Using ICMP to perform host discovery

Layer 3 discovery is probably the most commonly used tool among network administrators and technicians. It uses the famous ICMP ping utility to identify live hosts. This recipe will demonstrate how to use the ping utility to perform layer 3 discovery on remote hosts.

Getting ready

Using ping to perform layer 3 discovery does not require a lab environment, as many systems on the Internet will reply to ICMP echo requests. However, it is highly recommended you perform any type of network scanning exclusively in your own lab unless you are thoroughly familiar with the legal regulations imposed by any governing authorities to whom you are subject. If you wish to use this technique within your lab, you will need to have at least one system that will respond to ICMP requests. In the examples provided, a combination of Linux and Windows systems is used. For more information on setting up systems in a local lab environment, refer to the Installing Metasploitable2...