One MAC address per IP address on same interface in bridge

Hello Folks!

I face a problem.

I need to have one MAC address per IP address on the same physical interface.

I can solve this by using several physical RB devices or physical ports, but this is not feasable in this solution.

So I did the following.

First I did assign one IP A address on the physical interface which has MAC X.
Then I did create a bridge and added one mac y address to the bridge interface.
Next I did add the physical port to the bridge.
Then I set IP B address on bridge.

It seemed to work at first glance, but both ip addresses show MAC Y address of bridge.

I extended the topic little by following this: http://wiki.mikrotik.com/wiki/Change_MAC_address_of_VLAN_interface

Same story, both IP addresses uses the same MAC bridge has.

How do I make this work ?