执行命令

systemctl stop firewalld

systemctl mask firewalld

安装iptables-services

yum install iptables-services

设置开机启动

systemctl enable iptables

systemctl stop iptables

systemctl start iptables

systemctl restart iptables

systemctl reload iptables

保存设置

service iptables save

解决CentOS7关闭/开启防火墙出现Unit iptables.service failed to load: No such file or directory.