1. An information processing device comprising: a plurality of processing units capable of running in parallel; a memory shared by the plurality of processing units and recorded with management information enabling a relationship to be determined, the relationship between a communication connection and a processing unit in charge of analysis of a packet related to the communication connection; and a distributing unit that distributes analysis of a received packet to any of the processing units based on information included in the packet, each of the plurality of processing units including: a determining unit to determine whether or not own processing unit is appropriate as a processing unit for analyzing the packet distributed by the distributing unit by referring to the management information; an analyzing unit to analyze the packet when it is determined that own processing unit is appropriate as a processing unit for analyzing the packet distributed by the distributing unit; a request information recording unit to record request information for requesting another processing unit to perform analysis of the packet when it is determined that own processing unit is not appropriate as a processing unit for analyzing the packet distributed by the distributing unit; and a specifying unit to specify a packet related to request information intended for own processing unit by referring to the memory, wherein the analyzing unit further analyzes the packet specified by the specifying unit.