How to add rules in Firewall Exception in CentOS7

Firewalld is a firewall management tool available by default on CentOS 7 servers. It provides command line and graphical interfaces and is available in the repositories of most Linux

distributions.

Supposing the new service/port is httpd/80, enter the following commands:

[root@linuxcnf ~]# firewall-cmd --permanent --zone=public –add-port=80/tcp

Once this is done, reload the firewall configuration:

[root@linuxcnf ~]# firewall-cmd --reload

It is done!!!