Microsoft® Windows Server™ 2003 Inside Out

Using Subnets and Subnet Masks

Anyone that works with computers should learn about subnetting and what it means. A subnet is a portion of a network that operates as a separate network. Logically, it exists separately from other networks even if hosts on those other networks share the same network ID. Typically, such networks are also physically separated by a router. This ensures the subnet is isolated and doesn't affect other subnets.

Subnetting is designed to make more efficient use of the IP address space. Thus, rather than having networks with hundreds, thousands, or millions of nodes, you have a subnet that is sized appropriately for the number of nodes that you use. This is important, especially for the crowded public IP address space where ...