A reconfigurable, scalable and flexible island-based network flow processor integrated circuit architecture includes a plurality of rectangular islands of identical shape and size. The islands are disposed in rows, and a configurable mesh command/push/pull data bus extends through all the islands. The integrated circuit includes first SerDes I/O blocks, an ingress MAC island that converts incoming symbols into packets, an ingress NBI island that analyzes packets and generates ingress packet descriptors, a microengine (ME) island that receives ingress packet descriptors and headers from the ingress NBI and analyzes the headers, a memory unit (MU) island that receives payloads from the ingress NBI and performs lookup operations and stores payloads, an egress NBI island that receives the header portions and the payload portions and egress descriptors and performs egress scheduling, and an egress MAC island that outputs packets to second SerDes I/O blocks.