I'm trying to forward my ports to play half-life with my friend (Steam version), I did everything correct, and he couldn't join. So we tried TF2. Same thing. Then we tried Garry's Mod. He couldn't connect. I ported all the ports correctly, what's going on?!

# Service Name Start Port End Port Server IP Address
1 Half-Life 27015 27015 192.168.1.3
(I'm not editing the rest, :P)
Edit: I made the server.