You can use whatismyip to determine your IP address.
Launch TripleA and host a direct network game. Then use canyouseeme.org to check that your IP address at port 3300 is reachable. If not, you’ll need to be sure you have both firewall and port forwarding rules in place.
Your Firewall is what blocks unallowed requests from being processed and/or answered from your Computer. This is a good thing, but in this case we need to setup a special rule for it in order to allow TripleA to be accessed by other clients over the web.
TripleA uses port 3300 (TCP) by default.
Windows
Open the Control Panel, click on “Windows Firewall” > “Allow a program or feature through Windows Firewall”
More detailed instructions can be found at: https://www.windowscentral.com/how-open-port-windows-firewall
Linux
This will vary by distrubtion. On Ubuntu and Debian based systems using ufw, the command is:
ufw allow 3300
Mac
See: https://support.apple.com/en-us/HT201642
If you have a router (if you’re not plugged directly into your modem), you’ll need to set up port forwarding rules so requests are forwarded from your router to your computer. Each router can be slightly different, your best bet is to do an internet search for your brand of router and “how to set up port forwarding”.
Make sure your Router forwards Port 3300 to Port 3300 on your local machine. If you are asked for the Protocol select TCP.
If you still have any questions, feel free to ask on the player help forum: https://forums.triplea-game.org/category/10/player-help