Transparent routing

[jackhab]

Please, help to configure the following configuration:

Node A             Node B                Node C
eth0   <----->  eth0 <--> eth1   <----->  eth0

A, B and C are in the same subnet.
B is default gateway of C.
B is not default gateway of A.
A and C can reach each other without static routes.

I set IP forwarding between B-eth0 and B-eth1, and B-eth1 is a default gw of C.
I can reach A from C but I cannot reach C from A because B needs to answer ARP
on behalf of C and I don't know how to do it.

If I set static route on A like this

ip route add to C-eth0-ip via B-eth0-ip dev A-eth0-ip

it works but, unfortunately, the requirement is to not use static routes.
In fact B should be kind of proxy transparent for all types and level of traffic.

Please, recommend what things in addition to IP forwarding I need to setup.
Thanks.

[HROAdmin26]

If Node_B's only purpose is to connect the networks of Node_A and Node_C, then drop the routing requirement altogether and just make Node_B a bridge.

This removes all routing issues.

Google: linux bridge

[jackhab]

That's what I thought after googling around, but it's always good to get a clear answer from a professional. Thanks.