The tool nload makes it simple for us to check the incoming/outcoming traffic rate in server, it’s pretty nice and handy tool. This is very useful to check traffic stat when a server is under ddos attack.
How to install it?
Download nload source from http://sourceforge.net/projects/nload/
# tar xvf nload-0.7.4.tar.gz
# cd nload-0.7.4
# make install
Or you can install it using rpm, download it from here http://pkgs.repoforge.org/nload/
$ nload eth0
$ nload em0 em2
Once we confirm whether it is inbound or outbound, we can use further methods like iftop, tcpdump, apache status through WHM or httpd fullstatus via shell.