> But, the whole idea of a passive approach seems the wrong way around
> for my situation, anyway.
> 
> I guess that when I have time, I'll begin modifying my
> /etc/rc.d/network script.  What I want to do shouldn't be too complicated.

Try giving the interface an address in each subnet.
It is probable it will use the local address from the same subnet
as the destination address when making outward connections.

Try to ping some system (that should be up), then delete the incorrect
addresses (may not be needed) and add your default route.

    David