vnstat
A console-based network traffic monitor.
TLDR
Display traffic summary for all interfaces
$ vnstat
Display traffic summary for a specific network interface
$ vnstat -i [eth0]
Display live stats for a specific network interface
$ vnstat -l -i [eth0]
Show traffic statistics on an hourly basis for the last 24 hours using a bar graph
$ vnstat -hg
Measure and show average traffic for 30 seconds
$ vnstat -tr [30]
