Which protocol can be used for remote authentication in FortiGate?

RADIUS (Remote Authentication Dial-In User Service) is widely used for remote authentication in FortiGate devices as it provides centralized user management and authentication for network access. It is designed to communicate between an authentication server and a network access server, enabling secure management of user credentials. This protocol facilitates not just authentication but also accounting and authorization, allowing for more comprehensive control over user access in network environments.

In comparison, HTTP (Hypertext Transfer Protocol) is primarily used for transferring web pages and does not serve any purpose in the context of authentication for network devices like FortiGate. FTP (File Transfer Protocol) is utilized for transferring files and is not relevant for authentication processes. SMTP (Simple Mail Transfer Protocol) is designed for email transmission and does not provide mechanisms for authentication related to network access.

Therefore, RADIUS is the most appropriate choice for remote authentication in FortiGate, as it is specifically engineered for this purpose, ensuring secure and manageable user access to network resources.