LinuxQuestions.org - downloading bittorrent using a vpn connection

I recently built a new linux box running ubuntu 9.04 on an Asus eeebox. So far everything works great, but I am having an issue setting up my iptables rules. What I am trying to do is only allow bittorrent traffic over my vpn connection ppp0. I have created a rule to drop all bittorrent traffic over eth0 and allow all bittorrent traffic over ppp0. Currently my script is not blocking the eth0 connection, so I am still able to download over eth0. My goal is to hide my ISP's ip address and only show the VPN ip address when I am using bittorrent. Here is my iptables script. I hope someone can look at it a tell me what I have done wrong or what I am missing. Thanks in advance for all the help.

Code:

#!/bin/bash



# Remove all rules and chains

iptables -F

iptables -X



# first set the default behaviour => accept connections

iptables -P INPUT ACCEPT

iptables -P OUTPUT ACCEPT

iptables -P FORWARD ACCEPT



# Allow ESTABLISHED and RELATED incoming connection

iptables -A INPUT -i eth0 -m state --state ESTABLISHED,RELATED -j ACCEPT

# Allow loopback traffic

iptables -A INPUT -i lo -j ACCEPT

# DROP all forward packets, I don't share this internet connection

iptables -A FORWARD -j DROP

# Drop all Bittorrent packets going over eth0

iptables -A OUTPUT -o eth0 -p tcp -m multiport --dport 6881:6999 -j DROP

# Allow all Bittorent traffic going over vpn connection pp0

iptables -A OUTPUT -o ppp0 -p tcp -m multiport --dport 6881:6999 -j ACCEPT



# End message

echo " [iptables rules are set]"