https://www.jb51.net/article/101576.htm
centos6:
1 关闭防火墙-----service iptables stop
2 启动防火墙-----service iptables start
3 重启防火墙-----service iptables restart
4 查看防火墙状态--service iptables status
5 永久关闭防火墙--chkconfig iptables off
6 永久关闭后启用--chkconfig iptables on
centos7:
关闭防火墙
1 vim /etc/selinux/config
2 setenforce 0
3 systemctl stop firewalld