CentOS 7 iptables防火墙开启

CentOS 7 中默认的防火墙不再是iptables了，需要先关闭防火墙firewall再安装iptables

systemctl stop firewalld.service #停止firewall
systemctl disable firewalld.service #禁止firewall开机启动

yum install iptables-services #安装