关闭及停止使用 Firewalld:
systemctl mask firewalld
systemctl stop firewalls
安裝 iptables
yum install iptables-services
生效及iptables开机启动
systemctl enable iptables
systemctl start iptables
systemctl mask firewalld
systemctl stop firewalls
yum install iptables-services
systemctl enable iptables
systemctl start iptables