Impossible routing/firewall problem?
I've got this dream in mind:
Work => Home
Uses the cable modem interface eth0 but only from syn packets coming
from work (firewall at WORK blocks incoming connections)
Home => Work
Goes over a dialup connection to work over ppp0.
How can I make it so only packets that are initiating from home => work
start the ppp link and when that link is up all current work => home
connections continue to use the eth0 interface instead of changing the
routing table with a sledgehammer?
If I could tell route to route only syn packets to work and existing
ppp0 connections to stay on ppp0 I'd be very happy. Unfortunately I
don't know how to do that. I've considered mapping a bogus internet
unrouteable domain and masqerading all traffic to them with ipchains so
the routing table could work by routing the bogus domain over ppp0 (but
then does the firewall with ppp0 figure it out if it masqerades itself
This is a bit over my head with my current understanding of the tools I
know. Does anyone have a better way?