How does a hub differ from a switch in terms of data forwarding?

• A. A hub broadcasts frames to all ports; a switch forwards frames only to the destination port via the MAC address table.
• B. Both forward frames to the same port.
• C. A hub forwards frames to a single destination port; a switch broadcasts.
• D. Hubs filter traffic by MAC; switches forward to all ports.

Answer: (A)

The main idea is how forwarding decisions differ between a hub and a switch. A hub is a simple repeater: when any device sends a frame, the hub repeats it out to every other connected port. That means every device on that network segment can see the frame, so traffic is broadcast to all ports and the collision domain is shared, which can slow things down as more devices talk at once.

A switch, on the other hand, is smart about forwarding. It learns which devices (by their MAC addresses) are reachable on which ports and builds a MAC address table. When a frame arrives, the switch checks the destination address and sends the frame only to the specific port where that destination device is connected. If it doesn’t yet know the destination, or if the frame is a broadcast, the switch floods that frame to all ports except the one it came from. This targeted forwarding reduces unnecessary traffic, eliminates many collisions, and allows full-duplex communication on individual links.