With this video, you’re going to learn how to set up an OSPF VPN connection, creating a redundant secure connection between two FortiGate units. By using OSPF on the IPsec interface, you can better control VPN traffic and have secure redundancies easily built into the network structure. This example shows a simple 2-site redundant IPsec setup. With the system in place, both locations can share internet connections, and neither will lose access if one ISP is unavailable.
The original article/video can be found at Redundant OSPF routing over IPsec VPN