In tenant network interconnection

Hello,

I try to configure Folsom/Quantum/Ovs/GRE on Ubuntu 12.04 on a multi-node base.
One controller host (Horizon, keystone, glance, cinder, quantum server, network controller), two compute nodes.

I created 2 networks each associated to a subnet (10.10.10.0/24 and 10.10.20.0/24).
I created through the horizon dashboard 2 Vms attached one on the first network, and the other on the second.
Each of my VMs get an ip with the dhcp protocol (10.10.10.3 and 10.10.20.3).

I created a routeer for tenant project_one through the quantum cli.
I attached the router to both networks.

I added route to the other network in each VM.
              ip route add 10.10.20.0/24 via 10.10.10.1 on the first VM
              ip route add 10.10.10.0/24 via 10.10.20.1 on the second VM

Now from VMs if I ping router network IP in subnet, it works.
          on 10.10.10.3 :
                      ping 10.10.20.1 works
                      ping 10.10.20.3 doesn't

          on 10.10.20.3 :
                      ping 10.10.10.1 works
                      ping 10.10.10.3 doesn't

I am ready to send any configuration information.

Any clue to get this working would be appreciated.

Thanks,

JL