using bittorrent through iptables on gateway (slackw)
 

Hi Everyone,

I have a computer used as firewall with slackware and iptables on it. I use Bittorrent on another computer that connects to the internet via the firewall computer.

I tried addig rules to the rc.firewall to let the bittorrent traffic pass through it but it does not seem to work.

I searched the web of course to see what could be faulty but there must be some detail i missed.

Here is a sample of the rules i set up.
No point in showing each of the 9 ports' rules so i'll show you the first port's one:

$IPT -t nat -A PREROUTING -p tcp -d $INET_ADDRESS --dport 6881 -j DNAT --to-destination 192.168.0.2:6881

$IPT -t nat -A PREROUTING -p udp -d $INET_ADDRESS --dport 6881 -j DNAT --to-destination 192.168.0.2:6881


$IPT -A tcp_inbound -p TCP -s 0/0 --dport 6881 -j ACCEPT
$IPT -A tcp_inbound -p UDP -s 0/0 --dport 6881 -j ACCEPT
$IPT -A FORWARD -p tcp --destination-port 6881 -j ACCEPT
$IPT -A FORWARD -p udp --destination-port 6881 -j ACCEPT

...

Earlier I had this command similar effect... not functioning...

#$IPT -t nat -A PREROUTING -p tcp --dport 6881 -j DNAT --to 192.168.0.2:6881 -i ppp0

...

Now I just don't know what is wrong.

Could you help me out?

Thanks in advance.

I have a rule which NAT's all outgoing connections
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

I don't try to firewall outgoing.

For incoming connections on a machine where eth0 is an ethernet card that just goes to the internet I use iptables rules like;

iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 6881 -j DNAT --to-destination 192.168.1.1

Ok, so i suppose the main difference being that you choose by interface instead of the ip of the interface.

I'll try it out and see what it does.

Thanks

If This doesnt work, what else could it be? I'm new to iptables. I copied the example from the RedHat Bible and made the neccesary ip changes but I still cant get it to forward port requests (by using the line above)

Please help! Thanks