A data distribution device for stably distributing specific data such as video data is provided. Video distribution device as a data distribution device includes video distribution unit as a specific data distribution unit, video distribution determining unit as a specific data distribution determining unit, and routing setting unit. When video distribution determining unit determines that video distribution unit is distributing video data as the specific data, and when the default route information has been acquired from a second communication device connected to a second network, routing setting unit holds the default route information without changing the default route.