[ale] multiple interfaces

[lou]

I have a machine with 2 ethernet interfaces. I would like to specify
different services running on each interface. I would also like to ensure
that if a packet if recieved on one interface, say eth0, that it's reply
will also be sent out eth0, even if the destination is closer to eth1. Is
this possible with the stock out of the box kernal? If not, can someone
point me in the direction necessary? Many thanks in advance.