Port Scanning identifies open TCP/UDP ports and running services on a target.
Nmap
nmap -sC -sV -oN output.txt TARGET
nmap -p- --min-rate=1000 TARGET
Scan Types
- SYN scan (
-sS) — stealth, no full TCP handshake. - Connect scan (
-sT) — full connection. - UDP scan (
-sU) — slow but important.