Darkstat - Web Based Network Traffic & Bandwidth Monitoring Tool on Linux

darkstat is an ntop-workalike network statistics gatherer. It runs as a background process on a cable or DSL router, uses libpcap to capture network traffic, and has a Web interface that serves up reports of statistics such as data transferred by host, port, and protocol. It also has a neat bandwidth usage graph.

Author of the program, Emil Mikulic, had "ntop" in use for a long time. But he was disaffected of its stability issues and its bad memory behavior. For this reason he developed "darkstat".

Installation:
OpenSuSe user can use "1-click" installer to install darkstat - here
Ubuntu / debian: $ sudo apt-get install darkstat

To start DarkStat

# darkstat -i eth0

where “eth0″ is the interface that you monitor traffic coming in and going out. Change it as in your system.

Now, darkstat starts and sniffs in the background and loads a simple web interface at http://localhost:667 or if you are browsing from a different machine then http://:667 (example: http://192.168.1.1:667)

At the "hosts" tab you can see all the machines which take part in the communication. These can be arranged by the caused traffic or their particular IP address. By this possibility you can detect the machines, which have produced the highest traffic in the local network, very fast. Thereby the responsible system administrator has a chance to get to the bottom of a problem.