This is my scenario:
I have a linux gateway using four network interface cards: eth0: intranet / eth1: loadbalancer / eth2: link X / eth3: link Y
The default gateway to my linux is the eth1 interface (it's connected to a routerboard device which manages the loadbalancing with all links connected to it).
I have two more links connected directly to my linux box (eth2 and eth3).
When I leave the connection going directly to the loadbalancer (coming from eth0 and being forwarded to eth1) I get a error: "550 Passive connection must come from same host as control connection."
I tried to set the output to the FTP protocols (ports 20 and 21) to one of the links (eth2) using iptables postrouting... didn't work...
I tried to set the output to the FTP protocols using the iptables MARK module and using the iproute2 to lookup the table for the link at interface eth2... without success too.
Please... may someone help me with this? I'm losing the few hairs I still have and I'm awake for three days now (with virtually no sleep).
Thanks in advance!