How does a network switch direct data packets?

A network switch directs data packets by using MAC addresses to identify the correct destination port for each packet.

A network switch, also known as a switching hub, is a crucial component in many types of computer networks. It operates at the data link layer (Layer 2) of the OSI model, which means it deals with physical addressing, error notification, network topology, and flow control. The primary function of a network switch is to receive incoming data packets and direct them to their intended destination within the network.

The switch accomplishes this by using a table of MAC (Media Access Control) addresses. Each device connected to the network has a unique MAC address, which is stored in the switch's MAC address table. When a data packet arrives at the switch, it examines the packet's destination MAC address and compares it with its table. The switch then forwards the packet to the appropriate port that leads to the device with the matching MAC address.

This process is known as 'frame switching', and it's a more efficient method of data transmission compared to a hub, which simply broadcasts the packet to all connected devices. By directing packets only to the intended recipient, a switch reduces network congestion and improves overall performance.

In addition to directing data packets, a network switch also has the ability to learn and update its MAC address table. When a device first connects to the network, the switch doesn't know its MAC address. However, when the device sends its first packet, the switch can 'learn' the device's MAC address and the port it's connected to. This information is then added to the MAC address table. If a device is moved to a different port or removed from the network, the switch updates the table accordingly.

In summary, a network switch directs data packets by using MAC addresses to identify the correct destination port. This process, combined with the switch's ability to learn and update its MAC address table, ensures efficient and accurate data transmission within the network.