*Step two: find the OS wanted, in this case, CentOS i386. http://isoredirect.centos.org/centos/6/isos/i386/
*Step three: it should be working.
now, as an introduction to linux, search for a program in the internet, download it, run it, and know all the packets coming in and out from your router, or network.
reference:
http://linuxcommand.org/
https://www.centos.org/
https://www.wireshark.org/
https://www.virtualbox.org/wiki/Downloads
