I'm using netcat as a backend to shovel data back and forth for a program I'm making. I tested my program on the local network, and once it worked I thought it would be a matter of simply forwarding a port from my router to have my program work over the internet. Alas! This seems not to be the case.

If I start netcat listening on port 6666 with:

`nc -vv -l -p 6666`,

then go to `127.0.0.1:6666` in a browser, as expected I see a HTTP GET request come through netcat (and my browser sits waiting in vain). If I go to `my.external.ip.address:6666`, however, nothing comes through at all and the browser displays 'could not connect to `my.external.ip.address:6666`'. 

I know that the port is correctly forwarded, as www.canyouseeme.org says port 6666 is open (and when netcat is not listening, that its closed). 

If I run netcat with `-g my.adslmodem's.local.address` to set the gateway address, I get the same behavior. Am I using this command line option correctly? Any insight as to what I'm doing wrong?