[LARTC] exporting service on multiple wan

[Mohan Sundaram]

Fabio Marcone wrote:
> Hi all,
> I've a routing problem. I'm setting up a router based on debian (kernel
> 2.4).
> 
> I need to setup routing to export an ftp service (ftp server is in dmz)
> to 2 wan (both).
> 
> I setup prerouting ad forward rule with no problem.
> 
> The problem is that reply packet use default gateway (default wan) even
> though they are enter using the other wan.
> 
> I solved it marking packets in input from the dmz iface and force to use
> another gateway (iproute2), but in this way I don't export ftp service
> on default wan.
> 
> how I can setup routing to export ftp service on both iface?
> 
> Thanks in advance,
> Fabio
One way to do this:
1. Assign 2 private domain IP addresses to the ftp server and listen to 
both for ftp. IP1 and IP2
2. Map one IP each for WAN address. WAN1>>IP1 and WAN2>>IP2
3. On the Linux machine, set policy routing based on src IP of reply 
packet i.e. src IP1 goes thro' WAN1 and src IP2 goes thro' WAN2.

Mohan