telnet 220.127.116.11 33491 Trying 18.104.22.168... Connected to 22.214.171.124.. Escape character is '^]' ^] telnet> close Connection closed.
As you can see, the above telnet command shows port 33491 is open.
Running NMAP with
-PN on that same IP and port shows it as closed:
root@Ubuntu:~# nmap -PN 126.96.36.199 -p33491 Starting Nmap 5.00 ( http://nmap.org ) at 2011-10-18 18:18 EDT Interesting ports on xxx.com (188.8.131.52): PORT STATE SERVICE 33491/tcp filtered unknown Nmap done: 1 IP address (1 host up) scanned in 2.07 seconds
In the above example, telnet shows the port open, but NMAP shows the port as 'filtered' aka closed.
How can I get NMAP to show open ports for remote hosts (that disable ping)?