修改防火墙设置

vim /etc/sysconfig/iptables
-A INPUT -m state --state NEW -m tcp -p tcp --dport 21 -j ACCEPT # 加入这一行打开21端口

重启防火墙

service iptables stop
service iptables start

centOs7

查看防火墙状态

systemctl status firewalld.service

关闭防火墙

systemctl stop firewalld.service

禁用防火墙服务

systemctl disable firewalld.service