JP6665620B2 - Server device, terminal device, client server system, notification method, information acquisition method, and computer program - Google Patents

Description

  The present invention relates to a technology for notifying a management state of a terminal device.

  In a client-server type system using a network, a client needs new information about a connection destination of a server when the client cannot communicate with the server due to a change in an IP (Internet Protocol) address of the server.

  In such a case, for example, there is a method in which a connection destination of a spare server is registered in the client in advance. However, there is a problem that the information of the spare server is not always determined in advance. Further, there is a problem that the client cannot recognize a connection destination other than information registered in advance, such as a changed IP address of a connected server. If the server whose address has been changed is running, it is desirable for the client to use the server again.

  A method is also conceivable in which the client transmits a request for searching for server information to a wide area of the network using a communication protocol unique to the application, and waits for a response from the server to the request. However, there is a problem that it is not easy for a client to transmit a request to a different network segment by using a dedicated communication protocol for searching for server information. The reason is that, for example, it is considered that it takes a lot of trouble and cost to arrange a router capable of interpreting a unique communication protocol in each network segment.

  As a technique related to obtaining an effective connection destination when communication with the server becomes impossible as described above, for example, there are the following patent documents.

  Patent Literature 1 discloses a network device which becomes a DHCP (Dynamic Host Configuration Protocol) server when a failure occurs in a DHCP (Dynamic Host Configuration Protocol) server and communication becomes impossible, and the server becomes a DHCP server in place of the failed DHCP server. This network device operates as a wireless access point connected between a DHCP server and a DHCP client.

  Further, Patent Document 2 discloses a system in which a DHCP service is load-balanced in a client-driven manner. In this system, a client can acquire load information of a plurality of servers and select a connection destination server based on the load information.

JP 2014-175748 A US Patent Application Publication No. 2013/0166748

  However, the network device disclosed in Patent Document 1 has a problem that the network device needs to have a function of a service provided by a server. For example, if clients using the service are distributed over a plurality of networks, a plurality of such network devices may be required. Further, when the server address change causes communication failure, the client cannot use the original server even if the original server continues to provide the service.

  Further, also in the system disclosed in Patent Document 2, since the client selects a server based on the load of each server, there is a problem that the original server whose address has been changed cannot always be used. That is, in this system, there is a problem that even if there is a server that has been used before, the client cannot distinguish it.

  Therefore, even if the network devices and systems described in Patent Literatures 1 and 2 are used, there remains a problem that it is not known how the terminal device is recognized as a management target of the terminal device in the server.

  One object of the present invention is to respond to a request transmitted from a terminal device without specifying a destination by using a communication protocol whose purpose is not to transmit information indicating a management state of the terminal device in a specific service. It is an object of the present invention to provide a server device for notifying information indicating a management state of a terminal device.

  In order to achieve the above object, a server device according to one embodiment of the present invention has the following configuration.

That is, the server device according to one embodiment of the present invention includes:
Request receiving means for transmitting a request that does not specify a destination, using a communication protocol for returning a response including predetermined service information to the request to the request source, receiving the request from the terminal device,
Response means for transmitting, using the communication protocol, the response to the request, which is at least information different from the service information and includes management status information indicating a management status of the terminal device.

In addition, in order to achieve the above object, a terminal device according to one embodiment of the present invention,
A request not specifying a destination is transmitted to one or more server devices, and the request not specifying a destination is transmitted using a communication protocol that obtains a response including predetermined service information for the request from each of the server devices. Requesting means to
In response to the request, the service information is at least information different from the service information, the response including the management status information indicating the management status of its own device in each server device, received using the communication protocol, at least And response receiving means for outputting information indicating a transmission source of the response selected based on the management state information.

In order to achieve the above object, a client-server system according to one embodiment of the present invention includes at least one server device and a terminal device having the above-described configuration,
Using a communication protocol that transmits a request that does not specify a destination and returns a response including predetermined service information to the request to the request source,
Transmitting the request without specifying the destination, a terminal device having the configuration described above,
For the received request, transmitting the response including the management state information indicating the management state of the terminal device to the terminal device, comprising the above-described configuration, including at least one server device,
The terminal device outputs information indicating a transmission source of the response selected based on management status information indicating a management status of the terminal device in each of the server devices.

In order to achieve the above object, the notification method according to one embodiment of the present invention provides an information processing device
Transmitting a request that does not specify a destination, using a communication protocol that returns a response including predetermined service information to the request to the requestor, receiving the request from the terminal device;
The response to the request, which is at least information different from the service information and includes management status information indicating a management status of the terminal device, is transmitted using the communication protocol.

In order to achieve the above object, an information acquisition method according to one embodiment of the present invention provides an information processing device
A request not specifying a destination is transmitted to one or more server devices, and the request not specifying a destination is transmitted using a communication protocol that obtains a response including predetermined service information for the request from each of the server devices. And
For each of the requests, the service information is at least different from the service information, the response including the management status information indicating the management status of its own device in each server device, received using the communication protocol,
At least information indicating a source of the response selected based on the management state information is output.

  The same object is also achieved by a computer program for realizing a server apparatus, a terminal apparatus, a client server system, and a corresponding method each having the above-described configuration by a computer, and a computer-readable program storing the computer program. This is also achieved by a possible storage medium.

  The present invention has the effect that the managed state of the terminal device can be notified from the server device.

FIG. 2 is a configuration diagram illustrating an example of a communication environment in the client server system according to the first embodiment of the present invention. It is a lineblock diagram showing an example of a communication environment in a client server system concerning a second embodiment of the present invention. 9 is a flowchart illustrating operations performed by the server device 100A or 100B and the terminal device 200 in the second embodiment. It is a figure showing an example of the communication sequence in a 2nd embodiment. FIG. 13 is a configuration diagram illustrating an example of a communication environment in a client server system according to a third embodiment of the present invention. 13 is a flowchart illustrating operations performed by a server device 400 and a terminal device 500 in a third embodiment. It is a figure showing an example of the communication sequence in a 3rd embodiment. FIG. 11 is a diagram illustrating a configuration of a computer (information processing device) applicable to each embodiment of the present invention and a client server system according to a modified example thereof.

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

<First embodiment>
FIG. 1 is a configuration diagram illustrating an example of a communication environment in the client server system according to the first embodiment of the present invention. Referring to FIG. 1, the client server system according to the present embodiment includes a server device 1 and a terminal device 10.

  The server device 1 and the terminal device 10 can communicate with each other via a communication network (hereinafter simply referred to as a network) 1001 such as the Internet or a local LAN (local area network). The network 1001 may include a communication device that relays according to a communication protocol between the server device 1 and the terminal device 10. Further, in the client server system according to the present embodiment, a plurality of server devices 1 may be included. Similarly, in the client server system according to the present embodiment, a plurality of terminal devices 10 may be included.

  The server device 1 and the terminal device 10 are configured by a general information processing device (computer) that operates under the control of a computer program (software program) executed using a CPU (Central Processing Unit: not shown). May be. Alternatively, each unit of the server device 1 and the terminal device 10 may be configured by a dedicated hardware device or a logic circuit. An example of a hardware configuration in which the server device 1 and the terminal device 10 are realized by a computer will be described later with reference to FIG.

  The server device 1 includes a request receiving unit 2 and a response unit 3.

  The request receiving unit 2 can receive a request from the terminal device 10. The communication protocol used by the request receiving unit 2 to receive the request can transmit a request without specifying a destination sent from the terminal device 10 and return a response including predetermined service information to the request to the request source. Communication protocol. The transmission of the request includes that the request can be delivered to the server device 1 that can receive the request even if the destination is not specified. For example, such a communication protocol may include a definition of a mechanism for routing a request to the server devices 1 belonging to different segments.

  In response to the received request, the response unit 3 transmits, using a communication protocol, a response that is at least information different from the service information and includes management status information indicating the management status of the terminal device 10 that has sent the request. be able to. The management status information is, for example, information based on whether or not the terminal device 10 has accessed the server device 1, the use status of the service provided by the server device 1, or whether or not the terminal device 10 is recognized as managing the terminal device 10. There may be. The management state information may be generated by the server device 1. Alternatively, the management state information may be obtained from an external device (not shown) or a functional unit (not shown) that provides a service.

  The terminal device 10 includes a request unit 11 and a response receiving unit 12.

  The request unit 11 can transmit a request without specifying a destination by using the above-described communication protocol. In the terminal device 10, this communication protocol is a communication protocol for transmitting a request not specifying a destination to one or more server devices 1 and obtaining a response including predetermined service information for the request from each server device. It can also be said.

  The response receiving unit 12 can receive each response including at least the above management state information in response to the request using the above-described communication protocol. In the terminal device 10, this management status information is different from the service information, and can be said to be information indicating the management status (managed status) of its own device in each server device 1. Then, the response receiving unit 12 can output at least information indicating the transmission source (server device 1) of the response selected based on the management state information included in each response. The response receiving unit 12 may output information on the plurality of server devices 1. The response receiving unit 12 may output to an external device (not shown), a functional unit (not shown) that uses the service of the server device 1, or an output device (not shown). The response receiving unit 12 may output, for example, the content of the management state information, in addition to the information indicating the transmission source of the response.

  As described above, in the present embodiment, a request transmitted from a terminal device without specifying a destination using a communication protocol that is not intended to transmit information indicating the management state of the terminal device in a specific service is used. On the other hand, there is an effect that a server device or the like that notifies information indicating the management state of the terminal device can be provided.

  The reason is that the request receiving unit 2 and the response unit 3 of the server device 1 transmit a request from the terminal device 10 whose destination is not specified, and return a response including predetermined service information to the request to the request source. Is used to receive a request and return (transmit) a response. Also, this is because the response unit 3 returns a response including management status information indicating the management status of the terminal device 10 that has transmitted the request, using the communication protocol.

<Second embodiment>
Next, a second embodiment based on the first embodiment will be described. In the following, a description will be given mainly of a characteristic portion according to the second embodiment, and a duplicate detailed description of the components of the second embodiment having the same configuration as the first embodiment will be omitted.

  First, the configuration of the present embodiment will be described below with reference to FIG. FIG. 2 is a configuration diagram illustrating an example of a communication environment in the client server system according to the second embodiment of the present invention. Referring to FIG. 2, the present embodiment includes server devices 100A and 100B, terminal device 200, and router 300.

  The server device 100A and the router 300 can communicate with each other via a communication network (hereinafter simply referred to as a network) such as the Internet or a local LAN (local area network). The terminal device 200 and the router 300 can communicate with each other via a communication network such as the Internet or a private LAN. The server device 100A and the terminal device 200 can communicate with each other via the router 300. The server device 100B and the terminal device 200 can communicate with each other via the Internet or a private LAN. The client server system according to the present embodiment may include one or three or more server devices 100, a plurality of terminal devices 200, and a plurality of routers 300, respectively.

  The present embodiment is a client server system using a communication sequence of PXE (Preboot Execution Environment) boot as a specific example of the communication protocol in the first embodiment. The PXE boot is a network boot standard for starting a computer by acquiring an OS (Operating System) image from a server.

  The communication sequence of the PXE boot used in the present embodiment is a part in which a booting computer acquires an IP address by DHCP. Specifically, a DHCP Discover packet is used as a request in the first embodiment. In addition, a DHCP Offer packet is used as a response in the first embodiment. That is, in the present embodiment, it can be said that DHCP corresponds to the communication protocol in the first embodiment. Details of the communication sequence of this PXE boot are described in RFC4578 (M. Johnston, et al., "Dynamic Host Configuration Protocol (DHCP) Options for the Intel Preboot eXecution Environment (PXE)", [online], November 2006, IEEE. , [Search on March 11, 2016], and the Internet <URL: https://www.ietf.org/rfc/rfc4578.txt>).

  In a normal PXE boot, a DHCP server is required as means for allocating a temporary IP address to a computer to be started. However, in the present embodiment, since the terminal device 200 is in a communicable state as described above, the terminal device 200 has already acquired the IP address. That is, the client server system according to the present embodiment does not require a DHCP server, unlike a system using a normal PXE boot. In the present embodiment, the server devices 100A and 100B correspond to a PXE boot server. Further, the terminal device 200 corresponds to a computer to be booted.

  The server devices 100A and 100B, the terminal device 200, and the router 300 are operated by a general information processing device (computer) operated under the control of a computer program (software program) executed using a CPU (not shown). It may be configured. Alternatively, each unit of the server devices 100A and 100B, the terminal device 200, and the router 300 may be configured by a dedicated hardware device or a logic circuit. A hardware configuration example in which the server devices 100A and 100B, the terminal device 200, and the router 300 are implemented by a computer will be described later with reference to FIG.

  Although omitted in FIG. 2, the server device 100B has the same configuration and function as the server device 100A. In the present embodiment, the functional units having the same function of the server devices 100A and 100B are distinguished from each other by the symbol “A” or “B” added to the end of the reference numeral. In the following description of the configuration, the description of the configuration in which “A” is added to the reference numeral can be replaced with the description of the configuration in which “B” is added to the reference numeral. In the following, if the server device 100A or 100B has not been determined, or if the server device 100A or 100B is the same, it is also described as “server device 100”.

  The server device 100A includes a request receiving unit 102A, a response unit 103A, a storage device 110A, and a service server unit 120A. The storage device 110A can store the management status information 111A. The storage device 110A is realized by, for example, a semiconductor memory device or a disk device.

  The management state information 111A is based on the management state information in the first embodiment. In the present embodiment, the management status information 111A manages the management status of the terminal device 200 according to three statuses. The terminal device 200 connected to the service server unit 120 is registered in the management status information 111A as a management status of “Managed” indicating that the terminal device has already been managed. The terminal device 200 that has received the request and returned a response but has not been managed is registered in the management status information 111A as a management status of “Unmanaged” indicating that it may be managed by another server device 100. Is done. The terminal device 200 to which the request has not been sent has not been registered in the management status information 111A. The terminal device 200 that is not registered in such management state information 111A is represented in the response as a management state of “New”, which is a new management state.

  The request receiving unit 102A is based on the request receiving unit 2 in the first embodiment. In the present embodiment, the request receiving unit 102A can receive a DHCP Discover packet as a request from the terminal device 200.

  The response unit 103A is based on the response unit 3 in the first embodiment. In the present embodiment, the response unit 103A transmits a DHCP Offer packet as a response to the terminal device 200. According to the DHCP specification, a normal DHCP Offer packet includes information indicating an IP address that can be assigned to the computer that is the source of the DHCP Discover packet. That is, in the present embodiment, the “information indicating an assignable IP address” corresponds to the “predetermined service information included in the response” in the first embodiment. The response unit 103A transmits a DHCP Offer packet including information indicating a management state of the terminal device 200 based on the management state information 111A without including information indicating an assignable IP address. The response unit 103A in the present embodiment further updates the management state information 111A based on the reception of the DHCP Offer packet.

  The service server unit 120A is a server function unit of a service provided by the server device 100A to a service client unit 210 (described later) of the terminal device 200. The service server unit 120A updates the management status information 111A based on the management status of the terminal device 200 that receives the service.

  The configurations and functions of the request receiving unit 102A and the responding unit 103A in the server device 100A are the same as those of the first embodiment except for the above-described points, and therefore, duplicate detailed description will be omitted.

  The terminal device 200 includes a request unit 201, a response receiving unit 202, and a service client unit 210.

  The request unit 201 is based on the request unit 11 in the first embodiment. In the present embodiment, the request unit 201 can transmit a DHCP Discover packet, which is a specific example of the request in the first embodiment, without specifying the server device 100 that requests a response as the destination.

  The response receiving unit 202 is based on the response receiving unit 12 in the first embodiment. In the present embodiment, the response receiving unit 202 can receive a DHCP Offer packet from the server devices 100A and 100B as a response to the DHCP Discover packet. The response receiving unit 202 selects the transmission source server device 100A or 100B based on the management status information included in the received DHCP Offer packet. In the present embodiment, the response receiving unit 202 outputs address information indicating the IP address of the selected server device 100A or 100B to the service client unit 210.

  The service client unit 210 is a client function unit that can use services provided by the server device 100. The service client unit 210 requests, via the request unit 201, address information of the server device 100 that provides the service. Further, the service client unit 210 can access the service of the server device 100A or 100B based on the address information of the server device 100A or 100B received from the response receiving unit 202.

  The configurations and functions of the request unit 201 and the response receiving unit 202 in the terminal device 200 are the same as those of the first embodiment except for the above-described points, and therefore, duplicate detailed description will be omitted.

  The router 300 includes a transfer unit 301.

  The transfer unit 301 is a communication device that can transfer a request (DHCP Discover) and a response (DHCP Offer) by the DHCP relay function.

  Next, the operation of the present embodiment having the above-described configuration will be described in detail. FIG. 3 is a flowchart illustrating operations performed by the server device 100A or 100B and the terminal device 200 in the second embodiment. First, an operation when the terminal device 200 uses a service for the first time will be described as an example. At this time, it is assumed that the terminal device 200 is not registered in any of the management status information 111A and 111B of the server devices 100A and 100B.

  First, in the terminal device 200, the service client unit 210 requests the request unit 201 for address information of the server device 100 that provides the service. The request unit 201 requests management state information of the server device 100 (Step A10). Specifically, the request unit 201 transmits a DHCP Discover packet by broadcast. The DHCP Discover packet is received by the router 300 and the server 100B in the same network segment (Step B20). The router 300 transfers the DHCP Discover packet received from the terminal device 200 to the server device 100A in a different network segment by the function of the DHCP relay. The server device 100A receives the DHCP Discover packet transferred by the router 300 (Step B20). The router 300 may acquire, for example, routing information to the transferable server device 100 such as the server device 100A by setting in advance. The router 300 can be realized by a general router that can execute a normal DHCP relay function.

  Since the operation of the server device 100B in steps B20 to B23 is the same as the operation of the server device 100A, the following operation of the server device 100A can be replaced with the description of the operation of the server device 100B.

  In the server device 100A, the request receiving unit 102A receives the request (DHCP Discover packet) from the terminal device 200 (Step B20).

  Next, the response unit 103A transmits a response including management state information corresponding to the transmission source of the received request (Step B21). Specifically, the response unit 103A reads the management state information 111A corresponding to the terminal device 200 that is the transmission source of the DHCP Discover packet from the storage device 110A. In this case, the information corresponding to the terminal device 200 is not registered in the management status information 111A. Therefore, the response unit 103A returns, via the router 300, a response including management state information in which the management state of the terminal device 200 is new, that is, “New”.

  For example, the response unit 103A may set “New” in the DHCP option 60 in the DHCP Offer packet as the management state information. The DHCP option 60 is an area in which a class identifier (Class Id) can be stored. The router 300 transfers the DHCP Offer packet transmitted from the server device 100A to the terminal device 200 by the DHCP relay function.

  At this time, the response unit 103A does not include information indicating an assignable IP address or the like in the DHCP Offer packet. The response unit 103A does not manage the assignable IP addresses.

  After transmitting the response, if the management state is “New” (YES in step B22), the response unit 103A updates the management state information 111A of the terminal device 200 to “Unmanaged” (step B23).

  The response unit 103B of the server device 100B also directly transmits the DHCP Offer packet in which the option 60 having the same content is set to the terminal device 200 in the same network segment.

  On the other hand, after transmitting the request, in the terminal device 200, the response receiving unit 202 may wait for a response over a predetermined period, for example. The response receiving unit 202 receives a response from each of the server devices 100A and 100B (Step A11). Specifically, the response receiving unit 202 receives two DHCP Offers in which the option 60 storing the management state information is set to “New”.

  The response receiving unit 202 outputs the source of the selected response based on the management status information included in the response (step A12). For example, the response receiving unit 202 may select the transmission source of the response, with the management state information giving priority to "Managed", "Unmanaged", and "New" in this order. When the management state information is the same, the response receiving unit 202 may output the source of one response selected by a predetermined method. Alternatively, the response receiving unit 202 may output a plurality of transmission sources that have received the response of the same management state information. As an example, the response receiving unit 202 selects the response of the server device 100B that is the transmission source of the response received earlier, and outputs the address information of the server device 100B to the service client unit 210.

  If the DHCP Discover packet is received by a general DHCP server (not shown), the general DHCP server sends a DHCP Offer packet which is a general response in which the management status information is not set in the option 60. Should be returned. Therefore, when valid management state information is not set in the response, the response receiving unit 202 may perform the above-described operation of step A12 except for the response.

  In this way, the service client unit 210 can acquire the address information of the server device 100B that provides the target service. When the service client unit 210 of the terminal device 200 accesses the service of the server device 100B, in the server device 100B, the service server unit 120B provides the service to the terminal device 200. In the present embodiment, the service server unit 120B updates the management status information 111B corresponding to the terminal device 200 providing the service to “Managed” indicating that the terminal device 200 has been managed. At this time, the management status information 111A of the server device 100A remains "Unmanaged" indicating that the server device 100A may be managed by another server device 100.

  Next, with reference to FIG. 4, an operation when the service client unit 210 becomes unable to communicate with the server device 100B while using the service of the server device 100B will be described. FIG. 4 is a diagram illustrating an example of a communication sequence according to the second embodiment. In the following description, as an example, it is assumed that communication becomes impossible due to a change in the IP address of the server device 100B. That is, each unit of the server device 100B is operating normally.

  As in the case where the service is used for the first time as described above, a DHCP Discover packet is transmitted from the terminal device 200 (Step A10 in FIG. 3) and received by the server devices 100A and 100B (Step B20 in FIG. 3). Referring to FIG. 4, the server device 100B receives the DHCP Discover packet 600. Similarly, the server device 100A receives the DHCP Discover packet 601.

  The response unit 103B of the server device 100B transmits a DHCP Offer packet 603 (FIG. 4) in which “Managed” is set to the DHCP option 60 to the terminal device 200 based on the management status information 111B (Step B21). The source of the DHCP Offer packet 603 is the changed IP address of the server device 100B. Similarly, the response unit 103A of the server device 100A transmits the DHCP Offer packet 604 (FIG. 4) in which “Unmanaged” is set to the DHCP option 60 to the terminal device 200 (Step B21).

  Thereafter, the response units 103A and 103B of the server devices 100A and 100B end the operation without updating the management state information 111A and 111B because the management state information is not “New” (NO in step B22). .

  In the terminal device 200, the response receiving unit 202 receives two DHCP Offer packets in which different management state information is set (Step A11). The response receiving unit 202 selects the server device 100B that has transmitted the DHCP Offer packet 603 in which “Managed” is set to the option 60 as the management state information (step A12). Then, the response receiving unit 202 outputs, to the service client unit 210, the changed address information of the server device 100B that is the transmission source of the DHCP Offer packet 603.

  In this manner, the server devices 100A and 100B in the present embodiment change the management status of the terminal device 200 using the PXE protocol (DHCP protocol), which is not intended to transmit information indicating the management status of the terminal device in the service. The terminal device 200 can be notified. The terminal device 200 can transmit a request without specifying a destination, and in response to the request, can acquire management state information of the terminal device 200 from the server devices 100A and 100B. As described above, the present embodiment has the same effects as those of the above-described first embodiment.

  Further, in the present embodiment, the DHCP protocol which is a communication protocol for requesting the provision of a resource called an IP address is used, but the above-described response including the management state information is transmitted and received without providing the resource. There is also an effect that can be done. As a result, a DHCP server, which is indispensable for normal PXE boot, is not required, so that there is an effect that the system configuration is simple.

  The reason is that the terminal device 200 and the server device 100 do not provide resources (addresses), which are unnecessary operations, and are required to transmit and receive the management status information of the request and the response within a range not deviating from the protocol specification. This is because only the part is used.

(Modification of Second Embodiment)
In addition, the following can be considered as a modified example of the present embodiment.

  For example, in the present embodiment, unlike DHCP, it is possible to adopt a type of protocol that does not require the provision of resources. This embodiment may employ, for example, a protocol used for a discovery service or the like for acquiring setting information or configuration information in a communication device. Further, a protocol used for system management for transmitting and receiving a command to a communication device included in the system and a response to the management device may be employed.

  The management state of the terminal device 200 in the server device 100 only needs to be able to represent at least two states of whether or not the terminal device 200 is managed. For example, the response unit 103 may simply respond based on the “Managed” management status updated by the service server unit 120 without updating the management status information 111. Alternatively, the management state may be four or more states.

  Further, the management status information included in the response may include a management status based on the status of the server device 100. For example, the server device 100 may include, as the management status, a status indicating that a new connection request for a service from the terminal device 200 cannot be accepted.

  The method in which the units of the server device 100 and the terminal device 200 in the present embodiment transfer information to each other is not limited to the above-described method. For example, instead of directly updating the management status information, the service server unit 120 of the server device 100 may notify the response unit 103 of the management status. In addition, the response unit 103 or another functional unit (not shown) may receive the notification of the management status in the server device 100 from another server device 100 and update the management status information 111 to “Unmanaged”.

<Third embodiment>
Next, a third embodiment based on the above-described first and second embodiments and a modified example thereof (hereinafter, also simply referred to as “each embodiment”) will be described. Hereinafter, a description will be given mainly of a characteristic portion according to the third embodiment. In the following, the components of the third embodiment having the same configuration as those of the embodiments are denoted by the same reference numerals as those of the embodiments, and the detailed description overlapping the components will be omitted. Omitted.

  The present embodiment is a system in which an original DHCP service function is added to a client-server system using the same PXE boot communication sequence as the second embodiment. That is, the present embodiment is an example of a system that enables the use of the DHCP protocol packet used in the second embodiment and the original DHCP protocol packet that allocates an IP address resource.

  First, the configuration of the present embodiment will be described below with reference to FIG. FIG. 5 is a configuration diagram illustrating an example of a communication environment in the client server system according to the third embodiment of the present invention. Referring to FIG. 5, the present embodiment includes a server device 400 and a terminal device 500.

  The server device 400 and the terminal device 500 can communicate with each other via a communication network (hereinafter simply referred to as a network) 1001 such as the Internet or a local LAN (local area network). The network 1001 may include a communication device that relays according to a communication protocol between the server device 400 and the terminal device 500, such as the router 300 in the second embodiment. Further, in the client server system according to the present embodiment, a plurality of server devices 400 may be included. Similarly, the client server system according to the present embodiment may include a plurality of terminal devices 500.

  The server device 400 and the terminal device 500 may be configured by a general information processing device (computer) that operates under the control of a computer program (software program) executed using a CPU (not shown). . Alternatively, each unit of the server device 400 and the terminal device 500 may be configured by a dedicated hardware device or a logic circuit. An example of a hardware configuration in which the server device 400 and the terminal device 500 are realized by a computer will be described later with reference to FIG.

  The server device 400 includes, in addition to the request receiving unit 402, the response unit 403, the storage device 110, and the service server unit 120 based on the respective units of the server devices 100A and 100B in the second embodiment, a DHCP server unit 401 ( Hereinafter, it may be simply referred to as “server unit 401”). The storage device 110 can store management state information 111 based on the second embodiment. The storage device 110, the management status information 111 stored in the storage device 110, and the service server unit 120 are the same as those in the second embodiment, and a detailed description thereof will not be repeated.

  The DHCP server unit 401 receives a DHCP Discover packet (hereinafter, also referred to as “first request”), and, as a response to the first request, a DHCP Offer packet including notification valid information (hereinafter, “first response”). Can be sent. The notification valid information is information indicating that a notification service for notifying the management state of the terminal device can be provided. In other words, the notification service is a function of the present invention, which is realized by the request receiving unit 402 and the response unit 403 and described in the present embodiment. The DHCP server unit 401 can receive a first request and transmit a first response via a first port that provides a DHCP service. In the present embodiment, as an example, the first port is the same as the port on which the request receiving units 102A and 102B in the second embodiment wait for a DHCP Discover packet. It can be said that the first request is a request corresponding to the request (DHCP Discover packet) in the second embodiment. However, the first response is different from the response (DHCP Offer packet) in the second embodiment, and is a response newly provided in the present embodiment.

  In addition, the DHCP server unit 401 can execute, for example, a server function of providing a general DHCP service. That is, the DHCP server unit 401 can receive a series of DHCP requests via the first port that provides the DHCP service. The DHCP request received by the DHCP server unit 401 includes a request for requesting the management state of the terminal device 500. The DHCP server unit 401 can return a DHCP response corresponding to the received series of DHCP requests to the transmission source. Well-known techniques can be used for the general DHCP service functions, request and response data structures, protocol sequences, and the like, and thus detailed descriptions in this embodiment are omitted.

  The request receiving unit 402 and the response unit 403 in the present embodiment communicate with the terminal device 500 via a second port different from the DHCP server unit 401. In addition, the request receiving unit 402 can receive a DHCP Request packet (hereinafter, also referred to as a “second request”) instead of the DHCP Discover packet. The second request can be said to be a request in which the first request sent to the DHCP server unit 401 is resent by the terminal device 500 to the second port.

  The response unit 403 can transmit a DHCP Ack packet (hereinafter, also referred to as a “second response”) including information including a management state, instead of the DHCP Offer packet. It can be said that this second response is a response corresponding to the DHCP Offer packet in the second embodiment. The configurations and functions of the request receiving unit 402 and the response unit 403 are the same as those of the second embodiment except for the above-described points, and therefore, duplicate detailed description will be omitted.

  The terminal device 500 includes a request unit 501, a response receiving unit 502, and a service client unit 210 based on each unit of the terminal device 500 in the second embodiment. The service client unit 210 is the same as that of the second embodiment, and a detailed description thereof will not be repeated.

  As in the second embodiment, the request unit 501 can transmit a DHCP Discover packet (first request) without designating the server device 100 requesting a response as a destination. As a response thereto, if the DHCP Offer packet (first response) received from the server device 400 includes notification validity information indicating that a service for notifying the management status of the terminal device can be provided, the server device 400 A DHCP Request packet (second request) can be transmitted to the second port. This DHCP Request packet is a packet that plays the role of a DHCP Discover packet in the second embodiment.

  The response receiving unit 502 can receive a DHCP Ack packet (second response) instead of a DHCP Offer packet (first response) via the second port of the server device 400. The response receiving unit 502 acquires information on the management state from the DHCP Ack packet.

  The configurations and functions of the request unit 501 and the response receiving unit 502 are the same as those of the second embodiment except for those described above, and a detailed description thereof will not be repeated.

  Next, the operation of the present embodiment having the above-described configuration will be described in detail. FIG. 6 is a flowchart illustrating operations performed by the server device 400 and the terminal device 500 in the third embodiment.

  Referring to the operation of the server device 400 in FIG. 6, the difference between the present embodiment and the operation in the second embodiment shown in FIG. 3 is that the request receiving unit 402 receives another request before step B20 of receiving the request. The point is that the exchange of the request and the response of the stage is executed. Further, in steps A30 (corresponding to step A11 in FIG. 3), B20 and B21 of FIG. 6, the ports for transmission and reception are simply different. Therefore, the operation of the present embodiment will be described below using a communication sequence in which the difference in operation from the second embodiment is easily understood. FIG. 7 is a diagram illustrating an example of a communication sequence according to the third embodiment.

  In the following description, it is assumed that the first port is, for example, port 67 of UDP (User Datagram Protocol) known as a port of a general DHCP service. The second port is assumed to be, for example, UDP port 4011. The first port and the second port may be ports other than the above example. In FIG. 7 and the following description, a port may be expressed as “UDP: 67” by associating a protocol with a port number.

  First, the request unit 501 of the terminal device 500 receives a request from the service client unit 210 and transmits a request for management state information (first request) to the first port (step A10 in FIG. 6). . This operation is the same as the operation of step A10 in FIG. 3 in the second embodiment. Specifically, referring to FIG. 7, the request unit 501 transmits a DHCP Discover packet 610 by broadcast specifying UDP: 67 as the first port as the destination port, as in the second embodiment.

  In the server device 400, the DHCP server unit 401 waiting for reception at the first port receives the DHCP Discover packet 610 (first request) (Step B40 in FIG. 6). The DHCP server unit 401 transmits a response obtained by adding notification valid information indicating that a service for notifying the management state of the terminal device can be provided to the contents of a DHCP Offer packet which is a response of a general DHCP service ( Step B41 in FIG. 6). Specifically, the DHCP server unit 401 transmits, to the terminal device 500, a DHCP Offer packet 611 in which the notification valid information “PXECClient” is set in the DHCP option 60. The character string “PXECClient” is an example. The notification effective information may be represented by another character string, a code number, or the like. Also, the DHCP server unit 401 may transmit a DHCP Offer in which notification valid information is set, even for a DHCP Discover packet transmitted by a general DHCP client.

  The response receiving unit 502 of the terminal device 500 receives the DHCP Offer packet 611 (first response) as a response to the DHCP Discover packet 610 (first request) (Step A30). The response receiving unit 502 checks whether the received DHCP Offer packet 611 includes notification valid information (step A31). Specifically, the response receiving unit 502 checks whether the option 60 of the DHCP Offer packet 611 includes a character string “PXECClient”.

  If the response includes the notification valid information (YES in step A31), the request unit 501 requests management state information from the second port at the transmission source of the DHCP Offer packet 611 (second request). Is transmitted (step A10 in FIG. 6). Specifically, the requesting unit 501 transmits the DHCP Request packet 612 (second request) with the address of the server device 400 as the destination IP address and UDP: 4011 as the destination port. When the notification valid information is included in the plurality of DHCP Offer packets 611, the request unit 501 transmits the DHCP Request packet 612 to the transmission source of each DHCP Offer packet 611.

  In the server device 400, the request receiving unit 402 waiting for reception on the second port receives the DHCP Request packet 612 (second request) (Step B20 in FIG. 6). The operation of the request receiving unit 402 in this step is basically the same as the operation in step B20 of FIG. 3 in the second embodiment. That is, in the present embodiment, the type of the requested packet is replaced with DHCP Request instead of DHCP Discover.

  Next, the response unit 403 transmits a response (second response) including the management status information corresponding to the transmission source of the request (step B21). Specifically, the response unit 403 transmits the response to the management status information 111. Based on this, information indicating the management state is set in the DHCP option 60, and the DHCP Ack packet 613 (second response) is transmitted to the terminal device 500. The operation of the response unit 403 in this step is basically the same as the operation of step B21 in FIG. 3 in the second embodiment. That is, in the present embodiment, the type of the response packet is replaced with DHCP Ack instead of DHCP Offer. This step and subsequent steps B22 and B23 in FIG. 6, which are operations in the server device 400, are the same as steps B22 and B23 in FIG. Detailed description is omitted.

  On the other hand, in the terminal device 500, the response receiving unit 502 receives a DHCP Ack packet 613 (second response) as a response to the DHCP Request packet 612 (second request) (Step A30 in FIG. 6). This time, since the notification does not include the notification valid information (NO in step A31), the response receiving unit 502 outputs the transmission source of the response selected based on the management state information included in the response (step A12). The operation of the response receiving unit 502 in this step is basically the same as the operation of step A12 in FIG. 3 in the second embodiment. That is, in the present embodiment, the type of the response packet is replaced with DHCP Ack instead of DHCP Offer. This step and the subsequent operation of the terminal device 500 are the same as those of the second embodiment, and therefore, duplicate detailed description will be omitted.

  In step A31, if the received response (DHCP Offer or DHCP Ack) does not include any of the notification valid information and the management state information, the response receiving unit 502 performs the above-described operations except for such a response. Operation may be performed. This is because such a response may be a response from a general DHCP server.

  Even if a general DHCP client (not shown) who wants to use a normal DHCP service receives the DHCP Offer packet 611 in which the notification valid information is set in the option 60 from the DHCP server unit 401, the notification is valid. Do not reference information. That is, a general DHCP client can transmit a DHCP Request to the DHCP server unit 401 based on the general response content of the DHCP Offer packet 611. Thereafter, the DHCP server unit 401 and the general DHCP client can continue the communication relating to the address assignment in accordance with the normal DHCP protocol. When it is necessary to receive an IP address assignment, the terminal device 500 may receive an IP address assignment from the DHCP server unit 401 by performing the same operation as the above-described general DHCP client.

  Further, the part where the notification valid information and the management state information can be set is not limited to the DHCP option 60. Such information can be set in any part of various DHCP packets that does not affect the operation of general DHCP clients and DHCP servers.

  In the present embodiment, the request unit 501 of the terminal device 500 may hold the second port in advance by using setting information or the like. Alternatively, the request unit 501 may acquire the information of the second port from the server device 400 by using the DHCP Offer packet 611 or the like.

  In this manner, the server device 400 according to the present embodiment can notify the terminal device 500 of the management state of the terminal device 500. Further, the server device 400 and the terminal device 500 according to the present embodiment can coexist while avoiding port conflict with a general DHCP service by the DHCP server unit 401.

  As described above, in the present embodiment, in addition to the same effects as those of the above-described embodiments, a general DHCP service and a service to be described by the present embodiment in the same server apparatus 400 are also described. There is also an effect that the management status notification service of the invention can coexist.

  The reason is that the DHCP server unit 401 sets, in a portion of the DHCP Offer packet that does not affect the operation of a general DHCP client, notification effective information indicating that the service for notifying the management state is effective. . Then, the request unit 501 of the terminal device 500 requests the request receiving unit 402 waiting at the second port again for information on the management state based on the notification validity information.

<Example of hardware configuration>
In each of the above-described embodiments, each unit shown in FIGS. 1, 2, and 5 may be configured by an independent hardware circuit, or may be a function (processing) unit (software module) of a software program. It can be regarded as. However, the division of each unit shown in these drawings is a configuration for convenience of explanation, and various configurations can be assumed at the time of mounting. An example of a hardware environment in such a case will be described with reference to FIG.

  FIG. 8 is a diagram illustrating a configuration of a computer (information processing device) applicable to each embodiment of the present invention and a client server system according to a modified example thereof. That is, FIG. 8 illustrates a configuration of a computer capable of realizing at least one of the server devices 1, 100A, 100B, and 400, the terminal devices 10, 200, and 500, and the router 300 in each of the above-described embodiments. A hardware environment capable of realizing each function in each of the embodiments described above is shown.

  8 includes a CPU (Central Processing Unit) 901, a ROM (Read Only Memory) 902, a RAM (Random Access Memory) 903, a communication interface (IF: Interface) 904, a display 905, and a hard disk drive (HDD). : Hard Disk Drive) 906, which are connected via a bus 907. When the computer illustrated in FIG. 8 functions as the server devices 1, 100A, 100B, and 400, the terminal devices 10, 200, and 500, and the router 300, the display 905 does not need to be provided at all times.

  The communication interface 904 is a general communication unit that realizes communication between the computers in each of the above-described embodiments. The hard disk device 906 stores a program group 906A and various types of storage information 906B. The program group 906A is, for example, a computer program for realizing a function corresponding to each block (each unit) shown in FIG. 1, FIG. 2, and FIG. The various types of storage information 906B are, for example, the management state information 111 illustrated in FIGS. 2 and 5. In such a hardware configuration, the CPU 901 controls the entire operation of the computer 900.

  The present invention, which has been described with reference to the above embodiments, uses the functions of the block diagrams (FIGS. 1, 2, and 5) or the flowcharts (FIGS. 3 and 6) referred to in the description of each embodiment. This is achieved by supplying a feasible computer program, reading the computer program to the CPU 901 of the hardware, and executing the computer program. The computer program supplied to the computer may be stored in a nonvolatile storage device (storage medium) such as a RAM 903 or a hard disk device 906 which is a readable and writable temporary storage memory.

  In the above case, the method of supplying the computer program to each device is determined by installing the computer program in the device via various recording media such as a floppy disk (registered trademark) or a CD-ROM (Compact Disc-ROM). In general, a general procedure can be adopted as in the method. As a method of supplying a computer program to each device, a method of externally downloading the program via a communication network 1000 such as the Internet is also common. In such a case, the present invention can be considered to be constituted by a code constituting the computer program or a computer-readable storage medium in which the code is recorded.

  Note that some or all of the above-described embodiments can be described as in the following supplementary notes, but are not limited to the following supplementary notes.

(Appendix 1)
Request receiving means for transmitting a request that does not specify a destination, using a communication protocol for returning a response including predetermined service information to the request to the request source, receiving the request from the terminal device,
A response unit that transmits, using the communication protocol, the response to the request, the response including at least information different from the service information and including management status information indicating a management status of the terminal device. .

(Appendix 2)
The communication protocol is a protocol for requesting the provision of resources by the request,
The server device according to claim 1, wherein the response unit transmits the response without providing the resource.

(Appendix 3)
Using a PXE (Preboot Execution Environment) boot protocol as the communication protocol,
The request receiving means receives a DHCP (Dynamic Host Configuration Protocol) Discover packet as the request,
The server device according to claim 1 or 2, wherein the response unit transmits a DHCP Offer packet including the management state information as the response.

(Appendix 4)
The request is received as a first request via a first port, and a service notifying a response including the predetermined service information and the management state information can be provided as a response to the first request. Server means for returning a first response including the notification valid information;
The request receiving means receives a second request sent from the terminal device using the communication protocol through a second port different from the first port,
The server device according to claim 1 or 2, wherein the response unit transmits a second response including the management state information using the communication protocol in response to the second request, instead of the response.

(Appendix 5)
Using a PXE boot protocol as the communication protocol,
The server means receives a DHCP Discover packet as the first request, and transmits a DHCP Offer packet including the notification valid information as the first response,
The request receiving means receives a DHCP Request packet as the second request,
The server device according to claim 4, wherein the response unit transmits a DHCP Ack packet as the second response.

(Appendix 6)
A request not specifying a destination is transmitted to one or more server devices, and the request not specifying a destination is transmitted using a communication protocol that obtains a response including predetermined service information for the request from each of the server devices. Requesting means to
In response to the request, the service information is at least information different from the service information, the response including the management status information indicating the management status of its own device in each server device, received using the communication protocol, at least A response receiving unit that outputs information indicating a transmission source of the response selected based on the management state information.

(Appendix 7)
Using a PXE (Preboot Execution Environment) boot protocol as the communication protocol,
The request means transmits a DHCP (Dynamic Host Configuration Protocol) Discover packet as the request,
7. The terminal device according to claim 6, wherein the response receiving unit receives a DHCP Offer packet as the response.

(Appendix 8)
The request means transmits the request as a first request to a first port using the communication protocol,
The response receiving means,
As each response to the first request, each first response received using the communication protocol includes notification valid information indicating that a service for notifying a response including the management state information can be provided. The request means transmits a second request to a second port different from the first port,
As each response to the second request, when each of the second responses received using the communication protocol includes the management state information, at least transmission of the response selected based on the management state information The terminal device according to attachment 6 or 7, wherein the terminal device outputs information representing an element.

(Appendix 9)
Using a PXE boot protocol as the communication protocol,
The request means transmits a DHCP Discover packet as the first request, and transmits a DHCP Request packet as the second request,
The terminal according to claim 8, wherein the response receiving unit receives, as the first response, a DHCP Offer packet including the notification valid information, and receives, as the second response, a DHCP Ack packet including the management state information. apparatus.

(Appendix 10)
At least one server device according to any one of supplementary notes 1 to 3, a terminal device according to supplementary note 6 or 7,
Or
At least one of the server device according to Supplementary Note 4 or 5 and the terminal device according to Supplementary Note 8 or 9,
A client server system that outputs information indicating a source of the response, selected based on management status information indicating a management status of the terminal device in each server device, to the terminal device.

(Appendix 11)
Transmitting a request that does not specify a destination, using a communication protocol that returns a response including predetermined service information to the request to the requestor, receiving the request from the terminal device;
A notification method for transmitting, using the communication protocol, the response to the request, the response including at least information different from the service information and including management status information indicating a management status of the terminal device.

(Appendix 12)
The communication protocol is a protocol for requesting the provision of resources by the request,
12. The notification method according to claim 11, wherein when transmitting the response, the response is transmitted without providing the resource.

(Appendix 13)
Using a PXE (Preboot Execution Environment) boot protocol as the communication protocol,
A DHCP (Dynamic Host Configuration Protocol) Discover packet is received as the request,
13. The notification method according to supplementary note 11 or 12, wherein a DHCP Offer packet including the management state information is transmitted as the response.

(Appendix 14)
Upon receiving the request, receiving the request as a first request via a first port;
As a response to the first request, a first response including the predetermined service information and notification effective information indicating that a service for notifying a response including the management state information can be provided,
After returning the first response, receiving a second request sent from the terminal device using the communication protocol through a second port different from the first port,
13. The notification method according to Supplementary Note 11 or 12, wherein a second response including the management state information to the second request is transmitted using the communication protocol instead of transmitting the response.

(Appendix 15)
Using a PXE boot protocol as the communication protocol,
Receiving a DHCP Discover packet as the first request;
Transmitting, as the first response, a DHCP Offer packet including the notification valid information;
Receiving a DHCP Request packet as the second request,
The notification method according to supplementary note 14, wherein a DHCP Ack packet is transmitted as the second response.

(Appendix 16)
A request not specifying a destination is transmitted to one or more server devices, and the request not specifying a destination is transmitted using a communication protocol that obtains a response including predetermined service information for the request from each of the server devices. And
For each of the requests, the service information is at least different from the service information, the response including the management status information indicating the management status of its own device in each server device, received using the communication protocol,
At least an information acquisition method for outputting information indicating a transmission source of the response selected based on the management state information.

(Appendix 17)
Using a PXE (Preboot Execution Environment) boot protocol as the communication protocol,
As the request, a DHCP (Dynamic Host Configuration Protocol) Discover packet is transmitted,
17. The information acquisition method according to supplementary note 16, wherein a DHCP Offer packet is received as the response.

(Appendix 18)
When transmitting the request, to the first port, the request is transmitted as a first request using the communication protocol,
Receiving each response to the first request as each first response using the communication protocol;
In a case where notification effective information indicating that a service for notifying a response including the management state information can be provided is included in each of the first responses, a response to a second port different from the first port is provided. Sends a second request,
Receiving each response to the second request as each second response using the communication protocol;
18. The information acquisition method according to claim 16 or 17, wherein, when the management status information is included in each of the second responses, at least information indicating a transmission source of the response selected based on the management status information is output.

(Appendix 19)
Using a PXE boot protocol as the communication protocol,
Transmitting a DHCP Discover packet as the first request;
Transmitting a DHCP Request packet as the second request,
Receiving, as the first response, a DHCP Offer packet including the notification valid information;
19. The information acquisition method according to claim 18, wherein a DHCP Ack packet including the management state information is received as the second response.

(Appendix 20)
A request receiving process of receiving a request from a terminal device using a communication protocol that transmits a request that does not specify a destination and returns a response including predetermined service information to the request to a request source,
A response process for transmitting, using the communication protocol, the response to the request, which is at least information different from the service information and includes management status information indicating a management status of the terminal device. A first computer program for causing

(Appendix 21)
The communication protocol is a protocol for requesting the provision of resources by the request,
21. The first computer program according to claim 20, wherein, in the response process, the response is transmitted without providing the resource.

(Appendix 22)
Using a PXE (Preboot Execution Environment) boot protocol as the communication protocol,
In the request receiving process, a DHCP (Dynamic Host Configuration Protocol) Discover packet is received as the request,
22. The first computer program according to supplementary note 20 or 21, wherein, in the response process, a DHCP Offer packet including the management state information is transmitted as the response.

(Appendix 23)
The request is received as a first request via a first port, and a service notifying a response including the predetermined service information and the management state information can be provided as a response to the first request. Further performing a server process of returning a first response including the notification valid information;
In the request receiving process, via a second port different from the first port, receiving a second request sent from the terminal device using the communication protocol,
The first computer according to Supplementary Note 20 or 21, wherein, in the response process, a second response including the management state information is transmitted using the communication protocol in response to the second request in place of the response. ·program.

(Appendix 24)
Using a PXE boot protocol as the communication protocol,
In the server processing, a DHCP Discover packet is received as the first request, and a DHCP Offer packet including the notification valid information is transmitted as the first response,
In the request receiving process, a DHCP Request packet is received as the second request,
24. The first computer program according to claim 23, wherein in the response process, a DHCP Ack packet is transmitted as the second response.

(Appendix 25)
A request not specifying a destination is transmitted to one or more server devices, and the request not specifying a destination is transmitted using a communication protocol that obtains a response including predetermined service information for the request from each of the server devices. Request processing,
In response to the request, the service information is at least information different from the service information, the response including the management status information indicating the management status of its own device in each server device, received using the communication protocol, at least A response receiving process of outputting information indicating a transmission source of the response selected based on the management state information.

(Supplementary Note 26)
Using a PXE (Preboot Execution Environment) boot protocol as the communication protocol,
In the request processing, a DHCP (Dynamic Host Configuration Protocol) Discover packet is transmitted as the request,
26. The second computer program according to claim 25, wherein in the response receiving process, a DHCP Offer packet is received as the response.

(Appendix 27)
In the request processing, the request is transmitted to a first port as a first request using the communication protocol, and in the response receiving processing, the communication protocol is used as each response to the first request. When it is recognized that each first response received by using the notification effective information indicating that a service notifying the response including the management state information can be provided, the first response different from the first port is recognized. Send a second request to port 2;
In the response receiving process, when it is recognized that each second response received using the communication protocol as each response to the second request includes the management state information, at least the management state information 27. The second computer program according to claim 25 or 26, wherein information representing a transmission source of the response selected based on the information is output.

(Appendix 28)
Using a PXE boot protocol as the communication protocol,
In the request processing, a DHCP Discover packet is transmitted as the first request, and a DHCP Request packet is transmitted as the second request,
In the response receiving process, a DHCP Offer packet including the notification valid information is received as the first response, and a DHCP Ack packet including the management state information is received as the second response. 2 computer programs.

1, 100, 400 server device 2, 102, 402 request receiving unit 3, 103, 403 responding unit 110 storage device 111 management status information 120 service server unit 10, 200, 500 terminal device 11, 201, 501 requesting unit 12, 202 , 502 Response receiving unit 210 Service client unit 300 Router 301 Transfer unit 401 DHCP server unit (server unit)
900 Information processing device (computer)
901 CPU
902 ROM
903 RAM
904 Communication interface (IF)
905 display 906 hard disk drive (HDD)
906A Program group 906B Various stored information 907 Bus 1000, 1001 Communication network (network)

Claims (6)

Transmits a broadcast including a request, using a communication protocol to send back a response including a predetermined service information to the request to the requester, a request receiving means for receiving the request from the terminal device,
To the request, an information different from at least the service information, the response including the management status information indicating the management status of the terminal device, viewed contains a response means for transmitting by using the communication protocol,
The communication protocol is a DHCP (Dynamic Host Configuration Protocol) requesting the provision of an IP (Internet Protocol) address according to the request,
The response means transmits the response without providing the IP address;
Server device. The request is received as a first request via a first port, and a service notifying a response including the predetermined service information and the management state information can be provided as a response to the first request. Server means for returning a first response including the notification valid information;
The request receiving means receives a second request sent from the terminal device using the communication protocol through a second port different from the first port,
Said response means, instead of the response, the relative second request, the second response including the management state information, according to claim 1 Symbol placement of the server apparatus transmits using the communication protocol. It includes a server apparatus according to claim 1 of at least one, and the end terminal apparatus, a
The terminal device outputs information indicating a transmission source of the response, which is selected based on management status information indicating a management status of the terminal device in each of the server devices ,
The terminal device,
Requesting means for transmitting the request to one or more server devices and transmitting the request using the communication protocol for obtaining a response including predetermined service information for the request from each of the server devices;
In response to the request, at least the service information is different from the service information, the response including the management status information indicating the management status of its own device in each server device, received using the communication protocol, at least Response receiving means for outputting information indicating a transmission source of the response selected based on the management state information,
including,
Client server system. Even without least it includes a server apparatus according to claim 2 one, and the end terminal apparatus, a
The terminal device outputs information indicating a transmission source of the response, which is selected based on management status information indicating a management status of the terminal device in each of the server devices ,
The terminal device,
Requesting means for transmitting the request to one or more server devices and transmitting the request using the communication protocol for obtaining a response including predetermined service information for the request from each of the server devices;
In response to the request, the service information is at least information different from the service information, the response including the management status information indicating the management status of its own device in each server device, received using the communication protocol, at least Response receiving means for outputting information indicating a transmission source of the response selected based on the management state information,
Including
The request means transmits the first request to the first port using the communication protocol,
The response receiving means,
As each response to the first request, each first received using the communication protocol
Notification that a service for notifying a response including the management state information can be provided to the response
When recognizing that valid information was included, the requesting unit transmits the second request to the second port,
As each response to the second request, when each of the second responses received using the communication protocol includes the management state information, at least transmission of the response selected based on the management state information Output information representing the origin,
Client server system. Transmits a broadcast including a request, using a communication protocol to send back to the requester a response containing a predetermined service information to the request, receives the request from the terminal device,
A method for transmitting, using the communication protocol, the response to the request, which is at least information different from the service information and includes management status information indicating a management status of the terminal device ,
The communication protocol is a DHCP requesting provision of an IP address according to the request,
Sending the response without providing the IP address;
Notification method. Transmits a broadcast including a request, and using said communication protocol to send back to the requester a response containing a predetermined service information to the request, the request receiving process of receiving the request from the terminal device,
A response process for transmitting, using the communication protocol, the response to the request, which is at least information different from the service information and includes management status information indicating a management status of the terminal device. then,
The communication protocol is a DHCP requesting provision of an IP address according to the request,
The response process transmits the response without providing the IP address.
Computer program.

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