Nmap
Basic
Scan 100 most common ports (fast)
nmap -F [ip|hostname]
Scan a single port
Add `-sV` to detect what service is running on the specified port.
UDP
nmap -sU -p [port#] [ip|hostname]
TCP
nmap -sT -p [port#] [ip|hostname]
Scan a range of ports
nmap -p 80-81 [ip|hostname]
Advanced
OS and version detection, script scanning, and traceroute
Warning: This will likely be detected by an IDS/IPS
nmap -A -T4 [ip|hostname]
Firewall Audit (from another machine)
2020-06-07 - I don't think this is right...need to find a better command
nmap –v –sA –n [ip|hostname] –oA [output-filename]