Please add a popup that tells hosts they need to port forward.

[palehorse864]

Please add some text to the hosting screen that explains that port 9995 has to be forwarded before anyone can join. It's about impossible to join a multiplayer game because people don't seem to understand this.  A friendly reminder would probably go a long way. 

I'm not sure if you can check whether a host has ports forwarded, though that would be nice if you could alert them when they don't.

Edit: The text should also include whether this is a TCP or UDP port.

[Linaru]

i do not think there is anyway the game can check if your port forwarded so such a pop up would pop up for everyone every time they host.

[palehorse864]

The best way would be to put it around the border of one of the menus if it had to show up everytime. It would be out of the way and unobstructive, but it would be there for everyone to see.

An option could be added to the main menu to disable it if it really bugged someone, but it would be on by default.