network to network and VPN

Hi,

I’m looking for a solution to access to a firewall checkpoint from my local network. My powerbook is connected to my modem ADSL (a freebox) and my other computer is connected by ethernet.
Only my powerbook need to access via VPN.
– a direct connection (when I disable the router properties of my freebox) works well ;
– if I active the router properties (my powerbook has the IP 192.168.0.1), web and mail works well on the two computers. Vaporsec seems ok, but no ping is possible to reach the remote network. It’s the same situation with IPSecuritas or VPN tracker (green check, but no ping).

ROUTER PROPERTIES THAT I PUT ON MY FREEBOX
IP Lan: 192.168.0.254
Serveur DHCP: Desactive
Machine DMZ: 192.168.0.1
Reponse au ping: Active

IP forwarding:
Port: 500 – Protocole: udp – Destination: 192.168.0.1 – Port: 500
Port: 500 – Protocole: tcp – Destination: 192.168.0.1 – Port: 500
Port: 264 – Protocole: tcp – Destination: 192.168.0.1 – Port: 264
Port: 265 – Protocole: tcp – Destination: 192.168.0.1 – Port: 265
Port: 266 – Protocole: tcp – Destination: 192.168.0.1 – Port: 266
Port: 3389 – Protocole: tcp – Destination: 192.168.0.1 – Port: 3389
Port: 9 – Protocole: udp – Destination: 192.168.0.1 – Port: 9
Port: 9 – Protocole: tcp – Destination: 192.168.0.1 – Port: 9

(I’m not sure of the port that I must use)

VPN CLIENT
Mode of operation : network to network
Remote IP : ip of remote firewall
Remote network : 172.23.0.0 (mask 255.255.0.0)
Local network : 192.168.0.0 (mask 255.255.255.0)

Any idea ?
Thanks a lot in advance