centos下/etc/sysconfig/下找不到iptables文件

原因：在新安装的Linux系统中，防火墙默认是被禁掉的，一般也没有配置过任何防火墙的策略，所有不存在/etc/sysconfig/iptables文件。

解决办法：
1、随便写一条iptables命令配置个防火墙规则：如：

iptables -P OUTPUT ACCEPT

2，进行保存

service iptables save

3，service iptables restart

异常

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

With RHEL 7 / CentOS 7,firewalld was introduced to manage iptables. IMHO,firewalld is more suited for workstations than for server environments.

It is possible to go back to a more classic iptables setup. First,stop and mask the firewalld service:

systemctl stop firewalld
systemctl mask firewalld

Then,install the iptables-services package:

yum install iptables-services

Enable the service at boot-time:

systemctl enable iptables

Managing the service

systemctl stop iptables

systemctl start iptables

systemctl |restart iptables

Saving your firewall rules can be done as follows:

service iptables save

or

/usr/libexec/iptables/iptables.init save

参考文章：

http://www.centoscn.com/CentosBug/osbug/2014/0919/3779.html

http://www.cnblogs.com/love3556/p/5923392.html