This counts frames the port received whose destination address matches a station already known to be local to that same port -- i.e., traffic that didn't need to be switched anywhere because sender and receiver share the segment. An admin watching this alongside cat2600TsPortForwardedFrames can judge how much of a port's traffic stays local versus crosses the switch fabric, useful for deciding whether a segment would benefit from further subdivision. A high local-frame count relative to forwarded frames suggests that port's segment is largely self-contained chatter.