Dynamic routing

[beko]

HI,

i have to make some kind of dynamic routing, i have:

–-------                            --------------
              |        | ---- ipsec over WAN ---- |              |
192.168.1.0/24 | pfsense |                          | linux router | 192.168.2.0/24
    LAN1      |        | ----- LEASED LINE ------ |              |      LAN2
                ---------                            --------------

i need to route traffic from LAN1 to LAN2 over LEASED LINE. When leased line is unreachable I need to auto route it through ipsec VPN.

how can i make it?

thank you