Discovering hosts with IP protocol ping scans

Ping sweeps are very important for host discovery. System administrators and penetration testers use them to determine which hosts are online and responding. Nmap implements several ping scanning techniques, including one called an IP protocol ping scan. This technique tries sending different packets using different IP protocols, hoping to get a response indicating that a host is online.

This recipe describes how to perform IP protocol ping scans.

How to do it...

Open your terminal and enter the following command:

# nmap -sP -PO scanme.nmap.org

If the host responded to any of the requests, you should see something like this:

# nmap -sP -PO scanme.nmap.org  
Nmap scan report for scanme.nmap.org (74.207.244.221) 
Host is up (0.091s latency). 
Nmap done: 1 IP address (1 host up) scanned in 13.25 seconds 

How it works...

The arguments -sP -PO scanme.nmap.org tell Nmap to perform an IP protocol ping scan of the host scanme.nmap.org.

By default, this ping...