JP7208060B2 - Information processing program, information processing apparatus, and information processing method - Google Patents

Description

The present invention relates to an information processing program, an information processing apparatus, and an information processing method.

If the routing protocol is working properly, the frame will be forwarded from the source to the destination via the optimal route. However, when a failure occurs in a device in the network or recovery from the failure, the frame in the network may not pass through the expected route. In a network that relays communication based on a protocol used in the network layer, a command such as Traceroute can be used to identify a path (communication path) used for frame transfer. For this reason, it is possible to check whether the assumed route matches the communication route based on the failure occurrence status.

As a related technology, a system has been proposed that selects the shortest path route between the source and destination nodes of a double reverse ring and forwards frames via the shortest path route (eg, Patent Document 1). A method has also been proposed in which the controller calculates the link cost of each link based on the flow rate and support speed of the connection port, and selects the path with the lowest total link cost from among a plurality of preliminary transmission paths (for example, patent Reference 2). A device has also been devised that updates a neighbor registration table used in a layer 3 routing protocol based on changes in topology map information generated by transmitting and receiving topology information including link states (for example, Patent Document 3).

Japanese Patent Application Laid-Open No. 2001-127782 JP 2014-103656 Japanese Patent Application Laid-Open No. 2006-157716

A device that relays communication based on the protocol used in the data link layer does not perform processing using TTL (Time to Live). Therefore, in a network formed by devices that relay communication based on the protocol used in the data link layer, even if a command such as Traceroute is used, the communication path of frames cannot be specified. Therefore, in a network that performs communication based on the protocol of the data link layer, a dedicated interface is often introduced to each device in order to check the communication path. However, introducing an interface into each device is complicated and costly, and is inefficient. Moreover, using any of the techniques described as related techniques does not solve this problem.

An object of the present invention, as one aspect, is to provide a method for efficiently determining whether a communication route is appropriate.

An information processing program according to one aspect is executed by a computer. The computer obtains information about the presence or absence of a failure in each of a plurality of devices included in the network, and information on frames that have passed through the network between each of the plurality of devices. Based on the acquired information of the frame, the computer identifies the first communication path through which the data passed and the devices corresponding to the start and end points of the communication path of the data. Based on the information of the device corresponding to the specified start point and end point and the information about the presence or absence of failure of each of the plurality of devices, the computer performs the communication between the device corresponding to the specified start point and end point of the communication path of the data. specifies the second communication path that is the shortest path of . The computer outputs a comparison result between the first communication path and the second communication path.

It is possible to efficiently determine whether the communication path is appropriate.

It is a figure explaining the example of the route confirmation process concerning embodiment. It is a figure explaining the example of a structure of a monitoring server. It is a figure explaining the example of the hardware constitutions of a monitoring server. FIG. 2 is a diagram illustrating an example of a network; FIG. FIG. 10 is a diagram illustrating an example of a connection relationship table; FIG. FIG. 4 is a diagram illustrating an example of information notified from a sensor; It is a figure explaining the example of a traffic information table. FIG. 10 is a diagram illustrating an example of a failure information table; FIG. FIG. 10 is a diagram illustrating an example of how to obtain communication paths of frames; It is a figure explaining the example of the process performed by a monitoring server. FIG. 10 is a diagram illustrating an example of a case where frames pass through the shortest route; FIG. 10 is a diagram illustrating an example of a case where frames do not pass through the shortest route; FIG. 11 is a diagram illustrating an example of a forwarding table; FIG. FIG. 10 is a diagram illustrating a calculation example of a shortest path and an example of communication paths of frames;

FIG. 1 is a diagram illustrating an example of route confirmation processing according to the embodiment. The network shown in FIG. 1 includes devices A to H. FIG. Connections between devices and connections between terminals and devices are as shown in FIG. 1, and all of the solid lines, dashed lines, and one-dot chain lines in FIG. 1 indicate links between devices or between terminals and devices. and Each link between devices is provided with sensors (sensor 1 to sensor 11) for acquiring information on frames passing through the link. Here, it is assumed that each of the devices A to H is a device that relays communication based on the protocol used in the data link layer, and is not assigned an IP (Internet Protocol) address. On the other hand, IP addresses are assigned to the terminals 1 to 8 and the monitoring server 20 .

Assume that terminals 1 and 5 are communicating with each other in the network shown in FIG. The monitoring server 20 acquires information on the occurrence of failures in devices in the network, the occurrence of failures in links between devices, and information on frames passing through each link from sensors and devices in the network. The monitoring server 20 uses the obtained information to identify the path through which the frame passed. In the following explanation, of the path from the source of the frame to the destination, the part included in the network formed by the equipment that relays communication based on the protocol used in the data link layer is called the "communication path". may be described. In the example of FIG. 1, the communication path of a frame transmitted from terminal 1 to terminal 5 is the path of device A-device H-device G-device F-device E, as indicated by the dashed line in FIG. . Note that the communication path is obtained by connecting the link where the frame including the header information to be processed is detected by the sensor so as to satisfy the connection relationship of the devices.

Next, the monitoring server 20 identifies the start point device and the end point device of the communication path. Here, the starting point of the communication route is the device with the smallest number of transfers to the frame transmission source among the devices included in the communication route. Similarly, the end point of the communication route is the device with the smallest number of transfers to the destination of the frame among the devices included in the communication route. In the example of FIG. 1, the terminal 1, which is the transmission source of the frame, is connected to the device A, so the device A becomes the starting point of the communication path. Similarly, since terminal 5, which is the destination of the frame, is connected to device E, device E becomes the end point of the communication path.

After specifying the start point and end point of the communication path, the monitoring server 20 calculates the shortest route from the start point to the end point of the communication path based on the occurrence of failures in links and devices in the network. In the example of FIG. 1, as indicated by broken lines, the path of device A-device G-device F-device E, the route of device A-device B-device F-device E, and the route of device A-device B-device C - Three of the paths of device E have been calculated as shortest paths.

The monitoring server 20 compares the calculated shortest route with the communication route of the current frame. In the example of FIG. 1, the frame communication path is device A-device H-device G-device F-device E, so the frame communication route is different from any of the shortest paths. The monitoring server 20 outputs the result of comparison between the communication path of the frame and the shortest path. For example, the monitoring server 20 may display the information shown in FIG. 1 on a display included in the monitoring server 20. FIG. Also, the monitoring server 20 may transmit the information shown in FIG. 1 to a predesignated device such as a terminal of an operator who manages the network.

In the example of FIG. 1, the comparison result is output that the communication path of the frame is different from the shortest path. Therefore, based on the output from the monitoring server 20, the operator can efficiently determine whether the communication route and the shortest route match. Thus, according to the route confirmation processing according to the embodiment, it is possible to efficiently determine whether the communication route and the shortest route match.

<Device configuration>
FIG. 2 is a diagram illustrating an example of the configuration of the monitoring server 20. As shown in FIG. The detection device 20 includes a communication section 21 , a control section 30 and a storage section 40 . The communication unit 21 has a transmission unit 22 and a reception unit 23 . The transmission unit 22 transmits frames to other devices such as devices and sensors in the network. The receiving unit 23 receives frames from other devices such as devices and sensors in the network.

The storage unit 40 stores a traffic information table 41, a connection relation table 42, and a fault information table 43, and can optionally store a forwarding table 44 as well. The traffic information table 41 stores information on frames passing through each link. The connection relation table 42 stores information specifying the connection destination of each port of each device in the network. The failure information table 43 records information about failures occurring in links, devices, or sensors in the network. The forwarding table 44 is used when the devices in the network include a device for which the forwarding port is set in association with the header information of the received frame. The transfer table 44 records the information of the device for which the transfer destination port is set in association with the header information of the received frame, and the correspondence between the header information of the received frame and the transfer destination of the device. Examples of the traffic information table 41, the connection relationship table 42, the failure information table 43, and the transfer table 44 will be described later.

The control unit 30 includes an acquisition unit 31 , an identification unit 32 , a route calculation unit 33 and a comparison processing unit 34 . The acquiring unit 31 acquires information of frames passing through the link on which the sensor is installed from the sensor in the network. Furthermore, the acquisition unit 31 also acquires information about failure occurrence conditions in each link and device. The acquisition unit 31 can appropriately update the traffic information table 41 and the failure information table 43 using the acquired information. The specifying unit 32 uses the traffic information table 41, the connection relationship table 42, and the failure information table 43 to specify the communication path currently used for transferring the frame. The identifying unit 32 also identifies the start point and end point of the communication path.

The route calculator 33 uses the connection relationship table 42 and the failure information table 43 to identify the shortest route for frame transfer. In the following description, the shortest path is assumed to be the path with the lowest cost among the paths that can be used for frame transfer. Note that the shortest path may be determined using the number of hops or the number of metrics, depending on the implementation. When the monitoring server 20 holds the transfer table 44, the route calculator 33 uses the connection relationship table 42, the failure information table 43, and the transfer table 44 when calculating the shortest route. The comparison processing unit 34 compares the communication route identified by the identification unit 32 and the shortest route calculated by the route calculation unit 33, and performs processing for outputting the comparison result. Output of the comparison results may be transmission of the comparison results to a predetermined device, such as, for example, an operator's terminal. Also, the comparison processing unit 34 may perform processing for outputting the comparison result to the output device 104 (FIG. 3) such as a display provided in the monitoring server 20 .

FIG. 3 is a diagram explaining an example of the hardware configuration of the monitoring server 20. As shown in FIG. The monitoring server 20 comprises a processor 101 , memory 102 , bus 105 and network interface 109 . Furthermore, the monitoring server 20 may have one or more of the input device 103 , the output device 104 , the storage device 106 and the portable storage medium drive device 107 . The monitoring server 20 can be realized by any information processing device. For example, the monitoring server 20 can be implemented by a computer, server device, or the like.

Processor 101 is any processing circuit and may be, for example, a Central Processing Unit (CPU). Processor 101 operates as control unit 30 . The processor 101 can execute programs stored in the memory 102 and the storage device 106, for example. The memory 102 appropriately stores data obtained by the operation of the processor 101 and data used for processing by the processor 101 . The storage device 106 stores programs, data, and the like, and appropriately provides the stored information to the processor 101 and the like. The memory 102 and the storage device 106 operate as the storage unit 40 in the monitoring server 20 . The network interface 109 performs processing for the monitoring server 20 to communicate with other devices. That is, network interface 109 operates as communication unit 21 .

A bus 105 connects the processor 101, the memory 102, the input device 103, the output device 104, the storage device 106, the portable storage medium drive device 107, and the network interface 109 so that they can transmit and receive data to each other. The input device 103 is any device used to input information, such as a keyboard, mouse, microphone, or camera, and the output device 104 is any device used to output data, such as a display. The portable storage medium drive device 107 can output data in the memory 102 and the storage device 106 to the portable storage medium 108 and can read programs, data, and the like from the portable storage medium 108 . Here, the portable storage medium 108 can be any portable storage medium including Compact Disc Recordable (CD-R) and Digital Versatile Disk Recordable (DVD-R).

<First Embodiment>
In the following, the route confirmation processing will be described in detail when the transfer destination port is not set in association with the header information of the received frame in any device in the network. Examples of tables held by the monitoring server 20, update processing of those tables, and comparison processing between communication paths and shortest paths will be described below. In the first embodiment, the monitoring server 20 does not need to hold the transfer table 44 because the transfer destination of the frame is not set in any of the devices.

(1) Example of table held by monitoring server 20 and example of table update processing In the following description, terminal 1 is assigned an IP address of 192.168.0.1/24, and terminal 5 is assigned an IP address of 192.168.0.1/24. = 192.168.2.1/24 is assigned.

FIG. 4 is a diagram illustrating an example of a network. The network in FIG. 4 includes devices A to H to which IP addresses are not assigned, terminals 1 to 8 to which IP addresses are assigned, and a monitoring server 20, as in FIG. Squares containing numbers in the equipment shown in FIG. 4 represent ports, and numbers written in the squares represent port numbers. In the following description, the port number is described following the character string Po. For example, device A's port Po1 is connected to device B's port Po3, and device A's port Po2 is connected to device G's port Po4. Connection relationships can be similarly specified for other devices. For example, port Po2 of device H is connected to terminal 8 and port Po3 of device H is connected to monitoring server 20 .

FIG. 5 is a diagram illustrating an example of the connection relationship table 42. As shown in FIG. The connection relation table 42 stores devices, ports, connection destinations, costs, and installed sensors. The connection destination is information indicating the port of the terminal or device to which the port of the device whose information is recorded in the entry is connected. The cost is the cost value calculated for the link between the port of the entry and the port of the connection destination when the connection destination of the port of the entry is the port of another device. Calculation of the cost value is appropriately performed by the acquisition unit 31 of the monitoring server 20 using any known method. An installed sensor is a sensor that is installed to acquire information on frames that pass through the link between the entry port and the connection destination port when the connection destination of the entry port is the port of another device. is.

For example, the first entry in the connection relationship table 42 indicates that the port Po1 of the device A is connected to the port Po3 of the device B, and that the link between the port Po1 of the device A and the port Po3 of the device B has a sensor. 1 is recorded. Further, the cost value of the link between port Po1 of device A and port Po3 of device B is one. The second entry indicates that port Po2 of device A is connected to port Po4 of device G, and that sensor 5 is installed on the link between port Po2 of device A and port Po4 of device G. is recorded. Further, it is recorded that the cost value of the link between the port Po2 of the device A and the port Po4 of the device G is 1. The third entry indicates that port Po3 of device A is connected to port Po4 of device H, and that sensor 4 is installed on the link between port Po3 of device A and port Po4 of device H. is recorded. Further, it is recorded that the cost value of the link between port Po3 of device A and port Po4 of device H is 10. The fourth entry records that port Po4 of device A is connected to terminal 1 . For devices other than device A, the connection destination of each port, the cost value of the link, and the sensor installed on the link can be specified from the connection relation table 42 in the same manner. Among the information recorded in the connection relationship table 42, information other than the cost value is illustrated in FIG.

FIG. 6 is a diagram explaining an example of information notified from the sensor. Each sensor acquires and aggregates header information of frames passing through the link on which the sensor is installed, and periodically notifies the monitoring server 20 of information as shown in FIG. The information notified from the sensor includes the notification time and information for each type of frame specified by the sensor. Here, each sensor determines that the frames are of the same type when the header information in the frames is the same. The information for each frame is information that may be used in layer 2-4 processing and the communication rate for that type of frame. In the example of FIG. 6, the source IP address, source port number, destination IP address, and destination port number are included for each type of frame. Furthermore, the VLAN (Virtual Local Area Network) number, COS (Class of Service) value, DSCP (Differentiated Services Code Point) value, and protocol number of each frame are also reported from the sensor to the monitoring server 20 as frame information.

For example, in the example of FIG. 6, for frame 1, the source IP address=192.168.0.1/24 (terminal 1) and the destination IP address=192.168.2.1/24 (terminal 5) is reported to the monitoring server 20 . Furthermore, the monitoring server 20 is also notified that the frame 1 has a source port number of xxx, a destination port number of yyy, a VLAN number of zz, a COS value of aa, a DSCP value of ab, and a protocol number of ac. . Furthermore, the monitoring server 20 is also notified that the communication rate of frame 1 is 100 Mbps.

Similarly, for frame 2, source IP address = 192.168.0.5/24, source port number = xx, destination IP address = 192.168.2.10/24, destination port number = xy is reported to the monitoring server 20 . Furthermore, regarding frame 2, the monitoring server 20 is also notified that VLAN number=zy, COS value=ac, DSCP value=aa, and protocol number=cd. Furthermore, the monitoring server 20 is also notified that the communication rate of frame 2 is 110 Mbps. The monitoring server 20 is similarly notified of other frames.

FIG. 7 is a diagram illustrating an example of the traffic information table 41. As shown in FIG. The traffic information table 41 records, for each link in the network, information about frames passing through that link. In the example of FIG. 7, the frame information includes source IP address, source port number, destination IP address, destination port number, VLAN number, COS value, DSCP value, and protocol number. The information about frames included in the traffic information table 41 is the same as the information notified from the sensor. Therefore, FIG. 7 is an example of the traffic information table 41 when the information notified from the sensor to the monitoring server 20 is as shown in FIG.

For example, assume that a control frame including the information shown in FIG. Then, the acquisition unit 31 of the monitoring server 20 acquires the control frame including the information notified via the reception unit 23, and records the information in the control frame as shown in the first table of FIG. The acquisition unit 31 similarly processes frames transmitted from other sensors to the monitoring server 20 . For example, information transmitted from the sensor 10 installed on the link between the device G and the device F to the monitoring server 20 is recorded as shown in the second table of FIG. Information transmitted from the sensor 11 installed on the link between the device F and the device E to the monitoring server 20 is recorded as shown in the second table of FIG. Information notified from sensors installed in other links is also recorded in the traffic information table 41 in the same manner.

FIG. 8 is a diagram illustrating an example of the fault information table 43. As shown in FIG. The fault information table 43 records the states of the ports of the devices and the states of the sensors. For example, the first entry in the fault information table 43 indicates that communication via port Po01 of device A is possible (Link UP). On the other hand, the second entry indicates that communication via port Po02 of device A is disabled (Down). In the example of FIG. 8, ports Po3 and Po4 of device A and ports Po1 to Po4 of device B are both communicable. The third entry from the bottom of the fault information table 43 indicates that sensor 1 is operating normally. Similarly, the second entry from the bottom indicates that sensor 2 is operating normally.

The acquisition unit 31 of the monitoring server 20 can also acquire control frames that notify the occurrence of failures transmitted from devices and sensors in the network. Here, failures notified from devices include link failures, occurrence of failures in the device itself, occurrences of failures in connected devices, and the like. On the other hand, the failure notified from the sensor includes failure of the link in which the sensor is installed, failure of the sensor itself, and the like. Upon receiving a control frame containing information about the occurrence of a failure, the acquiring unit 31 updates the failure information table 43 using the information included in the control frame.

(2) Example of Comparing Process of Communication Route and Shortest Route In the following explanation, as an example, a case where a route is determined for each combination of a source IP address and a destination IP address will be explained. In this case, a communication route and a shortest route are obtained for each combination of source IP address and destination IP address. In this example, it is assumed that the monitoring server 20 has a connection relationship table 42 shown in FIG. 5 and a traffic information table 41 shown in FIG.

FIG. 9 is a diagram for explaining an example of how to obtain communication paths of frames. After selecting the type of frame to be processed, the specifying unit 32 specifies the source IP address and the destination IP address of the frame to be processed. Further, the identifying unit 32 identifies, from the traffic information table 41, a link through which a frame containing a combination of a source IP address and a destination IP address to be processed passes as a passing link (step S1). For example, assume that source IP address = 192.168.0.1/24 (terminal 1) and destination IP address = 192.168.2.1/24 (terminal 5) are selected for processing. In this case, the identifying unit 32 identifies an entry including source IP address=192.168.0.1/24 and destination IP address=192.168.2.1/24 from the traffic information table 41 as a passing link. . In this example, the first entry in the device A-device G link table, the first entry in the device G-device F link table, and the first entry in the device F-device E link table in FIG. contains information on the frame to be processed. Therefore, the identification unit 32 identifies the device A-device G link, the device G-device F link, and the device F-device E link as passing links.

The identifying unit 32 determines whether or not there is a failed sensor (abnormal sensor) in the network (step S2). If there is no abnormal sensor, the specifying unit 32 arranges the passing links in the order of connection using the specified start point and end point of each link (No in step S2, step S5). The identifying unit 32 sets the obtained path as the communication path of the frame (step S8).

For example, it is assumed that the fault information table 43 stored in the monitoring server 20 does not record any abnormalities in any of the sensors. Then, the specifying unit 32 determines whether each device at the start point and the end point of each passing link specified in the processing of step S1 is operating as a device on the transmission side of the frame and whether it is operating as a device on the reception side of the frame. judge. In the device A-device G link, the device A is the device on the frame transmission side, and the device G is the device on the frame reception side. In the device G-device F link, the device G is the device on the transmission side of the frame, and the device F is the device on the reception side of the frame. In the device F-device E link, the device F is the device on the transmission side of the frame, and the device E is the device on the reception side of the frame. That is, each device operates as follows for a frame to be processed.

Operates only as a device on the sending side of frames: Device A
Act as both sender and receiver of frames: Device G, Device F
Operates only as a device on the receiving side of frames: Device E
Therefore, the specifying unit 32 determines that a device that operates only as a frame transmission side is the start point of the communication path, a device that operates only as the frame reception side is the end point of the communication path, and a device that operates as both the frame transmission side and the frame reception side. is an intermediate device in the communication path. The identification unit 32 identifies communication paths by arranging passing links by connecting the start point and end point of each link so as to satisfy the determination result. In this example, if the passing links are arranged in the order of device A-device G, device G-device F, and device F-device E, the route of device A-device G-device F-device E is obtained as the communication route.

On the other hand, it is assumed that it is determined in step S2 that there is an abnormal sensor (Yes in step S2). In this case, there is a possibility that the monitoring server 20 is not notified of the information of the frame passing through the link in which the abnormal sensor is installed because the abnormal sensor cannot communicate normally with the monitoring server 20 . For this reason, if it is assumed that the frame passes through the link on which the abnormal sensor is installed, and if one route including all the passing links is obtained, the identifying unit 32 determines the communication route including the link on which the abnormal sensor is installed. process to identify the Therefore, the identifying unit 32 determines whether a link including the starting point of the link on which the abnormal sensor is installed is identified as a passing link (step S3). If the link including the starting point of the link on which the abnormal sensor is installed is not identified as the passing link, the identifying unit 32 determines that there is no possibility that the frame is passing through the link on which the abnormal sensor is installed (step No in S3). Therefore, the specifying unit 32 determines a communication route by performing the processes of steps S5 and S8.

If the link including the starting point of the link on which the abnormal sensor is installed is specified as the passing link, there is a possibility that the frame passes through the link on which the abnormal sensor is installed (Yes in step S3). Therefore, the specifying unit 32 determines whether a link including the end point of the link on which the abnormal sensor is installed is specified as a passing link (step S4). When the link including the end point of the link on which the abnormal sensor is installed is not identified as the passing link, the identifying unit 32 determines that there is no possibility that the frame passes through the link on which the abnormal sensor is installed (step No in S4). Therefore, the specifying unit 32 determines a communication route by performing the processes of steps S5 and S8.

Next, when both the link including the start point of the link on which the abnormal sensor is installed and the link including the end point of the link on which the abnormal sensor is installed are identified as passing links (Yes in step S3, Yes in step S4 ) will be explained. In this case, the identifying unit 32 determines that the frame passes through the link on which the abnormal sensor is installed. Therefore, the identifying unit 32 adds the link on which the abnormal sensor is installed to the passing links (step S6). The identification unit 32 arranges the identified passing links and the added links in the order of connection using the start point and the end point of each link, and sets the obtained path as the communication path of the frame (steps S7 and S8). The method of obtaining the communication path in step S7 is the same as the processing described in relation to the description of step S5. Note that the process when it is determined as Yes in step S4 corresponds to a relief measure when one continuous route cannot be identified from the passing links due to lack of information on the link on which the abnormal sensor is installed.

For example, if the sensor 10 is an abnormal sensor, the monitoring server 20 is not notified of information on frames passing through the device G-device F link. Therefore, the information about the frames passing through the device G-device F link is missing from the traffic information table 41 . In this state, it is assumed that the device A-device G link and the device F-device E link are identified as passing links. In this case, the identifying unit 32 determines that the device (device G) serving as the starting point of the link (device G-device F) in which the abnormal sensor is installed is included in the device A-device G link. Further, the identification unit 32 determines that the device (device F) that is the end point of the link (device G-device F) in which the abnormal sensor is installed is included in the link of device F-device E. FIG. Therefore, the specifying unit 32 adds the link of the device G-device F link to the passing links, and then obtains the communication route. In this example, by adding the link of device G-device F, the route of device A-device G-device F-device E is obtained as a communication route.

Here, if the abnormal sensor is installed at the first or last link of the route, it is judged as No in either step S2 or step S3, so the route is obtained from the link specified as the passing link. . For example, if the sensor 5 is an abnormal sensor, the information of the frame passing through the link between the device A and the device G is lost, so the link between the device G and the device F and the link between the device F and the device E are regarded as passing links. Become. Therefore, the communication path is determined to be Device G-Device F-Device E. Also, the start point of the communication route is the device G, and the end point of the communication route is the device E. In this case, the communication route and the optimum route are compared for routes other than the links on which the abnormal sensors are installed. If the anomaly sensor is installed on the last link of the route, it will be processed in the same way.

Therefore, even if some of the links in the route used for frame transfer are not included in the passing links due to the occurrence of an abnormality in the sensor, a communication route including links specified as passing links is required. . Therefore, as will be described later, it is determined whether or not the route from the start point to the end point of the communication route passes through the shortest route. Since the object to be compared with the shortest route is the communication route obtained by the processing described with reference to FIG. may not be all of the parts included in the network. Therefore, the monitoring server 20 does not have to hold information on all terminals connected to the network. Therefore, the processing burden on the operator of the monitoring server 20 is reduced compared to the case where terminal information is registered in the monitoring server 20 .

Note that FIG. 9 is an example of how to obtain a communication path, and the processing procedure may be changed according to the implementation. For example, the order of processing of steps S3 and S4 can be arbitrarily changed. Further, step S2 may be omitted, and steps S3 and S4 may be performed.

FIG. 10 is a diagram illustrating an example of processing performed by the monitoring server 20. As illustrated in FIG. The processing of FIG. 10 also includes identification of communication paths described with reference to FIG. In FIG. 10, variable n and constant N are used. The constant N is the number of routes to be processed, and the variable n is used to count the number of processed routes.

The identification unit 32 identifies a combination of terminals through which frames are communicated from the traffic information (step S21). Note that this process corresponds to specifying a combination of the source IP address and the destination IP address of the frame. The specifying unit 32 sets the variable n to 1 (step S22). The specifying unit 32 selects the n-th combination as a processing target (step S23). The specifying unit 32 specifies a communication route between the terminals of the n-th combination (step S24). The details of the processing performed in step S24 are as explained with reference to FIG. Further, the identification unit 32 notifies the route calculation unit 33 and the comparison processing unit 34 of the obtained communication route and the value of the variable n.

The route calculation unit 33 determines whether a failure has occurred in the network (step S25). If no failure has occurred in the network, the route calculation unit 33 calculates the shortest route connecting the start point and the end point of the identified communication route (No in step S25, step S26). In step S26, the route calculation unit 33 traces transferable device candidates for each of the links connected to the device specified as the starting point, and also finds links connected to the transferable device candidates from the transferable device candidates. Find possible forwarding destinations from . By repeating this process, a route that reaches the end point device of the communication route is selected from all the obtained routes. After that, by comparing the cost values of the routes reaching the terminal device of the communication routes, the route with the relatively small cost value is determined as the shortest route.

For example, assume that device A is the starting point of the communication path and device E is the end point of the communication path. Then, the path calculation unit 33 identifies the device B, the device G, and the device H as transfer destinations reachable from the device A. FIG. Note that the route calculation unit 33 can use the connection relationship table 42 when specifying the transfer destination. After that, the route calculation unit 33 identifies the device C and the device F as reachable transfer destinations on the device A-device B route. The path calculation unit 33 identifies the device D and the device E as reachable transfer destinations on the device A-device B-device C route. Then, the path calculation unit 33 determines that the path from the device A to the device E is device A-device B-device C-device E. FIG. In addition, since the route calculation unit 33 can also transfer to the device E through the route of device A-device B-device C-device D, the device A-device B-device C-device D-device E A route that can reach the device E from the device A is assumed. Even when the transfer destination from the device A is a device other than the device B, the route calculation unit 33 calculates all routes by which the device A can reach the device E by performing the same processing. After calculating all the routes that can reach the device E from the device A, the sum of the cost values of the routes is compared, and the route with the relatively small sum of the cost values is determined as the shortest route. Note that the cost value of each link is also specified from the connection relation table 42 .

If a fault occurs in the network, the route calculation unit 33 calculates the shortest route that connects the start point and the end point of the specified communication route and does not include the fault occurrence point (Yes in step S25, step S27). During the processing in step S27, the path calculation unit 33 excludes ports whose failure information is included in the failure information table 43 among the links recorded in the connection relationship table 42 from the transfer destination candidates. The processing of the route calculation unit 33 when obtaining the shortest route is the same as that of step S26, except that the port whose fault information is included in the fault information table 43 is excluded from the transfer destination candidates. That is, the route calculation unit 33 calculates the distance from the communication path start point device to the communication path start point device based on the communication path start point device and end point device information and the failure information table 43 indicating the failure occurrence status of the devices in the network. Identifies the shortest route to the terminal device.

The comparison processing unit 34 acquires information on the shortest route calculated in step S26 or step S27 and compares it with the communication route. Through this processing, the comparison processing unit 34 determines whether or not communication is being performed through the shortest route (step S28). In the process of step S28, it is determined whether the shortest route and the communication route match. If the shortest route and the communication route do not match, the comparison processing unit 34 determines that communication is not being performed through the shortest route. (No in step S28). Then, the comparison processing unit 34 outputs a screen notifying that the shortest route and the communication route are different for the n-th combination (step S29). Note that the screen for notifying that the shortest route and the communication route are different may be changed depending on the implementation. For example, the screen notifying that the shortest route and the reachable route are different may be a screen showing both the shortest route and the reachable route, as shown in FIG. Also, the screen notifying that the shortest path and the communication path are different may list the names of the devices included in each of the shortest path and the communication path.

After that, the comparison processor 34 increments the variable n by 1 and compares the obtained variable n with the constant N (steps S30 and S31). If the obtained variable n does not exceed the constant N, all combinations have not been processed (No in step S31). Therefore, the comparison processing unit 34 notifies the variable n to the specifying unit 32, and the specifying unit 32 starts the processes after step S24.

On the other hand, when the communication route matches the shortest route, the comparison processing unit 34 determines that communication is being performed through the shortest route (Yes in step S28). Note that when a plurality of shortest routes are calculated, if any of the shortest routes matches a communication route, it is determined that communication is being performed through the shortest route. If the shortest path communication is being performed, the process from step S30 onwards is performed.

(2a) Example of Processing When Communication Path and Shortest Path Match FIG. 11 is a diagram illustrating an example of a case where a frame passes through the shortest path. In this example, it is assumed that no device in the network has failed. In the example of FIG. 11, device A is the starting point of the communication path, and device E is the end point of the communication path. Also, the communication route and the shortest route are as follows.

Communication path: Device A - Device G - Device F - Device E
Shortest path_1: device A - device B - device C - device E
Shortest path_2: device A - device B - device F - device E
Shortest path_3: device A-device G-device F-device E
The comparison processing unit 34 compares the communication route with the shortest route_1 to shortest route_3 to determine whether the communication route matches any of the shortest route_1 to shortest route_3. In the example of FIG. 11, the communication route matches the shortest route_3.

Although not shown in FIG. 10, when the reachable route matches any of the shortest routes, the comparison processing unit 34 may output a notification indicating that the reachable route matches the shortest route. As a notification indicating that the communication path matches the shortest path, for example, the comparison processing unit 34 may perform processing to display the diagram shown in FIG. 11 on the display provided in the monitoring server 20. Further, the comparison processing unit 34 may perform processing for transmitting a notification in any format indicating that the communication route matches the shortest route to a terminal or the like used by the operator.

(2b) Example of processing when communication route and shortest route do not match Next, an example will be described in which the communication route does not match the shortest route due to a failure in the network.

For example, assume that a failure occurs in the link between device A and device G while communication as shown in FIG. 11 is being performed. Assume that due to the occurrence of a failure, device A changes the transfer destination of frames transmitted from terminal 1 to terminal 5 from device G to device H. FIG. Therefore, it is assumed that the communication path of a frame transmitted from terminal 1 to terminal 5 is updated from device A-device G-device F-device E to device A-device H-device G-device F-device E. At this point, the monitoring server 20 does not recognize that the communication path for frames transmitted from the terminal 1 to the terminal 5 has been changed.

After that, each sensor notifies the monitoring server 20 of information on frames that have passed through the link on which the sensor is installed. Therefore, in the monitoring server 20 , the traffic information table 41 is updated by the processing of the acquisition unit 31 .

When the sensor 5 detects the occurrence of a failure in the link between the device A and the device G, the sensor 5 notifies the monitoring server 20 of the occurrence of the failure. Then, the acquisition unit 31 identifies the start point and end point of the link in which the failure occurs by searching the connection relationship table 42 (FIG. 5) using the installed sensor=sensor 5 as a key. In this example, the sensor 5 is installed on the link connecting the device A port Po2 and the device G port Po4. Therefore, the acquisition unit 31 determines that the link connecting the port Po2 of the device A and the port Po4 of the device G is faulty. The acquisition unit 31 updates the state of both the entry of the port Po2 of the device A and the entry of the port Po4 of the device G in the fault information table 43 from Link UP to Down. That is, the acquiring unit 31 records the occurrence of a failure in the failure information table 43 for each of the start port and the end port of the link in which the failure has occurred. Assume that the fault information table 43 is updated as shown in FIG.

Assume that the specifying unit 32 subsequently obtains the communication route for the frame transmitted from the terminal 1 to the terminal 5 using the information in the traffic information table 41 . The processing for obtaining communication paths is as described with reference to FIG. Assume that the identification unit 32 has identified device A-device H-device G-device F-device E as the communication path for frames transmitted from terminal 1 to terminal 5. FIG. Therefore, the device A is specified as the starting point of the communication path, and the device E is specified as the end point of the communication path.

The route calculation unit 33 obtains the shortest route using the start point and end point of the communication route. In this example, a failure occurs in the link between the device A and the device G, so the path calculation unit 33 identifies the device B and the device H as possible transfer destinations from the device A. FIG. The subsequent processing for obtaining the shortest path is the same as the processing described with reference to FIG. Assume that the shortest route obtained by the route calculating unit 33 and the communication route obtained by the specifying unit 32 are as follows.

Communication path: Device A - Device H - Device G - Device F - Device E
Shortest path_1: device A - device B - device C - device E
Shortest path_2: device A - device B - device F - device E
FIG. 12 is a diagram illustrating an example in which frames do not pass through the shortest route. Shortest path_1 and shortest path_2 are indicated by dashed lines in FIG. The communication path is as indicated by the one-dot chain line in FIG. The communication route is a route connecting links through which the sensor detects the passage of the frame to be processed. Furthermore, FIG. 12 also shows that the link between device A and device G has failed.

The comparison processing unit 34 compares the reachable route with the shortest route_1 and the shortest route_2 to determine whether the reachable route matches any of the shortest routes. In the example of FIG. 11, the communication path does not match any shortest path. Therefore, the comparison processing unit 34 outputs a notification indicating that the communication route does not match the shortest route. As a notification indicating that the communication path does not match the shortest path, for example, the comparison processing unit 34 may perform processing to display the diagram shown in FIG. 12 on the display provided in the monitoring server 20. Further, the comparison processing unit 34 may perform processing for transmitting an arbitrary form of notification indicating that the communication route does not match the shortest route to the terminal or the like used by the operator.

9 to 12, the case where the route is determined for each combination of the source IP address and destination IP address to be processed has been described. A route may be determined. In other words, among the information recorded in the traffic information table 41 (FIG. 7) as frame information, an arbitrary combination of information other than the time and the communication rate may be used to sort the routes. For example, a route may be determined for each combination of source IP address, source port number, destination IP address, and destination port number. Even when a route is determined by a combination of address information in the header of a frame and other information, methods for obtaining communication routes of frames, methods for obtaining shortest routes, comparison processing between communication routes and shortest routes, and comparison results The output and the like are the same as the processing described with reference to FIGS. 9 to 12. FIG.

As described above, when the communication path of the frame is different from the shortest path, the result of comparison between the communication path and the shortest path is output to the monitoring server 20 or the terminal used by the operator. Therefore, based on the output from the monitoring server 20, the operator can efficiently determine whether the communication route and the shortest route match. Therefore, according to the route confirmation processing according to the first embodiment, the operator can efficiently determine whether the communication route and the shortest route match.

By efficiently determining whether the communication route and the shortest route match, the operator can perform processing for matching the communication route and the shortest route. If a failure occurs in the network under the condition that the communication route and the shortest route do not match, there is a possibility that the frame is not transferred to the intersection of the shortest route and the detour route. For example, in a case where the communication route does not include the intersection of the shortest route and the detour route, the frame is not transferred to the intersection of the shortest route and the detour route. In this case, even if a detour route is calculated, the frames are not transferred to the detour route. An operator who discovers that the communication route and the shortest route do not match can match the communication route with the shortest route. can also reduce the possibility of communication failure.

<Second embodiment>
In the second embodiment, a case will be described where a network includes a device for which a transfer destination port is set in association with header information of a received frame. The table held by the monitoring server 20 and the update process of the table are the same as in the first embodiment. In the second embodiment, it is assumed that a route is determined for each combination of source IP address, source port number, destination IP address, and destination port number. Also in the second embodiment, it is assumed that communication is performed through the network shown in FIG. In the second embodiment, the monitoring server 20 holds a forwarding table 44. FIG.

FIG. 13 is a diagram illustrating an example of the transfer table 44. As shown in FIG. The forwarding table 44 includes information on devices, source IP addresses, source port numbers, destination IP addresses, destination port numbers, and forwarding destination ports. The device is information specifying the device for which the transfer condition of the entry is set. The transfer destination of the frame is set according to a combination of header information used for setting the route. Therefore, the combination of the source IP address, source port number, destination IP address, and destination port number in each entry is used to specify the frame for which the forwarding destination is set. The transfer destination port column of each entry records the information of the transfer destination port in the device of that entry for the frame that satisfies the conditions in that entry.

For example, the first entry in FIG. 13 is information on settings in device B. In FIG. Device B receives a frame with source IP address = 192.168.0.1/24, source port number = 1030, destination IP address = 192.168.2.1/24, and destination port number = 80. A setting is made to transfer to port Po2. Similarly, according to the second entry, device G has source IP address = 192.168.0.1/24, source port number = 1030, destination IP address = 192.168.2.1/24, Transfer the frame with destination port number=80 to port Po1. Furthermore, according to the third entry, device F has source IP address = 192.168.0.1/24, source port number = 1030, destination IP address = 192.168.2.1/24, destination The frame with port number=80 is transferred to port Po1.

Note that FIG. 13 is an example. The information recorded in the forwarding table 44 can be changed according to the combination of conditions used for route determination. In the example of FIG. 13, the transfer destination port information for one type of frame is recorded. information regarding the forwarding settings of the .

FIG. 14 is a diagram for explaining a calculation example of the shortest path and an example of communication paths of frames. In the example below, the transfer settings described with reference to FIG. It is assumed that no settings have been made. In FIG. 14, the port number of the port for which the transfer destination is set is represented by the number written in the square.

For example, terminal 1 (192.168.0.1/24) sends a frame with source port number = 1030 and destination port number = 80 to terminal 5 (192.168.2.1/24). . Also in this case, it is assumed that the traffic information table 41 shown in FIG. 7 is obtained based on the information notified to the monitoring server 20 from each sensor. Based on the traffic information table 41, the specifying unit 32 then specifies a communication path of device A-device G-device F-device E by the same processing as in the first embodiment.

For devices whose transfer destination port is set in the transfer table 44, the route calculation unit 33 limits the transfer destination according to the transfer table 44, and then determines possible transfers from the start point device to the end point device of the communication route. Calculate the forwardable paths by looking ahead. In the example of FIG. 14, the device A is the starting point of the communication path, and the device E is the end point of the communication path. Then, the route calculation unit 33 refers to the transfer table 44 (FIG. 13) for the device A. FIG. Since there is no entry for device A in the transfer table 44, the path calculation unit 33 determines the case where the frame is transferred to each of all the devices (device B, device G, and device H) connected to device A. Find a transfer route.

The route calculation unit 33 refers to the transfer table 44 in order to determine a possible transfer destination on a route including the link of device A-device B. FIG. According to the transfer table 44, the port Po2 is set as the transfer destination port of the frame to be processed in the device B. FIG. Also, the port Po2 of the device B is connected to the device F. Therefore, the frames to be processed are transferred in the order of device A-device B-device F. FIG. The route calculation unit 33 refers to the transfer table 44 in order to determine the transfer destination from the device F. FIG. According to the transfer table 44, the port Po1 is set as the transfer destination port of the frame to be processed in the device F. FIG. Also, the port Po1 of the device F is connected to the device E. Furthermore, device E is the end point of the communication path. Therefore, the route calculation unit 33 obtains device A-device B-device F-device E as a route including the link of device A-device B. FIG.

Similar processing is performed for the route including the link of device A-device G. FIG. According to the transfer table 44, the transfer destination port of the frame to be processed is set to the port Po1 in the device G, and the port Po1 of the device G is set to the device F. FIG. In the device F, the transfer destination port of the frame to be processed is set to the port Po1, and the port Po1 of the device F is set to the device E, which is the end point of the communication path. Therefore, the route calculation unit 33 obtains device A-device G-device F-device E as a route including the device A-device G link.

Similar processing is performed for the route including device A-device H. Therefore, the route calculation unit 33 obtains device A-device H-device G-device F-device E as a route including the device A-device H link.

The route calculation unit 33 calculates the cost value of the entire route for each of the calculated three routes, and determines the route with the relatively small cost value as the shortest route. The route of device A - device H - device G - device F - device E has a higher cost value than the other two routes, and the cost value of the route other than device A - device H - device G - device F - device E are the same. Then, as shown in FIG. 14, the communication route and the shortest route are as follows.

Communication path: Device A - Device G - Device F - Device E
Shortest path_1: device A - device B - device F - device E
Shortest path_2: device A-device G-device F-device E
The processing in the comparison processing section 34 is the same as in the first embodiment. Therefore, in the example of FIG. 14, it is determined that the communication route matches the shortest route_2. Note that when the communication route does not match any of the shortest routes, the comparison processing unit 34 performs processing for outputting information indicating that the communication route does not match the shortest route, as in the first embodiment. conduct.

In the second embodiment, the transfer destination of the frame is set by the transfer table 44, so the total number of routes calculated by the route calculator 33 can be smaller than in the first embodiment. Therefore, in the second embodiment, the processing load on the monitoring server 20 is reduced compared to the first embodiment. Furthermore, in the second embodiment, similarly to the first embodiment, when the communication path of the frame is different from the shortest path, the comparison processing unit 34 outputs the result of comparison between the communication path and the shortest path. Therefore, even in the route confirmation process according to the second embodiment, it can be efficiently determined whether the communication route and the shortest route match, as in the first embodiment. Therefore, an operator who discovers that the communication route and the shortest route do not match can perform processing for matching the communication route with the shortest route. Therefore, when a failure occurs in the network, it is possible to reduce the possibility of failing to avoid interruption of communication using the detour route due to frames not being transferred to the intersection of the shortest route and the detour route.

<Others>
Note that the embodiment is not limited to the above, and various modifications are possible. Some examples are given below.

The information in the table shown in the above description is an example, and this information can also be changed according to the implementation. For example, in any of the traffic information table 41, the connection relation table 42, the failure information table 43, and the forwarding table 44, information elements can be changed according to implementation.

Any method can be used as a process for the operator who finds that the communication route and the shortest route do not match to match the communication route with the shortest route.

In the above description, the cost value is used when selecting the shortest route, but the route calculation unit 33 may use an index other than the cost value to select the shortest route. For example, the route calculator 33 may obtain the shortest route using a metric value and a hop value.

20 monitoring server 21 communication unit 22 transmission unit 23 reception unit 30 control unit 31 acquisition unit 32 identification unit 33 route calculation unit 34 comparison processing unit 40 storage unit 41 traffic information table 42 connection relationship table 43 failure information table 44 transfer table 101 processor 102 Memory 103 Input device 104 Output device 105 Bus 106 Storage device 107 Portable storage medium drive 108 Portable storage medium 109 Network interface

Claims (6)

Acquiring information about the presence or absence of a failure in each of a plurality of devices included in the network and information on frames passing through the network between each of the plurality of devices;
Based on the acquired information of the frame, identifying the first communication path through which the data passed and the devices corresponding to the start and end points of the communication path of the data,
The shortest distance between the devices corresponding to the start and end points of the specified data communication path based on the information on the devices corresponding to the specified start and end points and the information on the presence or absence of faults in each of the plurality of devices. identifying a second communication path that is a path;
An information processing program causing a computer to execute a process of outputting a comparison result between the first communication path and the second communication path. receiving header information of a frame passing through the link on which the sensor is installed as information of the frame from the sensor installed on each of the links connecting the plurality of devices;
using the header information to identify a link through which the data frame used for communication of the data passed;
2. The information processing program according to claim 1, causing the computer to execute a process of specifying the first communication path using the link through which the data frame passes and the connection relationship between the plurality of devices. A forwarding table that records a device, among the plurality of devices, for which a forwarding port is set in association with the header information of the received frame, and the correspondence between the header information of the received frame and the forwarding destination in the device. hold and
The second communication path is the shortest path that satisfies the information in the forwarding table and does not go through the link in which the failure occurs, among the paths from the device corresponding to the start point to the device corresponding to the end point. 3. The information processing program according to claim 1, causing the computer to execute a process specified as. 4. The apparatus according to any one of claims 1 to 3, wherein each of the plurality of devices forms a layer 2 network by relaying communication based on a protocol used in a data link layer. The information processing program described. an acquisition unit that acquires information about the presence or absence of a failure in each of a plurality of devices included in a network and information on frames that have passed through a network between each of the plurality of devices;
an identifying unit that identifies, based on the acquired information of the frame, a first communication path through which data passes and devices corresponding to the start and end points of the communication path of the data;
The shortest path between the devices corresponding to the specified start and end points of the data communication path based on the information on the devices corresponding to the specified start and end points and the information on the presence or absence of faults in each of the plurality of devices. a calculation unit that calculates a second communication path that is
An information processing apparatus, comprising: a comparison unit that outputs a comparison result between the first communication path and the second communication path. Acquiring information about the presence or absence of a failure in each of a plurality of devices included in the network and information on frames passing through the network between each of the plurality of devices;
Based on the acquired information of the frame, identifying the first communication path through which the data passed and the devices corresponding to the start and end points of the communication path of the data,
The shortest path between the devices corresponding to the specified start and end points of the data communication path based on the information on the devices corresponding to the specified start and end points and the information on the presence or absence of faults in each of the plurality of devices. Identify a second communication path that is
An information processing method, wherein a computer executes a process of outputting a comparison result between the first communication path and the second communication path.

Images