yum install nethogs
nethogs eth0 eth1 both
usage: nethogs [-V] [-b] [-d seconds] [-v mode] [-c count] [-t] [-p] [-s] [device [device [device ...]]]
-V : prints version.
-b : bughunt mode - implies tracemode.
-d : delay for update refresh rate in seconds. default is 1.
-v : view mode (0 = KB/s, 1 = total KB, 2 = total B, 3 = total MB). default is 0.
-c : number of updates. default is 0 (unlimited).
-t : tracemode.
-p : sniff in promiscious mode (not recommended).
-s : sort output by sent column.
device : device(s) to monitor. default is all interfaces up and running excluding loopback
When nethogs is running, press:
s: sort by SENT traffic
r: sort by RECEIVE traffic
m: switch between total (KB, B, MB) and KB/s mode