CentOS 7开放端口和关闭防火墙

$ sudo firewall-cmd --zone=public --add-port=3000/tcp --permanent
$ sudo firewall-cmd --reload

$ sudo firewall-cmd --list-all

$ systemctl restart firewalld

$ firewall-cmd --state
$ firewall-cmd --list-all

$ systemctl disable firewalld
$ systemctl stop firewalld
$ systemctl status firewalld

$ systemctl enable firewalld
$ systemctl start firewalld
$ systemctl status firewalld