Packets received at a network appliance are classified according to a packet classification rules based on flow state information maintained by the network appliance and evaluated for each packet as it is received at the appliance on the basis of OSI Level 2-Level 4 (L2-L4) information retrieved from the packet. The received packets are acted upon according to outcomes of the classification; and the flow state information is updated according to actions taken on the received packets. The updated flow state information is then made available to modules performing additional processing of one or more of the packets at OSI Layer 7 (L7).