If both ends of the leased line have a VPN router and are connecting to the Internet, we can create a VPN tunnel between them to add a failover connection. This article shows how to set up a VPN for the routing LAN subnet and make it active only when the primary line fails.
Suppose WAN 1 the leased line, and WAN 2 is an Internet connection.
1. In the LAN-to-LAN VPN profile. select "WAN2 only: Only establish VPN if WAN1 down" for VPN Dial-Out through, and "Dial-Out" for Call Direction.
2. Type the command
vpn pass2nd on on router's CLI.
Now, if the primary line (the leased line) is down, VPN will establish on WAN 2 automatically, and the routing subnet can continuously access the remote network via VPN.
Suppose WAN 2 the leased line, and WAN 1 is an Internet connection.
In the LAN-to-LAN VPN profile.
Now, if WAN2 is down, WAN1 will be up and VPN will establish automatically on WAN 1 and the routing subnet can continuously access the remote network via VPN.