Including the reason for a port or host state
To make Nmap, include the reason why a port is marked as opened or closed and why the host is marked as alive; use the option --reason, as shown in the following command:
$ nmap --reason <target>The option --reason will make Nmap include the packet type that determined the port and host state. We have the following example:
$ nmap --reason scanme.nmap.org
Nmap scan report for scanme.nmap.org (74.207.244.221)
Host is up, received echo-reply (0.12s latency).
Not shown: 96 closed ports
Reason: 96 resets
PORT STATE SERVICE REASON
22/tcp open sshsyn-ack
25/tcp filtered smtp no-response
80/tcp open http syn-ack
646/tcp filtered ldp no-response
Nmap done: 1 IP address (1 host up) scanned in 3.60 seconds
