Uncomplicated FireWall application preset
Please note: When you installed syncthing using the official deb package, you can skip the copying.
Copy the file
syncthing to your ufw applications directory usually located at
/etc/ufw/applications.d/ (root permissions required).
In a terminal run
sudo ufw app update syncthing sudo ufw app update syncthing-gui
to load the presets. To allow the syncthing ports, run
sudo ufw allow syncthing
If you want to access the web gui from anywhere (not only from localhost), you can also allow the gui port. This is step is not necessary for a "normal" installation!
sudo ufw allow syncthing-gui
You can verify the opened ports by running
sudo ufw status verbose