An Introduction to Firewalld

Refer to An Introduction to Firewalld

Add a Port for TCP or UDP

You do have to specify TCP or UDP and to open a port for both. You will need to add rules for each protocol.

firewall-cmd --permanent --add-port=443/tcp

Saving Firewall Rules

After you have completed all the additions and subtraction of rules, you need to reload the firewall rules to make them active. To do this, you again use the firewall-cmd tool but using the option –reload.

firewall-cmd --reload

Config to accept all traffic between the nodes:

[root@mgt ~]$ firewall-cmd --permanent --direct --add-rule ipv4 filter INPUT 0 -s  192.168.x.xxx -j ACCEPT
success
[root@mgt ~]$ firewall-cmd --reload
success

Refer to add rule to firewalld in Centos7 to allow all traffic from a server