# Installation
yum list installed | grep firewalld
yum list available | grep firewalld
yum install firewalld

# Service management
systemctl enable firewalld
systemctl stop firewalld
systemctl start firewalld
systemctl restart firewalld

# Status and listing
firewall-cmd --list-ports
firewall-cmd --list-services
firewall-cmd --list-all
firewall-cmd --state

# Adding service and ports
firewall-cmd --zone=public --permanent --add-port=8080/tcp
firewall-cmd --add-service=postgresql --permanent

# Always reload
firewall-cmd --reload