GMOD server

http://cpfx.ca/srcds/portcheck.php
If i try to check some port here i get this
Port TCP UDP
27015 Fail Fail
Some ports failed! Please visit http://portforward.com/ for details on how to forward those ports on your router!
Nobody can join my server.
I have cable internet. What to do?

Do what it bloody says, go to portforward.com and find out how to open port 27015 for your router…