What does a network switch do?

A network switch is a device used in computer networks to connect devices together within a local area network (LAN). Its primary function is to forward data packets between devices on the same network.

Here are some key functions and features of a network switch:

1. Packet Forwarding: When a switch receives data (in the form of packets) from one device, it examines the destination MAC (Media Access Control) address of the packet and forwards it to the specific device that the packet is intended for. This process is done by maintaining a table of MAC addresses and their corresponding switch ports.

2. Efficient Data Transmission: Unlike older network devices like hubs, switches can transmit data more efficiently. Hubs forward data to all ports regardless of the destination, causing unnecessary traffic. Switches, on the other hand, only send data to the port where the intended device is connected, minimizing unnecessary traffic and improving network efficiency.

3. Segmentation and VLANs: Switches allow the network to be segmented into different virtual LANs (VLANs). VLANs separate broadcast domains in a network, enhancing security, performance, and manageability by logically grouping devices based on factors like department, function, or project.

4. Bandwidth Management: Switches have the capability to manage bandwidth more effectively by using features like Quality of Service (QoS) to prioritize certain types of traffic, ensuring that critical data, such as voice or video, receives higher priority and better performance.

5. Expansion and Scalability: Switches typically offer multiple ports, allowing for the connection of numerous devices. They can be cascaded or connected together to expand the network and accommodate more devices as needed.

Overall, a network switch plays a crucial role in efficiently directing and managing data traffic within a network, facilitating communication between devices and ensuring that data reaches its intended destination effectively and securely.