Graph
From Secure Computing Wiki
ping request has source address of 10.8.0.6 and destination address of 10.10.2.20
ping reply has source address of 10.10.2.20 and destination address of 10.8.0.6
You need to add a static route to your gateway: route add -net 10.8.0.0/24 gw 10.10.2.10 or the equiv in your routers OS
You will need a route like this for every network you wish to reach over the vpn.