1.任意运行一条iptables防火墙规则配置命令:

iptables -P OUTPUT ACCEPT

2.对iptables服务进行保存:

service iptables save

如果上述命令执行失败报出:The service command supports only basic LSB actions (start, stop, restart, try-restart, reload, force-reload, status). For other actions, please try to use systemctl.

解决方法:
systemctl stop firewalld 关闭防火墙
yum install iptables-services 安装或更新服务
再使用systemctl enable iptables 启动iptables
最后 systemctl start iptables 打开iptables

再执行service iptables save

3.重启iptables服务:

service iptables restart

执行完毕之后/etc/syscofig/iptables文件就有了