Hmm, I'm not convinced. The same ax.25 route should be used
irrespective of what interface is generating the datagram, so I think
the ax.25 route should be completely decoupled from the IP device.
The AX.25 route should be chosen on the basis of the destination IP
address, at least for IP purposes and care nothing for the source address.
What possible network topology has necessitated this arrangement ?
I'll look into the problem and see what it will take to make it work.
Terry