How To Open A Port In CentOS 7 With Firewalld

From: How To Open A Port In CentOS 7 With Firewalld and also here.

And 5 Useful Examples of firewall-cmd command

Open Specific Port

[root@centos7 ~]# firewall-cmd --permanent --add-port=100/tcp
success
[root@centos7 ~]# firewall-cmd --reload
success

We can also open a range of ports in the same way.

[root@centos7 ~]# firewall-cmd --permanent --add-port=200-300/tcp
success