A system which uses per-port last source address registers, which are part of the repeater function, for making filtering/forwarding decisions, which are part of the bridging function. The system includes a single repeater collision domain divided into segments, one or more transceivers for each segment,...http://www.google.de/patents/US5764638?utm_source=gb-gplus-sharePatent US5764638 - Method and apparatus for filtering and forwarding messages in a computer network using a last source address 
