A communication device includes a memory and a processor. The processor is configured to extract first division data from transmission data when transmitting the transmission data. The processor is configured to store, as held data, the first division data in the memory in association with first identification information that identifies the transmission data. The processor is configured to transmit, to a communication destination, a first transmission packet including the transmission data and information that identifies the held data to cause the communication destination to store second division data which is not included in the held data, among the transmission data in association with the first identification information. The processor is configured to transmit, when transmitting the transmission data after the transmission of the first transmission packet, a second transmission packet including the first identification information and the held data instead of the transmission data to the communication destination.