How to do L2 switching/bridging + routing on same interface.

Hi.

I have a special Ethernettype frame that i want to handle on layer2 with my
own software for a test. And on the same interfaces i want to recieve/handle
IP packets on leyer 3 (management traffic + routingupdates) where do i
seperate the traffic.
Do anybody have any suggestions or recommendations ?

Best regards.
Per ((E-Mail Removed))




P Mattsson