Network port not listen while running game

I downloaded the Shootout Demo to try networking.
I packaged it to window standalone and ran two instances in same PC. That was work!
It can create and join Session.

But I try to run instances in two PC(192.168.0.100, 192.168.0.101),
192.168.0.100: Create Session
192.168.0.101: Find Session
I would found no session in 192.168.0.101
I already set the port forwarding,
and i use some port checker that show the port is open

However, i checked my game in process that show the it used 27015, not 7777!

" that show the it used 27015, not 7777!"

if u open 27015 then does it work?