Connection state acquisition device and connection state acquisition method

Abstract

This acquisition device acquires connection states indicating the connection states of a plurality of NW devices, and comprises: a connection pair storage unit (232) that stores a connection pair table indicating the connection states of ports provided in the respective NW devices; a NW management unit (11) that transmits, to the NW devices, a state change instruction for changing the connection states between the NW devices, and receives a state change notification transmitted from the NW devices; a change table storage unit (233) that stores a connection state change table created by the NW management unit on the basis of the state change notification; and an analysis unit (22) that compares the connection pair table and the change table, and updates the connection pair table on the basis of the result of the comparison.

Description

Connection State Acquisition Device and Connection State Acquisition Method

[0001] The present disclosure relates to a connection state acquisition device and a connection state acquisition method.

[0002] In order to stably operate an IT system constructed by connecting a plurality of NW (network) devices such as L2 switches and server devices, it is necessary to monitor the connection state of each NW device and immediately detect and address any troubles such as connection failures when they occur. For this reason, it is required to create a map (for example, a topology map) showing the connection state of each NW device connected to the network. By referring to the map showing the connection state, when a trouble occurs, the cause of the trouble can be quickly investigated.

[0003] Non-Patent Documents 1 and 2 disclose that a topology map can be automatically created by using protocols such as LLDP (Link Layer Discovery Protocol) and CDP (Cisco Discovery Protocol) to automatically acquire the connection state with adjacent devices.

[0004] “LLDP,” Network Beginners Site. [Searched on September 5, 2024], Internet <URL: https: / / beginners-network.com / lldp.html>“LLDP and CDP Detection Protocols: Understanding the Differences,” FIBERROAD. [Searched on September z, 2024], Internet <URL: https: / / fiberroad.com / ja / resources / glossary / lldp-vs-cdp-understanding-the-differences / >

[0005] However, the protocols such as LLDP and CDP disclosed in Non-Patent Documents 1 and 2 mentioned above have different support methods for each NW device. For NW devices supported by different support methods, the connection state between the two cannot be automatically discovered. For this reason, there was a problem that maintenance personnel needed to manually set the connection state.

[0006] This disclosure is made in view of the above circumstances and aims to provide a connection status acquisition device and a connection status acquisition method that can acquire the connection status between devices supported by different protocols.

[0007] A connection status acquisition device according to one aspect of the present disclosure is an acquisition device for acquiring connection status indicating the connection status of a plurality of NW devices, comprising: a connection pair storage unit that stores a connection pair table indicating the connection status of ports provided on each NW device; an NW management unit that transmits a status change instruction to the NW device to change the connection status between NW devices and receives a status change notification transmitted from the NW device; a change table storage unit that stores a connection status change table created by the NW management unit based on the status change notification; and an analysis unit that compares the connection pair table with the change table and updates the connection pair table based on the comparison result.

[0008] A connection status acquisition method according to one aspect of the present disclosure is a method for acquiring a connection status indicating the connection status of a plurality of network devices, wherein the connection status acquisition device transmits a status change instruction to change the connection status between network devices to the network devices, receives a status change notification transmitted from the network devices, stores a connection status change table created based on the status change notification in a change table storage unit, compares the connection pair table indicating the connection status of ports provided on each network device with the connection pair table, and updates the connection pair table based on the comparison result.

[0009] According to this disclosure, it becomes possible to obtain the connection status between devices supported by different protocols.

[0010] Figure 1 is a block diagram showing the configuration of a connection status acquisition device and its peripheral devices according to an embodiment. Figure 2 is an explanatory diagram showing an example of log data stored in a database. Figure 3 is an explanatory diagram showing an example of an IP correspondence table showing the correspondence between IP addresses and NW devices. Figure 4 is an explanatory diagram showing an example of a connection pair table showing the connection status of ports of each NW device installed in the network. Figure 5 is an explanatory diagram showing an example of a change table that stores port information when the connection has been changed. Figure 6 is a flowchart showing the procedure for acquiring the connection status using the connection status acquisition device according to an embodiment. Figure 7 is a flowchart showing the procedure for changing the connection status using the connection status acquisition device according to an embodiment. Figure 8 is an explanatory diagram showing how the connection of an NW device has been changed in the network. Figure 9 is an explanatory diagram showing an example of log data stored in a database when the change shown in Figure 8 occurs. Figure 10 is an explanatory diagram showing an example where the data stored in the connection pair table differs from the data in the change table shown in Figure 5. Figure 11 is a block diagram showing the hardware configuration of this embodiment.

[0011] Embodiments will be described below with reference to the drawings. Figure 1 is a block diagram showing the configuration of the connection status acquisition device 100 and its peripheral equipment according to the embodiment. As shown in Figure 1, the connection status acquisition device 100 according to the embodiment comprises a monitoring unit 1 and an acquisition unit 2. The monitoring unit 1 and the acquisition unit 2 are connected to the network 3 whose connection status is to be monitored. That is, the connection status acquisition device 100 according to this embodiment automatically acquires the connection status indicating the connection status of a plurality of NW devices connected to the network 3. When a connection pair is changed between the ports of each NW device, the connection status acquisition device 100 automatically changes the connection pair table indicating the connection status of each NW device in accordance with this change.

[0012] Network 3 has multiple network devices installed. Network devices include, for example, servers and L2 switches (hereinafter simply referred to as "switches"). Each network device is assigned an IP (Internet Protocol) address. Figure 1 shows an example where three servers S1, S2, and S3 and three switches SW1, SW2, and SW3 are installed in Network 3. The IP addresses of each switch SW1 to SW3 are set to IP1 to IP3, respectively. The IP addresses of each server S1 to S3 are set to IP4 to IP6, respectively.

[0013] Each server S1 to S3 and each switch SW1 to SW3 is equipped with a management port M and multiple ports p (p1 to pn). Here, n = 1 to N, where "N" refers to the number of ports installed on each network device. For example, switch SW1 is equipped with four ports p1 to p4. In the following, when a specific port is indicated, it will be shown with a suffix such as "port p1," and when not specific or when referring to them collectively, it will be shown without a suffix as "port p."

[0014] The management ports M installed on each server S1 to S3 and each switch SW1 to SW3 are connected to the respective management ports M of the monitoring unit 1 and the acquisition unit 2. The management ports M are ports that transmit control signals and the like between each network device, the monitoring unit 1, and the acquisition unit 2.

[0015] The monitoring unit 1 includes an NW management unit 11 and a database 12 (labeled "DB" in the diagram).

[0016] Database 12 stores information on status change notifications (details of which will be described later) sent from each network device. Based on the status change notifications, Database 12 stores log data indicating the connection status between network devices. Database 12 contains the IP address and MIB (Management Information Base) of each network device.

[0017] The NW management unit 11 acquires status change instructions output from the instruction unit 21 of the acquisition unit 2. Status change instructions include link-down instructions to bring down the link between NW devices (between two ports) and link-up instructions to bring up the link between NW devices. The NW management unit 11 transmits the acquired status change instructions from the management port M to the target NW device.

[0018] The NW management unit 11 receives status change notifications transmitted from each NW device. Specifically, the NW management unit 11 sends status change instructions to the NW devices to change the connection status between them, and receives status change notifications transmitted from the NW devices. Status change notifications include link down notifications indicating that the link between two NW devices (between two ports) has gone down, and link up notifications indicating that the link between two NW devices has gone up. Status change notifications include information on link down, which disconnects the connection between ports, and link up, which connects the ports. The NW management unit 11 stores the status change notifications received from each NW device in chronological order in the database 12.

[0019] Figure 2 is an explanatory diagram illustrating an example of a status change notification stored in database 12. For example, the NW management unit 11 sends a link-down instruction to port p2 of switch SW1 (IP address; IP1). This link-down instruction causes port p2 of switch SW1 and port p1 of switch SW2, which is connected to it, to go down. Log data of these link-down events is stored in database 12. Furthermore, the time X1:1 when port p2 of switch SW1 went down and the time X1:2 when port p1 of switch SW2 went down are stored as log data in database 12. In this case, if the time from time X1:1 to time X1:3 (the time when the next instruction is sent) is set to be sufficiently long, crossover with other log data can be avoided. Therefore, from the above log data, it is possible to detect that the link-down of port p2 of switch SW1 and the link-down of port p1 of switch SW2 are an event pair (evidence that they are connected).

[0020] Subsequently, when the NW management unit 11 sends a link-up instruction to port p2 of switch SW1, port p2 of switch SW1 and port p1 of switch SW2 link up. Log data of these link-ups are stored in the database 12. Furthermore, the time X1:3 when port p2 of switch SW1 links up and the time X1:4 when port p1 of switch SW2 links up are stored as log data in the database 12. In this case, if the time from time X1:3 to time Y1:1 (the time when the next instruction is sent) is set to be sufficiently long, crossover with other log data can be avoided. Therefore, from the above log data, it can be detected that the link-up of port p2 of switch SW1 and the link-up of port p1 of switch SW2 are an event pair.

[0021] Furthermore, the NW management unit 11 sends a link-down instruction to port p3 of switch SW2 (IP address; IP2). This link-down instruction causes port p3 of switch SW2 and port p2 of switch SW3, which is connected to it, to go down. Log data of these link-down events is stored in the database 12. In addition, the time Y1:1 when port p3 of switch SW2 went down and the time Y1:2 when port p2 of switch SW3 went down are stored in the database 12. Therefore, from the above log data, it is possible to detect that the link-down of port p3 of switch SW2 and the link-down of port p2 of switch SW3 are event pairs. By continuing to perform the above process, it is possible to detect pairs of ports whose relationship was previously unknown.

[0022] Database 12 stores log data indicating the time the status change notification was sent, the IP address, the notification content, and the event pair.

[0023] The network management unit 11 sets the time interval for sending status change instructions to different ports to be longer than the time interval for sending status change instructions to the same port. Specifically, when the time from X1:1 to X1:3 shown in Figure 2 is T1, and the time from X1:1 to Y1:1 is T2, the network management unit 11 sends status change instructions such that T2 > T1.

[0024] Returning to Figure 1, the acquisition unit 2 comprises an instruction unit 21, an analysis unit 22, and a storage device 23.

[0025] The storage device 23 includes an IP-compatible table storage unit 231, a connection pair storage unit 232, and a change table storage unit 233.

[0026] As shown in Figure 3, the IP correspondence table storage unit 231 stores an IP correspondence table that shows the correspondence between IP addresses and network devices. As shown in Figure 3, the IP correspondence table describes that "IP1" corresponds to switch SW1, "IP2" corresponds to switch SW2, "IP3" corresponds to switch SW3, "IP4" corresponds to server S1, "IP5" corresponds to server S2, and "IP6" corresponds to server S3.

[0027] The connection pair storage unit 232 stores a connection pair table showing the connection status of each port p in each NW device, as shown in Figure 4. Figure 4 shows the connection pairs of each NW device in network 3 shown in Figure 1. The connection pair table stores data indicating that port p2 of switch SW1 is connected to port p1 of switch SW2, and data indicating that port p1 of switch SW1 is connected to port p1 of server S1, etc. Connection pairs showing the connections between ports can be obtained by sending a status change instruction from the monitoring unit 1 to each NW device in network 3, and based on the status change notification data sent from each NW device.

[0028] As shown in Figure 5, the change table storage unit 233 stores a change table that shows the correspondence between network devices and ports whose connection status has changed due to link down and link up. For example, if the link between port p3 of switch SW2 and port p2 of switch SW3 shown in Figure 1 goes down, data indicating that the connection between these ports has been erased is stored. Also, if the link between port p2 of switch SW2 and port p2 of switch SW3 is newly established, data indicating that the connection between these ports has been added is stored. In other words, the change table storage unit 233 stores a change table that contains change information extracted from log data.

[0029] Returning to Figure 1, the instruction unit 21 outputs a status change instruction to the monitoring unit 1. The instruction unit 21 outputs the connection status change instructions to the monitoring unit 1 in order from the smallest port number.

[0030] When creating a connection pair table (see Figure 4), the analysis unit 22 reads log data (see Figure 2) stored in the database 12 of the monitoring unit 1. The analysis unit 22 stores the connection information of each port p stored in the log data in the connection pair table set up in the connection pair storage unit 232. For example, as shown in Figure 2, if the log data stored in the database 12 contains data indicating that port p2 of switch SW1 (IP1) and port p1 of switch SW2 (IP2) have linked up, this data is read and stored in the connection pair table shown in Figure 4.

[0031] The analysis unit 22 retrieves change information for connection pairs already stored in the connection pair table and updates the connection pair table stored in the change table storage unit 233 if a change in connection occurs. For example, if the log data stored in the database 12 contains data indicating that port p3 of switch SW2 and port p2 of switch SW3 have gone down, the analysis unit 22 stores data in the change table indicating that these connections have been deleted, as shown in Figure 5.

[0032] Specifically, the analysis unit 22 collects log data stored in the database 12 and extracts event pairs from the data stored in the log data that result in link down and link up with different IP addresses within a specified time for a status change instruction to the same port. The analysis unit 22 analyzes the extracted event pairs and identifies the network device corresponding to the IP address by referring to the IP correspondence table (Figure 3), and stores the data in the change table shown in Figure 5.

[0033] Furthermore, the analysis unit 22 compares the contents stored in the connection pair table shown in Figure 4 with the contents stored in the change table shown in Figure 5, and updates the data where there are differences. For example, in the connection pair correspondence table shown in Figure 10, it is shown that port p3 of switch SW2 and port p2 of switch SW3 are connected, as indicated by the symbol q1. In contrast, as shown in Figure 5, data is stored indicating that the connection between port p3 of switch SW2 and port p2 of switch SW3 has been erased, and a new connection between port p2 of switch SW2 and port p2 of switch SW3 has been added.

[0034] Based on the differences between the two, the analysis unit 22 updates the data listed in symbol q1 of the connection pair correspondence table to reflect the connection between port p2 of switch SW2 and port p2 of switch SW3. If there is a change in the connection status of each NW device connected to network 3, the analysis unit 22 immediately analyzes this change and updates the contents of the connection pair table. That is, the analysis unit 22 compares the connection pair table with the change table and updates the connection pair table based on the comparison result. After updating the connection pair table, the analysis unit 22 clears the change table.

[0035] Next, the procedure for acquiring the connection status of each NW device connected to the network 3 using the connection status acquisition device 100 configured as described above according to this embodiment will be explained with reference to the flowchart shown in Figure 6.

[0036] First, in step S11 of Figure 6, the instruction unit 21 outputs a status change instruction to the NW management unit 11. For example, it outputs a status change instruction to link down port p2 of switch SW1 (IP1) connected to network 3.

[0037] In step S12, the NW management unit 11 sends a status change instruction to the NW device in the network 3 that is subject to the status change. Specifically, the management port M of the monitoring unit 1 sends a status change instruction to the management port M of the NW device. For example, it sends a status change instruction to the management port M of switch SW1 instructing it to link down port p2.

[0038] In step S13, the NW management unit 11 receives a status change notification transmitted from the NW device. Specifically, the management port M of the monitoring unit 1 receives a status change notification transmitted from the management port M of the NW device. For example, in response to the status change instruction transmitted in step S12, the monitoring unit 11 receives a status change notification indicating that port p2 of switch SW1 has gone down, and further, that port p1 of switch SW2 connected to it has also gone down.

[0039] In step S14, the NW management unit 11 stores the connection status of port p for each IP address in the database 12 based on the status change notification. As a result, as shown in Figure 2 as an example, data indicating that port p2 of switch SW1 (IP address; IP1) linked up at time X1:3 and port p1 of switch SW2 (IP address; IP2) linked up at time X1:4 is stored in the database 12 as an event pair.

[0040] In step S15, the analysis unit 22 extracts event pairs where the IP addresses are different, resulting in a link down and a link up, within a specified time frame for a state change instruction to the same port.

[0041] In step S16, the analysis unit 22 analyzes the event pairs extracted in the process of step S15, and creates a connection pair table (see FIG. 4) showing the correspondence of the connection pairs of each port p. For example, data indicating that port p2 of switch SW1 and port p1 of switch SW2 are connected is stored in the connection pair table. In this way, a connection pair map indicating the connection state of each NW device connected to the network 3 is generated.

[0042] Next, regarding the process when the connection state of the NW devices installed in the network 3 is changed in the network where the connection pair table has already been generated, it will be described with reference to the flowchart shown in FIG. 7. As shown in FIG. 8 as an example, the case where the connection is changed from the state where port p2 of switch SW3 and port p3 of switch SW2 are connected to the connection between port p2 of switch SW3 and port p2 of switch SW2 (see reference sign Q1) will be described.

[0043] In this case, in the database 12, as shown in FIG. 9 for example, log data indicating that port p2 of switch SW3 (IP address; IP3) went link-down at time Z1:1 and port p3 of switch SW2 (IP address; IP2) connected thereto went link-down at time Z1:2 is stored.

[0044] Also, in the database 12, log data indicating that port p2 of switch SW3 (IP address; IP3) went link-up at time Z2:1 and port p2 of switch SW2 (IP address; IP2) went link-up at time Z2:2 is stored.

[0045] First, in step S31 of FIG. 7, the analysis unit 22 monitors the log data stored in the database 12.

[0046] In step S32, the analysis unit 22 writes information on connection deletion and connection addition to the change table stored in the change table storage unit 233. As a result, as shown in FIG. 5, data indicating that the connection between port p3 of switch SW2 and port p2 of switch SW3 has been deleted is stored in the change table, and data indicating that port p2 of switch SW2 and port p2 of switch SW3 have been newly added is written.

[0047] In step S33, the analysis unit 22 compares the data described in the connection pair table of the connection pair storage unit 232 with the data described in the change table stored in the change table storage unit 233.

[0048] In step S34, the analysis unit 22 determines whether there is a changed connection pair. If it is determined that there is a changed connection pair (S34; YES), this process ends. Otherwise (S34; NO), the process proceeds to step S35.

[0049] In step S35, the analysis unit 22 updates the existing data described in the connection pair table with the new data described in the change table. By doing so, for example, as shown in FIG. 8, when the connection between port p2 of switch SW3 and port p3 of switch SW2 is changed to the connection between port p2 of switch SW3 and port p2 of switch SW2, the data stored in the connection pair table can be updated in correspondence with this change result. The analysis unit (see FIG. 5) deletes the data stored in the change table.

[0050] As described above, the connection status acquisition device 100 according to this embodiment is an acquisition device that acquires connection status indicating the connection status of a plurality of NW devices, and comprises: a connection pair storage unit 232 that stores a connection pair table indicating the connection status of ports provided on each NW device; an NW management unit 11 that transmits a status change instruction to an NW device to change the connection status between NW devices and receives a status change notification transmitted from an NW device; a change table storage unit 233 that stores a connection status change table created by the NW management unit based on the status change notification; and an analysis unit 22 that compares the connection pair table with the change table and updates the connection pair table based on the comparison result.

[0051] In this embodiment, the connection status between each NW device installed in network 3 can be automatically acquired and a connection pair table can be generated. Furthermore, if a change occurs in the connection status of each NW device that has been established, the change is extracted by monitoring the log data stored in database 12. When a change in the connection status occurs, the analysis unit 22 stores the status of the connection, i.e., the deletion of a connection or the addition of a connection, in the change table. If there is a discrepancy between the data stored in the change table and the data stored in the connection pair table, the data stored in the connection pair table is updated.

[0052] Therefore, even if there are differences in protocols, the connection status between each port can be reliably extracted and the connection pair table can be updated.

[0053] Therefore, it becomes possible to obtain data indicating the connection status of network devices without relying on protocols for discovering adjacent devices. Furthermore, during network operation, for example, if a connection change occurs between ports due to maintenance, the connection status of each port can be updated and kept current by extracting event pairs from the timing of the status change notification.

[0054] Furthermore, it eliminates the need for manual rewriting of connection statuses, as was done in the past, and allows for updating the connection status with simple operations. In other words, the connection status can be updated to the latest data with a simple configuration.

[0055] In this embodiment, the present invention sequentially sends status change instructions from the management port to each port of each device under monitoring, and extracts connection pairs from the timing of status change notifications (e.g., link down, link up) from each device to obtain the connection status. Therefore, event pairs can be extracted with high accuracy, and the connection status of each port can be extracted with high accuracy.

[0056] In this embodiment, the update table is cleared after the connection pair table update is complete, so it becomes possible to continue monitoring the connection status even after the update is complete.

[0057] As shown in Figure 11, the connection status acquisition device 100 of this embodiment described above can use a general-purpose computer system that includes, for example, a CPU (Central Processing Unit, processor) 901, memory 902, storage 903 (HDD: Hard Disk Drive, SSD: Solid State Drive), communication device 904, input device 905, and output device 906. The memory 902 and storage 903 are storage devices. In this computer system, the CPU 901 executes a predetermined program loaded onto the memory 902, thereby realizing each function of the connection status acquisition device 100.

[0058] The connection status acquisition device 100 may be implemented on one computer or on multiple computers. Furthermore, the connection status acquisition device 100 may be a virtual machine implemented on a computer.

[0059] The program for the connection status acquisition device 100 can be stored on a computer-readable recording medium such as an HDD, SSD, USB (Universal Serial Bus) memory, CD (Compact Disc), or DVD (Digital Versatile Disc), or it can be distributed via a network. A computer-readable recording medium is, for example, a non-transitory recording medium.

[0060] This disclosure is not limited to the embodiments described above, and numerous modifications are possible within the scope of its essence.

[0061] 1 Monitoring Unit 2 Acquisition Unit 3 Network 11 Network Management Unit 12 Database 21 Instruction Unit 22 Analysis Unit 23 Storage Device 100 Connection Status Acquisition Device 231 IP Compatible Table Storage Unit 232 Connection Pair Storage Unit 233 Change Table Storage Unit M Management Port p (p1 to pn) Port S1 to S3 Server (Network Device) SW1 to SW3 Switch (L2 Switch; Network Device)

Claims

1. A connection status acquisition device for acquiring connection status indicating the connection status of multiple network devices, comprising: a connection pair storage unit that stores a connection pair table indicating the connection status of ports provided on each network device; a network management unit that transmits a status change instruction to change the connection status between network devices to the network devices and receives a status change notification transmitted from the network devices; a change table storage unit that stores a connection status change table created by the network management unit based on the status change notification; and an analysis unit that compares the connection pair table with the change table and updates the connection pair table based on the comparison result.

2. The connection status acquisition device according to claim 1, wherein the status change notification includes information on link down, which disconnects the connection between ports, and link up, which connects the ports.

3. The connection status acquisition device according to claim 1 or 2, wherein the analysis unit updates the connection pair table and then clears the change table.

4. A connection status acquisition method for acquiring connection status, wherein a connection status acquisition device acquires connection status indicating the connection status of multiple network devices, comprising: transmitting a status change instruction to the network devices to change the connection status between the network devices; receiving a status change notification transmitted from the network devices; storing a connection status change table created based on the status change notification in a change table storage unit; comparing the connection pair table, which indicates the connection status of ports provided on each network device, with the connection pair table, and updating the connection pair table based on the comparison result.

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