Rule lookup using predictive tuples based rule lookup cache in the data plane

This disclosure describes an approach to handle packets that arrive at a network security device, such as a router. At a data plane of the security device, packet identifiers included in an incoming packet not currently belonging to an IP session of the device are compared to packet identifiers stored in a table stored in a memory of the security device. The incoming packet identifiers includes a source IP, a destination IP, a protocol, a destination port, and a source port while the identifiers stored in the table do not include the source port. A new session is established for the incoming packet in response to the set of packet identifiers matching one of the entries in the table.