"This means that once installed and configured, vnStat
quietly monitors a specified network interface and saves the
collected data. You can then use vnStat's command parameters to
view detailed reports of your bandwidth usage.
"vnStat is available in the software repositories of many
mainstream Linux distributions, so you can easily install it using
your distro's package manager. On an Ubuntu-based system, vnStat
can be installed using the sudo apt-get install vnstat command.
Before you can start using the utility, you must specify the
network interface you want vnStat to monitor. First, run the
ifconfig command to view a list of all available network
interfaces. You can then use the -u and -i parameters to create a
database for the specified network interface, for example:"