http://stackoverflow.com/questions/13296361/nmap-and-svnlib-client-not-working-together
http://nmap.org/book/osdetect-unidentified.html
http://serverfault.com/questions/522596/ping-only-os-detection-with-nmap
http://lcamtuf.coredump.cx/p0f3/
http://www.cyberciti.biz/networking/nmap-command-examples-tutorials/
http://www.ibm.com/developerworks/cn/aix/tutorials/au-unixnetworkanalysis/