An apparatus includes a receive port unit, a forwarding engine, a transmit port unit, and a reassembly unit. In an embodiment, the packet reassembly unit examines headers in received fragments of a data unit and using the headers to reassemble the data unit, wherein the headers correspond to a protocol layer above an IP-layer. In another embodiment, the packet reassembly unit is located downstream from the forwarding engine in a packet forwarding pipeline, and the forwarding engine skips processing fragments received subsequent to a first received fragment.