title: Can anyone provide list of open ports required for nmap OS detection?
body: <p>I know its sends out different TCP, UDP, and ICMP probes to known open and closed ports of the target machine. I am trying to use nmap to find out OS of all the computers in the network but they are behind the firewalls, so need to know which ports I need to open in the Firewall. Currently to fails to guess anything, and most of them are running some kind of windows version.</p>