1.首先关闭firewalld服务
systemctl stop firewalld
systemctl disable firewalld
systemctl mask firewalld

2.安装iptables
yum install  -y iptables  iptables-services

3.开启iptables服务
systemctl enable iptables
systemctl start iptables

4.保存
service iptables save
service iptables restart

5.开机启动
systemctl enable iptables

systemctl status iptables