What is the main purpose of a switch in a network?

A switch primarily operates at the data link layer (Layer 2) of the OSI model and is essential in connecting devices within the same local area network (LAN). Its main purpose is to filter and forward data packets based on MAC (Media Access Control) addresses. When a device sends data, the switch examines the destination MAC address in the ethernet frame, determines which port to forward that data to, and sends it only to the intended recipient. This process improves network efficiency by reducing unnecessary traffic, as the switch directs the data specifically to the intended device rather than broadcasting it to all devices on the network.

In contrast, other activities described in the incorrect choices highlight different functionalities. For instance, connecting multiple networks typically involves routers rather than switches, which are designed to operate within a single network. The conversion of protocol formats is a function often associated with gateways, which can translate between different networking protocols, rather than switches. Lastly, assigning IP addresses is a role fulfilled by Dynamic Host Configuration Protocol (DHCP) servers, not switches, which do not handle Layer 3 (Network Layer) duties like IP address allocation. Thus, the effective operation of a switch hinges on its ability to filter traffic specifically based on MAC addresses, making choice B the most