Nmap supports a very interesting feature that allows us to run scans against random targets on the Internet. This is very useful when conducting research that needs a sample of random hosts.
This recipe shows you how to generate random hosts as targets of your Nmap scans.
To generate a random target list of 100 hosts, use the following Nmap command:
$ nmap -iR 100
Nmap will generate a list of 100 external IP addresses and scan them using the specified options. Let's combine this option with a ping scan:
$ nmap -sP -iR 3 Nmap scan report for host86-190-227-45.wlms-broadband.com (86.190.227.45) Host is up (0.000072s latency). Nmap scan report for 126.182.245.207 Host is up (0.00023s latency). Nmap scan report for 158.sub-75-225-31.myvzw.com (75.225.31.158) Host is up (0.00017s latency). Nmap done: 3 IP addresses (3 hosts up) scanned in 0.78 seconds