A LAN interconnect device includes a plurality of Frame Processing Units (FPUs) for coupling each port of the device to a switch fabric. Each one of the Frame Processing Units includes an input section with input logic which prepares LS Headers and appends each one to a block of the frame as the block is forwarded to the switch fabric. The FPU, also, includes an output section with copy logic for copying and assembling frames to be forwarded to devices connected to the port. The copy decision is based upon the LS Header and configuration information in the port.