In a LAN, what is the primary function of a switch?

The primary function of a switch in a Local Area Network (LAN) is to connect devices within the same network. A switch operates at Layer 2 of the OSI model, which is the data link layer. Its main responsibility is to receive incoming data packets and forward them to the appropriate device based on MAC addresses. This process allows multiple devices, such as computers, printers, and servers, to communicate efficiently within the same local network.

In a switched network, each device has a dedicated connection to the switch, which enables full-duplex communication, meaning that data can be sent and received simultaneously without collisions. By utilizing switches, networks can achieve better performance, reduced latency, and enhanced bandwidth as compared to traditional hubs. This efficient traffic management is crucial for maintaining seamless communication among devices connected to the same network.

The other options, while related to network management, do not specifically define the primary function of a switch. Routing traffic to the internet pertains to routers, securing the network involves various security mechanisms and devices, and monitoring network performance is a function usually associated with specialized tools or software rather than with switches directly.