Technical Tip: Route-based IPsec site to site redundant VPN failover using BGP

• Configure IPSec Site to Site VPN redundant tunnel for both sites:

• Assign Tunnel Interface IP for both Sites Tunnel.

Site-1:

Site-2:

• Configure BGP on both Sites.
• Set weight for neighbors as required. 

Site-1:

Site-2:

• Check the routing table. VPN Tunnel with higher weight BGP neighbor will get priority.

Site-1:

• VPN-2 is active in the routing table as the neighbor weight is higher:

Site-2:

• When Tunnel VPN-2 goes down traffic will be forwarded using Tunnel VPN-1.

Site-1:

Site-2:

Related article:

https://community.fortinet.com/t5/FortiGate/Technical-Tip-How-to-fix-the-random-load-balancing-traffic-issue/ta-p/259496