yum install firewalld
service firewalld start
service firewalld status
service firewalld stop/disable
yum list | grep firewall
ps -ef | grep firewall
firewall-cmd --version
firewall-cmd --help
firewall-cmd --state
firewall-cmd --get-zones
firewall-cmd --get-default-zone
firewall-cmd --list-all-zones
firewall-cmd --list-ports
firewall-cmd --query-service=ssh
firewall-cmd --remove-service=ssh
firewall-cmd --add-service=ssh
firewall-cmd --list-services
firewall-cmd --query-port=22/tcp
firewall-cmd --add-port=22/tcp
firewall-cmd --remove-port=22/tcp