JP6662114B2 - Address setting method, address setting program, and information processing apparatus - Google Patents

Description

  The present invention relates to an IP address setting technique.

  In a relatively small network segment (hereinafter simply referred to as a segment), the terminal uses a fixed IP (Internet Protocol) address, or RARP (Reverse Address Resolution Protocol), BOOTP (BOOTstrap Protocol) or DHCP. (Dynamic Host Configuration Protocol) is generally used.

  DHCP is a protocol that has been particularly used in recent years. When using DHCP, an administrator sets up a DHCP server and a user who operates a terminal sets up a terminal. Specifically, the administrator sets a lease address and a lease period for the DHCP server. Also, the user who operates the terminal makes network settings of the OS (Operating System) for the terminal.

  In the DHCP, the same lease address is not assigned to a terminal other than the terminal to which the lease address is assigned during the lease period. However, if the processing for releasing the lease address is performed, the other terminal is given the lease address. Addresses can be assigned. However, if the terminal leaves the segment before executing the process of releasing the lease address, the state in which another terminal cannot use the lease address will continue until the lease period expires.

  As described above, when a lease address that is not actually used cannot be assigned to another terminal, the available IP address in the segment is depleted, and the number of terminals that can communicate in the segment is limited. Will be.

JP 2010-98687 A

  An object of the present invention, in one aspect, is to provide a technique for effectively using an IP address in a network to which an IP address is assigned by DHCP.

  The address setting method according to the present invention is executed by an information processing device connected to a network. Then, the address setting method specifies a range of addresses that can be used by a device connected to the network based on the source address and the destination address of the packet acquired from the network, and specifies a range of addresses included in the specified address range. A process for determining whether the first address is used by another device connected to the network, and when it is determined that the first address is not used by another device, a process of starting use of the first address including.

  In one aspect, an IP address can be effectively used in a network in which an IP address is assigned by DHCP.

FIG. 1 is a diagram showing an outline of a system according to the present embodiment. FIG. 2 is a functional block diagram of the DHCP client. FIG. 3 is a diagram illustrating an example of a usage table stored in the usage table storage unit. FIG. 4 is a diagram illustrating an example of a search table stored in a search table storage unit. FIG. 5 is a diagram illustrating an example of a confirmation table stored in the confirmation table storage unit. FIG. 6 is a diagram showing a main processing flow. FIG. 7 is a diagram depicting a processing flow of a range setting processing; FIG. 8 is a diagram for describing acquisition of a packet. FIG. 9 is a diagram for explaining the calculation of the netmask. FIG. 10 is a diagram illustrating an example of a network address and a broadcast address. FIG. 11 is a diagram illustrating a setting example of the search table. FIG. 12 is a diagram depicting a processing flow of an acquisition processing; FIG. 13 is a diagram illustrating a setting example of the confirmation table. FIG. 14 is a diagram depicting a processing flow of a priority setting processing; FIG. 15 is a diagram illustrating a setting example of a search table. FIG. 16 is a diagram depicting a processing flow of a judgment processing; FIG. 17 is a diagram showing a main processing flow. FIG. 18 is a diagram depicting a processing flow of a processing executed by a DHCP client which has received an acquisition request; FIG. 19 is a diagram illustrating a setting example of the usage table. FIG. 20 is a diagram illustrating a setting example of the usage table. FIG. 21 is a functional block diagram of a computer.

[Embodiment 1]
FIG. 1 shows an outline of a system according to the present embodiment. For example, a DHCP server 3 and DHCP clients 1t to 3t are connected to a segment 5 that is Ethernet (registered trademark). The DHCP server 3 is, for example, a physical server device, and the DHCP clients 1t to 3t are, for example, terminal devices such as personal computers, printers, and copiers. Although the number of DHCP clients is three in FIG. 1, the number is not limited.

  The DHCP processing unit 30 of the DHCP server 3 assigns IP addresses to the DHCP clients 1t to 3t by DHCP. The DHCP clients 1t to 3t communicate using the IP address assigned by DHCP when the assignment of the IP address by DHCP is possible, but when the assignment of the IP address by DHCP is not possible, The communication is performed using the IP address specified by the processing described below.

  FIG. 2 shows a functional block diagram of the DHCP client 1t. The DHCP client 1t includes a management unit 101, a range setting unit 102, an acquisition unit 103, a priority setting unit 104, a determination unit 105, a use table storage unit 106, a search table storage unit 107, and a confirmation table storage. Unit 108.

  The management unit 101 uses the IP used by the DHCP client 1t based on the usage table stored in the usage table storage unit 106, the search table stored in the search table storage unit 107, and the confirmation table stored in the confirmation table storage unit 108. Execute the process of determining the address. The range setting unit 102 executes a process of setting an address range that can be used by the DHCP clients 1t to 3t in the segment 5 in the usage table storage unit 106. The acquisition unit 103 executes a process of acquiring a confirmation table from another DHCP client. The priority setting unit 104 executes a process of setting the priority of each IP address stored in the search table. The determination unit 105 performs a process of searching the search table for an IP address used by the DHCP client 1t. Note that the functional block diagrams of the DHCP clients 2t and 3t are the same as the functional block diagram of the DHCP client 1t, and a description thereof will be omitted.

  FIG. 3 shows an example of a usage table stored in the usage table storage unit 106. In the example of FIG. 3, the start address and the end address of the address range that can be used in the segment 5, the net mask (also called the subnet mask), the gateway address, and the DHCP client connected to the segment 5 are fixedly set. And information indicating a range of local addresses to be stored. In the example of FIG. 3, the range of the IP address assigned by DHCP is 192.168.1.11 to 192.168.1.128, and the range of the IP address fixedly assigned to the DHCP client as a local address is 192. .168.1.129 to 192.168.1.254. Note that the local address and the gateway address need not always be set.

  FIG. 4 shows an example of a search table stored in the search table storage unit 107. In the example of FIG. 4, an IP address and a priority value of the IP address are stored. In the present embodiment, an IP address having a lower priority value is more likely to be assigned to a DHCP client.

  FIG. 5 shows an example of the confirmation table stored in the confirmation table storage unit 108. In the example of FIG. 5, the IP address, the identification information of the DHCP client that has confirmed that the IP address is used, and the information of the time when the use of the IP address was last confirmed are stored.

  Note that initially, NULL is stored in fields other than the fields set in advance by the administrator in the use table, and NULL is stored in all fields in the search table and the confirmation table. Thus, data as shown in FIGS. 3 to 5 is stored.

  Next, processing executed by the DHCP client 1t will be described with reference to FIGS. This processing is executed, for example, when the DHCP client 1t is newly connected to the segment 5. The processing executed by the DHCP clients 2t and 3t is the same as the processing executed by the DHCP client 1t.

  First, the management unit 101 of the DHCP client 1t determines whether an IP address can be obtained from the DHCP server 3 by DHCP (FIG. 6: step S1). For example, when the number of DHCP clients connected to the segment 5 is small and there is a surplus of usable IP addresses, the IP address can be acquired by DHCP. On the other hand, if there is no remaining available IP address (that is, the IP address is depleted), the IP address cannot be acquired by DHCP. Note that the assignment of an IP address by DHCP is well known, and a detailed description thereof will be omitted here.

  If the IP address can be acquired by DHCP (step S1: Yes route), the processing shifts to a processing illustrated in FIG. 17 via the terminal A, and the processing ends. On the other hand, when the IP address cannot be acquired by DHCP (step S1: No route), the management unit 101 determines whether an appropriate IP address is set in the usage table stored in the usage table storage unit 106 (step S1). S3).

  In step S3, if the following is confirmed, it is determined that an appropriate IP address has been set.

(1) The end address is larger than the start address.
(2) When a gateway address is set, the gateway address is in a range specified by the start address and the end address.
(3) When a local address is set, the range of the local address has an overlap with the range specified by the start address and the end address.

  When an appropriate IP address is not set in the usage table (step S3: No route), the management unit 101 instructs the range setting unit 102 to execute a range setting process. In response, the range setting unit 102 executes a range setting process to set a start address and an end address (Step S5). The range setting process will be described with reference to FIGS.

  First, the range setting unit 102 tries to acquire a packet for a predetermined period from the segment 5 to which the DHCP client 1t is connected (FIG. 7: step S41). Here, it is preferable to acquire a packet transmitted for the same segment by ARP, Microsoft Windows (registered trademark) Browser Protocol, NetBIOS Name Service, or the like. Therefore, considering that the frequency of checking the ARP entry is 60 seconds, for example, 60 seconds is adopted as the predetermined time.

  The range setting unit 102 determines whether there are a plurality of packets having the same address class of the source IP address and the address class of the destination IP address in the acquired packets (step S43). For example, when three packets as shown in FIG. 8 are obtained, the address class of the source IP address of the packet 1p is class A and the address class of the destination IP address is class C. Is discarded. The packets 2p and 3p are counted because the address class of the source IP address and the address class of the destination IP address are class C.

  If there are no packets with the same address class of the source IP address and the address class of the destination IP address (step S45: No route), the range setting unit 102 determines whether the process of step S41 has been tried a predetermined number of times. (Step S47).

  When the process of step S41 has not been tried a predetermined number of times (step S47: No route), the process returns to step S41. On the other hand, when the process in step S41 has been tried a predetermined number of times (step S47: Yes route), the process returns to the calling source process.

  On the other hand, when there are a plurality of packets having the same address class of the source IP address and the address class of the destination IP address (step S45: Yes route), the range setting unit 102 sets the source IP address, the destination IP address, and the In step S49, a net mask is calculated using the same part starting from the head as a network part (step S49). As an example, FIG. 9 shows the source IP address and the destination IP address of the packets 2p and 3p shown in FIG. 8 expressed in decimal and binary numbers. In this case, in the binary IP address, since the first 20 bits are the same, the net mask is calculated as 20 bits, that is, 255.255.240.0. The reason why a plurality of packets are obtained is to increase the reliability of the calculated information.

  The range setting unit 102 uses the IP address included in the packet obtained in step S41 and the netmask calculated in step S49 to determine the host of the packet obtained in step S41. Then, the range setting unit 102 specifies the range of the host address from the calculated host unit and the netmask, sets the first IP address included in the range in the usage table as a start address, and sets the last IP address included in the range. The IP address is set as the end address in the usage table (step S51). Then, the process returns to the calling process. For example, in the case of an IP address of 192.168.1.9, as shown in FIG. 10, a network address 192.168.0.0 is determined, and a broadcast address 192.168.15.255 is determined. . In this case, the start address is 192.168.0.1 obtained by adding 1 to the network address, and the end address is 192.168.15.254 obtained by subtracting 1 from the broadcast address.

  By executing the above processing, the range of the IP address usable in the segment 5 can be set appropriately.

  Returning to the description of FIG. 6, it is determined whether the range has been set by the range setting process (step S7). If the range could not be set (step S7: No route), the processing shifts to the processing of FIG. 17 via the terminal A, and the processing ends.

  On the other hand, when the range can be set by the range setting process (step S7: Yes route) or when an appropriate IP address is set in the usage table (step S3: Yes route), the management unit 101 sets the setting in the usage table. The IP addresses from the start address to the end address are expanded in the search table (step S9). Then, the management unit 101 sets the priority of each IP address in the search table (Step S11). For example, if the start address is 192.168.0.1 and the end address is 192.168.15.254, the search table will be in the state shown in FIG. 11 by the processing in step S11. At the time of the processing in step S11, the priority of each IP address is set to 0. However, when the use table is manually set and the local address is set, the priority of the IP address included in the range of the local address is set to 1.

  The management unit 101 instructs the acquisition unit 103 to execute an acquisition process, which is a process of acquiring a confirmation table from another DHCP client. In response, the acquisition unit 103 executes an acquisition process (Step S13). The acquisition process will be described with reference to FIGS.

  First, the acquisition unit 103 transmits an acquisition request for acquiring a confirmation table to other DHCP clients in the segment by broadcast (FIG. 12: step S61).

  The acquisition unit 103 determines whether a response to the acquisition request transmitted in step S61 has been received within a predetermined time (step S63). If the response has not been received within the predetermined time (step S63: No route), it is determined whether the process of step S61 has been tried a predetermined number of times (step S67). The response includes, for example, a confirmation table as shown in FIG. Note that a plurality of responses may be received.

  If the process has not been performed the predetermined number of times (step S67: No route), the process returns to step S61. On the other hand, when a predetermined number of attempts have been made (step S67: Yes route), the process returns to the calling source.

  On the other hand, when the response is received within the predetermined time (step S63: Yes route), the acquisition unit 103 extracts the confirmation table included in the received response (step S65). When a plurality of responses are received, a confirmation table is extracted from each response. Then, the process returns to the calling process.

  By executing the above processing, it becomes possible to specify an IP address whose use has been confirmed by another DHCP client.

  Returning to the description of FIG. 6, the management unit 101 determines whether the confirmation table has been acquired by the acquisition processing (step S15). If the confirmation table has not been acquired (step S15: No route), the process proceeds to step S19. On the other hand, when the confirmation table has been acquired (step S15: Yes route), the management unit 101 instructs the priority setting unit 104 to execute the priority setting process. In response, the priority setting unit 104 executes a priority setting process (Step S17). The priority setting process will be described with reference to FIGS.

  First, the priority setting unit 104 reads one row of an unprocessed IP address (hereinafter, referred to as a processing target IP address) from the confirmation table (FIG. 14: step S71). When a plurality of confirmation tables are received and there are a plurality of rows for the processing target IP address, the row having the latest final confirmation time is specified.

  The priority setting unit 104 calculates a time difference between the current time acquired from, for example, the system clock of the OS or the like, and the final confirmation time included in the line read in step S71 (step S73).

  The priority setting unit 104 determines whether the time difference calculated in step S73 is less than a first time (for example, one hour) (step S75). If the time difference calculated in step S73 is less than the first time (step S75: Yes route), the priority setting unit 104 stores the priority value corresponding to the processing target IP address stored in the search table Is added to (step S77). Then, control goes to a step S85. On the other hand, if the time difference calculated in step S73 is not less than the first time (step S75: No route), the priority setting unit 104 determines that the time difference calculated in step S73 is the second time (for example, 2 hours) It is determined whether it is less than (Step S79).

  If the time difference calculated in step S73 is less than the second time (step S79: Yes route), the priority setting unit 104 stores the priority value corresponding to the processing target IP address stored in the search table Is added to (step S81). Then, control goes to a step S85. On the other hand, when the time difference calculated in step S73 is not less than the second time (step S79: No route), the priority setting unit 104 stores the priority corresponding to the processing target IP address stored in the search table. Is added to the value (step S83).

  The priority setting unit 104 determines whether there is a row of an unprocessed IP address (step S85). If there is an unprocessed IP address line (step S85: Yes route), the process returns to step S71. On the other hand, if there is no unprocessed IP address line (step S85: No route), the process returns to the calling source process.

  By executing the above processing, the priority value can be set so that an IP address having a longer elapsed time since the last use is confirmed is more easily selected. For example, suppose that a search table as shown in FIG. 13 is received when a search table as shown in FIG. 11 is held at the start of the priority setting process. In this case, the priority value is changed by the processing described above as shown in FIG.

  Returning to the description of FIG. 6, the management unit 101 instructs the determination unit 105 to execute the determination processing. In response, the determination unit 105 performs a determination process (Step S19). The determination process will be described with reference to FIG.

  First, the determination unit 105 specifies the youngest IP address among the IP addresses with the smallest priority value among the unprocessed IP addresses in the search table (FIG. 16: step S91). For example, if the search table is in a state as shown in FIG. 4, 192.168.1.16 is specified in step S91.

  The determining unit 105 transmits a GARP (Gratuitous Address Resolution Protocol) packet for the IP address specified in step S91 (step S93).

  The determination unit 105 determines whether a reply to the GARP packet transmitted in step S93 has been received (step S95). If the reply has not been received (step S95: No route), the other DHCP client does not use the IP address specified in step S91. Therefore, the DHCP client 1t starts using the IP address specified in step S91 as the IP address of its own DHCP client (step S97). Then, the process returns to the calling process.

  On the other hand, if a reply is received (step S95: Yes route), another DHCP client is using the IP address specified in step S91. Therefore, the determination unit 105 deletes the line of the IP address specified in step S91 from the search table (step S99).

  The determination unit 105 writes the IP address, the DHCP client identification information (1t in this case), and the current time specified in step S91 into the confirmation table stored in the confirmation table storage unit 108 (step S101). As a result, it is possible to notify another DHCP client that the IP address specified in step S91 is being used.

  The determination unit 105 determines whether an unprocessed IP address exists in the search table (step S103). If there is an unprocessed IP address in the search table (step S103: Yes route), the process returns to step S91. On the other hand, if there is no unprocessed IP address in the search table (step S103: No route), the process returns to the calling source process.

  Returning to the description of FIG. 6, the management unit 101 determines whether there is an available IP address (step S21). If there is no usable IP address (step S21: No route), the processing shifts to FIG. 17 via the terminal A, and the processing ends. On the other hand, when there is an available IP address (step S21: Yes route), the processing shifts to the processing of step S23 in FIG.

  17, the DHCP client 1t shifts to the operating state (step S23), and the management unit 101 determines whether the own IP address is used by another DHCP client during the operation (step S25). . Since the DHCP client has a function of detecting duplication of the IP address by GARP or the like, the processing of step S25 is executed by using such a function.

  When it is determined during operation that the own IP address is used by another DHCP client (step S25: Yes route), the management unit 101 determines that the own IP address falls within the range of the local address set in the use table. It is determined whether it is included (step S27).

  When the own IP address is included in the range of the local address set in the use table (step S27: Yes route), the own IP address is assigned to a specific DHCP client by, for example, an administrator. Since the address is duplicated, the management unit 101 releases its own IP address (step S29). The processing returns to the processing of step S3 in FIG. On the other hand, if the own IP address is not included in the range of the local address set in the use table (step S27: No route), the own IP address is the same as the IP address assigned by DHCP, In the case of, the use permission is determined by issuing a ping before use, so that the own IP address need not be released. Therefore, the process returns to step S25.

  On the other hand, when it is determined during operation that the own IP address is not used by another DHCP client (step S25: No route), the management unit 101 determines whether to continue the operation (step S31). If the operation is to be continued (step S31: Yes route), the process returns to step S25. On the other hand, when the operation is not continued (step S31: No route), the process ends.

  Next, the processing executed by the DHCP client 1t that has received the acquisition request will be described with reference to FIG. The processing executed by the DHCP clients 2t and 3t is the same as the processing executed by the DHCP client 1t.

  First, the management unit 101 of the DHCP client 1t receives an acquisition request from another DHCP client (FIG. 18: step S111). Then, the management unit 101 reads the confirmation table from the confirmation table storage unit 108, and transmits the read confirmation table to the DHCP client that has transmitted the acquisition request (step S113). Then, the process ends.

  By executing the above-described processing, it is possible to use an IP address that has been assigned by DHCP but has not been used, so that the IP address can be used effectively and the depletion of the IP address can be prevented. Become.

  In addition, since the latest usage status information can be obtained by exchanging the confirmation table between the DHCP clients, it is possible to reduce the time and labor required for the DHCP client user or administrator to manually manage the information.

  Also, as compared with the case where DHCP is used, a management server such as the DHCP server 3 does not need to be prepared, and there is no influence from stopping the management server. Further, in determining the IP address, it is not necessary to consider the range of the fixed IP address, the range of the IP address by DHCP, and the like, so that the IP address can be used efficiently.

  Next, an example of setting a usage table will be described with reference to FIGS. 19 and 20.

  In an environment where the method of the present embodiment is not used, for example, the range of the fixed IP address is 192.168.1.10 to 192.168.1.128, and the range of the IP address by DHCP is 192.168.1. 129 to 192.168.1.250. The network address is 192.168.1.0/24. In this case, if the number of fixed IP addresses exceeds 118, the administrator may take measures such as reviewing the range of IP addresses by DHCP and expanding the range of fixed IP addresses.

  On the other hand, when using the method of the present embodiment, for example, the range of the fixed IP address is set to 192.168.1.10 to 192.168.1.250, and the value shown in FIG. Set. As described above, if the range of the fixed IP address and the range of the IP address by DHCP are not separated, it is possible to prevent a situation in which an address in one of the ranges is left. Can be used.

  Also, for example, if a usage table is set as shown in FIG. 20, this IP address is assigned to the DHCP client only when 192.168.1.1.100 is available. Therefore, by adopting the setting as shown in FIG. 20, it is possible to cope with a case where only a specific IP address is desired to be used for business reasons or the like.

  Although the embodiment of the present invention has been described above, the present invention is not limited to this. For example, the functional block configuration of the DHCP client 1t described above may not match the actual program module configuration.

  Further, the configuration of each table described above is an example, and does not have to be the above configuration. Further, in the processing flow, the order of the processing can be changed if the processing result does not change. Further, they may be executed in parallel.

  According to the above-described embodiment, in particular, even when there is an unused IP address, it is not possible to assign an IP address due to the inability to use DHCP during a lease period or the like. , The IP address can be used effectively.

  The DHCP server 3 and the DHCP clients 1t to 3t described above are computer devices, and as shown in FIG. 21, a memory 2501, a CPU (Central Processing Unit) 2503, and a hard disk drive (HDD: Hard Disk Drive). A display control unit 2507 connected to the display device 2505 and the display device 2509, a drive device 2513 for the removable disk 2511, an input device 2515, and a communication control unit 2517 for connecting to a network are connected by a bus 2519. An operating system (OS) and an application program for executing the processing in the present embodiment are stored in the HDD 2505, and are read from the HDD 2505 to the memory 2501 when executed by the CPU 2503. The CPU 2503 controls the display control unit 2507, the communication control unit 2517, and the drive device 2513 in accordance with the processing content of the application program to perform a predetermined operation. Although the data being processed is mainly stored in the memory 2501, the data may be stored in the HDD 2505. In the embodiment of the present invention, an application program for performing the above-described processing is stored in a computer-readable removable disk 2511 and distributed, and is installed from the drive device 2513 to the HDD 2505. It may be installed in the HDD 2505 via a network such as the Internet and the communication control unit 2517. Such a computer device realizes the above-described various functions by the hardware such as the CPU 2503 and the memory 2501 described above and the programs such as the OS and the application program cooperate organically. .

  The above-described embodiments of the present invention are summarized as follows.

  The address setting method according to the present embodiment is executed by an information processing device connected to a network. The address setting method includes: (A) specifying a range of addresses that can be used by a device connected to the network based on a source address and a destination address of a packet acquired from the network; and (B) specifying the specified address. It is determined whether the first address selected from the range is used by another device connected to the network, and (C) When it is determined that the first address is not used by another device , Starting the use of the first address.

  Also, the present address setting method includes: (D) obtaining, from another device, an address whose use has been confirmed by another device and information of a time at which use of the address has been confirmed, and (E) obtaining the obtained address and time. May further include a process of setting a priority to each of a plurality of addresses included in the specified address range based on the above information. Then, in the process of determining whether the first address is used by another device, (b1) the first address may be selected from a plurality of addresses included in the address range based on the priority. . In this way, it is possible to reduce the time required to specify an available address.

  Further, in the present address setting method, (F) a packet having the same address class of the source address and the address class of the destination address among the packets transferred in the network may be acquired from the network. This makes it possible to ensure that the source device and the destination device belong to the same segment.

  Further, the present address setting method includes: (G) when it is determined that the first address is used by another device, it is determined that the first address and the first address are used by another device. (H) When an acquisition request requesting acquisition of information on the use of an address is received from another device, the first address and the second address stored in the storage device are stored. It may further include a process of transmitting, to another device, information on a time when it is determined that one address is being used by another device. In this way, other devices can use the appropriate address.

  In the process of determining whether the first address is used by another device, (b2) whether the first address is used by another device is determined based on whether a reply to the GARP packet is received. It may be determined.

  A program for causing a computer to execute the process according to the above method can be created. The program can be a computer-readable storage medium such as a flexible disk, a CD-ROM, a magneto-optical disk, a semiconductor memory, a hard disk, or the like. Stored in a storage device. The intermediate processing result is temporarily stored in a storage device such as a main memory.

  Regarding the embodiment including the above-described example, the following supplementary notes are further disclosed.

(Appendix 1)
The information processing device connected to the network
Based on the source address and the destination address of the packet obtained from the network, specify a range of addresses that can be used by devices connected to the network,
Determining whether a first address included in the specified range of addresses is used by another device connected to the network;
If it is determined that the first address is not used by the other device, use of the first address is started,
Address setting method to execute processing.

(Appendix 2)
The information processing device,
The address of which the use is confirmed by the other device and the information of the time at which the use of the address is confirmed are obtained from the other device,
Based on the acquired address and the time information, set a priority for each of a plurality of addresses included in the specified address range,
Perform further processing,
In the process of determining whether the first address is used by the other device,
Selecting the first address from the plurality of addresses included in the address range based on priority;
The address setting method according to supplementary note 1.

(Appendix 3)
The information processing device,
Acquiring, from the network, the packet having the same address class of the source address and the address class of the destination address among the packets transferred in the network,
3. The address setting method according to claim 1 or 2, further performing a process.

(Appendix 4)
The information processing device,
When it is determined that the first address is used by the other device, information on the first address and the time at which the first address is determined to be used by the other device, Is stored in the storage device,
When an acquisition request for requesting acquisition of information on use of an address is received from the other device, the first address and the first address stored in the storage device are used by the other device. Transmitting the information of the time determined to be present to the other device,
4. The address setting method according to any one of Supplementary notes 1 to 3, further performing a process.

(Appendix 5)
In the process of determining whether the first address is used by the other device,
Determining whether the first address is used by the other device based on whether a reply to a packet of a GARP (Gratuitous Address Resolution Protocol) has been received,
An address setting method according to any one of supplementary notes 1 to 4.

(Appendix 6)
In the information processing device connected to the network,
Based on the source address and the destination address of the packet obtained from the network, specify a range of addresses that can be used by devices connected to the network,
Determining whether a first address included in the specified range of addresses is used by another device connected to the network;
If it is determined that the first address is not used by the other device, use of the first address is started,
Address setting program to execute processing.

(Appendix 7)
A specifying unit that specifies a range of addresses that can be used by a device connected to the network, based on a source address and a destination address of a packet obtained from the network;
A determining unit that determines whether a first address included in the address range specified by the specifying unit is used by another device connected to the network;
A management unit that starts using the first address when the determination unit determines that the first address is not used by the other device;
Information processing device having

3 DHCP server 30 DHCP processing unit 5 segment 1t, 2t, 3t DHCP client 101 Management unit 102 Range setting unit 103 Acquisition unit 104 Priority setting unit 105 Judgment unit 106 Usage table storage unit 107 Search table storage unit 108 Confirmation table storage unit

Claims (6)

A specifying unit that specifies a range of addresses that can be used by a device connected to the network, based on a source address and a destination address of a packet obtained from the network;
An acquisition unit that acquires, from the other device, an address whose use has been confirmed by another device connected to the network and information on the time at which the use of the address has been confirmed,
A setting unit that sets a priority to each of a plurality of addresses included in the address range specified by the specifying unit, based on the acquired address and the information of the time;
Selecting a first address from the plurality of addresses included in the address range based on the priority and determining whether the first address is used by another device connected to the network; A determination unit to perform
A management unit that starts using the first address when the determination unit determines that the first address is not used by the other device;
Information processing device having A second obtaining unit that obtains, from the network, the packet having the same address class of the source address and the address class of the destination address among the packets transferred in the network,
The information processing apparatus according to claim 1, further comprising a. When it is determined that the first address is used by the other device, information on the first address and the time at which the first address is determined to be used by the other device, Means for storing in a storage device;
When an acquisition request for requesting acquisition of information on use of an address is received from the other device, the first address and the first address stored in the storage device are used by the other device. Means for transmitting the information of the time determined to be present to the other device,
The information processing apparatus according to claim 1 or 2, wherein further comprising a. The determination unit includes:
Determining whether the first address is used by the other device based on whether a reply to a packet of a GARP (Gratuitous Address Resolution Protocol) has been received,
The information processing apparatus of any one of claims 1 to 3. In the information processing device connected to the network,
Based on the source address and the destination address of the packet obtained from the network, specify a range of addresses that can be used by devices connected to the network,
An address whose use has been confirmed by another device connected to the network and information on the time at which the use of the address has been confirmed are obtained from the other device,
Based on the acquired address and the time information, set a priority for each of a plurality of addresses included in the specified address range,
Selecting a first address from the plurality of addresses included in the address range based on the priority and determining whether the first address is used by another device connected to the network; And
If it is determined that the first address is not used by the other device, use of the first address is started,
Address setting program to execute processing. The information processing device connected to the network
Based on the source address and the destination address of the packet obtained from the network, specify a range of addresses that can be used by devices connected to the network,
An address whose use has been confirmed by another device connected to the network and information on the time at which the use of the address has been confirmed are obtained from the other device,
Based on the acquired address and the time information, set a priority for each of a plurality of addresses included in the specified address range,
Selecting a first address from the plurality of addresses included in the address range based on the priority and determining whether the first address is used by another device connected to the network; And
If it is determined that the first address is not used by the other device, use of the first address is started,
Address setting method to execute processing.

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