Subnetting

Subnetting is the logical division of a larger IP network into multiple smaller subnets. A subnet mask in IPv4, or a prefix length in both IPv4 and IPv6, determines which part of an IP address identifies the network and which part identifies the individual host. Subnetting allows available IP address ranges to be structured according to requirements and assigned to different locations, departments or network segments. In IPv4 networks, it also reduces the size of broadcast domains because routers do not forward broadcast traffic between subnets. Communication between different subnets requires routing, typically provided by routers or Layer 3 switches. Subnetting is a fundamental concept in IP addressing and plays an important role in network planning, segmentation, routing and IP Address Management.