If the firewall is turned off (not enabled), then you're good to go. If it's turned
on, make sure Java has permission to allow incoming connections:
Open Up Your Firewall on Linux
If you've set up a firewall using IPTables, make sure port 25565 is open.
For All Operating Systems
However, opening up the firewall on your computer itself may not be enough.
To check if the Internet can get to your port, point your browser to
http://canyouseeme.org . That will come up with your publicly visible IP address.
Type in the port to check as 25565, and click Check Port. If it works, you're
good to go. If not, there's one more thing you might need to do.
If you are connected to the Internet through a router or cable modem, then
that device may have a firewall as well. Also, even if it has the port open to
the Internet, you need to forward the port traffic from the router to your local
You need to exercise caution and restraint when changing settings on your
router. If you change something you didn't intend to, you could end up
mucking up the device and losing your Internet access. So stick to the plan
here. However, every router is different, so I can't really give you specific step-
by-step instructions. Here are the basics:
Log on to your router. You may already know the user name and password
for it. If not, it may have a default user name and password that you can