Failed to stop iptables.service: Unit iptables.service not loaded.

在关闭防火墙到时候，出现：

Redirecting to /bin/systemctl stop  iptables.service
Failed to stop iptables.service: Unit iptables.service not loaded.

解决方法：

yum install iptables-services

实际上，centos7后是使用的基于iptable的systemctl stop firewalld

systemctl stop firewalld

参考：https://blog.csdn.net/zhou_438/article/details/86761398