How to play online (host opens port 7777)
In order to be able to host a game successfully, TCP Port 7777 must be open in the *host*. If the clients trying to connect to the host are stuck in the connecting screen forever, or get a timeout error, the *host* must configure a port forwarding for port 7777.
Instructions for port forwarding:
To configure port forwarding, you need to access your router’s interface through the web browser.
- Run the program “cmd” (Win key + R, then type cmd in the textbox)
- Once inside the terminal, type ipconfig
- Write down the IP address of your default gateway. That should be your router’s IP.
- Also write down your own IP (IPv4 Address)
- Open the browser and type the IP.
- Log into your router, and look for a tab or menu called “Applications & Gaming,” “Advanced,” “Port Forwarding/Port Triggering,” “NAT/QoS,” or something similar.
- Set up a port forwarding for TCP port 7777. Don’t forget to save/activate the port forwarding.
Steps 6 and 7 can vary depending on your router’s brand/interface.
Here’s a more complete guide from PC World: http://www.pcworld.com/article/244314/how_to_forward_ports_on_your_router.html