1. A network switch comprising: a predictor using data in a packet to predict a flow for the packet; a forwarding engine forwarding at least a portion of the packet on a switch fabric to an egress port determined from the predicted flow; and a lookup module performing a lookup to determine a flow for the packet, wherein the forwarding engine forwards the at least a portion of the packet on the switch fabric to the egress port determined from the predicted flow prior to the lookup module determining the flow.