HUB

HUB

A hub is a central network device used to connect multiple nodes to form a single network. It contains a number of ports to connect multiple computers. When a computer connected to a hub needs to communicate, it sends data packets to the hub. When a data packet arrives at the hub, it broadcasts the data packet to all devices in the network. The destined recipient whose Media Access Control (MAC) address is mentioned in the data packet receives it,
and all the other devices discard the data packet. The following figure shows a hub.

A Hub This method of transmitting a data packet is inefficient because all the nodes receive the data packet even if the data packet is not meant for them. In addition, when the data packets are on the network, the network cannot be used by other devices, which results in network traffic. This wastes network bandwidth. It also causes security problems because all the nodes can read the data packet sent by the hub. When two nodes simultaneously send the data packet to the hub, a collision occurs. When this collision occurs, the message becomes unreadable and the network must reset itself before delivering the data packet again. A hub can have 5, 8, 16, or more ports depending on its size. In addition, a hub contains a port, known as uplink port, which is used to connect with the next hub.

NOTE

A data packet is a basic unit of communication on a network. The data always travels in the form of data packets in a network.
A MAC address is a binary address unique to a single network. This address is 4 8 -bit long and is used to identify each node of a network uniquely.