I ran the command cat /etc/services and got a long out of ports. Then I saw this one and i googled what is its purpose but I still don't get it. What does "cmd" mean here and why does it say "no passwords used"?
The line:
shell 514/tcp cmd # no passwords used
Port 514 is sometimes used for Remote Shell, a command called rsh. It is for remote control of a server but by default does not provide for encryption or passwords. Almost like telnet but with a shell around it.
It is legacy software that most people do not use. Instead, ssh is the secure (remote) shell that everyone uses.
man services? Also, the line wasn't t really presented in exactly that way, was it? There's a#missing. Could you also say something about why you singled out this particular line and not some other service's line?man servicesnow so that means that cmd and no passwords used belongs to aliases which again i don't fully understand. And yes there is a # missing. I singled it out because i associated "cmd" with Windows and I thought the "not passwords used" part looked concerning. Im sure if I look long enough in the list I will freak out on more ports