[K12OSN] K12OSN a bit OT - how to make responses on the same interface request came in

[Julius Szelagiewicz]

Dear Folks,
	I am somewhat stumped with a simple networking scenario:
eth0 - internal,
eth1 - external fast, dhcp non-routable, default route,
eth2 - external public address not very fast.
	I am using openvpn and for connections to other servers I can
easily specify which interface to use. What I need to do is to connect to
openvpn server process on eth2. Unfortunately packets come in on eth2 but
travel out on eth1 - default. Source based routing is no help, since I am
not just passing the packets based on the incoming interface, but I'm
trying to push responses on eth2. Essentialy, on receipt on eth2 of an UDP
packets on port 1194 I need to answer with UDP packet om port 1194 on
eth2.
	The computers trying to connect have only private addresses from
cable ISPs.
	Any suggestions? Please ...
julius