I believe FortiToken is the simplest to implement.
Fortinet FortiToken offers easy integration with existing Fortinet security systems and reliable two-factor authentication, ensuring efficient management through FortiGate. It is scalable to support numerous users and is cost-effective compared to other methods. However, it has limited integration with non-Fortinet systems, frequent connectivity issues, a cumbersome token activation process, slow customer support, and occasional token synchronization problems.
