Arpspoofing : no packets returned from outside network

[tatrefthekiller]

Hi,

I'm trying to intercept the network traffic between one of my computers and my Internet router.

The router is a Netgear CBVG834G, with NAT. It's private IP is 192.168.0.254/24. I can't do a lot of stuff because I have only access to the web interface with a few options.

The "victim" is a computer running Windows 7, 192.168.0.1/24.

I'm using the computer with IP 192.168.0.50 to try to spoof the network. Here is what I do :

echo 1 > .../ip_forward
arpspoof -i eth0 -t 192.168.0.254 192.168.0.1
arpspoof -i eth0 -t 192.168.0.1 192.168.0.254

The victim is fine, has access to local network + internet.
But if I sniff the network, I don't see packets coming back from Internet, it's like if my router was sending the packets directly to the victim.
If I ping 192.168.0.254 from the victim, I can see packets in both directions.

Very nice schema no summarize :-) :

Ping Gateway :
Victim ↔ bt ↔ gateway

Ping 8.8.8.8 :
Victim → bt → gateway ↔ internet
    ↑            ↓
    --------------

Do you have any idea what's wrong ?

Thank you in advance!