Nmap is an useful tool for checking the security of a server. Since I don’t use it very often I’ve made a list of useful resources to check when in need.
The first advice, also praised by nmap authors, I got from Trinity from The Matrix Reloaded film.
nmap -v -sS -O 10.2.2.2
-v – verbose output (try -vv for even more verbose)
-sS – “the default and most popular scan option for good reasons”*
-O – OS discovery
Since my server is behind (hope) a good firewall I had to add -P0 option.
nmap portscanner howto
Describing the basic nmap scans
Nmap – Free Security Scanner For Network Exploration & Security Audits
Nmap official page
Nmap reference guide
Nmap manual
Insecure.Org – Nmap Free Security Scanner, Tools & Hacking resources
News and links