Question about ports

Hey everyone. I am getting very frustrated with ports/port forwarding. No matter what port i enter on canyouseeme it says it cannot see me. No matter the port. I am attempting to allow a specific port to connect. But I cannot. I have looked at EVERYTHING. Allowed it thru firewall, read the manual on the r6300 netgear that I have. I have ports forwarded in the router, but no matter what, when I go to canyousee me, it never shows any open port. How do I see what listening port is open? Why would no ports appear to be connectable. Even port 80, it says it cannot see. Very frustrating. I have tried with firewall and antivirus totally off, nothing!

That is because the Gateway will always Stealth them, to keep outsiders from seeing that they are open.

Not sure what you mean, when I am at my work pc, at work, and go to canyouseee and use port 80, it immediately sees it.