Monitor Network Bandwidth

bwm-ng is the right tool for monitoring network bandwidth.

Install bwm-ng

sudo apt install bwm-ng

Use bwm-ng

bwm-ng

the output can be like this

bwm-ng v0.6 (probing every 0.500s), press 'h' for help
  input: /proc/net/dev type: rate
  -         iface                   Rx                   Tx                Total
  ==============================================================================
             eth0:         111.74 KB/s         6925.76 KB/s         7037.50 KB/s
               lo:           0.00 KB/s            0.00 KB/s            0.00 KB/s
  ------------------------------------------------------------------------------
            total:         111.74 KB/s         6925.76 KB/s         7037.50 KB/s

Use vnstat

vnstat -d
vnstat -m