The left hand red interface

What do Layer 2 switches use to make a forwarding decision?

A) TCP port number

B) IP subnet

C) UDP port number

D) MAC address

E) Twister spinner

The answer: D) MAC address

Switches use data link information, or MAC addresses, to determine where a frame should be forwarded. If the destination MAC address of a frame is not known by the switch, then the frame is forwarded to all ports.

Want to know more? Watch “Network Devices.”

We use many different network devices to connect our devices together. In this video, you’ll learn about hubs, switches, routers, firewalls, and much more.