1. An information processing device comprising: a plurality of processors capable of running in parallel; a memory shared by the plurality of processors and recorded with management information enabling a relationship to be determined, the relationship between a communication connection and a processor in charge of analysis of a packet related to the communication connection; and a distributor that distributes analysis of a received packet to any of the processors based on information included in the packet, each of the plurality of processors executes: determining whether or not own processor is appropriate as a processor for analyzing the packet distributed by the distributor by referring to the management information; analyzing the packet when it is determined that own processor is appropriate as a processor for analyzing the packet distributed by the distributor; recording request information for requesting another processor to perform analysis of the packet when it is determined that own processor is not appropriate as a processor for analyzing the packet distributed by the distributor; and specifying a packet related to request information intended for own processor by referring to the memory, wherein the analyzing further involves analyzing the packet specified by the specifying, and when management information is recorded which indicates that the packet distributed by the distributor includes a previously transmitted or received packet and that another processor had performed analysis of the included packet, the determining determines that own processor is not appropriate as a processor for analyzing the packet.