查看防火墙状态
service firewalld status #查看防火墙状态
systemctl status firewalld #查看防火墙状态
service iptables status
暂时关闭防火墙(即时生效)
systemctl firewalld stop
service iptables stop
开机启用防火墙（重启后生效）
systemctl firewalld enable
chkconfig iptables on
关闭防火墙（重启后生效）
systemctl disable firewalld
chkconfig iptables off
启动防火墙
systemctl firewalld start
service iptables start
重启防火墙
systemctl firewalld restart
service iptables restart