A packet communication apparatus is configured to relay packets transmitted and received between information processing apparatuses. The packet communication apparatus includes: a network interface connectable to a network; a CPU to be a destination of at least one of a plurality of packets to be received through the network interface; a first buffer configured to hold the packets destined to the CPU in order to output the packets to the CPU; a second buffer having a plurality of planes and configured to hold copies of the packets destined to the CPU held in the first buffer in one of the plurality of planes; and a reception history controller configured to store a copy of a packet to a specified plane of the second buffer or to save copies of packets held in the second buffer to another storage area based on usage of the first buffer.

Some embodiments provide a method of forwarding data messages to a machine that executes on a host computer and has an associated virtual network interface controller (VNIC) also executing on the host computer. The method retrieves data messages from a queue associated with the VNIC and stores these data messages in a first set of buffer data stores associated with the VNIC. When the first buffer set reaches a threshold congestion level, the method stores data messages subsequently retrieved from the VNIC queue in a second set of buffer data stores associated with the VNIC. In some embodiments, a set of one or more processes executing on the machine retrieves the data messages stored in the buffer sets for processing by these processes or other processes.