Although banner grabbing can be an extremely lucrative source of information at times, version disclosure in service banners is becoming less common. Nmap has a service identification function that goes far beyond simple banner grabbing techniques. This specific recipe will demonstrate how to use Nmap to perform service identification based on probe-response analysis.
To use Nmap to perform service identification, you will need to have a remote system that is running network services that can be probed and inspected. In the examples provided, an instance of Metasploitable2 is used to perform this task. For more information on setting up Metasploitable2, please refer to the Installing Metasploitable2 recipe in Chapter 1, Getting Started.