Chapter 11 IPsec VPN for FortiOS 5.0 : IPv6 IPsec VPNs : Site-to-site IPv6 over IPv4 VPN example : Configure FortiGate A routing
  
Configure FortiGate A routing
This simple example requires just two static routes. Traffic to the protected network behind FortiGate B is routed via the virtual IPsec interface toB using an IPv6 static route. A default route sends all IPv4 traffic, including the IPv4 IPsec packets, out on port2.
config router static6
edit 1
set device toB
set dst fec0:0000:0000:0004::/64
end
config router static
edit 1
set device port2
set dst 0.0.0.0/0
set gateway 10.0.0.254
end