What is the difference between a hub and a switch?

• A. Hubs transmit messages out of every interface other than the one it was received on, and switches break up a network into collision domains.
• B. Hubs operate at the Data-Link layer; switches operate at the Physical layer.
• C. Hubs transmit messages out of every interface including the one it was received on, and switches maintain a single collision domain.
• D. Hubs require routing; switches require switching.

Answer: (C)

The difference is in how they handle forwarding and network segmentation. A hub acts as a simple physical repeater: it takes anything it hears on one port and repeats it to all the other ports. That means every device connected to the hub shares the same collision domain, so devices must share the medium and contend for access, which can lead to collisions.

A switch, by contrast, works at the data-link layer and builds a table of which MAC addresses are reachable on which ports. It forwards frames only to the port where the destination device is reachable (or floods if the destination is unknown). This effectively creates separate collision domains for each switch port, so devices on different ports don’t contend with each other, enabling more efficient, often full-duplex communication.

So, describing the hub as broadcasting to every interface captures its broadcast behavior, while noting that the switch segments collision domains aligns with how switches improve network efficiency.