Hub

• A Hub is a networking device which receives signal from the source, amplifies it and send it to multiple destinations or computers.
• Below diagram computers A and B communicate to each other (network packets are sent from A to B and in reverse direction).
• When HUB receives a packet on one port, it sends out a copy of that packet to all other ports.

Types of Hub

• On the basis of its working methods, the Hubs can be divided into three types Passive Hub, Active Hub, Intelligent/Smart Hub.

Passive Hub

• Passive Hub works like a simple Bridge. It is used for just creating a connection between various devices.
• It does not have the ability to amplify or regenerate any incoming signal. It receives signal and then forward it to multiple devices.
• With a HUB computers C and D receive a copy of every packet, that is sent from A to B and back.

Active Hub

• As its name suggests, Active Hub is a hub which can amplify or regenerate the information signal.
• This type of bus has an advantage as it also amplifies the incoming signal as well as forward it to multiple devices.

Advantages of Hub

• Cheap.
• Can connect different media types.

Disadvantages of Hub

• Time consuming.
• Bandwidth is shared by all hosts.
• Passes packets to all connected segments.