A data relaying apparatus includes a first input port, a first output port, and a processor configured to select, based on a destination of a data frame received by the first input port, one of a first process and a second process, the first process including removing first header information of the data frame and transmitting, to the first output port, the data frame from which the first header information is removed, and the second process including adding second header information to the data frame received by the first input port and transmitting, to the first output port, the data frame to which the second header information is added, and perform the selected one of the first process and the second process on the data frame received by the first input port, wherein the first output port outputs the data frame for which the selected process is performed.