Patent Publication Number: US-2022231997-A1

Title: Setting device, communication system, and vehicle communication management method

Description:
TECHNICAL FIELD 
     The present disclosure relates to a setting device, a communication system, and a vehicle communication management method. 
     This application claims priority on Japanese Patent Application No. 2019-101427 filed on May 30, 2019, the entire content of which is incorporated herein by reference. 
     BACKGROUND ART 
     PATENT LITERATURE 1 (Japanese Laid-Open Patent Publication No. 2008-59450) discloses a vehicle information rewriting system as below. That is, disclosed is a vehicle information rewriting system in which: a rewriting tool functioning as a data sender is removably connected through communication means to a vehicle control unit that has a main controller implemented as a CPU and that performs, on the basis of execution of predetermined software by the main controller, a control process of electronic devices installed in a vehicle; and a memory content of a vehicle information storage that is provided as a nonvolatile memory on the vehicle control unit side and that stores vehicle information including the software is rewritten on the basis of rewriting data transferred through the communication means from the rewriting tool. In the vehicle information rewriting system, the rewriting tool is provided with: operation mode switching means that sets switching between a rewriting permitted mode in which a rewriting operation of the memory content of the vehicle information storage is permitted and a rewriting restricted mode in which the rewriting operation is restricted relative to the rewriting permitted mode; wireless polling means that, during rewriting operation with use of the rewriting tool, and in order to detect a wireless authentication medium that should be carried by an authorized user of the rewriting tool, wirelessly polls the wireless authentication medium; and mode switch ordering means that orders the operation mode switching means to switch to the rewriting permitted mode on a precondition of a success of detection of the wireless authentication medium through the wireless polling. 
     PATENT LITERATURE 2 (Japanese Laid-Open Patent Publication No. 2003-46536) discloses a vehicular relay device as below. That is, provided is a vehicular relay device disposed between an in-vehicle LAN constructed in a vehicle and a communication device that performs data communication with an external device located outside of the vehicle, the vehicular relay device being configured to relay communication between the external device connected through the communication device and various in-vehicle electronic devices connected to the in-vehicle LAN. The vehicular relay device includes: first identification means that identifies, upon reception of an access request for requesting access to an in-vehicle electronic device in the in-vehicle LAN from the external device, an access destination in-vehicle electronic device, and that determines, on the basis of a result of the identification, whether or not the access request is an access request, for requesting access to the in-vehicle electronic device, that requires authentication of the external device; first authentication means that determines, when the first identification means has determined that the access request requires authentication of the external device, whether or not the external device is an external device for which access to the in-vehicle electronic device has been permitted in advance, on the basis of first authentication information transmitted from the external device; and first delivery means that delivers, to the access destination in-vehicle electronic device, communication data transmitted through the communication device from the external device, when the first authentication means has determined that the external device that has sent the access request is an external device for which access to the in-vehicle electronic device has been permitted in advance, or when the first identification means has determined that the access request does not require authentication of the external device. 
     CITATION LIST 
     Patent Literature 
     PATENT LITERATURE 1: Japanese Laid-Open Patent Publication No. 2008-59450 
     PATENT LITERATURE 2: Japanese Laid-Open Patent Publication No. 2003-46536 
     SUMMARY OF INVENTION 
     A setting device of the present disclosure includes: an acquisition unit configured to acquire an authentication result regarding a new function unit serving as a function unit newly added to an in-vehicle network including one or a plurality of function units; and a setting unit capable of, when the authentication result acquired by the acquisition unit is affirmative, performing a setting process for allowing the new function unit and an existing function unit serving as a function unit included in the in-vehicle network before the new function unit is added thereto, to perform communication via a plurality of relay devices capable of relaying information between the function units, the setting process being regarding at least one of the relay devices, the existing function unit, and the new function unit. 
     A communication system of the present disclosure includes: a setting device; and a new function unit serving as a function unit newly added to an in-vehicle network including one or a plurality of function units. The setting device acquires information transmitted from the new function unit and capable of specifying a function unit serving as a communication target of the new function unit. The setting device acquires an authentication result regarding the new function unit. When the acquired authentication result is affirmative, the setting device transmits, to the new function unit, setting information for allowing the new function unit and an existing function unit serving as a function unit included in the in-vehicle network before the new function unit is added thereto, to perform communication via a plurality of relay devices capable of relaying information between the function units. The new function unit performs setting for the new function unit on the basis of the setting information received from the setting device. 
     A vehicle communication management method according to the present disclosure is a vehicle communication management method to be performed in a setting device. The vehicle communication management method includes the steps of: acquiring an authentication result regarding a new function unit serving as a function unit newly added to an in-vehicle network including one or a plurality of function units; and performing, when the acquired authentication result is affirmative, a setting process for allowing the new function unit and an existing function unit serving as a function unit included in the in-vehicle network before the new function unit is added thereto, to perform communication via a plurality of relay devices capable of relaying information between the function units, the setting process being regarding at least one of the relay devices, the existing function unit, and the new function unit. 
     A vehicle communication management method of the present disclosure is a vehicle communication management method to be performed in a communication system that includes a setting device and a new function unit serving as a function unit newly added to an in-vehicle network including one or a plurality of function units. The vehicle communication management method includes the steps of: acquiring, performed by the setting device, information transmitted from the new function unit and capable of specifying a function unit serving as a communication target of the new function unit; acquiring, performed by the setting device, an authentication result regarding the new function unit; transmitting to the new function unit, performed by the setting device, when the acquired authentication result is affirmative, setting information for allowing the new function unit and an existing function unit serving as a function unit included in the in-vehicle network before the new function unit is added thereto, to perform communication via a plurality of relay devices capable of relaying information between the function units; and performing setting for the new function unit, performed by the new function unit, on the basis of the setting information received from the setting device. 
     One mode of the present disclosure can be realized as a semiconductor integrated circuit that realizes a part or the entirety of the setting device. One mode of the present disclosure can be realized as a program for causing a computer to execute the steps of the processes in the setting device. 
     One mode of the present disclosure can be realized as a semiconductor integrated circuit that realizes a part or the entirety of the communication system. One mode of the present disclosure can be realized as a program for causing a computer to execute the steps of the processes in the communication system. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  shows a configuration of a communication system according to an embodiment of the present disclosure. 
         FIG. 2  shows setting information in an in-vehicle network according to the embodiment of the present disclosure. 
         FIG. 3  shows a configuration of a relay device according to the embodiment of the present disclosure. 
         FIG. 4  shows a configuration of the communication system according to the embodiment of the present disclosure. 
         FIG. 5  shows an example of a configuration of a new network in the communication system according to the embodiment of the present disclosure. 
         FIG. 6  shows an example of setting information of the new network according to the embodiment of the present disclosure. 
         FIG. 7  shows another example of a configuration of a new network in the communication system according to the embodiment of the present disclosure. 
         FIG. 8  shows another example of setting information of the new network according to the embodiment of the present disclosure. 
         FIG. 9  is a flow chart describing an operation procedure according to which the relay device constructs a new network in the communication system according to the embodiment of the present disclosure. 
         FIG. 10  shows an example of the sequence of a construction process of a new network in the communication system according to the embodiment of the present disclosure. 
         FIG. 11  shows another example of the sequence of a construction process of a new network in the communication system according to the embodiment of the present disclosure. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     To date, in-vehicle network systems for improving security in in-vehicle networks have been developed. 
     Problems to be Solved by the Present Disclosure 
     A technology that exceeds the technologies described in PATENT LITERATURE 1 and 2 and that can flexibly construct a network having a new configuration through a simple process while ensuring security in the network is desired. 
     The present disclosure has been made in order to solve the above problem. An object of the present disclosure is to provide a setting device, a communication system, and a vehicle communication management method that can flexibly construct a network having a new configuration through a simple process while ensuring security in the network. 
     Effects of the Present Disclosure 
     According to the present disclosure, a network having a new configuration can be flexibly constructed through a simple process while ensuring security in the network. 
     DESCRIPTION OF EMBODIMENT OF THE PRESENT DISCLOSURE 
     First, the contents of an embodiment of the present disclosure are listed and described. 
     (1) A setting device according to an embodiment of the present disclosure includes: an acquisition unit configured to acquire an authentication result regarding a new function unit serving as a function unit newly added to an in-vehicle network including one or a plurality of function units; and a setting unit capable of, when the authentication result acquired by the acquisition unit is affirmative, performing a setting process for allowing the new function unit and an existing function unit serving as a function unit included in the in-vehicle network before the new function unit is added thereto, to perform communication via a plurality of relay devices capable of relaying information between the function units, the setting process being regarding at least one of the relay devices, the existing function unit, and the new function unit. 
     As described above, when the authentication result regarding the new function unit is affirmative, the setting device performs the setting process for allowing the existing function unit and the new function unit to perform communication via the plurality of relay devices, the setting process being regarding at least one of the relay devices, the existing function unit, and the new function unit. Due to this configuration, for example, when a network for allowing the existing function unit and the new function unit to perform communication via the plurality of relay devices is to be constructed, the authentication process and the like regarding the new function unit by the relay device, which is a part of devices in the in-vehicle network, can be omitted. Therefore, a network having a new configuration can be flexibly constructed through a simple process while ensuring security in the network. 
     (2) Preferably, the setting device further includes a storage unit configured to store setting information for allowing each function unit in the in-vehicle network to perform communication, and the setting unit performs the setting process on the basis of the setting information in the storage unit. 
     Due to this configuration, when a new in-vehicle network including a new function unit is to be constructed while the storage unit retains the setting information of the in-vehicle network whose network configuration is basically fixed, setting information of the new in-vehicle network is generated by using the setting information of the existing in-vehicle network acquired from the storage unit. Therefore, the construction process of the new in-vehicle network can be simplified. 
     (3) Preferably, the setting unit performs the setting process by using a virtual network for transmitting, to each function unit in the in-vehicle network, setting information for allowing each function unit to perform communication. 
     Due to this configuration, the setting information can be transmitted to each function unit in the in-vehicle network from the setting device by using the virtual network. Therefore, the setting process regarding each function unit can be simplified. 
     (4) Preferably, the setting unit performs, as the setting process, a process of constructing a new virtual network for allowing the new function unit and one or a plurality of the existing function units serving as a communication target of the new function unit to perform communication. 
     Due to this configuration, it is possible to suppress adverse influence, such as an unauthorized access, that is associated with addition of a new function unit to the in-vehicle network, on an existing function unit that is not the communication target of the new function unit. 
     (5) Preferably, when an existing virtual network as a virtual network for allowing one or a plurality of the existing function units serving as a communication target of the new function unit only, to perform communication has been constructed, the setting unit performs, as the setting process, a setting process regarding the new function unit and the relay device and for allowing the new function unit and the one or the plurality of the existing function units serving as the communication target to perform communication by using the existing virtual network. 
     Due to this configuration, since the setting process regarding the addition of the new function unit to the existing virtual network is performed, the construction process of a new network for allowing only the new function unit and the existing function unit serving as the communication target to perform communication is not necessary. 
     (6) A communication system according to the embodiment the present disclosure includes: a setting device; and a new function unit serving as a function unit newly added to an in-vehicle network including one or a plurality of function units. The setting device acquires information transmitted from the new function unit and capable of specifying a function unit serving as a communication target of the new function unit. The setting device acquires an authentication result regarding the new function unit. When the acquired authentication result is affirmative, the setting device transmits, to the new function unit, setting information for allowing the function unit serving as the communication target and the new function unit to perform communication via a plurality of relay devices capable of relaying information between the function units. The new function unit performs setting for the new function unit on the basis of the setting information received from the setting device. 
     As described above, when the authentication result regarding the new function unit is affirmative, the setting device transmits, to the new function unit, setting information for allowing the existing function unit serving as the communication target and the new function unit to perform communication via the plurality of relay devices. Due to this configuration, for example, when a network for allowing the existing function unit and the new function unit to perform communication via the plurality of relay devices is to be constructed, the authentication process and the like regarding the new function unit by the relay device, which is a part of devices in the in-vehicle network, can be omitted. Therefore, a network having a new configuration can be flexibly constructed through a simple process while ensuring security in the network. 
     (7) A vehicle communication management method according to the embodiment of the present disclosure is performed in a setting device. The vehicle communication management method includes the steps of: acquiring an authentication result regarding a new function unit serving as a function unit newly added to an in-vehicle network including one or a plurality of function units; and performing, when the acquired authentication result is affirmative, a setting process for allowing the new function unit and an existing function unit serving as a function unit included in the in-vehicle network before the new function unit is added thereto, to perform communication via a plurality of relay devices capable of relaying information between the function units, the setting process being regarding at least one of the relay devices, the existing function unit, and the new function unit. 
     As described above, when the authentication result regarding the new function unit is affirmative, the setting device performs the setting process for allowing the existing function unit and the new function unit to perform communication via the plurality of relay devices, the setting process being regarding at least one of the relay devices, the existing function unit, and the new function unit. Due to this method, for example, when a network for allowing the existing function unit and the new function unit to perform communication via the plurality of relay devices is to be constructed, the authentication process and the like regarding the new function unit by the relay device, which is a part of devices in the in-vehicle network, can be omitted. Therefore, a network having a new configuration can be flexibly constructed through a simple process while ensuring security in the network. 
     (8) A vehicle communication management method according to the embodiment of the present disclosure is performed in a communication system that includes a setting device and a new function unit serving as a function unit newly added to an in-vehicle network including one or a plurality of function units. The vehicle communication management method includes the steps of: acquiring, performed by the setting device, information transmitted from the new function unit and capable of specifying a function unit serving as a communication target of the new function unit; acquiring, performed by the setting device, an authentication result regarding the new function unit; transmitting to the new function unit, performed by the setting device, when the acquired authentication result is affirmative, setting information for allowing the function unit serving as the communication target and the new function unit to perform communication via a plurality of relay devices capable of relaying information between the function units; and performing setting for the new function unit, performed by the new function unit, on the basis of the setting information received from the setting device. 
     As described above, when the authentication result regarding the new function unit is affirmative, the setting device transmits, to the new function unit, setting information for allowing the existing function unit serving as the communication target and the new function unit to perform communication via the plurality of relay devices. Due to this method, for example, when a network for allowing the existing function unit and the new function unit to perform communication via the plurality of relay devices is to be constructed, the authentication process and the like regarding the new function unit by the relay device, which is a part of devices of the in-vehicle network, can be omitted. Therefore, a network having a new configuration can be flexibly constructed through a simple process while ensuring security in the network. 
     Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference signs, and description thereof is not repeated. At least some of embodiments described below may be combined as desired. 
     [Communication System] 
       FIG. 1  shows a configuration of a communication system according to an embodiment of the present disclosure. 
     With reference to  FIG. 1 , a communication system  300  includes: one or a plurality of in-vehicle ECUs (Electronic Control Units)  111 ; a plurality of relay devices  100 ; and a server  200 . 
     More specifically, the communication system  300  includes in-vehicle ECUs  111 A to  111 D as the in-vehicle ECUs  111 ; and a relay device  100 A and a relay device  100 B as the relay devices  100 . The relay device  100 A is an example of a setting device. 
     Each in-vehicle ECU  111  is, for example, a TCU (Telematics Communication Unit), an automated driving ECU, an engine ECU, a sensor, a navigation device, a human machine interface, a camera, or the like. The TCU performs communication with a device outside the vehicle, e.g., the server  200 , via a wireless base station or the like (not shown). 
     Each relay device  100  is a gateway device, for example, and can relay information between a plurality of in-vehicle ECUs  111  connected to the relay device  100 . More specifically, the relay device  100  can perform a relay process according to a layer 2, and a layer 3, which is of a higher order than the layer 2, for example. 
     Each in-vehicle ECU  111  is an example of a function unit in an in-vehicle network  12 . The in-vehicle ECUs  111  and the relay devices  100  form the in-vehicle network  12 . 
     The configuration of the communication system  300  is not limited to a configuration that includes four in-vehicle ECUs  111 , but may be a configuration that includes one, two, three, five, or more in-vehicle ECUs  111 . The configuration of the communication system  300  is not limited to a configuration that includes two relay devices  100 , and may be a configuration that includes three or more relay devices  100 . 
     The connection relationship between the function units in the in-vehicle network  12  of the vehicle is fixed, for example. 
     In the in-vehicle network  12 , the in-vehicle ECU  111  is connected to the relay device  100  via an Ethernet (registered trademark) cable  11 , for example. 
     More specifically, the relay device  100 A includes communication ports  1 A,  2 A,  3 A,  4 A. The relay device  100 B includes communication ports  1 B,  2 B,  3 B,  4 B. The communication ports  1 A,  2 A,  3 A,  4 A,  1 B,  2 B,  3 B,  4 B are each a terminal to which an Ethernet cable  11  can be connected, for example. 
     The in-vehicle ECU  111 A is connected via an Ethernet cable  11  to the communication port  2 A in the relay device  100 A. 
     The in-vehicle ECU  111 B is connected via an Ethernet cable  11  to the communication port  3 A in the relay device  100 A. 
     The in-vehicle ECU  111 C is connected via an Ethernet cable  11  to the communication port  2 B in the relay device  100 B. 
     The in-vehicle ECU  111 D is connected via an Ethernet cable  11  to the communication port  3 B in the relay device  100 B. 
     The communication port  4 A in the relay device  100 A and the communication port  1 B in the relay device  100 B are connected to each other via an Ethernet cable  11 . 
     The relay device  100  performs a relay process of an Ethernet frame in accordance with an Ethernet communication standard. Specifically, the relay device  100  relays an Ethernet frame that is communicated between in-vehicle ECUs  111 , for example. An IP packet is stored in the Ethernet frame. 
     The configuration of the communication system  300  is not limited to a configuration in which relay of the Ethernet frame is performed in accordance with the Ethernet communication standard, and may be a configuration in which relay of data is performed in accordance with a communication standard such as CAN (Controller Area Network) (registered trademark), FlexRay (registered trademark), MOST (Media Oriented Systems Transport) (registered trademark), or LIN (Local Interconnect Network), for example. 
     In the in-vehicle network  12 , one or a plurality of virtual networks are constructed. Specifically, the in-vehicle ECU  111 A and the in-vehicle ECU  111 C belong to a VLAN (Virtual Local Area Network)  10 , and the in-vehicle ECU  111 B and the in-vehicle ECU  111 D belong to a VLAN  20  different from the VLAN  10 . 
       FIG. 2  shows setting information of the in-vehicle network according to the embodiment of the present disclosure. 
     In the following, for convenience, the port numbers of the communication ports  1 A,  2 A,  3 A,  4 A of the relay device  100 A are defined as “ 1 ”, “ 2 ”, “ 3 ”, “ 4 ”, respectively, and the port numbers of the communication ports  1 B,  2 B,  3 B,  4 B of the relay device  100 B are defined as “ 1 ”, “ 2 ”, “ 3 ”, “ 4 ”, respectively. Each in-vehicle ECU  111  includes one communication port, and the port number of the communication port is defined as “ 1 ”. 
     With reference to  FIG. 2 , the ID of the VLAN corresponding to the communication port  2 A of the relay device  100 A is “VLAN  10 ”, the ID of the VLAN corresponding to the communication port  3 A of the relay device  100 A is “VLAN  20 ”, and the ID of the VLAN corresponding to the communication port  4 A of the relay device  100 A is “VLAN  10 ” and “VLAN  20 ”. 
     The ID of the VLAN corresponding to the communication port  1 B of the relay device  100 B is “VLAN  10 ” and “VLAN  20 ”, the ID of the VLAN corresponding to the communication port  2 B of the relay device  100 B is “VLAN  10 ”, and the ID of the VLAN corresponding to the communication port  3 B of the relay device  100 B is “VLAN”  20 . 
     The ID of the VLAN corresponding to the communication port  1  of each of the in-vehicle ECUs  111 A,  111 C is “VLAN  10 ”, and the ID of the VLAN corresponding to the communication port  1  of each of the in-vehicle ECUs  111 B,  111 D is “VLAN  20 ”. 
     Each relay device  100  performs a relay process of an Ethernet frame between in-vehicle ECUs  111  that belong to the same VLAN, for example. Specifically, on the basis of the transmission source MAC (Media Access Control) address and the transmission destination MAC address included in a received Ethernet frame, the relay device  100  transmits the Ethernet frame to a transmission destination in-vehicle ECU  111  that belongs to the same VLAN as that of the transmission source. 
     In addition, the relay device  100  performs a relay process of an IP packet between in-vehicle ECUs  111  that belong to different VLANs, for example. Specifically, the relay device  100  acquires an IP packet from a received Ethernet frame, and on the basis of the transmission destination IP address of the acquired IP packet, the relay device  100  transmits the IP packet to a transmission destination in-vehicle ECU  111  that belongs to a VLAN different from that of the transmission source. 
     [Relay Device] 
       FIG. 3  shows a configuration of the relay device according to the embodiment of the present disclosure.  FIG. 3  shows a configuration of the relay device  100 A shown in  FIG. 1 . 
     With reference to  FIG. 3 , the relay device  100 A includes a relay processing unit  110 , a detection unit  120 , an authentication result acquisition unit  130 , an authentication unit  140 , a setting unit  150 , and a storage unit  160 . The storage unit  160  is a flash memory, for example. The relay processing unit  110 , the detection unit  120 , the authentication result acquisition unit  130 , the authentication unit  140 , and the setting unit  150  are each realized by a processor such as a CPU (Central Processing Unit) or a DSP (Digital Signal Processor), for example. 
     The relay processing unit  110  performs a relay process of an Ethernet frame between in-vehicle ECUs  111 . 
     More specifically, when the relay processing unit  110  has received an Ethernet frame from an in-vehicle ECU  111  or the relay device  100 B via a corresponding Ethernet cable  11 , the relay processing unit  110  transmits the received Ethernet frame to the transmission destination in-vehicle ECU  111  or the relay device  100 B via a corresponding Ethernet cable  11 . 
     In addition, when the relay processing unit  110  has received, from a new function unit newly added to the in-vehicle network  12 , an Ethernet frame addressed to the relay device  100  to which the relay processing unit  110  belongs, the relay processing unit  110  outputs the received Ethernet frame to the detection unit  120 . 
     [Detection Unit] 
     The detection unit  120  detects a new function unit newly added to the in-vehicle network  12 . 
       FIG. 4  shows a configuration of the communication system according to the embodiment of the present disclosure.  FIG. 4  shows a configuration of the in-vehicle network  12  obtained by newly adding an in-vehicle ECU  111 E to the in-vehicle network  12  shown in  FIG. 1 . 
     With reference to  FIG. 4 , the in-vehicle ECU  111 E is connected via an Ethernet cable  11  to the communication port  1 A in the relay device  100 A. 
     The in-vehicle ECU  111 E is an example of a new function unit, which is a function unit newly added to the in-vehicle network  12 . 
     Hereinafter, the in-vehicle network  12  including a new function unit is also referred to as a new network, the in-vehicle network  12  before the new function unit is added thereto is also referred to as an existing network, and each function unit included in the existing network is also referred to as an existing function unit. 
     The in-vehicle ECU  111 E communicates an Ethernet frame with a function unit serving as a communication target. Hereinafter, the function unit serving as a communication target of a new function unit is also referred to as a target function unit. 
     When the in-vehicle ECU  111 E has been connected via an Ethernet cable  11  to the relay device  100 A, the in-vehicle ECU  111 E transmits, to the relay device  100 A, information capable of specifying an in-vehicle ECU  111  serving as the communication target of the in-vehicle ECU  111 E. 
     More specifically, when the in-vehicle ECU  111 E has been connected via an Ethernet cable  11  to the communication port  1 A in the relay device  100 A, the in-vehicle ECU  111 E generates connection request information including the ID, e.g., MAC address, of the in-vehicle ECU  111 C serving as the communication target of the in-vehicle ECU  111 E. 
     Then, the in-vehicle ECU  111 E generates an Ethernet frame that includes the generated connection request information, the ID of the in-vehicle ECU  111 E, an authentication password as secret information, and the MAC address of the relay device  100 A as the transmission destination MAC address, and transmits the generated Ethernet frame to the relay device  100 A. 
     Upon receiving via the relay processing unit  110  the Ethernet frame from the in-vehicle ECU  111 E, the detection unit  120  in the relay device  100 A acquires the connection request information, the ID of the in-vehicle ECU  111 E, and the authentication password from the received Ethernet frame, thereby detecting the addition of the in-vehicle ECU  111 E to the in-vehicle network  12 . 
     The detection unit  120  outputs the connection request information, the ID of the in-vehicle ECU  111 E, and the authentication password that have been acquired, to the authentication result acquisition unit  130 . 
     [Authentication Result Acquisition Unit] 
     The authentication result acquisition unit  130  is an example of an acquisition unit that acquires the authentication result regarding the in-vehicle ECU  111 E serving as a new function unit that has been newly added to the in-vehicle network  12 . 
     For example, upon receiving the connection request information, the ID of the in-vehicle ECU  111 E, and the authentication password from the detection unit  120 , the authentication result acquisition unit  130  outputs the connection request information, the ID of the new function unit, and the authentication password that have been received, to the authentication unit  140 . 
     Upon receiving the connection request information, the ID of the in-vehicle ECU  111 E, and the authentication password from the authentication result acquisition unit  130 , the authentication unit  140  performs an authentication process regarding the in-vehicle ECU  111 E, by using the connection request information, the ID of the in-vehicle ECU  111 E, and the authentication password that have been received. 
     As a result of the authentication process, when the authentication unit  140  has determined that the in-vehicle ECU  111 E is not an authentic communication counterpart with the target function unit, the authentication unit  140  outputs, to the authentication result acquisition unit  130 , authentication information indicating a negative authentication result as the authentication result regarding the in-vehicle ECU  111 E. 
     Upon receiving the authentication information indicating the negative authentication result from the authentication unit  140 , the authentication result acquisition unit  130  generates an Ethernet frame that includes connection non-permitting information indicating that the connection is not permitted, and the MAC address of the in-vehicle ECU  111 E as the transmission destination MAC address, and transmits the generated Ethernet frame to the in-vehicle ECU  111 E via the relay processing unit  110 . 
     Meanwhile, as a result of the authentication process, when the authentication unit  140  has confirmed that the in-vehicle ECU  111 E is an authentic communication counterpart with the target function unit indicated by the connection request information, the authentication unit  140  outputs, to the authentication result acquisition unit  130 , authentication information indicating an affirmative authentication result as the authentication result regarding the in-vehicle ECU  111 E. 
     Upon receiving the authentication information indicating the affirmative authentication result from the authentication unit  140 , the authentication result acquisition unit  130  outputs, to the setting unit  150 , the connection request information and the ID of the in-vehicle ECU  111 E that have been received from the detection unit  120 . 
     [Setting Unit] 
     When the authentication result acquired by the authentication result acquisition unit  130  is affirmative, the setting unit  150  can perform a setting process for allowing an existing function unit and the in-vehicle ECU  111 E to perform communication via the relay devices  100 A,  100 B, the setting process being regarding at least one of the function units and the relay devices  100 A,  100 B. 
     Specifically, when the authentication result acquired by the authentication result acquisition unit  130  is affirmative, the setting unit  150  performs the setting process for allowing the existing function unit and the in-vehicle ECU  111 E to perform communication via the relay device  100 A and the relay device  100 B, the setting process being regarding each function unit. 
     More specifically, upon receiving the connection request information and the ID of the in-vehicle ECU  111 E from the authentication result acquisition unit  130 , the setting unit  150  generates, on the basis of the connection request information and the ID of the in-vehicle ECU  111 E that have been received, setting information of a new network for allowing the target function unit indicated by the connection request information and the in-vehicle ECU  111 E to perform communication via the relay device  100 A,  100 B. 
     For example, the storage unit  160  stores therein setting information of the in-vehicle network  12  whose connection relationship between function units is fixed as described above. 
     More specifically, the storage unit  160  stores setting information for allowing each existing function unit to perform communication in the existing network. Specifically, the storage unit  160  stores the setting information shown in  FIG. 2  as the setting information of the existing network. 
     The setting unit  150  performs the setting process on the basis of the setting information in the storage unit  160 . 
     More specifically, the setting unit  150  generates setting information of a new network on the basis of the setting information of the existing network in the storage unit  160  and the connection request information received from the authentication result acquisition unit  130 . 
     The setting unit  150  updates the existing setting information in the storage unit  160  to the generated new setting information. 
     Then, on the basis of the setting information after the update in the storage unit  160 , the setting unit  150  specifies a function unit for which setting change in the new network is necessary, and the setting unit  150  notifies the specified function unit and the in-vehicle ECU  111 E of the setting content. 
     Setting Process Example 1 
     For example, as the setting process, the setting unit  150  performs a process of constructing a new virtual network for allowing the in-vehicle ECU  111 E and one or a plurality of target function units to perform communication. 
     In the following, a case where the in-vehicle ECU  111 E serving as a new function unit is added to the in-vehicle network  12  as shown in  FIG. 4  and the target function unit indicated by the connection request information transmitted from the in-vehicle ECU  111 E is the in-vehicle ECU  111 C, is assumed. 
     When the setting unit  150  has received, from the authentication result acquisition unit  130 , connection request information indicating that the target function unit is the in-vehicle ECU  111 C, the setting unit  150  generates setting information of a new network including a new virtual network for allowing only the in-vehicle ECU  111 E and the in-vehicle ECU  111 C to perform communication. 
     Specifically, the setting unit  150  generates setting information of a new network including a new VLAN  30  for allowing only the in-vehicle ECU  111 E and the in-vehicle ECU  111 C to perform communication. 
       FIG. 5  shows an example of a configuration of a new network in the communication system according to the embodiment of the present disclosure. 
       FIG. 6  shows an example of setting information of the new network according to the embodiment of the present disclosure. 
     With reference to in  FIG. 6 , as the setting information of the new network, the setting unit  150  generates new setting information in which: in the setting information of the existing network shown in  FIG. 2 , “VLAN  30 ” is added as the ID of the VLAN that corresponds to the communication ports  1 A,  4 A of the relay device  100 A; “VLAN  30 ” is added as the ID of the VLAN that corresponds to the communication ports  1 B,  2 B of the relay device  100 B; and “VLAN  30 ” is added as the ID of the VLAN that corresponds to the communication port  1  of each of the in-vehicle ECUs  111 C,  111 E. 
     The setting unit  150  updates the existing setting information in the storage unit  160  to the generated new setting information. 
     On the basis of the setting information after the update in the storage unit  160 , the setting unit  150  notifies the relay device  100 B, the in-vehicle ECU  111 C, and the in-vehicle ECU  111 E, which are the function units for which setting change in the new network is necessary, of the setting content. 
     For example, it is assumed that, in the in-vehicle network  12 , a virtual network, e.g., VLAN  50 , in which setting information for allowing each function unit to perform communication is communicated between the function units, has been constructed. The setting unit  150  performs the setting process by using the VLAN  50 . 
     More specifically, the setting unit  150  generates an Ethernet frame including setting information of the new network, and transmits the generated Ethernet frame to the relay device  100 B and the in-vehicle ECUs  111 C,  111 E via the relay processing unit  110  by using the VLAN  50 . 
     For example, the relay devices  100 A,  100 B transmit the Ethernet frame including the setting information, by using an encryption scheme based on secret information shared in advance. 
     The in-vehicle ECU  111 E, the in-vehicle ECU  111 C, and the relay device  100 B perform setting change in accordance with the setting information included in the Ethernet frame received via the relay processing unit  110  from the setting unit  150 . 
     Specifically, the in-vehicle ECU  111 E adds “VLAN  30 ” as the VLAN that corresponds to communication port  1  of the in-vehicle ECU  111 E, in accordance with the setting information included in the received Ethernet frame. 
     The in-vehicle ECU  111 C adds “VLAN  30 ” as the VLAN that corresponds to the communication port  1  of the in-vehicle ECU  111 C, in accordance with the setting information included in the received Ethernet frame. 
     The setting unit  150  adds “VLAN  30 ” as the VLAN that corresponds to the communication ports  1 A,  4 A of the relay device  100 A. 
     The relay device  100 B adds “VLAN  30 ” as the VLAN that corresponds to the communication ports  1 B,  2 B, in accordance with the setting information included in the received Ethernet frame. 
     In this manner, in the communication system  300 , when a new VLAN  30  for allowing the in-vehicle ECU  111 E and the in-vehicle ECU  111 C to perform communication is to be constructed, the authentication process regarding the in-vehicle ECU  111 E by the relay device  100 B is not necessary. That is, without performing the authentication process regarding the in-vehicle ECU  111 E, the relay device  100 B can perform setting change in accordance with the setting information received from the setting unit  150 . 
     [Setting process example 2] For example, when an existing virtual network as a virtual network for allowing one or a plurality of target function units only, to perform communication has been constructed, the setting unit  150  performs, as the setting process, a setting process regarding the in-vehicle ECU  111 E and the relay device  100 A and for allowing the in-vehicle ECU  111 E and the target function units to perform communication by using the existing virtual network. 
     In the following, a case where the in-vehicle ECU  111 E serving as a new function unit is added to the in-vehicle network  12  as shown in  FIG. 4  and the target function unit indicated by the connection request information transmitted from the in-vehicle ECU  111 E is the in-vehicle ECU  111 A and the in-vehicle ECU  111 C, is assumed. 
     When the setting unit  150  has received from the authentication result acquisition unit  130 , connection request information indicating that the target function unit is the in-vehicle ECUs  111 A,  111 C, the setting unit  150  generates setting information of a new network including a virtual network for allowing the in-vehicle ECU  111 E and the in-vehicle ECUs  111 A,  111 C to perform communication. 
     Specifically, when the setting unit  150  has confirmed, with reference to the setting information in the storage unit  160 , that the VLAN  10  for allowing only the in-vehicle ECU  111 A and the in-vehicle ECU  111 C to perform communication is included in the existing network, the setting unit  150  generates setting information of a new network for allowing the in-vehicle ECU  111 E and the in-vehicle ECUs  111 A,  111 C to perform communication by using the VLAN  10 . 
       FIG. 7  shows another example of a configuration of a new network in the communication system according to the embodiment of the present disclosure. 
       FIG. 8  shows another example of setting information of the new network according to the embodiment of the present disclosure. 
     With reference to  FIG. 8 , as the setting information of the new network, the setting unit  150  generates new setting information in which: in the setting information of the existing network shown in  FIG. 2 , “VLAN  10 ” is added as the ID of the VLAN that corresponds to the communication port  1 A of the relay device  100 A; and “VLAN  10 ” is added as the ID of the VLAN that corresponds to the communication port  1  of the in-vehicle ECU  111 E serving as the new function unit. 
     The setting unit  150  updates the existing setting information in the storage unit  160  to the generated new setting information. 
     On the basis of the setting information after the update in the storage unit  160 , the setting unit  150  notifies the in-vehicle ECU  111 E, which is the function unit for which setting change in the new network is necessary, of the setting content. 
     More specifically, the setting unit  150  generates an Ethernet frame including the setting information, and transmits the generated Ethernet frame to the in-vehicle ECU  111 E via the relay processing unit  110  by using the VLAN  50  described above. 
     The in-vehicle ECU  111 E performs setting change in accordance with the setting information included in the Ethernet frame received via the relay processing unit  110  from the setting unit  150 . 
     Specifically, the in-vehicle ECU  111 E adds “VLAN  10 ” as the VLAN that corresponds to the communication port  1  of the in-vehicle ECU  111 E, in accordance with the setting information included in the received Ethernet frame. 
     The setting unit  150  adds “VLAN  10 ” as the VLAN that corresponds to the communication port  1 A of the relay device  100 A. 
     As described above, in the communication system  300 , when a new VLAN  30  for allowing the in-vehicle ECU  111 E and the in-vehicle ECU  111 C to perform communication is to be constructed, the authentication process regarding the in-vehicle ECU  111 E by the relay device  100 B is not necessary. 
     [Operation Flow] 
     Each device in the communication system according to the embodiment of the present disclosure includes a computer that includes a memory. An arithmetic processing unit such as a CPU in the computer reads out, from the memory, a program including a part or all of steps in the flow chart and sequence shown below, and executes the program. Programs of the plurality of devices can each be installed from outside. The programs of the plurality of devices are each distributed in a state of being stored in a storage medium. 
       FIG. 9  is a flow chart describing an operation procedure according to which the relay device constructs a new network in the communication system according to the embodiment of the present disclosure. 
     With reference to  FIG. 9 , first, the relay device  100 A waits for addition of a new function unit to the in-vehicle network  12  (NO in step S 102 ), and upon detection of addition of a new function unit to the in-vehicle network  12  (YES in step S 102 ), the relay device  100 A performs an authentication process regarding the detected new function unit (step S 104 ). 
     Next, when the authentication result is negative (NO in step S 106 ), the relay device  100 A transmits, to the new function unit, connection non-permitting information indicating that the connection is not permitted (step S 108 ). 
     Next, the relay device  100 A waits for new addition of a new function unit to the in-vehicle network  12  (NO in step S 102 ). 
     Meanwhile, when the authentication result is affirmative (YES in step S 106 ), the relay device  100 A generates setting information of a new network for allowing the relay device  100 B and the target function unit, and the new function unit to perform communication (step S 110 ). 
     Next, on the basis of the generated setting information, the relay device  100 A specifies a function unit for which setting change in the new network is necessary, and transmits the setting information to the specified function unit and the in-vehicle ECU  111 E (step S 112 ). 
     Next, the relay device  100 A waits for new addition of a new function unit to the in-vehicle network  12  (NO in step S 102 ). 
       FIG. 10  shows an example of the sequence of a construction process of a new network in the communication system according to the embodiment of the present disclosure.  FIG. 10  shows an example of the sequence of a construction process of the new network as shown in  FIG. 5 . 
     With reference to  FIG. 10 , first, in the existing in-vehicle network  12 , the in-vehicle ECU  111 A and the in-vehicle ECU  111 C belong to the same VLAN  10 , and are performing communication with each other via the relay devices  100 A,  100 B by using the VLAN  10  (step S 202 ). 
     Next, when the in-vehicle ECU  111 E serving as the new function unit newly added to the in-vehicle network  12  has been connected to the relay device  100 A, the in-vehicle ECU  111 E transmits, to the relay device  100 A, connection request information including information capable of specifying the in-vehicle ECU  111 C serving as the communication target of the in-vehicle ECU  111 E (step S 204 ). 
     Next, upon receiving the connection request information from the in-vehicle ECU  111 E, the relay device  100 A detects the in-vehicle ECU  111 E, and performs an authentication process regarding the in-vehicle ECU  111 E (step S 206 ). 
     Next, when the authentication result is affirmative, the relay device  100 A generates setting information of a new network for allowing the relay device  100 B and the in-vehicle ECU  111 C, and the in-vehicle ECU  111 E to perform communication by using the VLNA  30 . Specifically, the setting information as shown in  FIG. 6  is generated (step S 208 ). 
     Next, the relay device  100 A transmits the generated setting information to the relay device  100 B, the in-vehicle ECU  111 C, and the in-vehicle ECU  111 E, which are the function units for which setting change in the new network is necessary (step S 210 ). 
     Next, the relay device  100 A performs setting change on the basis of the generated setting information (step S 212 ). 
     The in-vehicle ECU  111 E performs setting change in accordance with the setting information received from the relay device  100 A (step S 214 ). 
     The relay device  100 B performs setting change in accordance with the setting information received from the relay device  100 A (step S 216 ). 
     The in-vehicle ECU  111 C performs setting change in accordance with the setting information received from the relay device  100 A (step S 218 ). 
     Next, in the new network  12 , the in-vehicle ECU  111 A and the in-vehicle ECU  111 C perform communication with each other via the relay devices  100 A,  100 B by using the VLAN  10  (step S 220 ). 
     In the new network  12 , the in-vehicle ECU  111 E and the in-vehicle ECU  111 C perform communication with each other via the relay devices  100 A,  100 B by using the newly generated VLAN  30  (step S 222 ). 
       FIG. 11  shows another example of the sequence of a construction process of a new network in the communication system according to the embodiment of the present disclosure.  FIG. 11  shows an example of the sequence of a construction process of the new network as shown in  FIG. 7 . 
     With reference to  FIG. 11 , first, in the existing in-vehicle network  12 , the in-vehicle ECU  111 A and the in-vehicle ECU  111 C belong to the same VLAN  10 , and are performing communication with each other via the relay devices  100 A,  100 B by using the VLAN  10  (step S 302 ). 
     Next, when the in-vehicle ECU  111 E serving as the new function unit newly added to the in-vehicle network  12  has been connected to the relay device  100 A, the in-vehicle ECU  111 E transmits, to the relay device  100 A, connection request information including information capable of specifying the in-vehicle ECUs  111 A,  111 C serving as the communication target of the in-vehicle ECU  111 E (step S 304 ). 
     Next, upon receiving the connection request information from the in-vehicle ECU  111 E, the relay device  100 A detects the in-vehicle ECU  111 E and performs an authentication process regarding the in-vehicle ECU  111 E (step S 306 ). 
     Next, when the authentication result is affirmative, the relay device  100 A generates setting information of a new network for allowing the relay device  100 B and the in-vehicle ECUs  111 A,  111 C, and the in-vehicle ECU  111 E to perform communication by using the VLNA  10 . Specifically, the setting information as shown in  FIG. 8  is generated (step S 308 ). 
     Next, the relay device  100 A transmits the generated setting information to the in-vehicle ECU  111 E, which is the function unit for which setting change in the new network is necessary (step S 310 ). 
     Next, the relay device  100 A performs setting change on the basis of the generated setting information (step S 312 ). 
     The in-vehicle ECU  111 E performs setting change in accordance with the setting information received from the relay device  100 A (step S 314 ). 
     Next, in the new network  12 , the in-vehicle ECU  111 A, the in-vehicle ECU  111 C, and the in-vehicle ECU  111 E perform communication with each other via the relay devices  100 A,  100 B by using the VLAN  10  (step S 316 ). 
     In the communication system  300  according to the embodiment of the present disclosure, out of the two relay devices  100 , the relay device  100 A, to which the in-vehicle ECU  111 E serving as the new function unit is connected, performs, as the setting device, the acquisition of the authentication result regarding the in-vehicle ECU  111 E and the setting process. However, the present disclosure is not limited thereto. Out of the two relay devices  100 , the relay device  100 B, which is the relay device  100  to which the in-vehicle ECU  111 E is not connected, may perform the acquisition of the authentication result and the setting process. 
     A device other than the relay device  100  in the in-vehicle network  12  may perform, as the setting device, the acquisition of the authentication result and the setting process. For example, a device not positioned on the communication path between a new function unit and a target function unit in the in-vehicle network  12  may perform, as the setting device, the acquisition of the authentication result and the setting process. 
     A device outside the vehicle, e.g., the server  200 , may perform, as the setting device, the acquisition of the authentication result and the setting process. In this case, the server  200  performs communication with a TCU in the in-vehicle network  12 , thereby performing acquisition of connection request information transmitted from the in-vehicle ECU  111 E, which is information capable of specifying the target function unit, the acquisition of the authentication result, the setting process, and the like. 
     In the communication system  300  according to the embodiment of the present disclosure, the in-vehicle ECU  111 E serving as the new function unit transmits, to the relay device  100 A, connection request information including the MAC address of the in-vehicle ECU  111 C, as the information capable of specifying the in-vehicle ECU  111 C serving as the target function unit. However, the present disclosure is not limited thereto. As the information capable of specifying the in-vehicle ECU  111 C, the in-vehicle ECU  111 E may transmit, to the relay device  100 A, another type of information such as the IP address of the in-vehicle ECU  111 C. 
     In the relay device  100 A according to the embodiment of the present disclosure, the authentication result acquisition unit  130  acquires the authentication result regarding the in-vehicle ECU  111 E from the authentication unit  140  in the relay device  100 A. However, the present disclosure is not limited thereto. The authentication result acquisition unit  130  may acquire the authentication result regarding the in-vehicle ECU  111 E from a device other than the relay device  100 A. 
     In the relay device  100 A according to the embodiment of the present disclosure, the detection unit  120  detects an in-vehicle ECU  111  serving as a new function unit that is newly added to the in-vehicle network  12 . However, the present disclosure is not limited thereto. The detection unit  120  may detect, as a new function unit, an application installed in an existing in-vehicle ECU  111  in the in-vehicle network  12 . That is, the new function unit may be hardware or may be software. 
     In the relay device  100 A according to the embodiment of the present disclosure, the setting unit  150  generates setting information of a new network on the basis of the setting information of the existing network in the storage unit  160 . However, the present disclosure is not limited thereto. The setting unit  150  may transmit to, each function unit in the in-vehicle network  12 , an information request notification for requesting transmission of information indicating the setting content of the function unit, and on the basis of the setting content received from each function unit as a response to the information request notification, the setting unit  150  may generate setting information of the new network. 
     In the relay device  100 A according to the embodiment of the present disclosure, the setting unit  150  transmits, to each function unit in the in-vehicle network  12 , setting information by using the VLAN  50  for allowing the setting information to be communicated between the function units. However, the present disclosure is not limited thereto. The setting unit  150  may transmit the setting information to a transmission destination function unit by using a VLAN for allowing communication to be performed between some function units in the in-vehicle network  12 . 
     Further, for example, the relay devices  100 A,  100 B may communicate setting information and the like by using a network setting API (Application Programming Interface) used in a consumer product. 
     In the relay device  100 A according to the embodiment of the present disclosure, the setting unit  150  specifies a function unit for which setting change in the new network is necessary, and transmits the setting information after update to the specified function unit and the in-vehicle ECU  111 E. However, the present disclosure is not limited thereto. The setting unit  150  may generate, for each of the specified function unit and the in-vehicle ECU  111 E, setting change information indicating the content of setting change for each function unit, and transmit, to the specified function unit and the in-vehicle ECU  111 E, the corresponding setting change information. 
     [Problem] 
     For example, if a high-performance sensor that transmits a measurement result to an automated driving ECU, which is an example of the in-vehicle ECU  111 , is added to the existing in-vehicle network  12  including the automated driving ECU, the control function of the automated driving ECU in automated driving can be improved. 
     Thus, there is a demand for a technology that customizes the in-vehicle network  12  by newly adding an in-vehicle ECU  111  to the existing in-vehicle network  12 . 
     However, in a state where an in-vehicle ECU  111  is newly added to the in-vehicle network  12 , that the in-vehicle ECU  111  and the target function unit perform communication by using an existing virtual network in the new in-vehicle network  12  is not preferable in terms of security of the in-vehicle network  12  in some cases. 
     Specific description is given below. In the following, a case where the in-vehicle ECU  111 E serving as a new function unit is added to the in-vehicle network  12  as shown in  FIG. 4  and the target function unit indicated by connection request information transmitted from the in-vehicle ECU  111 E is the in-vehicle ECU  111 C, is assumed. 
     For example, when the relay device  100 A has received the connection request information from the in-vehicle ECU  111 E and has constructed a new network as shown in  FIG. 7 , the in-vehicle ECU  111 E becomes able to perform communication not only with the in-vehicle ECU  111 C serving as the target function unit but also with the in-vehicle ECU  111 A with which, originally, the in-vehicle ECU  111 E need not perform communication. 
     For example, when the in-vehicle ECU  111 E is an unauthorized ECU, there is a risk that not only the in-vehicle ECU  111 C but also the in-vehicle ECU  111 A is subjected to an unauthorized access. 
     Therefore, in order to avoid a situation where the in-vehicle ECU  111 A is subjected to an unauthorized access, construction of a new network, e.g., a new network as shown in  FIG. 5 , in which only communication with the in-vehicle ECU  111 C serving as the target function unit is permitted to the in-vehicle ECU  111 E, is conceivable. 
     However, when the new network as shown in  FIG. 5  is constructed, the authentication process regarding the in-vehicle ECU  111 E and change of the network configuration need to be performed in each relay device  100 , i.e., the relay devices  100 A,  100 B, present on the communication path between the in-vehicle ECU  111 E and the in-vehicle ECU  111 C. 
     Therefore, it takes time from when the in-vehicle ECU  111 E is added to the in-vehicle network  12  until when communication between the in-vehicle ECU  111 E and the in-vehicle ECU  111 C is enabled. 
     Further, all of the relay devices  100  that are present on the communication path between the in-vehicle ECU  111 E and the in-vehicle ECU  111 C need to be provided with an authentication function for authenticating the in-vehicle ECU  111 E to be newly added. This increases the cost required in development of hardware and software. 
     In contrast to this, in the relay device  100 A according to the embodiment of the present disclosure, the authentication result acquisition unit  130  acquires an authentication result regarding a new function unit serving as a function unit newly added to the in-vehicle network  12  including one or a plurality of function units. When the authentication result acquired by the authentication result acquisition unit  130  is affirmative, the setting unit  150  can perform a setting process for allowing the new function unit and an existing function unit serving as a function unit included in the in-vehicle network  12  before the new function unit is added thereto, to perform communication via a plurality of relay devices  100 A,  100 B capable of relaying information between the function units, the setting process being regarding at least one of the relay devices, the existing function unit, and the new function unit. 
     As described above, when the authentication result regarding the new function unit is affirmative, the relay device  100 A performs the setting process for allowing the existing function unit and the new function unit to perform communication via the plurality of relay devices  100 A,  100 B, the setting process being regarding at least one of the relay devices  100 A,  100 B, the existing function unit, and the new function unit. Due to this configuration, for example, when a network for allowing the existing function unit and the new function unit to perform communication via the plurality of relay devices  100 A,  100 B is to be constructed, the authentication process and the like regarding the new function unit by the relay device  100 B, which is a part of devices in the in-vehicle network  12 , can be omitted. 
     Therefore, in the relay device  100 A according to the embodiment of the present disclosure, a network having a new configuration can be flexibly constructed through a simple process while ensuring security in the network. 
     In the relay device  100 A according to the embodiment of the present disclosure, the storage unit  160  stores setting information for allowing each function unit in the in-vehicle network  12  to perform communication. The setting unit  150  performs the setting process on the basis of the setting information in the storage unit  160 . 
     Due to this configuration, when a new in-vehicle network  12  including a new function unit is to be constructed while the storage unit  160  retains the setting information of the in-vehicle network  12  whose network configuration is basically fixed, setting information of the new in-vehicle network  12  is generated by using the setting information of the existing in-vehicle network  12  acquired from the storage unit  160 . Therefore, the construction process of the new in-vehicle network  12  can be simplified. 
     In the relay device  100 A according to the embodiment of the present disclosure, the setting unit  150  performs the setting process by using a virtual network for transmitting, to each function unit in the in-vehicle network  12 , setting information for allowing the function unit to perform communication. 
     Due to this configuration, the setting information can be transmitted to each function unit in the in-vehicle network  12  from the relay device  100 A by using the virtual network. Therefore, the setting process regarding each function unit can be simplified. 
     In the relay device  100 A according to the embodiment of the present disclosure, the setting unit  150  performs, as the setting process, a process of constructing a new virtual network for allowing a new function unit and one or a plurality of the existing function units serving as the communication target of the new function unit to perform communication. 
     Due to this configuration, it is possible to suppress adverse influence, such as an unauthorized access, that is associated with addition of a new function unit to the in-vehicle network  12 , on an existing function unit that is not the communication target of the new function unit. 
     In the relay device  100 A according to the embodiment of the present disclosure, when an existing virtual network as a virtual network for allowing one or a plurality of existing function units serving as the communication target of the new function unit only, to perform communication has been constructed, the setting unit  150  performs, as the setting process, a setting process regarding the new function unit and the relay device  100 A and for allowing the new function unit and the one or the plurality of existing function units serving as the communication target to perform communication by using the existing virtual network. 
     Due to this configuration, since the setting process regarding the addition of the new function unit to the existing virtual network is performed, the construction process of a new network for allowing only the new function unit and the existing function unit serving as the communication target to perform communication is not necessary. 
     The communication system  300  according to the embodiment of the present disclosure includes the relay device  100 A, and a new function unit serving as a function unit newly added to the in-vehicle network  12  including one or a plurality of function units. The relay device  100 A acquires information transmitted from the new function unit and capable of specifying a function unit serving as the communication target of the new function unit. The relay device  100 A acquires an authentication result regarding the new function unit. When the acquired authentication result is affirmative, the relay device  100 A transmits, to the new function unit, setting information for allowing the function unit serving as the communication target and the new function unit to perform communication via a plurality of relay devices  100 A,  100 B capable of relaying information between the function units. The new function unit performs setting for the new function unit on the basis of the setting information received from the relay device  100 A. 
     As described above, when the authentication result regarding the new function unit is affirmative, the relay device  100 A transmits, to the new function unit, setting information for allowing the existing function unit serving as the communication target and the new function unit to perform communication via the plurality of relay devices  100 A,  100 B. Due to this configuration, for example, when a network for allowing the existing function unit and the new function unit to perform communication via the plurality of relay devices  100 A,  100 B is to be constructed, the authentication process and the like regarding the new function unit by the relay device  100 B, which is a part of devices in the in-vehicle network  12 , can be omitted. 
     Therefore, in the communication system  300  according to the embodiment of the present disclosure, a network having a new configuration can be flexibly constructed through a simple process while ensuring security in the network. 
     A vehicle communication management method according to the embodiment of the present disclosure is a vehicle communication management method to be performed in the relay device  100 A. In this vehicle communication management method, first, the relay device  100 A acquires an authentication result regarding a new function unit serving as a function unit newly added to the in-vehicle network  12  including one or a plurality of function units. Next, when the acquired authentication result is affirmative, the relay device  100 A performs a setting process for allowing the new function unit and an existing function unit serving as a function unit included in the in-vehicle network  12  before the new function unit is added thereto, to perform communication via a plurality of relay devices  100 A,  100 B capable of relaying information between the function units, the setting process being regarding at least one of the relay devices  100 A,  100 B, the existing function unit, and the new function unit. 
     As described above, when the authentication result regarding the new function unit is affirmative, the relay device  100 A performs the setting process for allowing the existing function unit and the new function unit to perform communication via the plurality of the relay devices  100 A,  100 B, the setting process being regarding at least one of the relay devices  100 A,  100 B, the existing function unit, and the new function unit. Due to this method, for example, when a network for allowing the existing function unit and the new function unit to perform communication via the plurality of relay devices  100 A,  100 B is to be constructed, the authentication process and the like regarding the new function unit by the relay device  100 B, which is a part of devices in the in-vehicle network  12 , can be omitted. 
     Therefore, in the vehicle communication management method according to the embodiment of the present disclosure, a network having a new configuration can be flexibly constructed through a simple process while ensuring security in the network. 
     A vehicle communication management method according to the embodiment of the present disclosure is a vehicle communication management method to be performed in the communication system  300  including the relay device  100 A and a new function unit serving as a function unit newly added to the in-vehicle network  12  including one or a plurality of function units. In this vehicle communication management method, first, the relay device  100 A acquires information transmitted from the new function unit and capable of specifying a function unit serving as a communication target of the new function unit. Next, the relay device  100 A acquires an authentication result regarding the new function unit. Next, when the acquired authentication result is affirmative, the relay device  100 A transmits, to the new function unit, setting information for allowing the function unit serving as the communication target and the new function unit to perform communication via a plurality of relay devices  100 A,  100 B capable of relaying information between the function units. Next, the new function unit performs setting for the new function unit on the basis of the setting information received from the relay device  100 A. 
     As described above, when the authentication result regarding the new function unit is affirmative, the relay device  100 A transmits, to the new function unit, setting information for allowing the existing function unit serving as the communication target and the new function unit to perform communication via the plurality of relay devices  100 A,  100 B. Due to this method, for example, when a network for allowing the existing function unit and the new function unit to perform communication via the plurality of relay devices  100 A,  100 B is to be constructed, the authentication process and the like regarding the new function unit by the relay device  100 B, which is a part of devices of the in-vehicle network  12 , can be omitted. 
     Therefore, in the vehicle communication management method according to the embodiment of the present disclosure, a network having a new configuration can be flexibly constructed through a simple process while ensuring security in the network. 
     The above embodiment is merely illustrative in all aspects and should not be recognized as being restrictive. The scope of the present disclosure is defined by the scope of the claims rather than by the description above, and is intended to include meaning equivalent to the scope of the claims and all modifications within the scope. 
     The above description includes the features in the additional notes below. 
     [Additional Note 1] 
     A relay device capable of relaying information between function units in an in-vehicle network including one or a plurality of function units, the relay device comprising: 
     a detection unit configured to detect a new function unit serving as a function unit newly added to the in-vehicle network; 
     an acquisition unit configured to acquire an authentication result regarding the new function unit detected by the detection unit; and 
     a setting unit configured to, when the authentication result acquired by the acquisition unit is affirmative, perform a setting process for allowing the new function unit and an existing function unit serving as a function unit included in the in-vehicle network before the new function unit is added thereto, to perform communication via a plurality of relay devices capable of relaying information between the function units, the setting process being regarding at least one of the relay devices, the existing function unit, and the new function unit. 
     [Additional Note 2] 
     A setting device comprising: 
     an acquisition unit configured to acquire an authentication result regarding a new function unit serving as a function unit newly added to an in-vehicle network including one or a plurality of function units; and 
     a setting unit configured to, when the authentication result acquired by the acquisition unit is affirmative, perform a setting process for allowing the new function unit and an existing function unit serving as a function unit included in the in-vehicle network before the new function unit is added thereto, to perform communication via a plurality of relay devices capable of relaying information between the function units, the setting process being regarding at least one of the relay devices, the existing function unit, and the new function unit, wherein 
     the acquisition unit and the setting unit are each realized by a processor. 
     [Additional Note 3] 
     An in-vehicle communication system comprising: 
     a first relay device capable of relaying information between function units in an in-vehicle network including a plurality of function units, and a second relay device connected to the first relay device; and 
     a new function unit serving as a function unit newly added to the in-vehicle network, wherein 
     the new function unit transmits, to the first relay device, information capable of specifying a function unit serving as a communication target of the new function unit, 
     the first relay device detects addition of the new function unit to the in-vehicle network, 
     the first relay device acquires an authentication result regarding the detected new function unit, 
     when the acquired authentication result is affirmative, the first relay device transmits, to the new function unit, setting information for allowing the function unit serving as the communication target and the new function unit to perform communication via the first relay device and the second relay device, and 
     the new function unit performs setting for the new function unit on the basis of the setting information received from the first relay device. 
     [Additional Note 4] 
     An in-vehicle communication system comprising: 
     a setting device; and 
     a new function unit serving as a function unit newly added to an in-vehicle network including one or a plurality of function units, wherein 
     the setting device acquires information transmitted from the new function unit and capable of specifying a function unit serving as a communication target of the new function unit, 
     the setting device acquires an authentication result regarding the new function unit, 
     when the acquired authentication result is affirmative, the setting device transmits, to the new function unit, setting information for allowing the function unit serving as the communication target and the new function unit to perform communication via a plurality of relay devices capable of relaying information between the function units, 
     the new function unit performs setting for the new function unit on the basis of the setting information received from the setting device, and 
     the function unit is an ECU. 
     REFERENCE SIGNS LIST 
     
         
         
           
               1 ,  2 ,  3 ,  4  communication port 
               11  Ethernet cable 
               12  in-vehicle network 
               100  relay device 
               110  relay processing unit 
               111  in-vehicle ECU 
               120  detection unit 
               130  authentication result acquisition unit 
               140  authentication unit 
               150  setting unit 
               160  storage unit 
               200  server 
               300  communication system