.83.131.0 255.255.255.0 199.83.131.255 Classless Inter-Domain Routing CIDR stands for Classless Inter-Domain Routing. It allows networks to be subdivided regardless of their traditional class. These subdivided networks are called subnets. For example, the IP address 121.67.198.94 falls in the Class A network range. By default , the network is 121.0.0.0, the subnet mask is 255.0.0.0, and the broadcast address is 121.255.255.255. However, if you specify a subnet mask, you can alter the portion of the IP address that is used as the network and the portion that is used as the host address. By specifiying a 255.255.255.0 subnet with the 121.67.198.94 address, the network becomes 121.67.198.0 and the broadcast address becomes 121.67.198.255. Reserved Private Address Space The