1. A packet processing system, comprising: a packet interface to receive a packet; a flow engine, connected to the packet interface, to route the packet to a first processing engine; the first processing engine, connected to the flow engine, comprising a firewall processing engine, an intrusion detection system, or a network address translation (NAT) engine, to: receive the packet from the flow engine, process the packet, create a tag associated with the packet, where the tag includes: information about the processing of the packet, and an indication to drop other packets subsequently received at the packet processing system from a same session as the packet, and transmit the packet to the flow engine; where the flow engine is further to: receive the packet from the first processing engine, and route the packet to a second processing engine; the second processing engine, connected to the flow engine, comprising a firewall processing engine, an intrusion detection system, or a network address translation (NAT) engine, to: receive the packet from the flow engine, and process the packet using the tag information, where the first processing engine is different than the second processing engine.