Broadcast Domain

A broadcast domain is a logical area in a computer network where any computer connected to the computer network can directly transmit to any other in the domain without having to go through a routing device.

More specifically it is an area of the computer network made up of all the computers and networking devices able to be reached by sending a frame to the data link layer broadcast address.

In more real scenario, after a packet is broadcasted, all the devices connected to the same network can receive the packet. For example, if 10 systems are connected to a hub and one of the system broadcasts a packet then all the systems connected to that hub will receive the broadcast packet.

Tip: Virtual LAN’s (also known as VLAN’s) can be used on switches to reduce the size of the broadcast domains and at the same time increase security. This is also known as breaking down of broadcast domains.