The License Callback Mechanism
Last modified: June 17, 2021
Overview
The license callback mechanism immediately updates a server after the license changes in either Manage2 or the cPanel Store. It cannot make any changes to the server. It only alerts the server that a change as been made to the license.
At least one port in the following table must be open for the license callback mechanism to work. The server only accepts requests to this API from cPanel & WHM. The license system does not send any other information to the customer’s server.
The license callback mechanism tries the following ports until one succeeds:
| Service | Port | Inbound | Outbound |
|---|---|---|---|
| cPanel | 2082 |
 |
|
| cPanel SSL | 2083 |
|
|
| WHM | 2086 |
|
|
| WHM SSL | 2087 |
|
|
| Webmail SSL | 2096 |
|
The license callback mechanism uses the following IP addresses to perform the license check:
208.74.121.0/24208.74.123.0/24
For more information on how to configure your firewall for cPanel & WHM service, read our documentation.