|  | 10.6 | Basics of Subnetting
| 10.6.1 | Classical IP Addressing

Network administrators sometimes need to divide networks, especially large ones, into smaller networks. These smaller divisions are called subnetworks and provide addressing flexibility. Most of the time subnetworks are simply referred to as subnets.

Similar to the host number portion of Class A, Class B, and Class C addresses, subnet addresses are assigned locally, usually by the network administrator. Also, like other IP addresses , each subnet address is unique.