Which authentication servers can be grouped using Fortinet's system?

Grouping authentication servers in Fortinet's system can be accomplished through both the Command Line Interface (CLI) and the Graphic User Interface (GUI). Each of these interfaces provides capabilities for managing and configuring the authentication servers, allowing administrators to efficiently organize them according to their specific requirements.

The CLI offers a powerful way to script and automate the process of grouping authentication servers, which can be beneficial for environments that require consistent and quick configurations. On the other hand, the GUI provides a more visual and user-friendly approach, making it easier for users who may prefer an intuitive layout to configure settings related to authentication.

This flexibility supports various administrative preferences and operational needs, ensuring that users can utilize the method they are most comfortable with or the one best suited for the task at hand. Therefore, the correct answer encompasses the ability to use both methods, making it possible to group authentication servers via either interface.