Just curious about this. The output of the netstat -ta command shows two listening ports:
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 localhost.localdomain:ipp *:* LISTEN
tcp 0 0 localhost.localdomain:5335 *:* LISTEN
ipp is the CUPS server on port 631 tcp
the second entry is the MdnsResponder service listening on port 5335
When I run Nmap to scan myself, it shows CUPS listening on 631 ok, but it doesn't show 5335 as open. I was thinking that if a service was listening on a port then, then the port is open. Why doesn't Nmap pick up this port as "open"?
Edit: I am just using the "connect" scan option with Nmap.