Excerpts from netbsd: 26-Aug-98 Re: questions with route Paul
Goyette@whooppee.co (1430*)

> You need to
> get a _separate_ address space for the second interface. 

Well, there is a way which works for me:
the primary interface is eg:
	ifconfig le0 a.b.c.d netmask 0xffffff00
	route add -net default a.b.c.1
The secondary - only for connections to a.b.c.f:
	ifconfig ep0 a.b.c.e netmask 0xffffffff
	route add -net a.b.c.f -netmask 0xffffffff -iface a.b.c.e -cloning

It might work if you add more of these degenerated
net routes.
On other OSes one can use host routes at this point.
Did you see messages from the ARP code on the console
when you tried?

best regards
Matthias