Which device forwards frames within a local network and uses MAC addresses to direct traffic?

Which device forwards frames within a local network and uses MAC addresses to direct traffic?

• A. Switch
• B. Router
• C. Gateway
• D. Modem

Answer: (A)

Forwarding frames inside a local network using MAC addresses is a job for a switch. A switch operates at the data link layer and looks at the destination MAC address in each Ethernet frame to decide which port to forward it on. As frames arrive, the switch learns the source MAC address and notes which port it came from, building a MAC address (CAM) table. When a frame has a destination MAC that the switch already knows, it sends the frame only to the corresponding port, which keeps traffic localized. If the destination isn’t yet in the table, the switch broadcasts the frame to all ports except the source until the destination replies and its port is learned. This behavior differentiates a switch from devices like routers, gateways, or modems, which route traffic between networks or handle different kinds of connections.

Forwarding frames inside a local network using MAC addresses is a job for a switch. A switch operates at the data link layer and looks at the destination MAC address in each Ethernet frame to decide which port to forward it on. As frames arrive, the switch learns the source MAC address and notes which port it came from, building a MAC address (CAM) table. When a frame has a destination MAC that the switch already knows, it sends the frame only to the corresponding port, which keeps traffic localized. If the destination isn’t yet in the table, the switch broadcasts the frame to all ports except the source until the destination replies and its port is learned. This behavior differentiates a switch from devices like routers, gateways, or modems, which route traffic between networks or handle different kinds of connections.