HA (A-P) mode FortiGate pairs as switch controller
The following recipes provide instructions on configuring a FortiGate HA in Active-Passive (A-P) mode as a switch controller:
Network Security 
Network Security
NOC & SOC Management
Enterprise Networking
Business Communications
Zero Trust Access 
Cloud Security 
Hybrid Cloud Security
Cloud Native Protection
Web Application / API Protection
SAAS Security
Security Operations 
SOC Platform
Advanced Threat Protection
Endpoint Security