A communication device (10) having at least one interface used in communication including a default router in a path includes: an ID determination unit (110) that determines whether or not a Zone ID is assigned to a communication request including a link local address of Internet Protocol version 6 (IPv6) as a destination address; and an ID supplementing unit (120) that, when it is determined that the Zone ID is not assigned, acquires an interface ID for identifying the interface as a default interface ID and adds the acquired default interface ID as the Zone ID of the communication request.