NMAP (1)

High quality opensource portscanner

Very useful for different types of assessments

Support for multiple scanning types

TCP connect() scan Full 3 way handshake (SYN -> SYN/ACK -> ACK) Easily detectable nmap 192.168.0.1
TCP SYN scan Attacker sends SYN, then, after receiving a SYN/ACK, immediately breaks of with RST
- Very old sites don't seem to log this
- nmap -sS 192.168.0.1

TCP connect() scan Full 3 way handshake (SYN -> SYN/ACK -> ACK) Easily detectable nmap 192.168.0.1