1 Reply Latest reply: Aug 28, 2013 11:47 AM by heider RSS

    Port is open but not listening????


      Hi All,


      Please correct me if I am wrong.


      My security team telling me that telnet port 23 is open.

      However, I check on my server:

      • telnet SMF is disabled
      • port 23 telnet  is commented in /etc/services
      • netstat -an|grep -i listen | grep 23   show nothing.
      • telnet to port 23, it is not accepting.


      So based on the above result, I told my security team that the port is not open because we the service is down and it can't telnet.


      But security team said, it is not listening but the port is open.

      And I ask how can you tell the port is open?

      They said is based on their port scan software they use.




      It is something that I don't know? port is not listening but port is open? even netstat -an|grep -i listen | grep 23   show nothing?

        • 1. Re: Port is open but not listening????

          From the OS security standpoint it sounds like you have taken the necessary steps already. Your OS is not listening on port 23 and will not respond to requests. If they want to completely block traffic on port 23, that sounds like a job for the Network/Firewall team.