References:
Install
sudo pacman -S --needed firewalld
Enable
sudo systemctl enable firewalld.service --now
Check status
systemctl status firewalld.service
Find services:
sudo firewall-cmd --get-services
Get information (ports) about a service. For example:
sudo firewall-cmd --info-service=http
Open some ports. For example:
sudo firewall-cmd --add-service=http
sudo firewall-cmd --add-service=mdns
sudo firewall-cmd --add-service=syncthing
Make runtime changes permanent:
sudo firewall-cmd --runtime-to-permanent
Install a graphical user interface
sudo pacman -S --needed firewall-config