Communication device, log transfer method, and communication system

A communication device configured to relay or capture communication performed between a plurality of information processing apparatuses communicable with one another via a network, the communication device comprising circuitry configured to:

• generate a log indicating a record of the communication performed between the plurality of information processing apparatuses;
• store the generated log in a memory;
• infer which one of a normal mode or and energy saving mode an operation state of a transfer destination device is, based on content of communication performed between a transfer destination apparatus and another information processing apparatus in a predetermined latest period, the transfer destination apparatus being a particular information processing apparatus to which the log is to be transferred among the plurality of information processing apparatuses, the another information processing apparatus being another particular information processing apparatus other than the transfer destination apparatus among the plurality of information processing apparatuses;
• and
• controls transfer of the log based on a result obtained by inferring by the circuitry, so that the circuitry transfers the log to the transfer destination apparatus in a case where the result indicates the normal mode, and the circuitry postpones a transfer of the log in a case where the result indicates the energy saving mode.