Linux – nmap port 22 filtered implications

linuxnmap

I did the nmap scan on the list of external public ip (linux hosts). I tried to test out if any not needed services are opened.

I realized there are many unfiltered ports on ssh tcp/22, however when I tried to ssh on the hosts I got the connection timeout. My question is what is the implications of this nmap port 22 filtered result? Please advise. thanks

PORT   STATE    SERVICE VERSION
22/tcp filtered ssh

Best Answer

nmap "filtered" simply means there was no response at all. Typically, this means that the packets were dropped by a firewall rule.

If the result was "open", that means that nmap successfully made a connection. If the result was "closed", that means that the target host explicitly rejected the connection attempt (i.e. responded with a TCP RESET). Usually, "closed" means that nothing is listening on that remote port.

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