CentOS7.x上怎么安装iptables
1、关闭firewall
systemctl stop firewalld.service
systemctl disable firewalld.service
2、安装iptables
yum install iptables-services
3、启动iptalbes，设置为开机启动
systemctl restart iptables.service
systemctl enable iptables.service
4、iptables已启动，默认只打了SSH的22端口
