Re: routing_based_on_port/services

Hi!

1) Use iptables to mark the outgoing traffic in the mangle PREROUTING chain:

iptables -t mangle -A PREROUTING -i eth0 -p tcp --dport 80 -j MARK --set-mark 1

2) Create routing table for the marked traffic, we will call the new table "http".
This table will contain default route to the ADSL provider.

echo 200 http >> /etc/iproute2/rt_tables
ip route add default via <adsl_ip> dev <adsl_dev> table http

3) Standard default route will point to the P2P provider.

ip route add default via <p2p_ip> dev <p2p_dev>

4) Add routing policy rule to use table "http" for marked traffic:

ip rule add fwmark 1 table http

This configuration is not perfect (e.g. port 80 on the router is not accessible)
but I hope it will help. More on multiple routing tables can be found at

http://lartc.org/howto/lartc.rpdb.html

Of course, you have to turn on appropriate options (e.g. "use fwmark as
a routing key") in your kernel config.

Regards,
Bendis

Dne po 3. října 2005 11:41 [email protected] napsal(a):
> Dear List!
>
> I just want to ask you a question.I have a linux(Secure platform) gateway
> server with 2 external ip address to the internet (one S/0 ADSl, second S/1
> Point to Point) and one internal ip eth0 for my LAN. I need to split up the
> outgoing traffic.HTTP/HTTPS want to route through the ADSL and the rest of
> traffic (SMTP,POP3,FTP) through the Point to Point.Can i solve this with
> Linux iptables or whatever else. Any suggestion help..
>
> regards,
>
> Chris

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