Lesson 2 What is OS fingerprinting? OS fingerprinting is the process of differentiating the OS used by a host in a network. There can be different implementations in determining this like obtaining the TCP/IP stack (TTL value defaults), HTTP packets (via User-Agent field), via ICMP requests, open port patterns, TCP window size and more.
Lesson 1 Introduction Nmap (“Network Mapper”) is a free and open source (license) utility for network discovery and security auditing. Many systems and network administrators also find it useful for tasks such as network inventory, managing service upgrade schedules, and monitoring host or service uptime.