1、centos 6 是iptables, 7 开始就以firewalld代替iptables;
2、systemctl stop firewalld.service 停
systemctl start firewalld.service 开
systemctl enable iptables.service 设置开机启动
systemctl disable firewalld.service 禁止开机启动
firewall-cmd --restart 重启
firewall-cmd --state 查状态
firewall-cmd --reload 重新加载新配置