IP address sub-netting

Aim: To study IP address sub-netting.

THEORY:

A subnet is a segment of a network. Sub netting is a technique that allows a network administrator to divide one physical network into smaller logical networks and, thus, control the flow of traffic for security or efficiency reasons.

Dividing a network into several subnets can serve a number of purposes: to reduce network traffic by decreasing the number of broadcasts (if used in combination with a switch), to exceed the limitations in a local area network, for instance the maximum number of allowed hosts, or to enable employees to be able to dial in to the network from home, without opening the entire network up to unwanted visits from the Internet.

Subnets are created by using a so-called subnet mask to divide a single Class A, B, or C network number into smaller pieces, thus allowing an organization to add subnets without having to obtain a new network number through an Internet service provider. Subnets can again be sub netted into sub-subnets. Subnets were originally invented to help solve the lack of IP addresses on the Internet. The benefits of sub netting are:

1. Reduced network traffic

2. Simplified management

3. Smaller broadcast domain