nim + multiple interfaces/subnets

we've nim up and running well within our org. most of our systems have attachment to two networks; the public/LAN side of the house and a back-end/faster backup network. lan runs at 10/100, ban runs at gb/s (don't ask, not our choice :). both our nims have attachment to both networks. is there a way the nim can coexist/use both networks based on some sort of host preference? both nim's primary interface is the lan-connected interface. i tried some hosttable trickery to make the nim talk to a client but never had any totally succesful nim operations. i've done some cursory digging through the support site and the recently-updated redbook but so far nothing relative to this topic has shown itself. if someone's done this or can point me to the spot in the docs i'm missing i'd appreciate it.

thx,
-r
.