How to make a sec vpn tunnel failover 2 ISP ( Internet Service Provider ) to azure vpn

Hello adrianit,

Thank you for your inquiry. There are multiple ways to deploy a backup ipsec tunnel including the way the failover happens. The very basic step would be to achieve this with static routes using the following logic:
- setting up backup tunnel static route to the same destination as the primary tunnel with a higher "distance" value than the primary tunnel static route

- as long as the primary tunnel is up, its static route will be always the only active route for this traffic

- once the primary tunnel is down, the backup tunnel takes over as it will become the only available route for the same destinations.

Here is an article providing guidance to implement such configuration:

https://community.fortinet.com/t5/FortiGate/Technical-Tip-Implement-IPsec-Backup-Tunnel/ta-p/245084

Thank you,

saleha