two vpn endpoints ... 3 net connections

[Dave Harrison <dave_(_dot_)_l_(_dot_)_harrison_(_at_)_gmail_(_dot_)_com>]

Hi all,

Here's my problem, I have a remote machine that has two links, one is
high bandwidth but has bad latency, the other has low bandwidth but good
latency.

I need two VPN tunnels running between these machines, but one over each
link as below.  The reasons why are due to the traffic I need to push
over them, some is important but not high in volume, other is less
important but there's alot of it.


                                   Link2  +------------
                                 +------- |
+-----------+  Link              |        |
| Machine 1 | -------------------+        | Machine 2
+-----------+                    |        |
                                 +------- |
                                   Link1  +------------


My problem is that I can't seem to find a way around the need for
Machine 2 to have two default routes.

My understanding of my problem is that any time Machine 2 receives a
connection (irrespective of which link) it tries to respond over the
link that is the default route (for example Link1).  This means that
whenever Link2 gets a connection, Link1 tries to respond for it.

Can anyone suggest a solution for this problem ?  Do I not need multiple
default routes ?  Do I misunderstand my problem ?

All help is appreciated as ever,

Cheers
Dave