need to monitor router traffic

[Shapeless]

we have a guy living with us and I need to find out how much bandwidth he's using. anyone recommend any free programs that will help me determine the usage. This guy locks himself in his room most of the time And I have no idea what he's watching or doing on his laptop.

[DoomUK]

You could try MRTG, but it's more than a little complicated to set up. Try at your own peril.

There's other, simpler bandwidth meters out there like Bitmeter OS but they only seem to let you monitor the total amount of traffic coming in and going out of your router instead of individual devices connected to it, which is of no use to you. Unless you want to disconnect all other devices for a couple of days, leaving only his connected.

If you have a decent router you could also try something called DD-WRT, an alternative firmware for compatible routers that adds some new features such as detailed network monitoring with help of some scripts. That's assuming your router's existing firmware doesn't have this facility in the first place, which is hopefully much easier to use.

[Kirby]

Back in networking class at my university they'd have us monitor network traffic using Wireshark, which you set up and use to monitor whichever device you specify. It'll tell you what packets are being sent/received from the device and how much it uses the network.