HUBs and Switches

A HUB is a device with multiple network ports that listens to network traffic on each port and echos that same traffic back out on all of the rest of the ports. In a sense a HUB works like an amplifier. A switch is a little bit different. The basic idea is the same, but the switch remembers which computers are connected to each port. When a switch hears the network traffic on port A it looks to see where that traffic is bound. If the traffic is bound for a computer on port B, then the switch only echos the traffic down port B. No other ports hear the communication between the computers on port A and port B. Switches can also be placed between two networks. In this case the switch would usually have two IP addresses and would direct traffic from one network to another one.