If you received cPanel/WHM server recently, it could be that cPanel/WHM server has not finished installation. It can take 60-90 minutes to completely install.
In that case you can watch the status of installation by running following command via SSH:
tail -f /var/log/cpanel-auto*
If it is still not working, check out firewall settings.
Make sure that firewall isn’t blocking the port. You can make sure this isn’t happening by running:
# iptables -I INPUT -p tcp –dport 2086 -j ACCEPT && /etc/init.d/iptables save
Now, restart the cpanel service.
# service cpanel restart
If you are still unable access it, please submit a support ticket via your control panel.