JP2017175361A - Server device, terminal device, client server system, notification method, information acquisition method, and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for reporting information indicative of a management state of a terminal device in response to a request transmitted from the terminal device without designation of a destination using a communication protocol which is not intended to transmit information indicative of the management state of the terminal device in a specific service.SOLUTION: A server device 1 includes: request reception means 2 which transmits a request having no designated destination, and receives a request from a terminal device 10 using a communication protocol to return to a request source a response which includes predetermined service information to the request; and response means 3 which transmits, in reply to the request, a response which includes management state information indicative of the management state of the terminal device and different from at least the service information, using the communication protocol.SELECTED DRAWING: Figure 1

Description

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

  In a client-server system using a network, when a client becomes unable to communicate with the server due to a change in the IP (Internet Protocol) address of the server or the like, new information regarding the connection destination of the server is required.

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

  A method in which the client transmits a request for retrieving 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 in response to the request. However, there is a problem that it is not easy for a client to send a request to a different network segment using a dedicated communication protocol for retrieving server information. This is because, for example, it is considered that a large amount of labor and cost are required, such as arranging a router capable of interpreting a unique communication protocol in each network segment.

  Examples of the technology related to obtaining an effective connection destination when communication with the server is disabled as described above include the following patent documents.

  Patent Document 1 discloses a network device serving as a DHCP server in place of an abnormal DHCP server when an abnormality occurs in a DHCP (Dynamic Host Configuration Protocol) server and communication becomes impossible. 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 for distributing a load of a DHCP service by a client drive. 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 service function provided by the server. For example, if clients using the service are distributed across multiple networks, multiple such network devices may be required. Further, when the server address change is the cause of communication failure, there is a problem that the client cannot use the original server even if the original server continues to provide services.

  Further, even 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, even if there is a server that has been used before, there is a problem that the client cannot distinguish it.

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

  One object of the present invention is to respond to a request transmitted without specifying a destination from a terminal device using a communication protocol that is not intended to transmit information indicating the management status of the terminal device in a specific service. The object is to provide a server device or the like for notifying information indicating a management state of a terminal device.

  In order to achieve the above object, a server apparatus according to an aspect of the present invention includes the following configuration.

That is, the server device according to one aspect of the present invention provides:
A request receiving means for transmitting a request not specifying a destination and receiving the request from the terminal device using a communication protocol for returning a response including predetermined service information to the request to the request source;
Response means for transmitting, using the communication protocol, the response that is management information that is different from at least the service information and that represents the management status of the terminal device.

In order to achieve the above object, a terminal device according to one aspect of the present invention provides:
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 for obtaining a response including predetermined service information for the request from each server device. Requesting means, and
In response to the request, each of the responses is information different from the service information and includes management status information representing a management status of the server in each server device, using the communication protocol, and at least 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 an aspect of the present invention includes at least one server device and terminal device having the above-described configuration,
Using a communication protocol for transmitting a request not specifying a destination and returning a response including predetermined service information to the request to the request source,
A terminal device having the above-described configuration for transmitting the request not specifying a destination;
Including at least one server device having the above-described configuration, wherein the response including the management status information indicating the management status of the terminal device is transmitted to the terminal device in response to the received request.
Information representing the transmission source of the response selected based on the management state information representing the management state of the terminal device in each server device is output in the terminal device.

In order to achieve the above object, a notification method according to an aspect of the present invention is performed by an information processing device.
Transmitting a request not specifying a destination, using a communication protocol that returns a response including predetermined service information to the request to the request source, receiving the request from the terminal device,
In response to the request, the response is transmitted using the communication protocol, which is information different from at least the service information and includes management status information indicating the management status of the terminal device.

In order to achieve the above object, an information acquisition method according to an aspect of the present invention is performed by 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 for obtaining a response including predetermined service information for the request from each server device. And
In response to the request, each response including the management status information that is different from the service information and represents the management status of the server in each server device is received using the communication protocol,
At least information indicating a transmission source of the response selected based on the management status information is output.

  In addition, the same object is to provide a computer program that implements a server device, a terminal device, a client server system, and a corresponding method having each of the above-described configurations by a computer, and a computer read that stores the computer program. It is also achieved with possible storage media.

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

It is a block diagram which shows an example of the communication environment in the client server system which concerns on the 1st Embodiment of this invention. It is a block diagram which shows an example of the communication environment in the client server system which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows the operation | movement which the server apparatus 100A or 100B and the terminal device 200 perform in 2nd Embodiment. It is a figure which shows an example of the communication sequence in 2nd Embodiment. It is a block diagram which shows an example of the communication environment in the client server system which concerns on the 3rd Embodiment of this invention. It is a flowchart which shows the operation | movement which the server apparatus 400 and the terminal device 500 perform in 3rd Embodiment. It is a figure which shows an example of the communication sequence in 3rd Embodiment. It is a figure which illustrates the structure of the computer (information processing apparatus) applicable to each embodiment of this invention and the client server system which concerns on the modification.

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

<First Embodiment>
FIG. 1 is a configuration diagram showing 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 area network (LAN). The network 1001 may include a communication device that performs relay according to a communication protocol between the server device 1 and the terminal device 10. 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. Or each part of the server apparatus 1 and the terminal device 10 may be comprised by a dedicated hardware device or a logic circuit. A hardware configuration example 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 reception 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 a request can transmit a request sent from the terminal device 10 without designating a destination and return a response including predetermined service information to the request to the request source. It is a communication protocol. The transmission of the request includes that the request can be delivered to the server device 1 that can accept the request even if the destination is not specified. For example, such a communication protocol may include provisions for a mechanism for routing requests 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 including management state information that is at least different from the service information and represents the management state of the terminal device 10 that has transmitted the request. be able to. The management status information is information based on, for example, whether or not the terminal device 10 has accessed the server device 1, the usage status of services provided by the server device 1, or the presence or absence of recognition that the terminal device 10 is managed. There may be. The management status information may be generated by the server device 1. Alternatively, the management status information may be acquired from an external device (not shown) or a function unit (not shown) that provides a service.

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

  The request unit 11 can transmit a request not specifying a destination by using the communication protocol described above. 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.

  In response to the request, the response receiving unit 12 can receive each response including at least the management state information using the communication protocol described above. In the terminal device 10, this management status information is different from the service information and can be said to be information representing the management status (managed status) of the own device in each server device 1. And the response receiving part 12 can output the information showing the transmission origin (server apparatus 1) of the response selected based on the management status information contained in each response at least. The response receiving unit 12 may output information regarding 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, an output device (not shown), or the like. The response receiving unit 12 may output, for example, the contents of the management status information in addition to the information indicating the response transmission source.

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

  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 that does not specify a destination, and return a response including predetermined service information to the request to the request source. This is because a request can be received and a response can be returned (transmitted) using. Further, the response unit 3 returns a response including management state information indicating the management state of the terminal device 10 that has transmitted the request, using the communication protocol.

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

  First, the configuration of this embodiment will be described below with reference to FIG. FIG. 2 is a configuration diagram showing 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, a terminal device 200, and a router 300.

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

  This embodiment is a client server system using a PXE (Preboot Execution Environment) boot communication sequence as a specific example of the communication protocol in the first embodiment. 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 PXE boot used in this embodiment is a part where a booting computer acquires an IP address by DHCP. Specifically, a DHCP Discover packet is used as a request in the first embodiment. Further, a DHCP Offer packet is used as a response in the first embodiment. That is, in this 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 can be found in RFC4578 (M. Johnston, 1 other author, “Dynamic Host Configuration Protocol (DHCP) Options for the Intel Preboot eXecution Environment (PXE)”, [online], November 2006, IEEE). [Search on March 11, 2016], Internet <URL: https://www.ietf.org/rfc/rfc4578.txt>).

  In normal PXE boot, a DHCP server is required as means for assigning 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 IP address has already been acquired. That is, the client server system in this embodiment does not require a DHCP server, unlike a system that uses a normal PXE boot. In the present embodiment, the server apparatuses 100A and 100B correspond to PXE boot servers. The terminal device 200 corresponds to a booting computer.

  Server apparatuses 100A and 100B, terminal apparatus 200, and router 300 are operated by a general information processing apparatus (computer) that operates under the control of a computer program (software program) that is executed using a CPU (not shown). It may be configured. Or each part of server apparatus 100A and 100B, the terminal device 200, and the router 300 may be comprised 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 realized by a computer will be described later with reference to FIG.

  Although omitted in FIG. 2, the server apparatus 100B has the same configuration and functions as the server apparatus 100A. In the present embodiment, the functional units having the same functions of the server apparatuses 100A and 100B are distinguished from each other by the symbol “A” or “B” added to the end of the reference numerals. In the following description of the configuration, the description of the configuration with “A” added to the reference may be replaced with the description of the configuration with “B” added to the reference. Hereinafter, if the server apparatus 100A or 100B is unconfirmed or the server apparatus 100A or 100B is the same, it is also described as “server apparatus 100”.

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

  The management status information 111A is based on the management status 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 state information 111A as a management state “Managed” indicating that the terminal device is already a management target. The terminal device 200 that receives the request and returns a response but is not a management target is registered in the management status information 111 </ b> A as a management status “Unmanaged” indicating that it may be a management target of another server device 100. Is done. The terminal device 200 that has not sent a request yet is not registered in the management status information 111A. The terminal device 200 that is not registered in the management state information 111A is represented in the response as a management state “New” that 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 102 </ b> A 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 rule, a normal DHCP Offer packet includes information representing an IP address that can be assigned to a 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 “predetermined service information included in the response” in the first embodiment. The response unit 103A transmits a DHCP Offer packet including information indicating the management status of the terminal apparatus 200 based on the management status 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 that the server device 100A provides to a service client unit 210 (described later) of the terminal device 200. The service server unit 120A updates the management state information 111A based on the management state of the terminal device 200 that receives the service.

  Since the configurations and functions of the request receiving unit 102A and the response unit 103A in the server device 100A are the same as those in the first embodiment except for the points described above, a detailed description thereof is 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 a request in the first embodiment, without designating the server device 100 that requests a response as a 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 apparatuses 100A and 100B as a response to the DHCP Discover packet. The response receiving unit 202 selects the server apparatus 100A or 100B as the transmission source based on the management state information included in the received DHCP Offer packet. In the present embodiment, the response receiving unit 202 outputs the 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 a service provided by the server device 100. The service client unit 210 requests the address information of the server device 100 that provides the service via the request unit 201. 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 reception unit 202 in the terminal device 200 are the same as those in the first embodiment except for the points described above, and thus a detailed description thereof is 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 showing 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 either of the management state 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 status information of the server device 100 (step A10). Specifically, the request unit 201 transmits a DHCP Discover packet by broadcasting. The DHCP Discover packet is received by the router 300 and the server apparatus 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 of a different network segment by using the DHCP relay function. The server apparatus 100A receives the DHCP Discover packet transferred by the router 300 (step B20). For example, the router 300 may acquire in advance routing information to the transferable server device 100 such as the server device 100A by setting or the like. The router 300 can be realized by a general router capable of executing a normal DHCP relay function.

  Since the operation of the server apparatus 100B in steps B20 to B23 is the same as the operation of the server apparatus 100A, the following operation of the server apparatus 100A can be replaced with the description of the operation of the server apparatus 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 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, information corresponding to the terminal device 200 is not registered in the management state information 111A. Therefore, the response unit 103 </ b> A returns a response including the management status information in which the management status of the terminal device 200 is new, that is, “New”, via the router 300.

  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 apparatus 100A to the terminal apparatus 200 by the DHCP relay function.

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

  After transmitting the response, when 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 apparatus 100B also directly transmits the DHCP Offer packet in which the option 60 having the same content is set to the terminal apparatus 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 set to “New” in the option 60 for storing the management state information.

  The response receiving unit 202 outputs the transmission source of the selected response based on the management state information included in the response (step A12). For example, the response receiving unit 202 may select the transmission source of the response with priority given to the management state information in the order of “Managed”, “Unmanaged”, and “New”. When the management status information is the same, the response receiving unit 202 may output the transmission 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 responses 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 source of the response received earlier, and outputs the address information of the server device 100B to the service client unit 210.

  Note that if a 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 management status information is not set in option 60. Should be returned. Therefore, the response receiving unit 202 may perform the above-described operation of step A12 except for the response when effective management state information is not set in the response.

  In this way, the service client unit 210 can acquire 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, the service server unit 120B provides the service to the terminal device 200 in the server device 100B. In the present embodiment, the service server unit 120B updates the management status information 111B corresponding to the terminal device 200 that provides the service to “Managed” indicating that the service has become a management target. At this time, the management status information 111A of the server apparatus 100A remains “Unmanaged” indicating that there is a possibility that the management apparatus 111 is a management target of another server apparatus 100.

  Next, with reference to FIG. 4, the operation when the service client unit 210 becomes unable to communicate with the server apparatus 100B, for example, while using the service of the server apparatus 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 is disabled due to a change in the IP address of the server apparatus 100B. That is, each part of the server device 100B is operating normally.

  As in the case of using the service for the first time 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, server apparatus 100B receives DHCP Discover packet 600. Similarly, the server device 100A receives the DHCP Discover packet 601.

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

  Thereafter, the response units 103A and 103B of the server apparatuses 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 in the option 60 that is the management state information (step A12). Then, the response reception unit 202 outputs the address information after the change of the server device 100B that is the transmission source of the DHCP Offer packet 603 to the service client unit 210.

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

  Further, in this 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 management status information is transmitted and received without providing the resource. There is also an effect that can be done. As a result, the DHCP server which is essential in the normal PXE boot is not necessary, and 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) that are unnecessary operations, and are necessary for exchanging request and response management state information within a range that does not deviate from the protocol specifications. This is because only the portion is used.

(Modification of the second embodiment)
In addition, the following can be considered as a modification of this embodiment.

  For example, unlike the DHCP, this embodiment can adopt a type of protocol that does not require provision of resources. In the present embodiment, as an example, a protocol used for a discovery service or the like that acquires setting information or configuration information in a communication device may be employed. In addition, a protocol used for system management or the like for transmitting / receiving a command for a communication device constituting the system and a response to the management device may be employed.

  The management status of the terminal device 200 in the server device 100 only needs to represent at least two statuses of management or not. For example, the response unit 103 may not simply update the management status information 111, but may simply respond based on the “Managed” management status updated by the service server unit 120. 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 apparatus 100 may include a state indicating that a new connection request to the service from the terminal apparatus 200 cannot be accepted as the management state.

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

<Third Embodiment>
Next, a description will be given of a third embodiment based on the above-described first and second embodiments and modifications thereof (hereinafter also simply referred to as “each embodiment”). Below, it demonstrates centering on the characteristic part which concerns on 3rd Embodiment. In the following, the same reference numerals as those used in the respective embodiments are attached to the components of the third embodiment having the same configurations as those of the embodiments, and the detailed description of the components will not be repeated. Omitted.

  The present embodiment is a system in which the original DHCP service function is added to the client server system using the same PXE boot communication sequence as that of the second embodiment. In other words, the present embodiment is an example of a system that enables the DHCP protocol packet used in the second embodiment and the original DHCP protocol packet that assigns a resource called an IP address to be used properly.

  First, the configuration of the present embodiment will be described below with reference to FIG. FIG. 5 is a configuration diagram showing an example of a communication environment in a 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 area network (LAN). The network 1001 may include a communication device that performs relaying according to the communication protocol between the server device 400 and the terminal device 500, such as the router 300 in the second embodiment. In the client server system according to the present embodiment, a plurality of server devices 400 may be included. Similarly, in the client server system according to the present embodiment, a plurality of terminal devices 500 may be included.

  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) that is 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. A hardware configuration example 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 a DHCP server unit 401 (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 units of the server devices 100A and 100B in the second embodiment. Hereinafter, it is also 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 thus detailed description thereof is omitted.

  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 (hereinafter referred to as “first response”) including notification valid information. 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 described by the present embodiment, realized by the request reception unit 402 and the response unit 403. The DHCP server unit 401 can receive the first request and send the first response via the first port that provides the 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, unlike the response (DHCP Offer packet) in the second embodiment, the first response is a response newly provided in the present embodiment.

  Further, the DHCP server unit 401 can execute a server function for providing a general DHCP service, for example. In other words, 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 send back a DHCP response corresponding to the received series of DHCP requests to the transmission source. Since a well-known technique can be adopted for a general DHCP service function, a request and response data structure, a protocol sequence, and the like, a detailed description thereof will be omitted.

  The request reception 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. Further, the request receiving unit 402 can receive a DHCP Request packet (hereinafter also referred to as “second request”) in place of the DHCP Discover packet. It can be said that the second request is a request that is sent again to the second port by the terminal device 500 from the first request sent to the DHCP server unit 401.

  The response unit 403 can transmit a DHCP Ack packet (hereinafter, also referred to as “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 reception unit 402 and the response unit 403 are the same as those in the second embodiment except for the points described above, and thus a detailed description thereof is omitted.

  The terminal device 500 includes a request unit 501, a response reception unit 502, and a service client unit 210 based on each unit of the terminal device 500 in the second embodiment. Since the service client unit 210 is the same as that of the second embodiment, a detailed description thereof is omitted.

  Similar to the second embodiment, the request unit 501 can transmit a DHCP Discover packet (first request) without designating the server device 100 that requests a response as a destination. As a response to this, when the DHCP Offer packet (first response) received from the server apparatus 400 includes notification valid information indicating that a service for notifying the management state of the terminal apparatus can be provided, the server apparatus 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 the DHCP Offer packet (first response) via the second port of the server device 400. The response receiving unit 502 acquires management state information from the DHCP Ack packet.

  Since the configurations and functions of the request unit 501 and the response reception unit 502 are the same as those in the second embodiment except for those described above, a detailed description thereof will be omitted.

  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 apparatus 400 in FIG. 6, the difference between the present embodiment and the operation in the second embodiment shown in FIG. 3 is that there is another difference before step B20 in which the request reception unit 402 receives a request. The point request and response exchange is performed. Further, in step A30 in FIG. 6 (corresponding to step A11 in FIG. 3), B20 and B21, the transmission / reception ports are simply different. Therefore, hereinafter, the operation of the present embodiment will be described 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, the 67th port of UDP (User Datagram Protocol), which is known as a general DHCP service port. The second port is assumed to be a UDP port 4011 as an example. 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 written as “UDP: 67” by associating a protocol with a port number.

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

  In the server device 400, the DHCP server unit 401 that is waiting to receive the first port receives this 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 the DHCP Offer packet, which is a general DHCP service response ( Step B41 in FIG. Specifically, the DHCP server unit 401 transmits to the terminal device 500 a DHCP Offer packet 611 in which notification valid information “PXECClient” is set in the DHCP option 60. The character string “PXECclient” is an example. The notification valid information may be represented by other character strings or code numbers. Also, the DHCP server unit 401 may transmit a DHCP Offer in which notification valid information is set to 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 or not the notification valid information is included in the received DHCP Offer packet 611 (Step A31). Specifically, the response receiving unit 502 checks whether or not there is a character string “PXEClient” in the option 60 of the DHCP Offer packet 611.

  When the notification valid information is included in the response (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 request unit 501 transmits a DHCP request packet 612 (second request) with the address of the server device 400 as the destination IP address and further with 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 a DHCP Request packet 612 to the transmission source of each DHCP Offer packet 611.

  In the server device 400, the request receiving unit 402 that is waiting to receive 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 of Step B20 in FIG. 3 in the second embodiment. That is, in the present embodiment, the type of the request packet is replaced with DHCP Request instead of DHCP Discover.

  Next, the response unit 403 transmits a response (second response) including the management state information corresponding to the transmission source of the request (step B21). Specifically, the response unit 403 adds the management state information 111 to the management state 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 in step B21 of FIG. 3 in the second embodiment. That is, in this embodiment, the response packet type is replaced by DHCP Ack instead of DHCP Offer. Steps B22 and B23 in FIG. 6 that are operations in the server device 400 after this step are the same as steps B22 and B23 in FIG. 3 that are the server device 100 in the second embodiment, and thus overlap. Detailed description is omitted.

  On the other hand, in the terminal device 500, the response receiving unit 502 receives the 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 valid information is not included in the response (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 this embodiment, the response packet type is replaced by DHCP Ack instead of DHCP Offer. Since this step and the subsequent operation of the terminal device 500 are the same as those in the second embodiment, a detailed description thereof will be omitted.

  In step A31, when the received response (DHCP Offer or DHCP Ack) does not include any of the notification valid information and the management status information, the response receiving unit 502 excludes such a response and described above. An 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 the 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 a general DHCP client can continue communication related to address allocation in accordance with a normal DHCP protocol. If 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 that of the general DHCP client.

  Further, the portion where the notification valid information and the management status information can be set is not limited to the DHCP option 60. These pieces of information can be set anywhere in the various DHCP packets as long as they do not affect the operations of a general DHCP client and DHCP server.

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

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

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

  This is because the DHCP server unit 401 sets notification valid information indicating that the service for notifying the management state is valid in a portion that does not affect the operation of a general DHCP client in the DHCP Offer packet. . This is because the request unit 501 of the terminal device 500 requests the management state information again from the request reception unit 402 waiting at the second port based on the notification valid information.

<Hardware configuration example>
1, 2, and 5 in each of the above embodiments may be configured by independent hardware circuits, or a function (processing) unit (software module) of a software program Can be considered. However, the division of each part shown in these drawings is a configuration for convenience of explanation, and various configurations can be assumed for mounting. An example of the 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 apparatus) applicable to each embodiment of the present invention and the client server system according to the modification. That is, FIG. 8 is a configuration of a computer that can realize at least one of the server apparatuses 1, 100A, 100B, and 400, the terminal apparatuses 10, 200, and 500, and the router 300 in each of the above-described embodiments. The hardware environment which can implement | achieve each function in each embodiment mentioned above is shown.

  A computer 900 illustrated in FIG. 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 device (HDD). : Hard Disk Drive) 906, and these are connected via a bus 907. Note that when the computer shown in FIG. 8 functions as the server apparatuses 1, 100 </ b> A, 100 </ b> B, and 400, the terminal apparatuses 10, 200, and 500, and the router 300, the display 905 need not always be provided.

  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 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 storage information 906B is, for example, the management status information 111 shown in FIG. 2 and FIG. In such a hardware configuration, the CPU 901 governs the overall operation of the computer 900.

  The present invention described by taking each of the embodiments described above as an example has the functions of the block configuration diagrams (FIGS. 1, 2, and 5) or the flowcharts (FIGS. 3 and 6) referenced in the description of each embodiment. After the feasible computer program is supplied, the computer program is read out and executed by the CPU 901 of the hardware. The computer program supplied to the computer may be stored in a nonvolatile storage device (storage medium) such as the RAM 903 or the hard disk device 906 which is a readable / writable temporary storage memory.

  In the above case, the computer program can be supplied to each apparatus by installing it in the apparatus via various recording media such as a floppy disk (registered trademark) or a CD-ROM (Compact Disc-ROM). Like the method to do now, a general procedure can be adopted. As a method of supplying a computer program into each device, a method of downloading from the outside via a communication network 1000 such as the Internet is also common. In such a case, the present invention can be understood to be configured by a computer-readable storage medium in which the code constituting the computer program or the code is recorded.

  Note that a part or all of the above-described embodiment can be described as the following supplementary notes, but is not limited to the following supplementary notes.

(Appendix 1)
A request receiving means for transmitting a request not specifying a destination and receiving the request from the terminal device using a communication protocol for returning a response including predetermined service information to the request to the request source;
A server device comprising: response means for transmitting, using the communication protocol, the response that is management information that is at least different from the service information and represents the management status of the terminal device in response to the request .

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

(Appendix 3)
PXE (Preboot Execution Environment) boot protocol is used 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 attachment 1 or 2, wherein the response unit transmits a DHCP Offer packet including the management state information as the response.

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

(Appendix 5)
PXE boot protocol is used 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 means 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 for obtaining a response including predetermined service information for the request from each server device. Requesting means, and
In response to the request, each of the responses is information different from the service information and includes management status information representing a management status of the server in each server device, using the communication protocol, and at least And a response receiving means for outputting information indicating a transmission source of the response selected based on the management status information.

(Appendix 7)
PXE (Preboot Execution Environment) boot protocol is used as the communication protocol,
The request means transmits a DHCP (Dynamic Host Configuration Protocol) Discover packet as the request,
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 the first port using the communication protocol,
The response receiving means includes
As each response to the first request, notification valid information indicating that a service for notifying a response including the management status information can be provided in each first response received using the communication protocol. The request means transmits a second request to a second port different from the first port,
As each response to the second request, when the management status information is included in each second response received using the communication protocol, at least transmission of the response selected based on the management status information The terminal device according to appendix 6 or 7, wherein information representing the origin is output.

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

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

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

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

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

(Appendix 14)
When receiving the request, the request is received 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 valid information indicating that a service for notifying a response including the management state information can be provided is returned.
After returning the first response, receiving a second request sent from the terminal device using the communication protocol via a second port different from the first port;
The notification method according to claim 11 or 12, wherein, instead of transmitting the response, a second response including the management state information is transmitted using the communication protocol in response to the second request.

(Appendix 15)
PXE boot protocol is used as the communication protocol,
Receiving a DHCP Discover packet as the first request;
As the first response, a DHCP Offer packet including the notification valid information is transmitted,
Receiving a DHCP Request packet as the second request;
The notification method according to claim 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 for obtaining a response including predetermined service information for the request from each server device. And
In response to the request, each response including the management status information that is different from the service information and represents the management status of the server in each server device is received using the communication protocol,
An information acquisition method for outputting at least information indicating a transmission source of the response selected based on the management state information.

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

(Appendix 18)
When transmitting the request, the request is transmitted to the first port as the first request using the communication protocol,
Receiving each response to the first request as each first response using the communication protocol;
When each of the first responses includes notification valid information indicating that a service for notifying a response including the management status information can be provided, the second response is different from the first port. Send 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 appendix 16 or 17, wherein when each of the second responses includes the management status information, at least information indicating a transmission source of the response selected based on the management status information is output.

(Appendix 19)
PXE boot protocol is used as the communication protocol,
Sending a DHCP Discover packet as the first request;
A DHCP Request packet is transmitted as the second request;
As the first response, a DHCP Offer packet including the notification valid information is received,
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 reception process for transmitting a request not specifying a destination and receiving the request from a terminal device using a communication protocol for returning a response including predetermined service information to the request to the request source;
In response to the request, a response process that transmits at least the response information including the management status information indicating the management status of the terminal device using the communication protocol is information different from the service information. A first computer program to be executed.

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

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

(Appendix 23)
Represents that a service can be provided that receives the request as a first request via the first port and notifies the response including the predetermined service information and the management status information as a response to the first request. And further executing a server process for returning a first response including notification valid information,
In the request reception process, a second request sent from the terminal device using the communication protocol is received via a second port different from the first port;
In the response processing, instead of the response, a second response including the management status information is transmitted using the communication protocol in response to the second request. First computer according to appendix 20 or 21 ·program.

(Appendix 24)
PXE boot protocol is used as the communication protocol,
In the server process, 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 reception process, a DHCP Request packet is received as the second request,
24. The first computer program according to attachment 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 for obtaining a response including predetermined service information for the request from each server device. Request processing to
In response to the request, each of the responses is information different from the service information and includes management status information representing a management status of the server in each server device, using the communication protocol, and at least A second computer program that causes a computer to execute response reception processing that outputs information indicating a transmission source of the response selected based on the management state information.

(Appendix 26)
PXE (Preboot Execution Environment) boot protocol is used 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 attachment 25, wherein in the response reception process, a DHCP Offer packet is received as the response.

(Appendix 27)
In the request processing, the request is transmitted as a first request to the first port using the communication protocol, and in the response reception processing, the communication protocol is used as each response to the first request. Different from the first port when it is recognized that each first response received by using the notification valid information indicating that the service notifying the response including the management status information can be provided. Send a second request to two ports,
In the response reception process, when it is recognized that each management response information is included in each second response received using the communication protocol as each response to the second request, at least the management status information 27. The second computer program according to appendix 25 or 26, wherein information representing a transmission source of the response selected based on is output.

(Appendix 28)
PXE boot protocol is used as the communication protocol,
In the request processing, a DHCP Discover packet is transmitted as the first request, a DHCP Request packet is transmitted as the second request,
28. In the response reception process, a DHCP Offer packet including the notification valid information is received as the first response, and a DHCP Ack packet including the management status information is received as the second response. 2. Computer program.

1, 100, 400 Server device 2, 102, 402 Request receiving unit 3, 103, 403 Response unit 110 Storage device 111 Management status information 120 Service server unit 10, 200, 500 Terminal device 11, 201, 501 Request 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 device (HDD)
906A Program group 906B Various stored information 907 Bus 1000, 1001 Communication network (network)

Claims (10)

A request receiving means for transmitting a request not specifying a destination and receiving the request from the terminal device using a communication protocol for returning a response including predetermined service information to the request to the request source;
A server device comprising: response means for transmitting, using the communication protocol, the response that is management information that is at least different from the service information and represents the management status of the terminal device in response to the request . The communication protocol is a protocol for requesting provision of resources according to the request,
The server device according to claim 1, wherein the response unit transmits the response without providing the resource. Represents that a service can be provided that receives the request as a first request via the first port and notifies the response including the predetermined service information and the management status information as a response to the first request. Server means for returning a first response including notification valid information;
The request receiving means receives a second request sent from the terminal device using the communication protocol via a second port different from the first port;
The server device according to claim 1, wherein the response unit transmits a second response including the management state information to the second request using the communication protocol instead of the response. 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 for obtaining a response including predetermined service information for the request from each server device. Requesting means, and
In response to the request, each of the responses is information different from the service information and includes management status information representing a management status of the server in each server device, using the communication protocol, and at least And a response receiving means for outputting information indicating a transmission source of the response selected based on the management status information. The request means transmits the request as a first request to the first port using the communication protocol,
The response receiving means includes
As each response to the first request, notification valid information indicating that a service for notifying a response including the management status information can be provided in each first response received using the communication protocol. The request means transmits a second request to a second port different from the first port,
As each response to the second request, when the management status information is included in each second response received using the communication protocol, at least transmission of the response selected based on the management status information The terminal device according to claim 4, wherein information representing the origin is output. At least one server device according to any one of claims 1 or 2, and a terminal device according to claim 4,
Or
At least one server device according to claim 3, and a terminal device according to claim 5,
Including either
A client server system that outputs, on the terminal device, information indicating a transmission source of the response selected based on management state information indicating the management state of the terminal device in each server device. Transmitting a request not specifying a destination, using a communication protocol that returns a response including predetermined service information to the request to the request source, receiving the request from the terminal device,
A notification method for transmitting the response using the communication protocol, which is information different from at least the service information and including management status information indicating a management status of the terminal device, in response to the request. 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 for obtaining a response including predetermined service information for the request from each server device. And
In response to the request, each response including the management status information that is different from the service information and represents the management status of the server in each server device is received using the communication protocol,
An information acquisition method for outputting at least information indicating a transmission source of the response selected based on the management state information. A request reception process for transmitting a request not specifying a destination and receiving the request from a terminal device using a communication protocol for returning a response including predetermined service information to the request to the request source;
In response to the request, a response process that transmits at least the response information including the management status information indicating the management status of the terminal device using the communication protocol is information different from the service information. A first computer program to be executed. 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 for obtaining a response including predetermined service information for the request from each server device. Request processing to
In response to the request, each of the responses is information different from the service information and includes management status information representing a management status of the server in each server device, using the communication protocol, and at least A second computer program that causes a computer to execute response reception processing that outputs information indicating a transmission source of the response selected based on the management state information.

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