By default any application network port mostly will be blocked by the Operating System’s firewall. As a result you will face that applications from two system are not able to communicate to each other. The same works perfectly if you run them on the same system.

You can open or add the network port in the firewall by simply adding rules as below:

# firewall-cmd --zone=public --add-port=2379/tcp --permanent

After adding the rule you must restart the firewall.

# firewall-cmd --reload

Verify all rules and opened ports.

# firewall-cmd --list-all