http://blog.itpub.net/12707874/viewspace-2141432/
RedHat 7.x 默认不再用iptables管理防火墙，相关命令如下：
一、关闭防火墙
查看防火墙状态
systemctl status firewalld
实时关闭（重启恢复）
systemctl stop firewalld
查看防火墙服务是否开机启动
systemctl is-enabled firewalld
永久关闭
systemctl disable firewalld
二、关闭SELinux
查看当前SELinux状态
getenforce
实时关闭（重启恢复）
setenforce 0
永久关闭
vim /etc/selinux/config
#This file controls the state of SELinux on the system.
#SELINUX= can take one of these three values:
#enforcing - SELinux security policy is enforced.
#permissive - SELinux prints warnings instead of enforcing.
#disabled - No SELinux policy is loaded.
SELINUX=permissive #修改为disabled
#SELINUXTYPE= can take one of three two values:
#targeted - Targeted processes are protected,
#minimum - Modification of targeted policy. Only selected processes are protected.
#mls - Multi Level Security protection.
SELINUXTYPE=targeted
1、在之前的版本中关闭防火墙等服务的命令是
service iptables stop
/etc/init.d/iptables stop
2、RHEL7开始，使用systemctl工具来管理服务程序，包括了service和chkconfig
systemctl list-unit-files|grep enabled
查看防火墙状态。
systemctl status firewalld
临时关闭防火墙命令。重启电脑后，防火墙自动起来。
systemctl stop firewalld
永久关闭防火墙命令。重启后，防火墙不会自动启动。
systemctl disable firewalld
打开防火墙命令。
systemctl enable firewalld