Which device operates at Layer 2 of the OSI Model and forwards packets based upon MAC addresses?

A switch operates at Layer 2 of the OSI Model and forwards packets based on the MAC addresses of the devices connected to it. This layer, also known as the Data Link layer, is responsible for node-to-node data transfer and can effectively manage the physical addressing that allows devices on the same local area network to communicate.

When a switch receives a frame, it examines the MAC address contained in the frame to determine the appropriate output port to send the data to the intended recipient. This functionality enables switches to create a more efficient data traffic management system compared to other devices that operate at higher layers or function differently.

In contrast, a router operates at Layer 3, dealing with IP addresses and routing packets between different networks, while a hub simply broadcasts data to all ports regardless of destination, lacking the intelligence of a switch. A gateway serves as a "gate" between different networks, often performing protocol conversions, which occurs at multiple layers of the OSI model, but it does not primarily function to forward packets based on MAC addresses like a switch does.