iftop show bandwidth usage like top show cpu and memory usage.
To see network usage, run
iftop
If you have multiple network interface, you need to specify network interface to monitor, this can be done with -i option
iftop -i eth1
To install on CentOS, run
yum install iftop
For installing from source, see Install iftop from source on CentOS
On Ubuntu
apt -y install iftop
To use, run iftop
