How To Fix Firewall Issues while connecting the other server?

Check the status of the firewalld service:

systemctl status firewalld.service

The status displays as active (running) or inactive (dead).

If the firewall is active / running, enter this command to stop it:

systemctl stop firewalld.service

To completely disable the firewalld service, so it does not reload when you restart the host machine:

systemctl disable firewalld.service

Verify the status of the firewalld service:

systemctl status firewalld.service

The status should display as disabled and inactive (dead).
firewalld.service - firewalld - dynamic firewall daemon
  Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
  Active: inactive (dead)

Repeat these steps for all host machines.
The firewalld service is stopped and disabled. You can now start the CLC and other host machines.

Postrequisites
You should re-enable the firewall after installation is complete.