[clug] Routing disconnect

[Doug Palmer]

My machine lives on an experimental network. I have a PPTP connection
into the main network, so that I can collect mail, look at shared
drives, etc. My routing is set up so that most IP traffic goes out
through the experimental network, except for anything that is destined
for the main local network.

I recently set up TikiWiki. This all works fine and dandy for me and for
anyone outside the main local network. But anyone inside the main local
network can't see it. As far as I can see, what is happening is:

1. Connection to port 80 arrives via eth0 from a main local network
machine.
2. Return IP packets go out via ppp0 and the PPTP tunnel.
3. This runs afoul of some "established connection" filter somewhere and
the packets get zapped.

I'd rather not turn over the entire existing routing and firewall
infrastructure to fix this problem. So I was wondering if there is any
routing software I can use that knows about established connections and
can route accordingly? Or some other solution, since all I really want
is traffic that started with a connection to port 80 to go out via a
specific interface.