https://www.cnblogs.com/hellocjr/p/11431230.html

查看已开放的端口

firewall-cmd —list-ports
开放端口（开放后需要要重启防火墙才生效）
firewall-cmd —zone=public —add-port=3338/tcp —permanent
重启防火墙
firewall-cmd —reload
关闭端口（关闭后需要要重启防火墙才生效）
firewall-cmd —zone=public —remove-port=3338/tcp —permanent

开机启动防火墙

systemctl enable firewalld
开启防火墙
systemctl start firewalld

禁止防火墙开机启动

systemctl disable firewalld

停止防火墙

systemctl stop firewalld