JP5690008B1 - Relay device, setting method, and computer program - Google Patents

Abstract

An apparatus, a method, and a program capable of reducing the labor of setting that occurs when a relay apparatus is connected in multiple stages in an office. A setting unit 105 of an HGW 10 or 20 sets its own device as a parent HGW based on information received from another device, or an instruction to operate as a child HGW from another parent HGW. If received, it sets itself as a child HGW. When the own device is the parent HGW, the packet reading unit 1071 that detects the presence of the HGW at the bottom by checking the header of the received packet, and the detected relay device operates as a child HGW And a parent relay unit 1072 that relays communication performed between the device located on the upstream side and the child HGW. When the own device is a child HGW, a child relay unit 1081 that relays communication performed between the communication device and the parent HGW is provided. [Selection] Figure 2

Description

  The present invention relates to a setting control technique related to connection of a relay device.

In recent years, usage scenes of wireless LAN (Local Area Network; for example, Wi-Fi (registered trademark) (Wireless Fidelity)) are increasing (for example, see Patent Document 1).
At present, HGW (Home Gate Way) with a built-in wireless LAN (Local Area Network) function is widespread. Since such an HGW has a BBR (Broad Band Router) function and a wireless LAN function, a single HGW can be connected to a network using a wireless LAN without purchasing a separate wireless LAN router. can do.

JP 2005-094656 A

  By the way, in a wide space such as an office, a single HGW cannot sufficiently cover the range. For this reason, when a wireless LAN is used in an office, a plurality of wireless LAN routers different from the HGW are prepared and connected to the HGW in multiple stages. In such a case, it is necessary to prepare a controller that collectively manages the settings of the wireless LAN routers, and to manually set the wireless LAN routers using the controller. For this reason, when the relay devices are connected in multiple stages in the office, the trouble as described above is generated. Such a problem is common to all relay devices such as wireless LAN routers and HGWs connected in multiple stages in an office.

  In view of the above circumstances, an object of the present invention is to provide a technique that can reduce the trouble that occurs when a relay device is connected in multiple stages in an office.

  One aspect of the present invention is a relay device that relays communication between an upstream side where an external network is located and a downstream side where a communication device is located, and based on information received from another device, If the own device is a parent relay device and the setting unit that sets the own device as either the parent relay device or the child relay device, it is located downstream from the own device based on information received from other devices A detection unit that detects a relay device, an instruction unit that transmits an instruction to operate as a child relay device to the relay device detected by the detection unit when the own device is a parent relay device, and the own device When it is a parent relay device, it relays communication performed between a device located upstream from the own device and the child relay device, and when the own device is a child relay device, the communication device belonging to the own device Relay communications performed with the parent relay device And a relay unit, the setting unit is a relay device for setting the child relaying apparatus own apparatus when the instruction transmitted from the other parent relay device is received.

  One aspect of the present invention is the relay device described above, wherein the detection unit detects a relay device located downstream of the own device when an IPv6 packet is received.

  One aspect of the present invention is the above-described relay device, wherein the detection unit detects a relay device located downstream from the own device when a packet requesting IPv4 identification information is received.

  One aspect of the present invention is a setting method in a relay device that relays communication between an upstream side where an external network is located and a downstream side where a communication device is located, and includes information received from other devices. Based on the setting step for setting the own device as either the parent relay device or the child relay device, and when the own device is the parent relay device, the downstream side from the own device based on the information received from the other device A detection step of detecting a relay device located at the position, and an instruction step of transmitting an instruction to operate as a child relay device to the relay device detected in the detection step when the own device is a parent relay device; When the own device is a parent relay device, the communication performed between the device located upstream from the own device and the child relay device is relayed. When the own device is a child relay device, the communication belonging to the own device Equipment and A relay step for relaying communications performed with the relay device, and when the instruction transmitted from another parent relay device is received in the setting step, the own device is set as a child relay device This is the setting method.

  One aspect of the present invention is a computer program for operating a computer as a relay device that relays communication between an upstream side where an external network is located and a downstream side where a communication device is located. Based on the information received from the setting step for setting the own device as either the parent relay device or the child relay device, and when the own device is the parent relay device, based on the information received from the other device A detection step for detecting a relay device located downstream from the own device, and an instruction to operate as a child relay device for the relay device detected in the detection step when the own device is a parent relay device. When an instruction step to transmit and the own device is a parent relay device, the communication between the device located upstream from the own device and the child relay device is relayed, and the own device is a child relay The relay step of relaying communication performed between the communication device belonging to the own device and the parent relay device, and the setting step is transmitted from another parent relay device. It is a computer program for setting its own device as a child relay device when the instruction is received.

  According to the present invention, it is possible to reduce time and effort required when connecting relay devices in multiple stages in an office.

It is a figure which shows the system configuration | structure of the relay system 100 in this invention. It is a schematic block diagram showing the function structure of HGW in 1st Embodiment. It is a figure which shows the specific example of a HGW information database. It is a flowchart which shows the flow of a process of parent HGW10 in 1st Embodiment. It is a flowchart which shows the flow of a process of HGW in 1st Embodiment. It is a sequence diagram which shows operation | movement of the relay system 100 in 1st Embodiment. It is a sequence diagram which shows operation | movement of the relay system 100 in 1st Embodiment. It is a schematic block diagram showing the function structure of HGW in 2nd Embodiment. It is a flowchart which shows the flow of a process of parent HGW10a in 2nd Embodiment. It is a flowchart which shows the flow of a process of the child HGW20a in 2nd Embodiment. It is a sequence diagram which shows operation | movement of the relay system 100 in 2nd Embodiment. It is a sequence diagram which shows operation | movement of the relay system 100 in 2nd Embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a system configuration of a relay system 100 according to the present invention. The relay system 100 of the present invention includes a parent HGW 10 (parent relay device), a plurality of child HGWs 20-1 and 20-2 (child relay devices), a repeater 30, an IPv6 router 40, and a control server 50. A communication device 60 is connected to the relay system 100. The parent HGW 10 and the IPv6 router 40 are communicably connected by PPPoE (Point-to-Point Protocol over Ethernet (registered trademark)).
In the following description, child HGWs 20-1 and 20-2 will be referred to as child HGW 20 unless otherwise distinguished. Further, in the following description, the parent HGW 10 and the child HGW 20 are simply referred to as HGW (relay device) unless otherwise distinguished.

  The parent HGW 10 communicates with the child HGW 20 via the repeater 30. Further, the parent HGW 10 communicates with the IPv6 router 40. For example, the parent HGW 10 transmits and receives ICMPv6 (Internet Control Message Protocol for IPv6) packets to and from the IPv6 router 40 using NDP (Neighbor Discovery Protocol). The ICMPv6 packet is, for example, an RS (Router solicitation) packet, an RA (Router advertisement) packet, an NS (Neighbor Solicitation) packet, and an NA (Neighbor Advertisement) packet.

The RS packet is one of IPv6 address automatic setting functions, and is a packet transmitted to request prefix information from the IPv6 router 40. The RA packet is a response packet to the RS packet. The NS packet is a packet transmitted to request resolution of the L2 address. The NA packet is a response packet to the NS packet.
The child HGW 20 relays communication performed between the parent HGW 10 and the communication device 60 belonging to the own device (child HGW 20). The child HGW 20 transmits and receives ICMPv6 packets to and from the IPv6 router 40 via the repeater 30 and the parent HGW 10. The child HGW 20 communicates with the communication device 60 through a wireless LAN connection. For example, Wi-Fi is used for the wireless LAN connection. The child HGW 20 communicates with the control server 50 via the repeater 30, the IPv6 router 40, the parent HGW 10, and the first network 70.

The repeater 30 is a relay device that relays communication between the parent HGW 10 and the child HGW 20. The repeater 30 is, for example, an L2 switch or an L2 bridge. Moreover, the repeater 30 relays communication between the child HGW 20 and the child HGW 20. In the case of FIG. 1, the repeater 30 relays communication between the child HGW 20-1 and the child HGW 20-2.
The IPv6 router 40 is a relay device that relays communication between the parent HGW 10 and the first network 70. When receiving the RS packet from the parent HGW 10, the IPv6 router 40 transmits an RA packet to the parent HGW 10 as a response. In this case, the IPv6 router 40 stores information (for example, a value of “0”) indicating that an IPv6 address is acquired in the stateless mode in the field of the M flag in the RA packet. That is, the IPv6 router 40 stores information (for example, a value of “0”) indicating that an IPv6 address is automatically generated in the M flag field in the RA packet.

The control server 50 controls each HGW (parent HGW 10 and child HGW 20). For example, the control server 50 controls setting changes such as SSID (Service Set Identifier), channel, and command of the child HGW 20.
The communication device 60 is configured using an information processing device such as a smartphone, a tablet terminal, a mobile phone, a personal computer, a notebook computer, or a game device. The communication device 60 communicates with the child HGW 20.

The first network 70 may be a network configured in any way. For example, the first network 70 may be configured using NGN (Next Generation Network).
The second network 80 may be a network configured in any way. For example, the second network 80 may be configured using the Internet.
Hereinafter, a specific configuration example (first embodiment and second embodiment) of the relay system 100 according to the present invention will be described.

[First Embodiment]
FIG. 2 is a schematic block diagram showing the functional configuration of the HGW in the first embodiment. The parent HGW 10 and the child HGW 20 have the same configuration. In addition, the HGW operates as either the parent HGW 10 or the child HGW 20 when the HGW described later is activated or during processing. The HGW is compatible with both IPv4 and IPv6.
The HGW includes a CPU (Central Processing Unit), a memory, an auxiliary storage device, and the like connected by a bus, and executes a relay program. By executing the relay program, the HGW can generate a packet generation unit 101, a first communication unit 102, a communication control unit 103, an address acquisition unit 104, a setting unit 105, an HGW information storage unit 106, a parent function unit 107, a child function unit 108, It functions as a device including the second communication unit 109. The parent function unit 107 functions as a packet reading unit 1071, a parent relay unit 1072, a child operation instruction unit 1073, and a DHCPv4 server function unit 1074. The child function unit 108 functions as a child relay unit 1081 and a connection control unit 1082. Note that all or part of the functions of the HGW may be realized by using hardware such as an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA). The relay program may be recorded on a computer-readable recording medium. The computer-readable recording medium is, for example, a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, or a storage device such as a hard disk built in the computer system. Further, the relay program may be transmitted / received via a telecommunication line.

The packet generator 101 generates various packets. Packets generated by the packet generator 101 are, for example, NS packets and RS packets.
The first communication unit 102 communicates with other devices (the repeater 30 or the IPv6 router 40). The first communication unit 102 includes an IPv4 interface 1021 and an IPv6 interface 1022. The IPv4 interface 1021 inputs / outputs data with other devices using IPv4. The IPv6 interface 1022 inputs / outputs data with other devices using IPv6. For example, the NS packet and the RS packet generated by the packet generation unit 101 are transmitted to another device (the repeater 30 or the IPv6 router 40) via the IPv6 interface 1022. For example, NA packets and RA packets transmitted from other devices (the repeater 30 or the IPv6 router 40) are received via the IPv6 interface 1022.

  The communication control unit 103 performs control according to the packet received by the first communication unit 102. For example, when the received packet is an NA packet addressed to the own apparatus, the communication control unit 103 instructs the packet generation unit 101 to generate an RS packet. For example, when the received packet is an RA packet addressed to the own apparatus, the communication control unit 103 outputs the received RA packet to the address acquisition unit 104.

  The address acquisition unit 104 acquires an IPv6 address used by the own device according to the value of the M flag field in the RA packet. For example, when the value of the M flag field in the RA packet is information (for example, a value of “0”) indicating that the IPv6 address is acquired in the stateless mode, the address acquisition unit 104 automatically generates the IPv6 address. More specifically, the address acquisition unit 104 generates an IPv6 address used by the own device based on the prefix information stored in the RA packet and the MAC address of the own device. On the other hand, when the value of the M flag field in the RA packet is information (for example, a value of “1”) indicating that an IPv6 address is acquired in the stateful mode, the address acquisition unit 104 uses DHCPv6 to create DHCPv6. Address information such as an IPv6 address (prefix + interface ID) is acquired from a server (not shown).

The setting unit 105 sets the own device based on information received from another device. Specifically, when the IPv6 address is generated by the own device, that is, when the value of the field of the M flag in the received RA packet is 0, the setting unit 105 sets the own device as the parent HGW 10. When a control signal including an instruction to operate as a child HGW 20 (hereinafter referred to as “child operation instruction”) is received from another HGW, the setting unit 105 sets the own apparatus as the child HGW 20.
The HGW information storage unit 106 is configured using a storage device such as a magnetic hard disk device or a semiconductor storage device. The HGW information storage unit 106 stores an HGW information database. The HGW information database is a database in which operation setting information for each HGW including its own device is registered.

FIG. 3 is a diagram showing a specific example of the HGW information database.
The HGW information database has a plurality of records 90 representing information on the HGW. The record 90 has each value of MAC_HGW, v6 address, v6 packet passage presence / absence, and status. The value of MAC_HGW represents the MAC address of the HGW (including the own device) existing on the same network of the own device. The value of the v6 address represents the IPv6 address of the HGW of the same record 90. The value indicating whether or not the v6 packet has passed indicates whether the HGW of the same record 90 has relayed the IPv6 packet to another HGW. The status value indicates whether the HGW of the same record 90 is a parent HGW 10 or a child HGW 20.

  In the example shown in FIG. 3, a plurality of MAC_HGWs are recorded in the HGW information database. These MAC_HGWs are “AAA”, “BBB”, and “CCC”. In FIG. 3, the record 90 recorded at the top of the HGW information database has a MAC_HGW value of “AAA”, a v6 address value of “XXX”, a v6 packet passage presence / absence value of “Yes”, and a status value. Is the “parent”. That is, it is indicated that the IPv6 address of the HGW identified by the MAC address “AAA” is “XXX”, the IPv6 packet is relayed to another HGW, and the HGW is the parent HGW 10.

  In FIG. 3, the record 90 recorded in the second row of the HGW information database has a MAC_HGW value of “BBB”, a v6 address value of “YYY”, a v6 packet passage presence / absence value of “none”, The status value is “child”. That is, the IPv6 address of the HGW identified by the MAC address “BBB” is “YYY”, the IPv6 packet is not relayed to another HGW, and the HGW is a child HGW 20.

Returning to FIG. 2, the description of the HGW will be continued.
The parent function unit 107 is a function unit that functions when the own device is the parent HGW 10. That is, when the own device is a child HGW 20, the parent function unit 107 does not function. Hereinafter, a specific configuration of the parent function unit 107 will be described.
The packet reading unit 1071 reads a packet received by the first communication unit 102 or the second communication unit 109. For example, the packet reading unit 1071 confirms the header of the packet received by the second communication unit 109, and if the packet is an IPv6 packet and an NS packet, the packet reading unit 1071 confirms that the HGW exists in the lower part of the own device. Detect. In this way, the packet reading unit 1071 has at least a function as a detection unit. Then, the packet reading unit 1071 outputs the NS packet to the parent relay unit 1072. Further, the packet reading unit 1071 instructs the child operation instruction unit 1073 to generate a control signal when an NS packet for duplicate detection of an IPv6 address is received.

The parent relay unit 1072 performs a relay process between the first communication unit 102 and the second communication unit 109.
The child operation instruction unit 1073 generates a control signal in accordance with an instruction from the packet reading unit 1071. The control signal includes a child operation instruction and HGW information stored in the HGW information database. As described above, the child operation instruction unit 1073 has at least a function as an instruction unit.
In response to a request from the communication device 60, the DHCPv4 server function unit 1074 assigns an IPv4 address to the requesting communication device 60.

The child function unit 108 is a function unit that functions when the own device is the child HGW 20. That is, when the own device is the parent HGW 10, the child function unit 108 does not function. Hereinafter, a specific configuration of the child function unit 108 will be described.
The child relay unit 1081 performs a relay process between the first communication unit 102 and the second communication unit 109.
The connection control unit 1082 controls the connection between the own device (child HGW 20) and the control server 50. More specifically, the connection control unit 1082 transmits the spontaneous packet to the control server 50 via the communication control unit 103, the first communication unit 102, the repeater 30, and the parent HGW 10. Further, the connection control unit 1082 changes the setting of the own device according to the control from the control server 50.

  The second communication unit 109 communicates with other devices (the repeater 30 or the communication device 60). The second communication unit 109 includes an IPv4 interface 1091 and an IPv6 interface 1092. The IPv4 interface 1091 inputs and outputs data with other devices (the repeater 30 or the communication device 60) using IPv4. The IPv6 interface 1092 performs input / output of data by IPv6 with other devices (the repeater 30 or the communication device 60).

FIG. 4 is a flowchart showing a process flow of the parent HGW 10 in the first embodiment.
The packet reading unit 1071 determines whether an NS packet has been received (step S101). Specifically, the packet reading unit 1071 determines whether the value of the Type field in the header of the packet received by the IPv6 interface 1092 of the second communication unit 109 is a value indicating an NS packet (for example, “135”). To determine. When the value of the Type field in the header of the received packet is 135, the packet reading unit 1071 determines that the received packet is an NS packet. On the other hand, when the value of the Type field in the header of the received packet is not 135, the packet reading unit 1071 determines that the received packet is not an NS packet. When the NS packet is not received (step S101—NO), the parent HGW 10 ends the process.
On the other hand, when the NS packet is received (step S101—YES), the packet reading unit 1071 outputs the NS packet to the parent relay unit 1072. The parent relay unit 1072 relays the NS packet to the IPv6 router 40 via the communication control unit 103 and the IPv6 interface 1022 (step S102).

The communication control unit 103 receives the NA packet transmitted from the IPv6 router 40 via the IPv6 interface 1022. The communication control unit 103 outputs the received NA packet to the parent relay unit 1072. The parent relay unit 1072 relays the NA packet to the device (for example, HGW) that is the transmission source of the NS packet via the IPv6 interface 1092 (step S103).
The packet reading unit 1071 receives the RS packet via the IPv6 interface 1092. The packet reading unit 1071 outputs the received RS packet to the parent relay unit 1072. The parent relay unit 1072 relays the RS packet to the IPv6 router 40 via the communication control unit 103 and the IPv6 interface 1022 (step S104).

The communication control unit 103 receives the RA packet transmitted from the IPv6 router 40 via the IPv6 interface 1022. The communication control unit 103 outputs the received RA packet to the parent relay unit 1072. The parent relay unit 1072 relays the RA packet to the device that is the transmission source of the RS packet via the IPv6 interface 1092 (step S105).
The packet reading unit 1071 determines whether an NS packet is received via the IPv6 interface 1092 (step S106). When the NS packet has not been received (step S106—NO), the parent HGW 10 returns to the process of step S106.

On the other hand, when the NS packet is received (step S106-YES), the packet reading unit 1071 determines whether or not the IPv6 address is included in the received NS packet (step S107). When the IPv6 address is not included (step S107—NO), the parent HGW 10 repeatedly executes the processes after step S102.
On the other hand, when the IPv6 address is included (step S107—YES), the packet reading unit 1071 instructs the child operation instruction unit 1073 to generate a control signal. The child operation instruction unit 1073 generates a control signal in accordance with an instruction from the packet reading unit 1071 (step S108). The control signal includes a child operation instruction. Thereafter, the child operation instruction unit 1073 transmits the generated control signal via the IPv6 interface 1092 to the device that is the transmission source of the NS packet received in step S106 (step S109).

FIG. 5 is a flowchart showing the flow of processing of the HGW in the first embodiment. In addition, in FIG. 5, the process which HGW sets an own apparatus to the child HGW20 is demonstrated.
The communication control unit 103 receives the control signal transmitted from the parent HGW 10 via the IPv6 interface 1022 (step S201). The communication control unit 103 determines whether or not a child operation instruction is included in the received control signal (step S202). When the child operation instruction is not included (step S202—NO), the HGW ends the process.
On the other hand, when a child operation instruction is included (step S202—YES), the communication control unit 103 outputs the received control signal to the setting unit 105. The setting unit 105 sets the own apparatus to the child HGW 20 according to the child operation instruction included in the output control signal (step S203). The setting unit 105 includes information indicating that it is a child HGW 20 in the status item of the record 90 corresponding to the MAC address of the own device among the records 90 of the HGW information database stored in the HGW information storage unit 106 (for example, The character string “child”).

  6 and 7 are sequence diagrams illustrating the operation of the relay system 100 according to the first embodiment. 6 and 7, the case where the number of HGWs is two (HGW1 and HGW2) and the number of communication devices 60 is one will be described. At the start of processing, the HGW 2 is connected to the IPv6 router 40 and the HGW 1 is not connected to the HGW 2.

  First, the packet generation unit 101 of the HGW 2 generates an NS packet at a predetermined timing (step S301). For example, the packet generation unit 101 generates an NS packet at the timing when its own device (HGW2) is connected to the IPv6 router 40 and activated. The communication control unit 103 transmits an NS packet to the IPv6 router 40 via the IPv6 interface 1022 (step S302).

The IPv6 router 40 receives the NS packet transmitted from the HGW 2. Thereafter, the IPv6 router 40 generates an NA packet addressed to the HGW 2 that is the transmission source of the NS packet as a response to the NS packet, and transmits the generated NA packet to the HGW 2 (step S303).
The communication control unit 103 of the HGW 2 receives the NA packet transmitted from the IPv6 router 40 via the IPv6 interface 1022. The communication control unit 103 confirms the destination of the received NA packet. Since the destination of the received NA packet is addressed to its own device, the communication control unit 103 instructs the packet generation unit 101 to generate an RS packet. The packet generation unit 101 generates an RS packet in response to an instruction from the communication control unit 103 (step S304). The packet generation unit 101 outputs the generated RS packet to the communication control unit 103. The communication control unit 103 transmits an RS packet to the IPv6 router 40 via the IPv6 interface 1022 (step S305).

  The IPv6 router 40 receives the RS packet transmitted from the HGW 2. Thereafter, the IPv6 router 40 generates an RA packet addressed to the HGW 2 that is the transmission source of the RS packet as a response to the RS packet, and transmits the generated RA packet to the HGW 2 (step S306). The IPv6 router 40 stores a value of 0 in the M flag field when generating the RA packet.

  The communication control unit 103 of the HGW 2 receives the RA packet transmitted from the IPv6 router 40 via the IPv6 interface 1022. The communication control unit 103 confirms the destination of the received packet. Since the destination of the received packet is addressed to its own device, the communication control unit 103 outputs the received RA packet to the address acquisition unit 104. The address acquisition unit 104 checks the value of the M flag field in the RA packet (step S307). Since the value of the M flag field is 0 (M flag is off), the address acquisition unit 104 generates an IPv6 address based on the prefix information stored in the RA packet and the MAC address of the own device ( Step S308). In this case, the setting unit 105 sets its own device as the parent HGW 10 (step S309).

  Thereafter, the setting unit 105 records information on the set contents in the HGW information storage unit 106. Specifically, the setting unit 105 first reads an HGW information database stored in the HGW information storage unit 106. Next, the setting unit 105 determines the MAC address of the own device, the IPv6 address generated in step S308, the presence / absence of v6 packet passage ("None" is recorded at the time of registration), and the status (character indicating parent) Record 90 including information on the column) is generated. Then, the setting unit 105 newly adds the generated record 90 to the read HGW information database.

  The address acquisition unit 104 detects duplication of the generated IPv6 address. Specifically, the address acquisition unit 104 instructs the packet generation unit 101 to generate an NS packet for performing IPv6 address duplication detection, and outputs the generated IPv6 address information to the packet generation unit 101. The packet generator 101 generates a duplicate detection NS packet using the IPv6 address information. The packet generation unit 101 outputs the generated NS packet for duplication detection to the communication control unit 103. The communication control unit 103 transmits an NS packet to the IPv6 router 40 via the IPv6 interface 1022 (step S310). The address acquisition unit 104 determines that the generated IPv6 address is not duplicated if an NA packet including a notification that the IPv6 address is duplicated is not received within a predetermined time (for example, 1 second). . If the IPv6 address is duplicated, the address acquisition unit 104 acquires the IPv6 address using DHCPv6.

  Next, when the HGW 1 is connected to the HGW 2 via the repeater 30 (not shown in FIGS. 6 and 7, the same applies hereinafter), the packet generation unit 101 of the HGW 1 generates an NS packet at a predetermined timing (step S311). ). For example, the packet generation unit 101 generates an NS packet at the timing when the own device (HGW1) is connected to the HGW2 via the repeater 30 and activated. The communication control unit 103 transmits an NS packet to the HGW 2 via the IPv6 interface 1022 (step S312).

  The HGW 2 receives the NS packet transmitted from the HGW 1 via the IPv6 interface 1092. Since the HGW 2 operates as the parent HGW 10, the second communication unit 109 outputs the received NS packet to the parent function unit 107. The packet reading unit 1071 included in the parent function unit 107 reads the output NS packet (step S313). For example, the packet reading unit 1071 confirms the header of the received packet, and if the packet is an IPv6 packet and an NS packet, it detects that the HGW exists at the lower part of the own device. Thereafter, the packet reading unit 1071 outputs the NS packet to the parent relay unit 1072. At this time, the packet reading unit 1071 sets the value recorded in the item of presence / absence of v6 packet passage of the record 90 corresponding to the MAC address of the own device among the records 90 registered in the HGW information database from “none”. Change to “Yes”. The parent relay unit 1072 transmits the NS packet to the IPv6 router 40 via the communication control unit 103 and the IPv6 interface 1022 (step S314).

The IPv6 router 40 receives the NS packet transmitted from the HGW 2. Thereafter, the IPv6 router 40 generates an NA packet addressed to the HGW 1 that is the transmission source of the NS packet as a response to the NS packet, and transmits the generated NA packet to the HGW 2 (step S315).
The communication control unit 103 of the HGW 2 receives the NA packet transmitted from the IPv6 router 40 via the IPv6 interface 1022. The communication control unit 103 confirms the destination of the received NA packet. Since the destination of the received NA packet is not addressed to its own device, the communication control unit 103 outputs the received NA packet to the parent relay unit 1072. The parent relay unit 1072 transmits the NA packet to the HGW 1 via the IPv6 interface 1092 (Step S316).

  The communication control unit 103 of the HGW 1 receives the NA packet transmitted from the HGW 2 via the IPv6 interface 1022. The communication control unit 103 confirms the destination of the received NA packet. Since the destination of the received NA packet is addressed to its own device, the communication control unit 103 instructs the packet generation unit 101 to generate an RS packet. The packet generation unit 101 generates an RS packet in response to an instruction from the communication control unit 103 (step S317). The packet generation unit 101 outputs the generated RS packet to the communication control unit 103. The communication control unit 103 transmits an RS packet to the HGW 2 via the IPv6 interface 1022 (step S318).

The HGW 2 receives the RS packet transmitted from the HGW 1 via the IPv6 interface 1092. The IPv6 interface 1092 outputs the received RS packet to the packet reading unit 1071. The packet reading unit 1071 reads the output RS packet. For example, the packet reading unit 1071 confirms the header of the received packet, and outputs the RS packet to the parent relay unit 1072 because the packet is an RS packet. The parent relay unit 1072 transmits the RS packet to the IPv6 router 40 via the communication control unit 103 and the IPv6 interface 1022 (step S319).
The IPv6 router 40 receives the RS packet transmitted from the HGW 2. Thereafter, the IPv6 router 40 generates an RA packet addressed to the HGW 1 that is the transmission source of the RS packet as a response to the RS packet, and transmits the generated RA packet to the HGW 2 (step S320). The IPv6 router 40 stores a value of 0 in the M flag field when generating the RA packet.

  The communication control unit 103 of the HGW 2 receives the RA packet transmitted from the IPv6 router 40 via the IPv6 interface 1022. The communication control unit 103 confirms the destination of the received RA packet. Since the destination of the received RA packet is not addressed to the own apparatus, the communication control unit 103 outputs the received RA packet to the parent function unit 107. The parent relay unit 1072 transmits the RA packet to the HGW 1 via the IPv6 interface 1092 (step S321).

  The communication control unit 103 of the HGW 1 receives the RA packet transmitted from the HGW 2 via the IPv6 interface 1022. The communication control unit 103 confirms the destination of the received RA packet. Since the destination of the received RA packet is addressed to its own device, the communication control unit 103 outputs the received RA packet to the address acquisition unit 104. The address acquisition unit 104 checks the value of the M flag field in the RA packet (step S322). Since the value of the M flag field is 0 (M flag is off), the address acquisition unit 104 generates an IPv6 address based on the prefix information stored in the RA packet and the MAC address of the own device ( Step S323). In this case, the setting unit 105 sets the own device as the parent HGW 10 (step S324).

  Thereafter, the setting unit 105 records the set information in the HGW information storage unit 106. Specifically, the setting unit 105 first reads an HGW information database stored in the HGW information storage unit 106. Next, the setting unit 105 determines the MAC address of the device, the IPv6 address generated in step S323, whether or not the v6 packet passes (when registered, “none” is recorded), and the status (character indicating the parent). Record 90 including information on the column) is generated. Then, the setting unit 105 newly adds the generated record 90 to the read HGW information database.

  The address acquisition unit 104 detects duplication of the generated IPv6 address. The packet generator 101 generates a duplicate detection NS packet using the IPv6 address information. The packet generation unit 101 outputs the generated NS packet for duplication detection to the communication control unit 103. The communication control unit 103 transmits the generated NS packet to the HGW 2 via the IPv6 interface 1022 (step S325). The address acquisition unit 104 determines that the generated IPv6 address is not duplicated if an NA packet including a notification that the IPv6 address is duplicated is not received within a predetermined time (for example, 1 second). .

  The HGW 2 receives the NS packet transmitted from the HGW 1 via the IPv6 interface 1092. The second communication unit 109 outputs the received NS packet to the parent function unit 107. The packet reading unit 1071 included in the parent function unit 107 reads the output NS packet (step S326). For example, the packet reading unit 1071 confirms whether the received NS packet includes an IPv6 address. When the IPv6 address is included in the NS packet, the packet reading unit 1071 instructs the child operation instruction unit 1073 to generate a control signal.

  Further, the packet reading unit 1071 acquires the information of the transmission source MAC address and the IPv6 address from the NS packet. The packet reading unit 1071 records the acquired source MAC address and IPv6 address information in the HGW information database. Specifically, first, the packet reading unit 1071 reads the HGW information database stored in the HGW information storage unit 106. Next, the setting unit 105 checks that the source MAC address, IPv6 address, v6 packet passage presence / absence (recorded as “none” is recorded at the time of registration), and status (child) in the record 90 of the read HGW information database. Information) is newly recorded.

  The child operation instruction unit 1073 generates a control signal in accordance with an instruction from the packet reading unit 1071 (step S327). The control signal includes a child operation instruction and HGW information recorded in the HGW information database. The child operation instruction unit 1073 transmits a control signal to the HGW 1 via the IPv6 interface 1092 (step S328).

  The communication control unit 103 of the HGW 1 receives a control signal transmitted from the HGW 2 via the IPv6 interface 1022. The communication control unit 103 confirms the destination of the received control signal. Since the destination of the received control signal is addressed to its own device, the communication control unit 103 outputs the received control signal to the setting unit 105. The setting unit 105 sets the own apparatus to the child HGW 20 according to the child operation instruction included in the control signal (step S329).

  Thereafter, the setting unit 105 updates the value recorded in the HGW information storage unit 106 based on the set information. Specifically, the setting unit 105 first reads an HGW information database stored in the HGW information storage unit 106. Next, the setting unit 105 selects a record 90 corresponding to the MAC address of the own device from the records 90 of the read HGW information database. Then, the setting unit 105 updates the value recorded in the status item of the selected record 90 to information indicating that it operates as the child HGW 20 (for example, a character string “child”). In addition, the setting unit 105 records information (MAC_HGW, IPv6 address, v6 packet passage presence / absence and status) regarding other HGWs included in the control signal in the HGW information database.

  The HGW 1 communicates with the control server 50 via the HGW 2 and the IPv6 router 40 (step S330). For example, the HGW 1 receives setting change information transmitted from the control server 50 via the IPv6 interface 1022. The connection control unit 1082 changes the setting of the own device according to the setting change information.

  The communication device 60 requests the IPv4 address from the HGW 1 to which the own device (communication device 60) belongs (step S331). The HGW 1 receives the request transmitted from the communication device 60 via the IPv4 interface 1091. Since the HGW 1 operates as the child HGW 20, the IPv4 interface 1091 outputs the received request to the child function unit 108. The child relay unit 1081 included in the child function unit 108 relays the output request to the HGW 2 via the IPv4 interface 1021 (step S332).

The HGW 2 receives the request relayed from the HGW 1 via the IPv4 interface 1091. The DHCPv4 server function unit 1074 assigns an IPv4 address to the communication device 60 that is the request source in response to the relayed request. The DHCPv4 server function unit 1074 transmits information on the allocated IPv4 address to the HGW 1 via the IPv4 interface 1091 (step S333).
The HGW 1 receives the IPv4 address information transmitted from the HGW 2 via the IPv4 interface 1021. The IPv4 interface 1021 outputs the received IPv4 address information to the IPv4 interface 1091 via the communication control unit 103 and the child relay unit 1081. The IPv4 interface 1091 transmits the IPv4 address information to the communication device 60 that is the source of the IPv4 address request (step S334).

  In the HGW configured as described above, since the IPv6 address is automatically generated by the own device, any HGW first operates as the parent HGW 10. Thereafter, the parent HGW 10 changes the operation setting of the own device depending on whether or not the IPv6 packet such as the NS packet or the RS packet is relayed. Specifically, the parent HGW 10 detects the HGW existing at the lower part of its own device by relaying the IPv6 packet. In this case, the parent HGW 10 transmits a control signal including a child operation instruction to the HGW existing below the own device. As a result, the HGW that has received the control signal is changed from the parent HGW 10 to the child HGW 20. In this way, the HGW can automatically change the operation setting according to the connected situation. When the own device is the parent HGW 10, it functions as a relay that relays communication between the IPv6 router 40 and the child HGW 20. When the own device is the child HGW 20, it communicates with the parent HGW 10. It functions as a relay that relays communications performed with the device 60. For this reason, it is possible to reduce the labor required when connecting the relay devices in multiple stages in the office.

  In addition, since an HGW having the same configuration can be used, an operator providing this system can sell the HGW as a wireless LAN router for office use. In addition, with the increase in the number of HGWs procured, businesses that provide this system can negotiate prices that reduce the housing cost per HGW.

<Modification>
In the present embodiment, the configuration in which the relay system 100 includes two child HGWs 20 has been described. However, the relay system 100 may be configured to include one child HGW 20 or may include three or more child HGWs 20. It may be configured as follows.
In the present embodiment, the HGW has been described as an example, but it is not necessary to be limited to the HGW. For example, an access point with a broadband router function may be configured to have the same configuration as the HGW.
[Second Embodiment]
FIG. 8 is a schematic block diagram showing the functional configuration of the HGW in the second embodiment. The parent HGW 10a and the child HGW 20a have the same configuration.
The HGW includes a CPU, a memory, an auxiliary storage device, and the like connected by a bus and executes a relay program. By executing the relay program, the HGW can generate a packet generation unit 101, a first communication unit 102, a communication control unit 103, an address acquisition unit 104, a setting unit 105a, an HGW information storage unit 106, a parent function unit 107a, a child function unit 108, It functions as a device including the second communication unit 109 and the DHCPv4 client function unit 110. The parent function unit 107a functions as a packet reading unit 1071a, a parent relay unit 1072, and a DHCPv4 server function unit 1074a. The child function unit 108 functions as a child relay unit 1081 and a connection control unit 1082. All or some of the functions of the HGW may be realized using hardware such as an ASIC, PLD, or FPGA. The relay program may be recorded on a computer-readable recording medium. The computer-readable recording medium is, for example, a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, or a storage device such as a hard disk built in the computer system. Further, the relay program may be transmitted / received via a telecommunication line.

  The HGW in the second embodiment is different from the HGW in the first embodiment in that the setting unit 105a, the parent function unit 107a, and the DHCPv4 client function unit 110 are provided instead of the setting unit 105 and the parent function unit 107. The HGW in the second embodiment is the same as the HGW in the first embodiment with respect to other configurations. Therefore, description of the entire HGW in the second embodiment is omitted, and the setting unit 105a, the parent function unit 107a, and the DHCPv4 client function unit 110 will be described.

  The setting unit 105a sets its own device based on information received from another device. Specifically, when the IPv6 address is generated by the own device, that is, when the value of the M flag field in the received RA packet is 0, the setting unit 105a sets the own device to the parent HGW 10. In addition, when DHCPv4-Ack including a child operation instruction is received from another HGW, the setting unit 105a sets its own device as the child HGW 20.

The parent function unit 107a is a function unit that functions when the own device is the parent HGW 10a. That is, when the own device is the child HGW 20a, the parent function unit 107a does not function. Hereinafter, a specific configuration of the parent function unit 107a will be described.
The packet reading unit 1071a reads a packet received by the first communication unit 102 and the second communication unit 109. For example, when the packet received via the IPv4 interface 1091 is DHCPv4-Discover, the packet reading unit 1071a detects that the HGW exists in the lower part of the own device. In this way, the packet reading unit 1071a has at least a function as a detection unit. DHCPv4-Discover is a packet that is transmitted when an IPv4 address is requested. Then, the packet reading unit 1071a outputs DHCPv4-Discover to the DHCPv4 server function unit 1074a.

The parent relay unit 1072 performs a relay process between the first communication unit 102 and the second communication unit 109.
The DHCPv4 server function unit 1074a assigns an IPv4 address to another HGW or communication device 60 that is a request source in response to a request from another HGW or communication device 60.
The DHCPv4 client function unit 110 requests an IPv4 address using the DHCPv4 client function. For example, the DHCPv4 client function unit 110 requests an IPv4 address from the IPv6 router 40 when the own apparatus is connected to the IPv6 router 40. For example, when the own device is connected to another HGW, the DHCPv4 client function unit 110 requests an IPv4 address from another HGW located in a layer one level higher than the own device.

FIG. 9 is a flowchart showing the flow of processing of the parent HGW 10a in the second embodiment.
The packet reading unit 1071a receives DHCPv4-Discover transmitted from another device (for example, another HGW) via the IPv4 interface 1091 (step S401). The packet reading unit 1071a outputs the received DHCPv4-Discover to the DHCPv4 server function unit 1074a. The DHCPv4 server function unit 1074a generates DHCPv4-Offer (step S402). DHCPv4-Offer is a packet including information on an assignable IPv4 address. The DHCPv4 server function unit 1074a transmits DHCPv4-Offer to a device (for example, another HGW) that is a transmission source of DHCPv4-Discoverer via the IPv4 interface 1091 (step S403).

Next, the packet reading unit 1071a receives the DHCPv4-Request transmitted from another device via the IPv4 interface 1091 (step S404). DHCPv4-Request is a packet transmitted to notify that the IPv4 address included in DHCPv4-Offer is used. The packet reading unit 1071a outputs the received DHCPv4-Request to the DHCPv4 server function unit 1074a. The DHCPv4 server function unit 1074a generates DHCPv4-Ack (step S405). DHCPv4-Ack is a response packet of DHCPv4-Request. The DHCPv4 server function unit 1074a gives a child operation instruction to Vendor-Specific-content in IE (Information Element) defined in DHCPv4-Ack. Thus, the DHCPv4 server function unit 1074a has at least a function as an instruction unit. Further, DHCPv4-Ack includes HGW information stored in the HGW database in addition to the child operation instruction.
The DHCPv4 server function unit 1074a transmits DHCPv4-Ack to the device (for example, another HGW) that is the transmission source of the DHCPv4-Request via the IPv4 interface 1091 (step S406).

FIG. 10 is a flowchart showing the flow of processing of the child HGW 20a in the second embodiment. In addition, in FIG. 10, the process which HGW sets an own apparatus to the child HGW20a is demonstrated.
The DHCPv4 client function unit 110 generates DHCPv4-Discover (step S501). The DHCPv4 client function unit 110 transmits DHCPv4-Discover to the parent HGW 10a via the communication control unit 103 and the IPv4 interface 1021 (step S502). The communication control unit 103 receives the DHCPv4-Offer transmitted from the parent HGW 10a via the IPv4 interface 1021 (Step S503). When DHCPv4-Offer is received, the DHCPv4 client function unit 110 generates DHCPv4-Request (step S504). Then, the DHCPv4 client function unit 110 transmits DHCPv4-Request to the parent HGW 10a via the communication control unit 103 and the IPv4 interface 1021 (step S505).

The communication control unit 103 receives DHCPv4-Ack from the parent HGW 10a via the IPv4 interface 1021 (step S506). Thereby, HGW acquires an IPv4 address. The acquired IPv4 address is set in the IPv4 interface 1021. The communication control unit 103 determines whether or not the received DHCPv4-Ack includes a child operation instruction (step S507). When the child operation instruction is not included (step S507: NO), the HGW ends the process.
On the other hand, when the child operation instruction is included (step S507: YES), the communication control unit 103 outputs the received DHCPv4-Ack to the setting unit 105a. The setting unit 105a sets the own apparatus as the child HGW 20a in accordance with the child operation instruction included in DHCPv4-Ack (step S508).

  11 and 12 are sequence diagrams illustrating the operation of the relay system 100 according to the second embodiment. In the description of FIGS. 11 and 12, a case where the number of HGWs is two (HGW 1a and HGW 2a) and the number of communication devices 60 is one will be described. At the start of processing, the HGW 2a is connected to the IPv6 router 40, and the HGW 1a is not connected to the HGW 2a. Moreover, about the process similar to FIG.6 and FIG.7, the code | symbol similar to FIG.6 and FIG.7 is attached | subjected in FIG.11 and FIG.12, and description is abbreviate | omitted.

  When the processing up to step S325 is completed, the HGW 2a receives the NS packet transmitted from the HGW 1a via the IPv6 interface 1092. The second communication unit 109 outputs the received NS packet to the parent function unit 107a. The parent relay unit 1072 transmits an NS packet to the IPv6 router 40 via the communication control unit 103 and the IPv6 interface 1022 (step S601).

Thereafter, the DHCPv4 client function unit 110 generates DHCPv4-Discover (step S602). The DHCPv4 client function unit 110 transmits DHCPv4-Discover to the HGW 2 via the communication control unit 103 and the IPv4 interface 1021 (step S603).
The HGW 2a receives the DHCPv4-Discover transmitted from the HGW 1a via the IPv4 interface 1091. The packet reading unit 1071a outputs the received DHCPv4-Discover to the DHCPv4 server function unit 1074a. The DHCPv4 server function unit 1074a generates DHCPv4-Offer (step S604). The DHCPv4 server function unit 1074a transmits DHCPv4-Offer to the HGW 1a that is the transmission source of the DHCPv4-Discoverer via the IPv4 interface 1091 (step S605).

  The communication control unit 103 of the HGW 1a receives DHCPv4-Offer transmitted from the HGW 2a via the IPv4 interface 1021. When DHCPv4-Offer is received, the DHCPv4 client function unit 110 generates DHCPv4-Request (step S606). Then, the DHCPv4 client function unit 110 transmits DHCPv4-Request to the HGW 2a via the communication control unit 103 and the IPv4 interface 1021 (step S607).

  The HGW 2a receives the DHCPv4-Request transmitted from the HGW 1a via the IPv4 interface 1091. The packet reading unit 1071a outputs the received DHCPv4-Request to the DHCPv4 server function unit 1074a. The DHCPv4 server function unit 1074a generates DHCPv4-Ack (step S608). The DHCPv4 server function unit 1074a gives a child operation instruction to DHCPv4-Ack. The DHCPv4 server function unit 1074a transmits DHCPv4-Ack to the HGW 1a that is the transmission source of the DHCPv4-Request via the IPv4 interface 1091 (step S609).

  The communication control unit 103 of the HGW 1a receives DHCPv4-Ack from the HGW 2a via the IPv4 interface 1021. The communication control unit 103 outputs the received DHCPv4-Ack to the setting unit 105a. The setting unit 105a sets the own apparatus as the child HGW 20a in response to the child operation instruction included in DHCPv4-Ack (step S610).

  Thereafter, the setting unit 105a records information on the set contents in the HGW information storage unit 106. Specifically, the setting unit 105a first determines the MAC address, IPv6 address, presence / absence of v6 packet passing (recorded as “none” at the time of registration), and status (character string indicating child HGW 20a). For example, the record 90 including the information of the child)) is generated. Then, the setting unit 105a newly adds the generated record 90 to the read HGW information database.

  In addition, the setting unit 105 a records information (HGW information) regarding the setting content of the HGW included in the received child operation instruction in the HGW information storage unit 106. Specifically, first, the setting unit 105 a reads an HGW information database stored in the HGW information storage unit 106. Next, the setting unit 105a generates the records 90 including the MAC address, IPv6 address, v6 packet passing / non-passing status, and status information of other HGWs included in the HGW information for the number of HGWs included in the HGW information. Then, the setting unit 105a newly adds the generated record 90 to the read HGW information database. Thereafter, the processing from step S330 to step S334 is executed.

  In the HGW configured as described above, since the IPv6 address is automatically generated by the own device, any HGW first operates as the parent HGW 10a. Thereafter, the parent HGW 10a detects the HGW existing at the lower part of its own device by receiving DHCPv4-Discover. In this case, the parent HGW 10a transmits a control signal including a child operation instruction to the HGW existing below the own device. Thereby, the operation setting of the HGW that has received the control signal is changed from the parent HGW 10a to the child HGW 20a. In this way, the HGW can automatically change the operation setting according to the connected situation. When the own device is the parent HGW 10a, it functions as a relay that relays communication performed between the IPv6 router 40 and the child HGW 20a. When the own device is the child HGW 20a, the device communicates with the parent HGW 10a. It functions as a relay that relays communications performed with the device 60. For this reason, it is possible to reduce the labor required when connecting the relay devices in multiple stages in the office.

  In addition, since an HGW having the same configuration can be used, an operator providing this system can sell the HGW as a wireless LAN router for office use. In addition, with the increase in the number of HGWs procured, businesses that provide this system can negotiate prices that reduce the housing cost per HGW.

<Modification>
In the present embodiment, the configuration in which the DHCPv4 server function unit 1074a gives a child operation instruction to DHCPv4-Ack is shown. However, the DHCPv4 server function unit 1074a may be configured to give a child operation instruction to DHCPv4-Offer. . When configured in this way, the communication control unit 103 of the HGW that has received DHCPv4-Offer from the parent HGW 10a notifies the setting unit 105a that it operates on the child HGW 20a. The setting unit 105a sets the operation setting of the own device from the parent HGW 10a to the child HGW 20a in response to the notification from the communication control unit 103.

  In this embodiment (second embodiment), an example is shown in which the IPv6 router 40 stores information (for example, a value of “0”) indicating that an IPv6 address is automatically generated in the M flag field in the RA packet. However, the IPv6 router 40 may be configured to store information (for example, a value of “1”) indicating that the IPv6 address is acquired by DHCPv6 in the M flag field in the RA packet. In such a configuration, the address acquisition unit 104 of the HGW connected to the IPv6 router 40 uses DHCPv6 to send address information (for example, an IPv6 address (prefix + interface ID)) from a DHCPv6 server (not shown). And IPv4 address and phone number information for Hikari Denwa). In addition, when an IPv6 address is acquired using DHCPv6, the setting unit 105a sets the own device as the parent HGW 10. And when comprised in this way, the parent function part 107a may be comprised so that a Hikari telephone function part may be provided. In response to a request from the communication device 60, the Hikari Telephone function unit provides an IP telephone connection service using information on the IPv4 address and telephone number for Hikari Telephone.

When configured in this way, the child HGW 20a transfers a request for using the Hikari Telephone to the parent HGW 10a in response to a request from the user of the communication device 60, and the parent HGW 10a provides the IP phone connection service to the communication device 60. To do. That is, the child HGW 20a functions as a bridge, and the parent HGW 10a provides the IP telephone connection service to the user of the communication device 60. Therefore, even when the HGWs having the same configuration are connected in multiple stages, the telephone function that the HGW originally has can be used.
In the present embodiment, the HGW has been described as an example, but it is not necessary to be limited to the HGW. For example, an access point with a broadband router function may be configured to have the same configuration as the HGW.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10, 10a ... Parent HGW, 20 (20-1, 20-2), 20a ... Child HGW, 30 ... Repeater, 40 ... IPv6 router, 50 ... Control server, 60 ... Communication apparatus, 70 ... First network (external) Network), 80 ... second network, 101 ... packet generation unit, 102 ... first communication unit, 1021 ... IPv4 interface, 1022 ... IPv6 interface, 103 ... communication control unit, 104 ... address acquisition unit, 105, 105a ... setting unit 106, HGW information storage unit, 107, 107a ... parent function unit, 1071, 1071a ... packet reading unit (detection unit), 1072 ... parent relay unit, 1073 ... child operation instruction unit, 1074, 1074a ... DHCPv4 server function unit, 108 ... Child function part, 1081 ... Child relay part, 1082 ... Connection control unit, 109 ... second communication unit, 1091 ... IPv4 interface, 1092 ... IPv6 interface, 110 ... DHCPv4 client function unit

Claims (5)

A relay device that relays communication between an upstream side where an external network is located and a downstream side where a communication device is located,
Based on information received from other devices, a setting unit that sets the own device to either the parent relay device or the child relay device;
When the own device is a parent relay device, based on information received from other devices, a detection unit that detects a relay device located downstream from the own device;
When the own device is a parent relay device, an instruction unit that transmits an instruction to operate as a child relay device to the relay device detected by the detection unit;
When the own device is a parent relay device, it relays communications performed between the device located on the upstream side of the own device and the child relay device. When the own device is a child relay device, it belongs to the own device. A relay unit that relays communication performed between the communication device and the parent relay device;
With
The setting unit is a relay device that sets the own device as a child relay device when the instruction transmitted from another parent relay device is received.   The relay device according to claim 1, wherein when the IPv6 packet is received, the detection unit detects a relay device located downstream from the own device.   The relay device according to claim 1, wherein the detection unit detects a relay device located downstream from the own device when a packet requesting identification information of IPv4 is received. A setting method in a relay device that relays communication between an upstream side where an external network is located and a downstream side where a communication device is located,
Based on information received from other devices, a setting step for setting the own device as either a parent relay device or a child relay device;
When the own device is a parent relay device, based on information received from another device, a detection step of detecting a relay device located downstream from the own device;
If the own device is a parent relay device, an instruction step for transmitting an instruction to operate as a child relay device to the relay device detected in the detection step;
When the own device is a parent relay device, the communication performed between the device located upstream from the own device and the child relay device is relayed. When the own device is a child relay device, the communication belonging to the own device A relay step for relaying communication performed between the device and the parent relay device;
Have
A setting method for setting the own apparatus as a child relay apparatus when the instruction transmitted from another parent relay apparatus is received in the setting step. A computer program for operating a computer as a relay device that relays communication between an upstream side where an external network is located and a downstream side where a communication device is located,
Based on information received from other devices, a setting step for setting the own device as either a parent relay device or a child relay device;
When the own device is a parent relay device, based on information received from another device, a detection step of detecting a relay device located downstream from the own device;
If the own device is a parent relay device, an instruction step for transmitting an instruction to operate as a child relay device to the relay device detected in the detection step;
When the own device is a parent relay device, the communication performed between the device located upstream from the own device and the child relay device is relayed. When the own device is a child relay device, the communication belonging to the own device A relay step for relaying communication performed between the device and the parent relay device;
To the computer,
A computer program for setting the own device as a child relay device when the instruction transmitted from another parent relay device is received in the setting step.

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