If there’s suddenly a lot of network traffic, you can fire up NetHogs and immediately see which PID is causing this. This makes it easy to identify programs that have gone wild and are suddenly taking up your bandwidth.
Install NetHogsOn RHEL/CentOS, NetHogs is not available in official RHEL/CentOS repositories, so let us add EPEL repository to install NetHogs:
[root@server ~]# rpm -ivh http://dl.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpmInstall NetHags using the following command:
[root@server ~]# yum install nethogs -yOn Ubuntu/Debian:
vpscheap@:~$ sudo apt-get install nethogsUsage
Open up the terminal and enter the following command:
vpscheap@:~$ sudo nethogsBy default, NetHogs listens to eth0 interface and displays the bandwidth consumption of the processes. As you see above, the SENT and RECEIVED columns shows the amount of traffic being used around per process. The total bandwidth usage is shown in the TOTAL column. To cycle between bandwidth usage units, hit “m” (Available units: KB/sec, KB, B, MB). To sort by “sent” traffic or “received” traffic, hit “s” or “r” respectively. You can quit nethogs by hitting “q”.
More OptionsTo listen a particular interface, for example eth1, enter the following command:
vpscheap@:~$ sudo nethogs eth1To monitor bandwidth usage of eth1 interface only, use the following command:
vpscheap@:~$ sudo nethogs -device eth1Also you can set refresh intervals use the parameter -d along with number of seconds. For example, to set the refresh interval every 5 seconds, enter the following command:
vpscheap@:~$ sudo nethogs -d 5For more information about NetHogs refer the man pages:
vpscheap@:~$ man nethogs