Scanning random targets

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.

How to do it...

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

How it works...

The argument -iR 100 tells Nmap to generate 100 external IP addresses and use them as targets...