How to force open TCP 443 on my machine?
To force open any port you can use nc (netcat).

The command sudo nc -l 443 will open port 443. Of course this will not serve any web pages. But it will be listed in your namp output as open port.

By specifying an interface with -b &lt;if&gt; you can bind it exclusively to it - other interfaces (e.g. en1) shouldn't show an open port 443 then:

sudo nc -b en0 -l 443


Check for more options by executing man nc.