1. A computing device serving as host machine for a set of virtual machines, the computing device comprising: a physical network interface controller (PNIC) for receiving data packets from a network, the PNIC configured to store a plurality of sets of lookup tables for a plurality of different logical networks and to use a logical network identifier in each received data packet to select a set of lookup tables for providing a set of stateless lookup results, the set of stateless lookup results comprising an identifier for a firewall rule that matches a set of connection parameters of the received data packet; a set of processing units for executing instructions; and a computer readable storage medium storing sets of instructions for execution by the set of processing units, the sets of instructions for: operating the plurality of virtual machines; and forwarding each received packet to at least one of the plurality of virtual machines, wherein the set of instructions for forwarding each received packet comprises a set of instructions for using the set of stateless lookup results for the received packet provided by the PNIC to perform stateful firewall operations on the received packet.