The license cannot be updated because the cPanel license servers are not accessible from within this server

Symptoms

You receive an error similar to the following when you attempt to update your license:

The license cannot be updated because the cPanel license servers are not accessible from within this server:

Could not reach port 23 on auth.cpanel.net from this server -- connections may be throttled.

Could not reach port 2089 on auth.cpanel.net from this server -- connections may be throttled.

Description 

This typically occurs whenever you cannot reach auth.cpanel.net from your server.

Workaround

Unblock or allow connections on port 2089 to auth.cpanel.net from within your server. The cPanel licensing system tries to connect to auth.cpanel.net to validate the cPanel license. If it cannot establish a connection on its primary port 2089, it will attempt to connect through other popular service ports such as the following:

• 80
• 23
• 25
• 110
• 143
• 993
• 995