I'm working on a challenge and I notice this odd output for a full port scan?
abc@desktop:~$ nmap -T5 -p- -sV x.x.x.x -PN Interesting ports on x.x.x.x: Not shown: 65533 filtered ports PORT STATE SERVICE VERSION 3389/tcp open microsoft-rdp Microsoft Terminal Service 11111/tcp closed unknown Service Info: OS: Windows
I'm used to NMAP only displaying open ports. In this case the vast majority of ports were closed but NMAP explicitely stated port 60000 is closed.
What does an explicitely closed port mean?