Please visit the following URL to verify your WHM / cPanel license using your dedicated servers base IP for eth0:
If you do not now your primary ip address for eth0, issue the following command as root:
The ifconfig command will list the details of your ethernet card(s) and you can then view the first IP for eth0.
If this is verified but is still not working, issue the following command:
Also make sure your not blocking cpkeyctl via egress (outbound) filtering. Make sure that you have egress filtering for port 2089 unblocked in your firewall config.