iftop or Interface TOP is a free and open source terminal based bandwidth usage and monitoring application for Linux. Using this iftop, you can view real time network bandwidth usage and monitor your system. It is based on libpcap and libcurses and released under GNU General Public License.
Install iftop on Ubuntu Linux
Open terminal command-line application by pressing ctrl+alt+t keys or via application menu. And run below command one by one to install iftop on Ubuntu Linux.
sudo apt update
sudo apt install iftop
You can run iftop via below command.
You can change the current network interface using the below way. First run below command to find all attached network interfaces on your system.
After that use the -i to specify the interface you want to view.
sudo iftop -i wlp13s0
Here wlp13s0 is my wireless interface on my computer.
For the complete usage details please run this command in terminal to get more help.