A sufficient number of packets necessary for analysis of a fault in a network communication apparatus are obtained. A multi function peripheral (MFP) temporarily stores received packets as a file for every print job, and stores communication failure information as a log (communication failure log). The MFP deletes data in which no error has occurred in an application among the stored files. Then, in a case where an error has occurred during processing of a certain print job, the MFP stores received packets in a storage device, and compares a communication failure in the job packet in which the error has occurred with a communication failure in packets associated with all the received print jobs. As a result of the comparison, the MFP extracts a communication failure in only the job packet in which the error has occurred, and creates a log so that the extracted result can be identified.