If you are using internet connection with limited bandwidth, you might want to check how much is used on your elementary OS PC. One of the best methods I prefer is by using a combination of vnstati and vnstat tools. Both are available in Ubuntu Repositories for free download.
Launch Terminal and enter the following command to install vnstati.
sudo apt-get install vnstati
You will have to enter root password and key in ‘Y’ to install it successfully.
Find out Network Connection Interfaces
Next step is to know the type of network connection adapters on your PC. To find them use the ifconfig command line as follows:
ifconfig | cut -c 1-8 | sort | uniq -u
It will list all the available connections. In my test PC the results are ‘eth0’ and ‘l0’. If you have wireless connection, it would additionally list wlan0 as well.
Export Bandwidth Usage Report
Now you are all set to fetch out the internet usage report. Remember that the report accumulation starts only after the vnstati is installed on your computer. Enter the following command line in the terminal. Don’t forget to replace the interface with your PC adapter type.
vnstati -vs -i eth0 -o ~/bandwidth_statistics.png
A detailed report will get saved in the Home directory with the file name ‘bandwidth_statistics.png’. Open ‘Files’ and see the ‘Home’ directory.