The control panel runs on port 2082 so if you are behind a firewall or proxy server you might have trouble accessing your control panel if that port is blocked.
For some users who is on a LAN which the firewall is blocking the above outgoing port,
We have a simple workaround: access your site via http://cpanel.yourdomainname for Cpanel control panel , http://whm.yourdomainname for WHM or http://webmail.yourdomainname for webmail. Replace "yourdomainname" with your domain name e.g. mydomain.ie.