Which device primarily uses MAC addresses for communication within a local network?

The device that primarily uses MAC addresses for communication within a local network is the switch. A switch operates at the Data Link layer (Layer 2) of the OSI model, and its function is to forward data packets between devices on the same local area network (LAN).

When a device sends data to another device on the same network, it includes the MAC addresses of both the source and the destination in the frame header. The switch reads the destination MAC address and uses its MAC address table to determine the correct port to forward the frame. This process allows for efficient data traffic management within the local network, ensuring that data is delivered only to the intended recipient, reducing unnecessary traffic and enhancing overall network performance.

In contrast, a router operates at the Network layer (Layer 3) and uses IP addresses to route packets between different networks, while modems serve as a bridge between network types (for instance, from a digital signal to an analog one for internet access) but do not handle MAC address-based communication. An access point connects wireless devices to a wired network but is not primarily responsible for MAC address-based communication within the network itself.