Nmap – Port Scanner
Overview
Nmap is a popular tool used by both beginners and professional penetration testers for information gathering. Nmap is mainly used as a port scanner, finding open and closed ports and what services are running on them. But Nmap also has many scanning features such as identifying the geolocation of the device, scanning for vulnerabilities (like SSL Heartbleed) and more.
Nmap Cheat sheet (Most relevant port scanning commands)
-O (OS detection)
–sV (returns the version of the applications/service running on the port)
-sT (TCP connect port scan, full three-way handshake scan)
-p <port number/range> (allows specifying ports to scan)
-n (do not resolve the domain name)
-sn (Disable port scanning)
-sP (ping the hosts only)
-f (Request with fragmen...