In a method for processing network packets, a network packet is received at an ingress port. Before the network packet has been completely received at the ingress port, a first data structure representing the network packet is generated based on a received first portion of the network packet, and the first data structure is processed at a packet processor of the network device. Processing the first data structure includes making a forwarding decision for the network packet. A second data structure representing the network packet is generated and, after the network packet has been completely received at the ingress port, at least one or more non-forwarding operations are performed with respect to the network packet using at least the second data structure.