1、关闭firewall防火墙

systemctl stop firewalld

2、禁止firewall开机启动

systemctl disable firewalld

3、安装iptables防火墙

yum install -y iptables iptables-services

4、启动iptables

systemctl start iptables

5、将iptables加入开机自启动

systemctl enable iptables