In this roundup of Linux network testing utilities we use Bandwidthd, Speedometer, Nethogs, Darkstat, and iperf to track bandwidth usage, speed, find network hogs, and test performance.
Bandwidthd
Bandwidthd is a funny little app that hasn’t been updated since 2005, but (at least on my Kubuntu system) it still works. It makes nice colorful graphs of your incoming and outgoing bandwidth usage, and tallies it up by day, week, month, and year on a Web page. So you also need Apache, or some other HTTP server. You can monitor a single PC, or everyone on your LAN. This is a nice app for tracking your monthly usage if you need to worry about bandwidth caps.