JP6101149B2 - Relay device, relay method, and computer program - Google Patents

Description

  The present invention relates to an IPv4 / IPv6 conversion technology.

  2. Description of the Related Art Conventionally, with the widespread use of terminal devices that communicate using IPv6 (Internet Protocol Version 6) (hereinafter referred to as “IPv6 terminals”), terminal devices that perform communication using IPv4 (hereinafter referred to as “IPv4 terminals”). It is desired to make it possible to use the IPv6 service. In response to such a request, the IPv4 / IPv6 translator is used to translate not only the address but also the protocol itself between IPv4 and IPv6 (hereinafter referred to as “IPv4 / IPv6 translation”), even from an IPv4 terminal. A technique for using an IPv6 service has been proposed (see, for example, Patent Document 1).

JP 2005-286948 A

  However, in the technique of Patent Document 1, in response to a name resolution request from an IPv4 terminal, a GW (Gate Way) device functioning as a DNS proxy dynamically sends an IPv4 name resolution request and an IPv6 name resolution request to a DNS server. Inquires about the IP address. As a result, when the GW apparatus determines that communication using the IPv4 / IPv6 translator is necessary according to the name resolution response, communication is performed using the IPv4 / IPv6 translator regardless of the user's intention. End up. For this reason, there is a problem that the user cannot notice that communication is being performed after IPv4 / IPv6 conversion. When such a problem occurs, the user cannot recognize that it is necessary to establish an IPv6 connection. As a result, there is a possibility that communication cannot be performed when the IPv6 connection is not established.

  In view of the above circumstances, an object of the present invention is to provide a technology that makes a user aware of the use of IPv4 / IPv6 conversion.

One aspect of the present invention is a communication unit that receives data from a terminal device, and a notification that confirms whether to perform communication using IPv4 / IPv6 conversion based on the data received by the communication unit. comprising a conversion notifying unit for transmitting device, wherein the conversion notification section, when notification that performs communication using a IPv4 / IPv6 conversion is received by the communication unit, the relative said data IPv4 / This is a relay device that performs IPv6 conversion and transmits the converted data to another device .

  One aspect of the present invention is the relay device described above, which stores IPv4 identification information, IPv6 identification information, and information indicating whether communication using IPv4 / IPv6 conversion is effective in association with each other. A conversion table storage unit, and the conversion notification unit transmits the notification to the terminal device when communication using IPv4 / IPv6 conversion is not effective, and communication using IPv4 / IPv6 conversion is effective In this case, IPv4 / IPv6 conversion is performed, and the converted data is transmitted to another device.

One aspect of the present invention is the relay device described above, and when a notification indicating that communication using the IPv4 / IPv6 conversion is performed is received from the terminal device, an FQDN (Fully Qualified Domain) indicating a destination of the data is provided. When the IPv4 name resolution request is received from the terminal device and the IPv4 name resolution request FQDN is recorded in the destination identification information table storage unit. If the IPv4 name resolution request FQDN is recorded, the IPv4 identification information is not queried. If the IPv4 name resolution request FQDN is not recorded, the IPv4 identification is not identified. And a request unit for inquiring information and IPv6 identification information.

One aspect of the present invention is the relay device described above, in which, when data addressed to the FQDN recorded in the destination identification information table storage unit is received, an IPv4 or IPv6 connection is not established. Further includes a connection notification unit for notifying that the terminal device needs to be connected.

One aspect of the present invention is a communication step for receiving data from a terminal device, and a notification for confirming whether or not to perform communication using IPv4 / IPv6 conversion based on the data received by the communication step. possess a conversion notification transmitting device, and in the conversion notification step, the notification of performing communication using the IPv4 / IPv6 conversion is received in the communication step, the to the data IPv4 This is a relay method that performs / IPv6 conversion and transmits the converted data to another device .

One aspect of the present invention is a communication step for receiving data from a terminal device, and a notification for confirming whether or not to perform communication using IPv4 / IPv6 conversion based on the data received by the communication step. A conversion notification step to be transmitted to the device; and in the conversion notification step, when a notification indicating that communication is performed using IPv4 / IPv6 conversion is received in the communication step, It performs the IPv4 / IPv6 conversion is because of a computer program to transmit the converted data to another device.

  According to the present invention, it is possible to make the user aware of the use of IPv4 / IPv6 conversion.

It is a figure which shows the system configuration | structure of the radio | wireless communications system in this embodiment. It is a schematic block diagram showing the functional composition of HGW30 in this embodiment. It is a figure which shows the specific example of a FQDN table and a conversion table. It is a figure which shows an example of the example of a display of a usage confirmation image. It is a figure which shows an example of the example of a display of a connection notification image. It is a flowchart which shows the process of the DNS proxy part 305 in this embodiment. It is a flowchart which shows the process of the transfer control part 303 in this embodiment. It is a sequence diagram which shows the operation | movement of the IPv4 / IPv6 conversion process in this embodiment. It is a sequence diagram which shows the operation | movement of the IPv4 / IPv6 conversion process in this embodiment. It is a sequence diagram which shows the operation | movement of the IPv4 / IPv6 conversion process in this 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 wireless communication system in the present embodiment. The wireless communication system of the present embodiment includes one or a plurality of IPv4 terminals 10 (10-1 to 10-N: N is an integer equal to or greater than 1), a v4 DNS server 20-1, a v6 DNS server 20-2, an HGW 30, a network 40, and A target server 50 is provided.

The IPv4 terminal 10 is configured using an information processing device such as a smartphone, a mobile phone, a PDA (Personal Digital Assistant), a portable game device, a tablet device, or a notebook personal computer. The IPv4 terminal 10 communicates with the network 40 via the HGW 30. The IPv4 terminal 10 transmits an IPv4 name resolution request (hereinafter referred to as “v4 name resolution request”) to, for example, the HGW 30.
The v4 DNS server 20-1 is configured using an information processing device. The v4 DNS server 20-1 performs IPv4 name resolution.
The v6 DNS server 20-2 is configured using an information processing device. The v6 DNS server 20-1 performs IPv6 name resolution.

  The HGW 30 communicates with the IPv4 terminal 10 (hereinafter referred to as “attached terminal”) belonging to the own apparatus (HGW 30). The HGW 30 performs communication with communication devices connected to the network 40. Specific examples of communication devices connected to the network 40 include a v4 DNS server 20-1, a v6 DNS server 20-2, and a target server 50. The HGW 30 performs a relay process for communication between the belonging terminal and the communication device connected to the network 40.

The network 40 may be a network configured in any way. For example, the network 40 may be configured using an IPv4 network or an IPv6 network.
The target server 50 is configured using an information processing apparatus. The target server 50 is an IPv6 server that the IPv4 terminal 10 desires to connect to.

FIG. 2 is a schematic block diagram showing a functional configuration of the HGW 30 in the present embodiment.
The HGW 30 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 30 causes the communication unit 301, conversion table storage unit 302, transfer control unit 303, FQDN (Fully Qualified Domain Name) table storage unit (destination identification information table storage unit) 304, DNS proxy unit 305, IPv4. / IPv6 conversion notification unit 306, IPv6 connection notification unit 307, IPv4 interface 308, and IPv6 interface 309. All or some of the functions of the HGW 30 may be realized 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 communication unit 301 communicates with the IPv4 terminal 10. For example, the communication unit 301 receives a v4 name resolution request from the IPv4 terminal 10. For example, the communication unit 301 transmits a name resolution response to the IPv4 terminal 10.
The conversion table storage unit 302 is configured using a storage device such as a magnetic hard disk device or a semiconductor storage device. The conversion table storage unit 302 stores a conversion table.

The transfer control unit 303 controls the transfer destination according to the received packet.
The FQDN table storage unit 304 is configured using a storage device such as a magnetic hard disk device or a semiconductor storage device. The FQDN table storage unit 304 stores an FQDN table.
The DNS proxy unit 305 transfers the name resolution request transmitted from the IPv4 terminal 10 to the v4 DNS server 20-1 or v6 DNS server 20-2 and transfers the name resolution response to the IPv4 terminal 10.

When the packet is transferred by the transfer control unit 303, the IPv4 / IPv6 conversion notification unit 306 transmits a usage confirmation notification to the IPv4 terminal 10 that is the transmission source of the packet. The usage confirmation notification is a notification for allowing the user to select whether or not to use the IPv4 / IPv6 translator function. The usage confirmation image, which will be described later, is stored in the usage confirmation notification.
When the packet is transferred by the transfer control unit 303, the IPv6 connection notification unit 307 transmits a connection notification to the IPv4 terminal 10 that is the transmission source of the packet. The connection notification is a notification indicating that an IPv6 connection has not been established. In the connection notification, a connection notification image described later is stored.

The IPv4 interface 308 is connected to a network 40 such as a LAN (Local Area Network) or a WAN (Wide Area Network) by wired connection or wireless connection. The IPv4 interface 308 inputs and outputs data between the HGW 30 and the network 40 using IPv4.
The IPv6 interface 309 is connected to a network 40 such as a LAN or WAN by wired connection or wireless connection. The IPv6 interface 309 inputs and outputs data between the HGW 30 and the network 40 using IPv6.

FIG. 3 is a diagram illustrating specific examples of the FQDN table and the conversion table.
FIG. 3A is a configuration diagram of the FQDN table. In the FQDN table stored by the FQDN table storage unit 304, numbers and FQDNs (destination identification information) are registered in association with each other. The number value represents the order in which FQDNs are recorded in the FQDN table. The FQDN value represents the FQDN recorded in the FQDN table.

  FIG. 3B is a configuration diagram of the conversion table. The conversion table has a plurality of records 60. The record 60 includes values of a number, a source IP address (virtual IPv4 address), a destination IP address (communication destination IPv6 address), an FQDN, and an initial flag. The number value represents the order in which the values of the conversion source IP address, the conversion destination IP address, the FQDN, and the initial flag are recorded in the conversion table. The value of the translation source IP address represents the translation source virtual IPv4 address to be translated by the IPv4 / IPv6 translation. The value of the conversion destination IP address represents the converted IPv6 address converted by the IPv4 / IPv6 conversion. The value of FQDN indicates the FQDN for which name resolution is requested.

  The value of the initial flag indicates whether it is registered for the first time in the conversion table. Specifically, the values of the conversion source IP address, conversion destination IP address, and FQDN corresponding to the item whose initial flag value is “1” are the contents registered for the first time in the conversion table, and are IPv4 / IPv6 by the user. Indicates that the application of the conversion is not valid (not allowed). The values of the source IP address, destination IP address, and FQDN corresponding to the item whose initial flag value is “0” are not registered for the first time, and it is effective to apply IPv4 / IPv6 conversion by the user ( Is allowed). Further, each value recorded in the conversion table may be deleted after a certain time (for example, 1 minute, 10 minutes) has elapsed.

  In the example shown in FIG. 3B, each value of the conversion source IP address, the conversion destination IP address, the FQDN, and the initial flag is recorded in association with each number recorded in the conversion table. For example, in FIG. 3B, the top row of the conversion table has a number value “1”, a source IP address value “XXX.XXX.XXX.1”, and a destination IP address value. “AAAA: AAA :: 1”, the value of FQDN is “XXX.XXX.XXX”, and the value of the initial flag is “1”. That is, the value of the virtual IPv4 address recorded first in the conversion table is “XXX.XXX.XXX.1”, and the value of the IPv6 address after conversion of the virtual IPv4 address is “AAA: AAA :: 1”. Yes, the value of FQDN is “XXX.XXX.XXX”, indicating that application of IPv4 / IPv6 conversion is not permitted. In this case, the conversion notification unit 306 transmits a later-described use confirmation notification to the IPv4 terminal 10 and requests permission to apply IPv4 / IPv6 conversion from the user.

  Further, for example, in FIG. 3B, the second row of the conversion table has a number value “2”, a conversion source IP address value “XXX.XXX.XXX.2”, and a conversion destination IP address. The value of “AAAA: AAA :: 2”, the value of FQDN is “YYY.YYY.YYY”, and the value of the initial flag is “0”. That is, the value of the virtual IPv4 address recorded second in the conversion table is “XXX.XXX.XXX.2”, and the value of the IPv6 address after the conversion of the virtual IPv4 address is “AAA: AAA :: 2”. Yes, the value of FQDN is “YYY.YYY.YYY”, indicating that application of IPv4 / IPv6 conversion is permitted.

FIG. 4 is a diagram illustrating an example of a display example of a usage confirmation image.
The usage confirmation image shown in FIG. 4 is a pop-up image displayed on the screen of the IPv4 terminal 10 when the IPv4 terminal 10 receives the usage confirmation notification from the IPv4 / IPv6 conversion notification unit 306 of the HGW 30. In the example illustrated in FIG. 4, a “Yes” button that allows the user to select whether to perform communication using IPv4 / IPv6 conversion and a “No” button are displayed in the usage confirmation image. And based on a user's selection result, HGW30 performs the following processes. When the “Yes” button is pressed by the user, the HGW 30 performs communication using IPv4 / IPv6 conversion. On the other hand, when the “No” button is pressed by the user, the HGW 30 does not perform communication using IPv4 / IPv6 conversion, and deletes the corresponding item in the conversion table. More specifically, the HGW 30 deletes the record 60 of the conversion table in which the virtual IPv4 address that the IPv4 terminal 10 tried to access is recorded.

FIG. 5 is a diagram illustrating an example of a display example of a connection notification image.
The connection notification image shown in FIG. 5 is a pop-up image displayed on the screen of the IPv4 terminal 10 when the IPv4 terminal 10 receives a connection notification from the IPv6 connection notification unit 307 of the HGW 30. In the example illustrated in FIG. 5, the connection notification image includes a content indicating that communication is not possible because an IPv6 connection has not been established, and a “close” button used to close the connection notification image. ing. By viewing the connection notification image displayed on the screen of the IPv4 terminal 10, the user can know that the own apparatus (IPv4 terminal 10) cannot establish communication because the connection with IPv6 has not been established. Note that the connection notification image shown in FIG. 5 may display a “connection” button for executing the IPv6 connection. Then, when the user presses the “Connect” button, the connection with IPv6 is established. With this configuration, the IPv4 terminal 10 can make an IPv6 connection in accordance with a user operation.

FIG. 6 is a flowchart showing the processing of the DNS proxy unit 305 in the present embodiment.
The communication unit 301 receives a v4 name resolution request from the IPv4 terminal 10 (step S101). The DNS proxy unit 305 determines whether or not the FQDN of the received v4 name resolution request is recorded in the FQDN table (step S102). If it is recorded in the FQDN table (step S102—YES), the DNS proxy unit 305 generates an IPv6 name resolution request (hereinafter referred to as “v6 name resolution request”) (step S103). Thereafter, the DNS proxy unit 305 performs name resolution of the generated v6 name resolution request (step S104). The DNS proxy unit 305 determines whether there is no IPv6 connection (step S105). That is, the DNS proxy unit 305 determines whether or not an IPv6 connection has been established.

If there is no IPv6 connection (YES in step S105), the DNS proxy unit 305 transmits a virtual IPv4 address for connection notification (for example, a predetermined IPv4 address such as 192.168.255.1) to the IPv6 connection notification unit 307. To instruct. The IPv6 connection notification unit 307 transmits a virtual IPv4 address for connection notification to the IPv4 terminal 10 as a response in response to an instruction from the DNS proxy unit 305 (step S106). Thereafter, the process ends.
On the other hand, when there is no IPv6 connection, that is, when IPv6 connection is established (step S105-NO), the DNS proxy unit 305 determines whether or not name resolution of the v6 name resolution request has been completed (step S107). Specifically, the DNS proxy unit 305 determines whether a resolved IPv6 address has been received from the v6 DNS server 20-2.

When the name resolution of the v6 name resolution request is successful (step S107—YES), the DNS proxy unit 305 generates a virtual IPv4 address (step S108). Next, the DNS proxy unit 305 records the generated virtual IPv4 address, the IPv6 address generated in the process of step S103, and the FQDN of the v4 name resolution request received in the process of step S101 in association with each other in the conversion table. (Step S109). At this time, the DNS proxy unit 305 sets the value of the initial flag to “0”.
Thereafter, the DNS proxy unit 305 transmits the virtual IPv4 address as a response to the IPv4 terminal 10 via the communication unit 301 (step S110). Thereafter, the process ends.

In the process of step S107, the process when the name resolution of the v6 name resolution request cannot be performed (step S107—NO) will be described later.
Also, in the process of step S102, when not recorded in the FQDN table (step S102-NO), the DNS proxy unit 305 generates a v6 name resolution request (step S111).

  The DNS proxy unit 305 executes name resolution of the received v4 name resolution request and the generated v6 name resolution request. Specifically, the DNS proxy unit 305 transmits a v4 name resolution request to the v4 DNS server 20-1 via the IPv4 interface 308. Also, the DNS proxy unit 305 transmits a v6 name resolution request to the v6 DNS server 20-2 via the IPv6 interface 309 (step S112).

  Thereafter, the DNS proxy unit 305 determines whether or not the name resolution of the v4 name resolution request has been completed (step S113). When the name resolution of the v4 name resolution request cannot be performed (step S113-NO), the DNS proxy unit 305 determines whether the name resolution of the v6 name resolution request has been completed. (Step S114). When the name resolution of the v6 name resolution request cannot be performed (step S114-NO), or when the name resolution of the v6 name resolution request cannot be performed by the process of step S107 (step S107-NO), the DNS proxy unit 305 A name unresolved response indicating that the name could not be resolved is transmitted as a response to the IPv4 terminal 10 (step S115). Thereafter, the process ends.

  In the process of step S114, when the name resolution of the v6 name resolution request is completed (step S114-YES), the DNS proxy unit 305 generates a virtual IPv4 address (step S116). The DNS proxy unit 305 records the generated virtual IPv4 address, the IPv6 address generated in the process of step S111, and the FQDN of the v4 name resolution request received in the process of step S101 in association with each other (step). S117). At this time, the DNS proxy unit 305 sets the value of the initial flag to “1”.

Thereafter, the DNS proxy unit 305 transmits the virtual IPv4 address as a response to the IPv4 terminal 10 (step S118). Thereafter, the process ends.
If the name resolution of the v4 name resolution request is successful in the process of step S113 (step S113-YES), the DNS proxy unit 305 transmits the resolved IPv4 address to the IPv4 terminal 10 as a response (step S119). Thereafter, the process ends.

FIG. 7 is a flowchart showing the processing of the transfer control unit 303 in this embodiment.
The communication unit 301 receives a packet transmitted from the IPv4 terminal 10 (step S201). The transfer control unit 303 determines whether the destination of the received packet is other than the connection notification virtual IPv4 address (step S202). When the destination of the packet is not other than the IPv4 address for connection notification, that is, when the destination is the virtual IPv4 address for connection notification (step S202—NO), the transfer control unit 303 transfers the packet to the IPv6 connection notification unit 307. . Thereafter, when the packet is transferred from the transfer control unit 303, the IPv6 connection notification unit 307 transmits a connection notification to the IPv4 terminal 10 (step S203). Thereafter, the process ends.

  On the other hand, when the destination of the packet is other than the virtual IPv4 address for connection notification (step S202—YES), the IPv4 / IPv6 conversion notification unit 306 receives the virtual IPv4 in which the destination IPv4 address of the received packet is recorded in the conversion table. It is determined whether it is an address (step S204). Specifically, the IPv4 / IPv6 conversion notification unit 306 reads the conversion table stored in the conversion table storage unit 302. The IPv4 / IPv6 conversion notification unit 306 determines whether or not the destination IPv4 address of the packet received in the process of step S201 is recorded in the read conversion table.

When the destination IPv4 address of the received packet is not the virtual IPv4 address recorded in the translation table (NO in step S204), the IPv4 / IPv6 translation notification unit 306 sends the packet received via the transfer control unit 303 to the destination. Transfer to the IPv4 address (step S205). Thereafter, the process ends.
On the other hand, when the destination IPv4 address of the received packet is the virtual IPv4 address recorded in the translation table (step S204—YES), the IPv4 / IPv6 translation notification unit 306 refers to the translation table and sets the virtual IPv4 address. It is determined whether or not the value of the initial flag recorded in association is “1” (step S206).

  When the value of the initial flag is not “1” (for example, the value of the initial flag is “0”) (NO in step S206), the IPv4 / IPv6 conversion notification unit 306 refers to the conversion table, and receives the destination of the received packet. The IPv4 address is converted to IPv4 / IPv6 and transmitted to the target server 50 (step S207). Specifically, first, the IPv4 / IPv6 conversion notification unit 306 refers to the conversion table and selects the record 60 in which the virtual IPv4 address is recorded. Next, the IPv4 / IPv6 conversion notification unit 306 acquires the value of the communication destination IPv6 address recorded in the selected record 60. Thereafter, the IPv4 / IPv6 conversion notifying unit 306 performs IPv4 / IPv6 conversion, and converts the destination IPv4 address of the received packet into a communication destination IPv6 address. Then, the IPv4 / IPv6 conversion notification unit 306 transmits the destination-converted packet to the target server 50 via the transfer control unit 303. Thereafter, the process ends.

  On the other hand, when the value of the initial flag is “1” (step S206—YES), the IPv4 / IPv6 conversion notification unit 306 transmits a usage confirmation notification to the IPv4 terminal 10 (step S208). The communication unit 301 receives a response to the usage confirmation notification transmitted from the IPv4 terminal 10. The transfer control unit 303 determines whether or not the received response is a use permission notification indicating that the IPv4 / IPv6 conversion is used (step S209). When the received response is not a use permission notification indicating that the IPv4 / IPv6 conversion is used (step S209—NO), the DNS proxy unit 305 deletes the corresponding item from the conversion table. More specifically, the DNS proxy unit 305 deletes the translation table record 60 in which the virtual IPv4 address that the IPv4 terminal 10 tried to access is recorded. Thereafter, the process ends.

  On the other hand, when the received response is a use permission notification indicating that the IPv4 / IPv6 conversion is used (YES in step S209), the IPv4 / IPv6 conversion notification unit 306 determines the FQDN of the packet received in the process of step S201. Record in the FQDN table (step S211). The IPv4 / IPv6 conversion notification unit 306 refers to the conversion table and changes the value of the initial flag recorded in the record 60 corresponding to the virtual IPv4 address that is the destination of the received packet to “0” (step S212). ). Thereafter, the IPv4 / IPv6 conversion notifying unit 306 performs IPv4 / IPv6 conversion and transmits the packet to the target server 50 (step S213). Thereafter, the process ends.

8 and 9 are sequence diagrams showing the operation of the IPv4 / IPv6 conversion processing in the present embodiment. In the description of FIG. 8 and FIG. 9, a case where the FQDN is not registered in the FQDN table will be described.
The IPv4 terminal 10 transmits a v4 name resolution request (IPv4, A record) to the HGW 30 in accordance with a user operation (step S301). The communication unit 301 of the HGW 30 receives the v4 name resolution request. The DNS proxy unit 305 determines whether or not the FQDN of the received v4 name resolution request is recorded in the FQDN table (step S302). As a result of the determination, since the FQDN of the received v4 name resolution request is not recorded in the FQDN table, the DNS proxy unit 305 generates a v6 name resolution request (step S303).

Thereafter, the DNS proxy unit 305 transmits a v4 name resolution request to the v4 DNS server 20-1 via the IPv4 interface 308 (step S304).
The v4 DNS server 20-1 receives the v4 name resolution request. The v4 DNS server 20-1 determines whether there is an IPv4 address corresponding to the host name recorded in the A record of the received v4 name resolution request. As a result of the determination, since there is no IPv4 address corresponding to the host name recorded in the A record, the v4 DNS server 20-1 transmits a name resolution response including information indicating that there is no requested IPv4 address to the HGW 30 ( Step S305).

  The transfer control unit 303 of the HGW 30 receives the name resolution response from the v4 DNS server 20-1 via the IPv4 interface 308. Next, since the information stored in the received name resolution response indicates that there is no IPv4 address corresponding to the v4 name resolution request, the DNS proxy unit 305 then sends a v6 name resolution request (IPv6 via the IPv6 interface 309). , AAAA record) to the v6 DNS server 20-2. (Step S306).

  The v6 DNS server 20-2 receives the v6 name resolution request. The v6 DNS server 20-2 determines whether there is an IPv6 address corresponding to the host name recorded in the AAAA record of the received v6 name resolution request. As a result of the determination, since there is an IPv6 address corresponding to the host name recorded in the AAAA record, the v6 DNS server 20-2 transmits the resolved IPv6 address to the HGW 30 (step S307).

  The transfer control unit 303 of the HGW 30 receives a name resolution response from the v6 DNS server 20-2 via the IPv6 interface 309. Since the resolved IPv6 address is stored in the information stored in the received name resolution response, the DNS proxy unit 305 acquires the resolved IPv6 address from the name resolution response. Thereafter, the DNS proxy unit 305 generates a virtual IPv4 address (step S308).

  The DNS proxy unit 305 records the generated virtual IPv4 address, the IPv6 address acquired in the process of step S308, and the FQDN of the v4 name resolution request received in the process of step S301 in association with each other (step). S309). At this time, the DNS proxy unit 305 sets the value of the initial flag to “1”.

  The communication unit 301 transmits the generated virtual IPv4 address to the IPv4 terminal 10 as a name resolution response (step S310). Thereafter, the IPv4 terminal 10 performs a connection process with the HGW 30 by 3WHS (three-way handshaking) (step S311). The IPv4 terminal 10 transmits an HTTP (HyperText Transfer Protocol) request addressed to the virtual IPv4 address to the HGW 30 (step S312). The communication unit 301 of the HGW 30 receives an HTTP request. The transfer control unit 303 confirms the conversion table based on the received HTTP request (step S313).

  Specifically, the transfer control unit 303 refers to the conversion table and determines whether or not the destination of the received HTTP request is a virtual IPv4 address recorded in the conversion table. As a result of the determination, since it is the virtual IPv4 address recorded in the conversion table, the transfer control unit 303 next determines whether or not the value of the initial flag corresponding to the virtual IPv4 address is “1”.

  As a result of the determination, since the value of the initial flag corresponding to the virtual IPv4 address is “1”, the transfer control unit 303 transfers the HTTP request to the IPv4 / IPv6 conversion notification unit 306. The IPv4 / IPv6 conversion notification unit 306 transmits a usage confirmation notification as an HTTP response to the IPv4 terminal 10 (step S314).

  The IPv4 terminal 10 receives the HTTP response and displays a usage confirmation image (step S315). When the user presses the “Yes” button, the IPv4 terminal 10 transmits a use permission notification indicating that the IPv4 / IPv6 conversion is used to the HGW 30 (step S316). The communication unit 301 of the HGW 30 receives the use permission notification. The IPv4 / IPv6 conversion notification unit 306 records the FQDN of the v4 name resolution request received in the process of step S302 in the FQDN table in order to indicate that the received use confirmation notification uses IPv4 / IPv6 conversion (step 302). S317).

  At this time, the IPv4 / IPv6 conversion notification unit 306 refers to the conversion table and sets the value of the initial flag corresponding to the FQDN of the v4 name resolution request received in the process of step S302 to “0” (step S318). This makes it possible to convert a virtual IPv4 address into a communication destination IPv6 address. The IPv4 / IPv6 conversion notification unit 306 refers to the conversion table and acquires the value of the communication destination IPv6 address corresponding to the virtual IPv4 address that is the destination of the HTTP request. Thereafter, the IPv4 / IPv6 conversion notification unit 306 converts the destination of the HTTP request from the virtual IPv4 address to the value of the communication destination IPv6 address.

  The HGW 30 performs connection processing by 3WHS with the target server 50 (step S319). When the connection is completed, the IPv4 / IPv6 conversion notification unit 306 of the HGW 30 transmits an HTTP request to the target server 50 via the transfer control unit 303 (step S319). The target server 50 receives the HTTP request. Then, the target server 50 transmits information corresponding to the received HTTP request as an HTTP response to the HGW 30 (step S320). The transfer control unit 303 of the HGW 30 receives the HTTP response via the IPv6 interface 309.

Then, the transfer control unit 303 performs IPv4 / IPv6 conversion, and transmits the received HTTP response to the IPv4 terminal 10 (step S321). Specifically, the transfer control unit 303 acquires the destination IPv6 address from the received HTTP response. The transfer control unit 303 refers to the communication destination IPv6 address of the conversion table and selects the record 60 corresponding to the acquired IPv6 address. The transfer control unit 303 acquires the virtual IPv4 address recorded in the selected record 60. Thereafter, the transfer control unit 303 generates an HTTP response with the acquired virtual IPv4 address as a destination, and transmits the HTTP response to the IPv4 terminal 10.
When the communication between the IPv4 terminal 10 and the HGW 30 is disconnected after a predetermined time has elapsed, the process ends (step S322). Further, when the communication is disconnected between the HGW 30 and the target server 50, the process ends (step S323).

FIG. 10 is a sequence diagram showing the operation of the IPv4 / IPv6 conversion processing in the present embodiment. In the description of FIG. 10, a case where the FQDN is registered in the FQDN table will be described.
The IPv4 terminal 10 transmits a v4 name resolution request (IPv4, A record) to the HGW 30 according to the user's operation (step S401). The communication unit 301 of the HGW 30 receives the v4 name resolution request. The DNS proxy unit 305 determines whether or not the FQDN of the received v4 name resolution request is recorded in the FQDN table (step S402). As a result of the determination, since it is recorded in the FQDN table, the DNS proxy unit 305 generates a v6 name resolution request (IPv6, AAAA record) (step S403).

The DNS proxy unit 305 transmits the generated v6 name resolution request to the v6 DNS server 20-2 (step S404).
The v6 DNS server 20-2 receives the v6 name resolution request. The v6 DNS server 20-2 determines whether there is an IPv6 address corresponding to the host name recorded in the AAAA record of the received v6 name resolution request. As a result of the determination, since there is an IPv6 address corresponding to the host name recorded in the AAAA record, the v6 DNS server 20-2 transmits a name resolution response including the resolved IPv6 address to the HGW 30 (step S405).

The transfer control unit 303 of the HGW 30 receives a name resolution response from the v6 DNS server 20-2 via the IPv6 interface 309. The DNS proxy unit 305 acquires the resolved IPv6 address from the received name resolution response. Thereafter, the DNS proxy unit 305 generates a virtual IPv4 address (step S406).
The DNS proxy unit 305 records the generated virtual IPv4 address, the acquired IPv6 address, and the FQDN of the v4 name resolution request received in step S401 in the conversion table (step S407). At this time, the DNS proxy unit 305 sets the value of the initial flag to “0”.

  The communication unit 301 transmits the generated virtual IPv4 address to the IPv4 terminal 10 as a name resolution response (step S408). Thereafter, the IPv4 terminal 10 performs a connection process using 3WHS with the HGW 30 (step S409). The IPv4 terminal 10 transmits an HTTP request addressed to the virtual IPv4 address to the HGW 30 (step S410). The communication unit 301 of the HGW 30 receives an HTTP request. The IPv4 / IPv6 conversion notification unit 306 confirms the conversion table based on the received HTTP request.

  Specifically, the IPv4 / IPv6 conversion notification unit 306 refers to the conversion table and determines whether or not the destination of the received HTTP request is a virtual IPv4 address recorded in the conversion table. As a result of the determination, since it is the virtual IPv4 address recorded in the conversion table, the IPv4 / IPv6 conversion notification unit 306 next determines whether or not the value of the initial flag corresponding to the virtual IPv4 address is “1”. judge. As a result of the determination, since the value of the initial flag corresponding to the virtual IPv4 address is “0”, the IPv4 / IPv6 conversion notification unit 306 refers to the conversion table and corresponds to the virtual IPv4 address that is the destination of the HTTP request. Get the value of the destination IPv6 address. Thereafter, the IPv4 / IPv6 conversion notification unit 306 converts the destination of the HTTP request from the virtual IPv4 address to the value of the communication destination IPv6 address.

  The HGW 30 performs connection processing by 3WHS with the target server 50 (step S411). When the connection is completed, the IPv4 / IPv6 conversion notification unit 306 of the HGW 30 transmits an HTTP request to the target server 50 via the transfer control unit 303 (step S412). The target server 50 receives the HTTP request. Then, the target server 50 transmits information corresponding to the received HTTP request as an HTTP response to the HGW 30 (step S413). The transfer control unit 303 of the HGW 30 receives the HTTP response via the IPv6 interface 309.

Then, the transfer control unit 303 performs IPv4 / IPv6 conversion, and transmits the received HTTP response to the IPv4 terminal 10 (step S414). Specifically, the transfer control unit 303 acquires the destination IPv6 address from the received HTTP response. The transfer control unit 303 refers to the communication destination IPv6 address of the conversion table and selects the record 60 corresponding to the acquired IPv6 address. The transfer control unit 303 acquires the virtual IPv4 address recorded in the selected record 60. Thereafter, the transfer control unit 303 generates an HTTP response with the acquired virtual IPv4 address as a destination, and transmits the HTTP response to the IPv4 terminal 10.
When the communication is disconnected between the IPv4 terminal 10 and the HGW 30 after a predetermined time has elapsed, the process ends (step S415). Further, when communication is disconnected between the HGW 30 and the target server 50, the process ends (step S416).

  According to the HGW 30 configured as described above, when IPv4 / IPv6 conversion is necessary, a usage confirmation notification is transmitted to the IPv4 terminal 10. The IPv4 terminal 10 can make the user confirm whether or not to perform communication using IPv4 / IPv6 conversion by displaying a usage confirmation image stored in the received usage confirmation notification on the screen. Therefore, communication using IPv4 / IPv6 conversion can be performed at the user's will. Therefore, it becomes possible to make the user aware of the use of IPv4 / IPv6 conversion.

Further, conventionally, since v4 name resolution and v6 name resolution are executed every time a v4 name resolution request is received from the IPv4 terminal 10, there is a problem that unnecessary traffic occurs.
In the present embodiment, only the name resolution of the v6 name resolution request is executed for the name resolution request addressed to the FQDN recorded in the FQDN table. Therefore, it is possible to suppress the generation of unnecessary traffic.

<Modification>
The notification method of the connection notification need not be limited to the above-described method (display by pop-up image). For example, the user may be notified by voice notification that the IPv6 connection has not been established, or may be notified by other methods.
Further, the notification method of the usage confirmation notification need not be limited to the above-described method (display by pop-up image).
In the present embodiment, the HGW 30 is configured to generate the v6 name resolution request, but the present invention is not limited to this. For example, when the HGW 30 receives a v6 name resolution request, the vGW name resolution request may be generated.
In the present embodiment, the IPv4 terminal 10 has been described as an example, but the same processing as in the present embodiment may be performed for an IPv6 terminal. In this case as well, as described with the IPv4 terminal 10 as an example, when the packet addressed to the FQDN stored in the FQDN table is received, the HGW 30 transmits to the IPv6 terminal if the IPv4 connection is not established. Connection notification indicating that an IPv4 connection is required.

  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.

10 (10-1 to 10-N) ... IPv4 terminal 10, 20-1 ... v4 DNS server, 20-2 ... v6 DNS server, 30 ... HGW, 40 ... network, 50 ... target server, 301 ... communication section, 302 ... conversion Table storage unit 303: Transfer control unit (relay unit) 304 ... FQDN table storage unit 305 ... DNS proxy unit (request unit) 306 ... IPv4 / IPv6 conversion notification unit (conversion notification unit) 307 ... IPv6 connection notification 308 ... IPv4 interface 309 ... IPv6 interface

Claims (6)

A communication unit that receives data from the terminal device;
A conversion notification unit that transmits to the terminal device a notification for confirming whether to perform communication using IPv4 / IPv6 conversion based on the data received by the communication unit ;
Equipped with a,
The conversion notification unit performs the IPv4 / IPv6 conversion on the data when the notification that the communication is performed using the IPv4 / IPv6 conversion is received by the communication unit, and converts the converted data to another A relay device that transmits to a device. A conversion table storage unit that stores IPv4 identification information, IPv6 identification information, and information indicating whether communication using IPv4 / IPv6 conversion is effective in association with each other;
The conversion notification unit transmits the notification to the terminal device when communication using IPv4 / IPv6 conversion is not effective, and performs IPv4 / IPv6 conversion when communication using IPv4 / IPv6 conversion is effective. The relay apparatus according to claim 1, wherein the converted data is transmitted to another apparatus. A destination identification information table storage unit that records an FQDN (Fully Qualified Domain Name) indicating a destination of the data when a notification indicating that communication using the IPv4 / IPv6 conversion is performed is received from the terminal device;
When the IPv4 name resolution request is received from the terminal device, it is determined whether or not the IPv4 name resolution request FQDN is recorded in the destination identification information table storage unit, and the IPv4 name resolution request FQDN is determined. A request unit for inquiring about IPv4 identification information and IPv6 identification information when the IPv4 name resolution request FQDN is not recorded. ,
The relay device according to claim 1, further comprising: A connection for notifying that the terminal device needs to be connected when an IPv4 or IPv6 connection is not established when data addressed to the FQDN recorded in the destination identification information table storage unit is received The relay device according to claim 3, further comprising a notification unit. A communication step of receiving data from the terminal device;
A conversion notification step of transmitting to the terminal device a notification for confirming whether to perform communication using IPv4 / IPv6 conversion based on the data received in the communication step ;
I have a,
In the conversion notification step, when a notification indicating that communication is performed using IPv4 / IPv6 conversion is received in the communication step, the IPv4 / IPv6 conversion is performed on the data, and the converted data is transferred to another Relay method to send to the device . A communication step of receiving data from the terminal device;
A conversion notification step of transmitting to the terminal device a notification for confirming whether to perform communication using IPv4 / IPv6 conversion based on the data received in the communication step ;
To the computer ,
In the conversion notification step, when a notification indicating that communication is performed using IPv4 / IPv6 conversion is received in the communication step, the IPv4 / IPv6 conversion is performed on the data, and the converted data is transferred to another because of the computer program to the transmitting device to.

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