JP2006245893A - Dhcp client terminal and dhcp-pd requesting router - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a DHCP client terminal capable of immediately executing communication even when the DHCP client terminal is replaced in an IP network using the DHCP or the DHCP-PD to make settings to an IP address. <P>SOLUTION: A release switch 1 outputs a switch start signal to a control section 2. The control section 2 starts an IP address release process of the DHCP to generate a DHCP release message and outputs the DHCP release message to an IP network interface section 3. The IP network interface section 3 transmits the DHCP release message to a user accommodation router with a DHCP server function. Upon the receipt of the DHCP release message, the user accommodation router discriminates whether or not information associated with a DUID and an IP address of a DHCP client terminal included in the message is registered and deletes the DHCP information when the information is registered. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention provides an IP address or an IPv6 (Internet Protocol version 6) address prefix using DHCP (Dynamic Host Configuration Protocol) or DHCP-PD (Prefix Delegation) in an IP network including a terminal or a router that performs IP transfer. It is related with the technology to set.

  In the conventional IP network technology, automatic setting of an IP address can be realized by DHCP (see Non-Patent Document 1) for a client terminal connected to the IP network. In DHCP, as shown in FIG. 10, an IP address group that can be assigned in the IP network 100 is registered in advance in a DHCP server 101 installed in the IP network 100. The client terminals 105 and 106 access the DHCP server 101 via the user accommodation router 102, and the client terminals 107 and 108 access the DHCP server 101 via the requesting routers 109 and 110 and the user accommodation router 103, respectively. Request. The DHCP server 101 notifies the client terminals 105 to 108 of unassigned IP addresses from among the registered IP address group. In this case, the DHCP server 101 registers the assigned IP address and considers the convenience of the user, so that the same IP address is assigned to the same user. That is, the relationship between the accommodation location information and the IP address assigned to the client terminal is also registered.

  In DHCP, in order for the DHCP server 101 to identify the client terminals 105 to 108, an identifier called a client DUID (DHCP Unique Identifier) is used. The operation will be specifically described with reference to FIG. At the first activation, the client terminal generates a client DUID based on a link layer address such as a MAC address (step S1101), and notifies the DHCP server of an IP address assignment request (step S1102). When an IP address is assigned, the DHCP server associates and stores the client DUID, the assigned IP address, and information on the interface to which the IP address is assigned, that is, accommodation location information (step S1103). Examples of accommodation location information include an identifier of a router that accommodates a client terminal, an interface identifier of an interface to which the client terminal is connected, and the like. Then, the DHCP server transmits the client DUID, the assigned IP address, and the expiration date to the client terminal (step S1104), and the client terminal sets the received IP address (step S1105).

  In DHCP, the DHCP server 101 uses the client DUID to identify the client terminals 105 to 108 to which the IP address is assigned. For example, when receiving an IP address expiration request from the client terminals 105 to 108 (Step S1106), the relationship between the IP address, client DUID, and accommodation location information is confirmed (step S1107), and the validity period of the IP address can be extended only to the valid client terminals 105 to 108. (Steps S1108 and 1109). In other words, the DHCP server 101 can reject a request from an unauthorized device or an unauthorized interface by managing the client DUID.

  In DHCP, when an IP address is no longer needed, the client terminal performs an IP address release request, and the DHCP server that has received the release request stores the IP address, client DUID, and accommodation stored at the time of IP address assignment. The DHCP allocation information such as position information and interface is deleted, and reassignment is possible.

  The features of the client DUID are the same as in the case of DHCP-PD that assigns an IPv6 address prefix.

R. Droms et al., “RFC3315 Dynamic Host Configuration Protocol for IPv6 (DHCPv6)”, [online], July 2003, Internet <URL: http://www.ietf.org/rfc/rfc3315.txt> O. Troan et al., “RFC3633 IPv6 Prefix Option for Dynamic Host Configuration Protocol (DHCP) version 6”, [online], December 2003, Internet <URL: http://www.ietf.org/rfc/rfc363

  However, since the link layer address such as the MAC address that is the basis for generating the client DUID is assigned to the hardware of the interface, generally, when exchanging the client terminal or the interface part of the client terminal, the client DUID before the exchange is generally The value is different from the client DUID after the exchange.

  Therefore, when exchanging the client terminal or the interface part of the client terminal, if the client terminal fails to transmit an IP address release request due to a failure or the like before the exchange, the DHCP server stores the stored DHCP allocation. Information cannot be deleted. For this reason, when the DHCP server receives an IP address assignment request from an exchanged client terminal used by the same user, the DHCP server determines that the request is an unauthorized request from a different client DUID and rejects the IP address assignment request ( (See steps S1110 to S1114 in FIG. 11). In this case, the DHCP server rejects the IP address assignment request from the client terminal until the stored IP address expires and the DHCP assignment information is deleted.

  As a method for solving this problem, a method in which the operator of the IP network deletes the client DUID stored in the DHCP server can be considered, but it is difficult for the operator to identify the client DUID generated uniquely by the client terminal. Also, considering the technical level of general users, it is difficult for the user to read the client DUID from the client terminal and report it to the operator.

  Also, a solution for shortening the IP address expiration date in the DHCP server is conceivable. However, when the IP address expiration date is shortened, IP address update requests from the client terminal to the router and the DHCP server increase, and the router And there is concern that the DHCP server will be congested.

  Therefore, an object of the present invention is to immediately communicate even when a client terminal (hereinafter referred to as a DHCP client terminal) is exchanged in an IP network in which an IP address is set using DHCP or DHCP-PD. It is to provide a DHCP client terminal capable of the above. Another object of the present invention is to provide a DHCP-PD requesting router that can immediately communicate even when the DHCP-PD requesting router is replaced.

  In order to solve this problem, the control unit of the DHCP client terminal or the DHCP-PD requesting router sends a message requesting release of the IP address or the IPv6 address prefix to the DHCP server by an external switch operation before the exchange. Send. The DHCP server receives this message and deletes the information associated with the registered IP address or IPv6 address prefix and the client DUID before the exchange, so that the DHCP client terminal or the DHCP-PD requesting router After the exchange, re-registration of the client DUID can be performed immediately (Claims 1 and 2).

  If the DHCP client terminal or the DHCP-PD requesting router fails, there is a possibility that the message cannot be transmitted. Therefore, the detection unit detects a failure of the DHCP client terminal or the DHCP-PD requesting router, for example, at a minor stage, and the control unit transmits the message to the DHCP server. The DHCP server receives this message and deletes the information associated with the registered IP address or IPv6 address prefix and the client DUID before the exchange, so that the DHCP client terminal or the DHCP-PD requesting router After the exchange, re-registration of the client DUID can be performed immediately (Claims 3 and 4).

  In addition, the message may be lost on the IP network. In this case, deletion of information associated with the IP address or IPv6 address prefix registered in the DHCP server and the client DUID before the exchange fails. . Therefore, the control unit transmits the message twice or more. Thereby, the deletion failure of the information can be prevented (claims 5 and 6).

  In addition, when the control unit is congested because the message is stored in advance and the stored message is used when the switch activation signal is input from the release switch or when the control unit detects a failure. Even if it exists, the said message can be transmitted reliably (Claim 7, Claim 8).

  As described above in detail, according to the present invention, even when a DHCP client terminal or a DHCP-PD requesting router is replaced in an IP network in which an IP address is set using DHCP or DHCP-PD. The communication can be immediately established.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

A first embodiment of the present invention will be described using a configuration example of a DHCP client terminal shown in FIG. 1 and an operation example shown in FIG.
The DHCP client terminal 10 according to the first embodiment includes a release switch 1, a control unit 2, and an IP network interface unit 3 as shown in FIG. The release switch 1 is connected to the control unit 2, and the control unit 2 is connected to the IP network interface unit 3. The IP network interface unit 3 is connected to the IP network 50. The release switch 1 is activated by an operation such as pressing a switch, for example, and outputs a switch activation signal to the control unit 2. The present invention is characterized in that the switch activation signal is notified to the control unit 2 when the release switch 1 is activated. The operation method of the release switch 1 itself and the switch activation signal from the release switch 1 to the control unit 2 are characterized. It does not limit the transmission method.

  The control unit 2 generates a DHCP message by executing the DHCP function processing in the same manner as in the conventional technique, and outputs the DHCP message to the IP network interface unit 3. Here, the point that the DHCP IP address release request processing is executed upon receipt of the switch activation signal from the release switch 1 is different from the prior art.

  The IP network interface unit 3 inputs the DHCP message generated by the control unit 2 and transmits it to the IP network 50. Also, a DHCP message is received from the IP network 50 and transferred to the control unit 2.

  An operation example of the first embodiment will be described with reference to FIG. However, FIG. 2 shows an operation example when the user accommodating router has a DHCP server function for the sake of simplicity. When the user accommodation router does not have a DHCP server function and the DHCP server is installed independently, the user accommodation router relays a message to the DHCP server, so that it is basically the same as FIG. It becomes operation.

  When the release switch 1 of the DHCP client terminal 10 is activated by an operation such as pressing (step S201), the release switch 1 outputs a switch activation signal to the control unit 2 (step S202). The control unit 2 that has input the switch activation signal activates the DHCP IP address release process to generate a DHCP release message (step S203), and outputs the DHCP release message to the IP network interface unit 3 (step S204). Then, the IP network interface unit 3 transmits the DHCP release message to the user accommodating router (step S205). For example, in the case of DHCPv6 (RFC3315), the Release message corresponds to the DHCP release message. The DHCP release message includes at least the DUID and IP address of the DHCP client terminal 10.

  When the user accommodating router receives the DHCP release message, the user accommodating router determines whether or not information related to the DUID and IP address of the DHCP client terminal included in the message is registered. If yes, the DHCP information is deleted (step S206).

Next, a second embodiment of the present invention will be described using a configuration example of the DHCP-PD requesting router shown in FIG. 3 and an operation example shown in FIG.
As shown in FIG. 3, the DHCP-PD requesting router 20 according to the second embodiment includes a release switch 1, a control unit 2, and IP network interface units 3-1 and 3-2. The release switch 1 is connected to the control unit 2, and the control unit 2 is connected to the IP network interface units 3-1 and 3-2, respectively. The IP network interface units 3-1 and 3-2 are connected to the IP network 50. The release switch 1 is activated by an operation such as pressing a switch, for example, and outputs a switch activation signal to the control unit 2. The present invention is characterized in that the switch activation signal is notified to the control unit 2 when the release switch 1 is activated. The operation method of the release switch 1 itself and the switch activation signal from the release switch 1 to the control unit 2 are characterized. It does not limit the transmission method.

  The control unit 2 generates a DHCP-PD message by executing the processing of the DHCP-PD function in the same manner as in the prior art, and outputs the DHCP-PD message to the IP network interface units 3-1 and 3-2. . Here, the point that the IPv6 address prefix release request processing of DHCP is executed upon receipt of the switch activation signal from the release switch 1 is different from the prior art.

  The IP network interface units 3-1 and 3-2 receive the DHCP-PD message generated by the control unit 2 and transmit it to the IP network 50. Also, a DHCP-PD message is received from the IP network 50 and transferred to the control unit 2. In general, a router includes a plurality of IP network interfaces. The present invention does not limit the number of IP network interfaces. When the DHCP-PD requesting router 20 includes a plurality of IP network interface units, the control unit 2 is connected to an IP network interface unit to which a DHCP server is connected via the IP network 50, respectively. Examples of this connection method include a method in which a specific interface is an IP network interface unit to which a DHCP server is connected, and a method in which all IP network interfaces are connected to the control unit 2. 2 and the IP network interface unit are not limited. In the second embodiment, only the IP network interface unit used for communication with the DHCP server necessary for explaining the present invention is described.

  An operation example of the second embodiment will be described with reference to FIG. However, FIG. 4 shows an operation example when the user accommodating router has a DHCP server function for the sake of simplicity. If the user accommodation router does not have a DHCP server function and the DHCP server is installed independently, the user accommodation router relays a message to the DHCP server, so that it is basically the same as FIG. It becomes operation.

  When the release switch 1 of the DHCP-PD requesting router 20 is activated by an operation such as pressing (step S401), the release switch 1 outputs a switch activation signal to the control unit 2 (step S402). Upon receiving the switch activation signal, the control unit 2 activates the DHCP-PD IPv6 address prefix release process to generate a DHCP-PD release message (step S403), and sends the DHCP-PD release message to the IP network interface unit 3. Output (step S404). The IP network interface unit 3 transmits the DHCP-PD release message to the user accommodating router (step S405). The message DHCP-PD release message corresponds to, for example, a Release message in the case of DHCP-PD. The DHCP release message includes at least the DUID of the DHCP client terminal 10 and the IPv6 address prefix.

  When the user accommodating router receives the DHCP-PD release request message, the user accommodating router determines whether or not information related to the DHCP client terminal DUID and IPv6 address prefix included in the message is registered. If registered, the DHCP information is deleted (step S406).

Next, Embodiment 3 of the present invention will be described.
Since the configuration example of the DHCP client terminal according to the third embodiment is the same as that shown in FIG. 1, the description thereof is omitted here. An operation example of the third embodiment will be described with reference to FIG. In the third embodiment, the control unit 2 executes the DHCP IP address release request process not upon the notification of the switch activation signal from the release switch 1 but on the detection of a failure (step S501) ( Step S502) differs from the first embodiment shown in FIG. As this failure detection method, there is a method in which the control unit 2 periodically checks the normality of each part of the DHCP client terminal 10, but the present invention does not limit the failure detection method by the control unit 2. . In FIG. 5, steps S503 to S505 are the same as steps S204 to S206 of the first embodiment shown in FIG.

Next, a fourth embodiment of the present invention will be described.
Since the configuration example of the DHCP-PD requesting router according to the fourth embodiment is the same as that shown in FIG. 3, the description thereof is omitted here. An operation example of the fourth embodiment will be described with reference to FIG. In the fourth embodiment, the control unit 2 performs DHCP IPv6 address prefix release request processing not upon the notification of the switch activation signal from the release switch 1 but upon the detection of a failure (step S601). (Step S602) is different from the second embodiment shown in FIG. As a failure detection method, there is a method in which the control unit 2 periodically checks the normality of each part of the DHCP-PD requesting router 20, but the present invention limits the failure detection method by the control unit 2. is not. In FIG. 6, steps S603 to S605 are the same as steps S404 to S406 of the second embodiment shown in FIG.

Next, a fifth embodiment of the present invention will be described.
The configuration example of the DHCP client terminal according to the fifth embodiment is the same as that shown in FIG. 1, and the configuration example of the DHCP-PD requesting router is the same as that shown in FIG. An operation example of the fifth embodiment will be described with reference to FIG. FIG. 7 is a flowchart showing an operation example of the DHCP client terminal. The operation example of the DHCP-PD requesting router is the same as that in FIG. In the fifth embodiment, the control unit 2 performs DHCP IP address release request processing when triggered by notification of a switch activation signal from the release switch 1 (steps S701 and 702) or triggered by failure detection (not shown). When executed (step S703), the DHCP release message is transmitted for a predetermined number of times (steps S704 to S707), which differs from the first embodiment shown in FIG. 2 and the third embodiment shown in FIG. .

  Specifically, the control unit 2 that has received the switch activation signal or the control unit 2 that has detected the failure activates the DHCP IP address release process and sends a DHCP release message including the DUID and IP address of the DHCP client terminal 10. It generates (step S703) and outputs the DHCP release message to the IP network interface unit 3 (step S704). Then, the IP network interface unit 3 transmits the DHCP release message to the user accommodating router (step S705). Further, the control unit 2 outputs the DHCP release message to the IP network interface unit 3 (step S706), and the IP network interface unit 3 transmits the DHCP release message to the user accommodating router (step S707). The control unit 2 and the IP network interface unit 3 repeat the operations in steps 704 and 705 for a predetermined number of times. Repeating such an operation is effective when the DHCP release message in step 705 is lost on the IP network 50 as shown in FIG.

Next, a sixth embodiment of the present invention will be described using a configuration example of a DHCP client terminal shown in FIG. 8 and an operation example shown in FIG. The configuration example of the DHCP-PD requesting router is the same as that shown in FIG.
As shown in FIG. 8, the DHCP client terminal 11 of the sixth embodiment is configured by adding a message storage unit 4 to the configuration example of the first embodiment shown in FIG. The release switch 1 is connected to the message storage unit 4, the control unit 2 is connected to the message storage unit 4 and the IP network interface unit 3, and the IP network interface unit 3 is connected to the message storage unit 4 and the control unit 2. The message storage unit 4 is connected to the release switch 1, the control unit 2, and the IP network interface unit 3. The IP network interface unit 3 is connected to the IP network 50.

The release switch 1 is activated by an operation such as pressing a switch, for example, and outputs a switch activation signal to the message storage unit 4. The present invention is characterized in that the switch activation signal is notified to the message storage unit 4 when the release switch 1 is activated, and the operation method of the release switch 1 itself and the switch activation signal from the release switch 1 to the control unit 2 It does not limit the transmission method.

  The control unit 2 sets an IP address, generates a release message, and outputs it to the message storage unit 4 for storage.

  The IP network interface unit 3 inputs the release message stored in the message storage unit 4 and transmits it to the IP network 50 as a DHCP message. Further, a DHCP message including an IP address is received from the IP network 50 and transferred to the control unit 2.

  The message storage unit 4 stores the release message. When the switch activation signal is input from the release switch 1, the message storage unit 4 outputs the stored release message to the IP network interface unit 3. The message storage unit 4 is preferably a non-volatile memory so that the stored message is not lost even when the DHCP client terminal 11 is restarted.

An operation example of the sixth embodiment will be described with reference to FIG. The operation example of the DHCP-PD requesting router is the same.
The control unit 2 of the DHCP client terminal 11 inputs a DHCP response including the IP address transmitted from the user accommodating router via the IP network interface unit 3 (steps S901 and S902), and sets the IP address (step S903). ). At this time, a release message including the DUID and IP address of the DHCP client terminal 11 is generated and stored in the message storage unit 4 (steps S905 and S906).

  When the release switch 1 is activated by an operation such as pressing (step S907), the release switch 1 outputs a switch activation signal to the message storage unit 4 (step S908). When receiving the switch activation signal, the message storage unit 4 outputs the stored release message to the IP network interface 3. Then, the IP network interface unit 3 transmits a release message including the DUID and IP address of the DHCP client terminal 11 as a DHCP release message to the user accommodating router (step S910).

  When the user accommodating router receives the DHCP release message, the user accommodating router determines whether or not these pieces of information are registered in association with the DUID and IP address of the DHCP client terminal 11 included in the message. In that case, the DHCP information is deleted (step S911).

It is an example of a structure of the DHCP client terminal in Example 1 of this invention. It is a flowchart figure which shows the operation example in Example 1 of this invention. It is a structural example of the DHCP-PD requesting router in Example 2 of this invention. It is a flowchart figure which shows the operation example in Example 2 of this invention. It is a flowchart figure which shows the operation example in Example 3 of this invention. It is a flowchart figure which shows the operation example in Example 4 of this invention. It is a flowchart figure which shows the operation example in Example 5 of this invention. It is a structural example of the DHCP client terminal in Example 6 of this invention. It is a flowchart figure which shows the operation example in Example 6 of this invention. It is an example of a network structure of a prior art. It is a flowchart figure which shows the operation example of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Release switch 2 Control part 3 IP network interface part 4 Message storage part 10,11,105-108 DHCP client terminal 20,109,110 DHCP-PD requesting router 50,100 IP network 101 DHCP server 102,103 User accommodation router

Claims (8)

In a DHCP client terminal connected to a DHCP server via an IP network and having a DHCP client processing unit,
A release switch that outputs a switch activation signal;
A controller that inputs the switch activation signal and transmits a message requesting release of the IP address assigned by DHCP to the DHCP server;
A DHCP client terminal comprising: In a DHCP-PD requesting router that is connected to a DHCP server via an IP network and includes a DHCP-PD requesting router processing unit,
A release switch that outputs a switch activation signal;
A control unit that inputs the switch activation signal and transmits a message requesting release of an IPv6 address prefix assigned by DHCP-PD to a DHCP server;
A DHCP-PD requesting router comprising: In a DHCP client terminal connected to a DHCP server via an IP network and having a DHCP client processing unit,
A control unit for transmitting a message requesting release of an IP address assigned by DHCP to a DHCP server when a failure of the DHCP client terminal is detected;
DHCP client terminal characterized by comprising In a DHCP-PD requesting router that is connected to a DHCP server via an IP network and includes a DHCP-PD requesting router processing unit,
A control unit that transmits a message requesting release of an IPv6 address prefix assigned by DHCP-PD to a DHCP server when a failure of the DHCP client terminal is detected;
A DHCP-PD requesting router comprising: In the DHCP client terminal according to claim 1 or 3,
The DHCP client terminal, wherein the control unit transmits the message for a preset number of times to a DHCP server. In the DHCP-PD requesting router according to claim 2 or 4,
The DHCP-PD requesting router, wherein the control unit transmits the message for a preset number of times to a DHCP server. In the DHCP client terminal according to any one of claims 1, 3 and 5,
Furthermore, a message storage unit composed of a nonvolatile memory is provided,
When the control unit receives the IP address assigned by the DHCP server, the control unit generates a message requesting release of the IP address, and stores the message in the message storage unit.
When the switch activation signal according to claim 1 is input, or when the failure according to claim 3 is detected, the message stored in the message storage unit is transmitted to a DHCP server.
A DHCP client terminal. In the DHCP-PD requesting router according to any one of claims 2, 4 and 6,
Furthermore, a message storage unit composed of a nonvolatile memory is provided,
When the control unit receives the IPv6 address prefix assigned by the DHCP server, the control unit generates a message requesting release of the IPv6 address prefix, and stores the message in the message storage unit.
When the switch activation signal according to claim 2 is input or when the failure according to claim 4 is detected, the message stored in the message storage unit is transmitted to the DHCP server.
A DHCP-PD requesting router characterized by that.

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