JP5254196B2 - Loop detection system and loop detection method - Google Patents

Description

  The present invention relates to a loop detection system and a loop detection method, and more particularly, to a loop detection system and a loop detection method for specifying devices constituting a loop.

  In an L2 network, frames circulate in a loop due to physical connections that connect each device in a loop, incorrect setting of a logical path for the device, ring protocol operation abnormality such as STP (Spanning Tree Protocol), etc. There is a case. When the frame circulates in a loop shape, the network bandwidth is compressed, and a failure that hinders normal communication occurs. Therefore, a loop detection method for determining whether or not the frame has circulated in a loop shape has been proposed (for example, see Patent Document 1).

  In the loop detection method of Patent Document 1, when a loop detection frame is transmitted from a bridge device at the connection point of the L2 network and received at any port of the bridge device that transmitted the frame, a loop occurs. Judge that

Japanese Patent No. 4341918

  Since the loop detection method disclosed in Patent Document 1 determines that a loop has occurred when a frame transmitted by itself is received, it has not been possible to grasp the nodes constituting the loop on the L2 network. For this reason, there has been a problem that the root cause of the frame wrapping around cannot be pursued.

  In order to prevent the frame from going around in a loop, it is conceivable to limit the broadcast band on the communication network in advance so as to reduce the influence even when a loop occurs. However, since broadcast frames are restricted even on a network where no loop occurs, there is a problem that the bandwidth of the network cannot be used to the maximum.

  In order to prevent the frame from going around in a loop, it is conceivable to monitor the transmission source address on the receiving device side and determine that a loop has occurred when a frame having the address of its own device as the transmission source address is received. However, although the occurrence of the loop itself can be detected, there is a problem that it is not possible to specify the location where the loop actually occurs among the devices of the entire communication network.

  The present invention has been made in view of these problems, and an object of the present invention is to provide a loop detection system, a loop detection method, a relay device, and a relay method capable of specifying a device constituting a loop. It is in.

The loop detection system of the present invention is connected to an end of a communication network configured by connecting devices having a plurality of transmission / reception ports, and transmits a plurality of loop detection frames each including a specific bit string used for loop detection. Connected between an edge device and the edge device of the communication network, receives the loop detection frame, receives a port ID (identification) of the transmission / reception port that has received the loop detection frame, and the loop detection frame The transmission edge device ID of the edge device that transmitted the ID is identified and recorded in association with each other, the loop detection frame is transmitted from a transmission / reception port different from the transmission / reception port that received the loop detection frame, and the recorded port ID And a plurality of the transmission edge device IDs Loop detection system comprising the transmitting edge device ID recorded in association with the over preparative ID and a determining relay device whether a plurality, a.

  By extracting relay devices in which a plurality of port IDs are recorded for one transmission edge device ID, it is possible to enumerate relay device candidates constituting a loop. Further, by extracting relay devices having a plurality of transmission edge device IDs in which a plurality of port IDs are recorded from among the extracted relay devices, it is possible to identify a relay device in which a loop has occurred. Therefore, the loop detection system of the present invention can specify the devices constituting the loop.

According to the present invention, the relay device can determine whether one of the relay devices constituting the loop is used. By obtaining the connection relationship of the relay devices constituting the loop, the shape of the loop can be specified.

In the loop detection system of the present invention, the port ID that is a transmission / reception port of one of the relay devices determined to be plural and that is recorded in association with the same transmission edge device ID. Transmission / reception may be restricted for any of the transmission / reception ports.
According to the present invention, the loop can be eliminated.

The loop detection method of the present invention is a loop detection frame including a specific bit string used for loop detection from a plurality of edge devices connected to an end of a communication network configured by connecting devices having a plurality of transmission / reception ports. Transmitting to a plurality of edge devices of the communication network, and receiving the loop detection frame by a relay device connected between the edge devices of the communication network, and the loop detection frame The port ID of the transmission / reception port that received the loop detection frame and the transmission edge device ID of the edge device that transmitted the loop detection frame are associated with each other and recorded for each relay device, and the transmission / reception port that received the loop detection frame a relay step of transmitting the loop detection frame from a different transceiver port and the A specific procedure for the transmission edge device ID recorded in association with a plurality of said port ID for identifying the relay apparatus comprising: a plurality of said port ID and the transmission edge device ID recorded in the fitting order, the Have in order.

  By extracting relay devices in which a plurality of port IDs are recorded for one transmission edge device ID, it is possible to enumerate relay device candidates constituting a loop. Further, by extracting relay devices having a plurality of transmission edge device IDs in which a plurality of port IDs are recorded from among the extracted relay devices, it is possible to identify a relay device in which a loop has occurred. Therefore, the loop detection method of the present invention can identify the devices that constitute the loop.

According to the present invention, it is possible to specify a relay device that constitutes a loop. By obtaining the connection relationship of the relay devices constituting the loop, the shape of the loop can be specified.

In the loop detection method of the present invention, the port ID is a transmission / reception port of one of the relay devices specified in the specifying procedure and has the port ID recorded in association with the same transmission edge device ID For any of the transmission / reception ports, a loop elimination procedure for restricting transmission / reception may be further provided after the specific procedure.
According to the present invention, the loop can be eliminated.

The relay device of the present invention includes a relay device receiving unit that receives a loop detection frame including a specific bit string used for loop detection, a port ID of a transmission / reception port that has received the loop detection frame, and the loop detection frame. The recording unit that identifies and records the transmission edge device ID of the transmitted edge device and records the loop detection frame received by the relay device reception unit is different from the transmission / reception port that received the loop detection frame There are a plurality of transmission edge device IDs recorded in association with a plurality of port IDs among the port ID and the transmission edge device ID recorded in the recording unit , the relay device transmission unit transmitting from the transmission / reception port. It is determined that there are a plurality of loop configuration device determination units and a plurality of loop configuration device determination units. If you comprises a loop configuration information output unit that outputs the effect that constitutes a loop, a.

  Since the relay device includes the relay device reception unit, the recording unit, and the relay device transmission unit, each relay device of the communication network can determine whether or not one of the relay devices is included in the loop. By configuring a communication network using the relay device according to the present invention, it is possible to identify devices that constitute a loop. Therefore, the relay device according to the present invention can identify the devices constituting the loop.

According to the present invention, the relay device can determine whether one of the relay devices constituting the loop is used. The shape of the loop can be specified by obtaining the connection relationship of the relay devices that output that the loop is configured.

In the relay device of the present invention, the port ID and the transmission edge device ID recorded in the recording unit are recorded in association with the transmission edge device ID recorded in association with the plurality of port IDs. You may further provide the port control part which restricts transmission / reception about either of the transmission / reception ports which have port ID.
According to the present invention, the loop can be eliminated.

The relay method of the present invention provides a loop detection frame including a specific bit string used for loop detection from a plurality of edge devices connected to an end of a communication network configured by connecting devices having a plurality of transmission / reception ports. The loop detection frame reception procedure to be received, the port ID of the transmission / reception port that has received the loop detection frame, and the transmission edge device ID of the edge device that has transmitted the loop detection frame are identified and associated with each other and recorded. The loop detection frame transfer procedure for transmitting the received loop detection frame from a transmission / reception port different from the transmission / reception port that received the loop detection frame; the port ID recorded in the loop detection frame transfer procedure; and Associating with a plurality of the port IDs in the transmission edge device ID A loop configuration information output procedure for determining whether or not there are a plurality of recorded transmission edge device IDs and outputting a message indicating that a loop is configured when it is determined that there are a plurality of transmission edge device IDs; , In order.

  By having the loop detection frame receiving procedure and the loop detection frame transfer procedure, the relay device can determine whether or not one of the relay devices is included in the loop. When the relay device of the communication network executes the relay method according to the present invention, it is possible to identify the devices constituting the loop. Therefore, the relay method of the present invention can specify the devices that constitute the loop.

According to the present invention, the relay device can determine whether one of the relay devices constituting the loop is used. The shape of the loop can be specified by obtaining the connection relationship of the relay devices that output that the loop is configured.

In the relay method of the present invention, recording is performed in association with the transmission edge device ID recorded in association with the plurality of port IDs among the port ID and the transmission edge device ID recorded in the loop detection frame transfer procedure. For any one of the transmission / reception ports having the port ID, a loop elimination procedure for restricting transmission / reception may be further provided after the loop configuration information output procedure.
According to the present invention, the loop can be eliminated.

  The above inventions can be combined as much as possible.

  According to the present invention, it is possible to provide a loop detection system, a loop detection method, a relay device, and a relay method capable of specifying a device constituting a loop.

An example of the loop detection system which concerns on Embodiment 1 is shown. 3 is a flowchart illustrating an example of a loop detection method according to the first embodiment. It is explanatory drawing of a loop detection principle, (a) shows the path | route of the loop detection frame at the time of transmitting the loop detection frame from the edge apparatus 1021, (b) transmitted the loop detection frame from the edge apparatus 1021. Shows a transmission / reception port for receiving a loop detection frame, and (c) shows a loop detection frame path and a transmission / reception port for receiving the loop detection frame when a loop detection frame is transmitted from the edge device 1022. (D) shows a relay device forming a loop. A specific example of the edge device will be shown. A specific example of the relay device is shown. 3 is a flowchart illustrating an example of a relay method according to the first embodiment. A more specific configuration of the relay device is shown. 10 is a flowchart illustrating an example of a relay method according to the second embodiment. An example of a loop information recording table when no loop has occurred is shown. An example of a loop information recording table when a loop has occurred is shown. It is a block diagram which shows an example of the loop detection system which concerns on Embodiment 3. It is a block diagram which shows an example of the loop detection system which concerns on Embodiment 4. It is a figure which shows the structure of the L2 network which concerns on Embodiment 5. FIG. It is a figure which shows the structure of the L2 network which concerns on Embodiment 6. FIG. An example of a loop information recording table when a loop has occurred in the sixth embodiment is shown. 18 is a flowchart illustrating an example of a loop detection method according to the seventh embodiment. 18 is an example of a loop information recording table according to the seventh embodiment.

  Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments. In the present specification and drawings, the same reference numerals denote the same components.

(Embodiment 1)
FIG. 1 shows an example of a loop detection system according to the first embodiment. The loop detection system according to the first embodiment includes a plurality of edge devices 1021, 1022 and a plurality of relay devices 1031, 1032, 1033, 1034, 1035, 1036. The plurality of edge devices 1021 and 1022 and the plurality of relay devices 1031, 1032, 1033, 1034, 1035, and 1036 have a plurality of transmission / reception ports and constitute the L2 network 101. Relay devices 1032 to 1035 are connected in a loop.

  The loop detection system according to the first embodiment executes the loop detection method according to the first embodiment. FIG. 2 is a flowchart illustrating an example of the loop detection method according to the first embodiment. The loop detection method according to the first embodiment includes a transmission procedure S101, a relay procedure S102, a specific procedure S103, and a loop elimination procedure S104 in order.

  In the transmission procedure S101, the plurality of edge devices 1021 and 1022 transmit the loop detection frame toward the plurality of edge devices 1021 and 1022. Here, the loop detection frame is a frame including a specific bit string used for loop detection. The specific bit string is included in the data area of the frame, for example. The loop detection frame includes IDs of the edge devices 1021 and 1022 that transmit the frame.

  In the relay procedure S102, the relay devices 1031, 1032, 1033, 1034, 1035, and 1036 receive the loop detection frame. At this time, the port ID of the transmission / reception port that has received the loop detection frame is acquired. Then, the relay devices 1031, 1032, 1033, 1034, 1035, and 1036 identify the acquired port ID and transmission edge device ID and record them in association with each other. Here, the transmission edge device ID is identification information of the edge devices 1021 and 1022 that transmitted the loop detection frame, and can be obtained from the loop detection frame.

  In the relay procedure S102, the relay apparatuses 1031, 1032, 1033, 1034, 1035, and 1036 transmit the loop detection frame from a transmission / reception port different from the transmission / reception port that received the loop detection frame.

  Here, the relay apparatuses 1031, 1032, 1033, 1034, 1035, and 1036 detect and identify a specific bit string included in the loop detection frame. Thereby, the relay apparatuses 1031, 1032, 1033, 1034, 1035, and 1036 can selectively receive the loop detection frame from various frames. The transmission edge device ID is, for example, a transmission source address of a header of a loop detection frame. At this time, the relay apparatuses 1031, 1032, 1033, 1034, 1035, and 1036 record the port ID and the transmission edge apparatus ID in association with each other.

  In the specific procedure S103, the relay devices 1031, 1032, 1033, 1034, 1035, and 1036 are recorded in association with a plurality of port IDs among the port ID and the transmission edge device ID recorded in the relay procedure S102. The relay apparatuses 1032, 1033, 1034, and 1035 having a plurality of IDs are identified. Thereby, it is possible to identify the relay apparatuses 1032, 1033, 1034, and 1035 in which the extracted transmission edge apparatus IDs of the loop detection frame are plural.

  In the loop elimination procedure S104, a port ID that is a transmission / reception port of one relay device among the relay devices 1032, 1033, 1034, and 1035 specified in the specification procedure S103 and is recorded in association with the same transmission edge device ID. Transmission / reception is restricted for any of the transmission / reception ports having Thereby, a loop can be eliminated.

  For example, in the loop elimination procedure S104, a port blocking procedure, a transmission / reception stop procedure, or a reception flow rate restriction procedure is executed. When executing the port blocking procedure, sending and receiving is restricted by blocking the port.

  When the transmission / reception stop procedure is executed, transmission / reception is limited by logically stopping transmission / reception of frames. Thereby, a loop can be eliminated. Here, since the transmission / reception of the frame is logically stopped, the transmission / reception of the frame of the logical network in which no loop is generated can be continued. For this reason, it is possible to effectively use the bandwidth of the communication network.

  When the transmission / reception flow rate restriction procedure is executed, transmission / reception is restricted by restricting the frame transmission / reception flow rate. Thereby, the influence of a loop can be reduced. Here, since the transmission / reception flow rate of the frame is limited, communication is not completely blocked. For this reason, it is possible to reduce the influence of the loop while continuing the communication.

  The principle of loop detection will be described with reference to FIG. 3A and 3B are explanatory diagrams of the principle of loop detection. FIG. 3A shows the path of the loop detection frame when a loop detection frame is transmitted from the edge device 1021, and FIG. 3B shows the loop detection frame from the edge device 1021. A transmission / reception port for receiving a loop detection frame when a frame is transmitted is shown. (C) is a transmission / reception for receiving a loop detection frame path and a loop detection frame when a loop detection frame is transmitted from the edge device 1022. Ports are shown, and (d) shows relay devices forming a loop.

  When a loop detection frame is transmitted from the edge device 1021 by multicast or broadcast as indicated by a solid arrow in FIG. 3A, the relay devices 1031, 1032, 1033, 1035, 1036 are transmitted as indicated by the dotted arrow in FIG. Or a frame that reaches the opposite edge device 1022 via 1031, 1032, 1034, 1035, 1036, and a relay device 1031, 1032, 1033, 1035, 1034, 1032, 1031, or 1031, 1032, 1034, 1035, 1033 1032 and 1031, there is a frame that reaches the edge device 1021 that has transmitted the loop detection frame.

  In each case, there is also a frame that passes through the relay devices 1031 to 1034 constituting the loop a plurality of times. At this time, when the transmission / reception port that has received the loop detection frame is recorded in the relay device, the relay devices 1031, 1032, 1033, 1034, and 1035 shaded as shown in FIG. These relay devices are candidates for devices that form a loop.

  Further, when a loop detection frame is transmitted from the opposite edge device 1022 in the same manner, the device that has received the loop detection frame at a plurality of ports, as shown in FIG. 3C, relay devices 1032, 1033, 1034, 1035. 1036. By comparing the relay device networked in FIG. 3 (b) and the relay device networked in FIG. 3 (c) on a record, loops from a plurality of ports in both cases as shown in FIG. 3 (d). It turns out that the device that received the detection frame is the device that forms the loop.

  If the edge devices 1021 and 1022 are a part of the devices constituting the loop, the edge devices 1021 and 1022 function as the relay devices 1031, 1032, 1033, 1034, 1035, and 1036, so that the shape of the loop is changed. It is possible to determine.

  As described above, by using the loop detection system according to the first embodiment and executing the loop detection method according to the first embodiment, the configuration of the hardware and the edge device or relay device that does not have a loop detection function are changed. Without any problem, it is possible to determine which device is economical to form a loop. Therefore, in the L2 network in which no loop has occurred, the bandwidth of the network can be utilized to the maximum, and when a loop has occurred, the devices constituting the loop can be strictly specified.

  FIG. 4 shows a specific example of the edge device. The edge device 301 includes a transmission / reception port 302, a loop detection frame generation unit 303, a loop detection frame transmission unit 304, and a frame transmission / reception unit 305. The transmission / reception port 302 is connected to the transmission / reception port of the relay apparatus. The loop detection frame generation unit 303 generates a loop detection frame. The loop detection frame transmission unit 304 transmits the loop detection frame generated by the loop detection frame generation unit 303. The frame transmission / reception unit 305 transmits / receives frames other than the loop detection frame.

  The edge device 301 is configured to transmit and receive general frames that are not for loop detection from the transmission / reception port 302 via the frame transmission / reception unit 305, but the loop detection frame is transmitted by the loop detection frame transmission unit 304. is there. At this time, the loop detection frame has a function of describing information indicating that it is transmitted from the edge device 301 in the loop detection frame.

  The edge device 301 described above shows an example having a single transmission / reception port, but a configuration having a plurality of transmission / reception ports 302 may also be used. Further, among the plurality of transmission / reception ports 302, there may be a port in which the loop detection frame generation unit 303 and the loop detection frame transmission unit 304 are not functionally provided.

  FIG. 5 shows a specific example of the relay device. The relay device 30 includes a relay device reception unit 31, a relay device transmission unit 32, a recording unit 33, a loop configuration device determination unit 34, a loop configuration information output unit 35, a transmission / reception port 36, a transmission / reception port 37, Is provided.

  The relay device 30 executes the relay method according to the first embodiment. FIG. 6 is a flowchart illustrating an example of the relay method according to the first embodiment. The relay method according to the first embodiment includes a loop detection frame reception procedure S131, a loop detection frame transfer procedure S132, a loop configuration information output procedure S133, and a loop cancellation procedure S134 in this order.

  In the loop detection frame reception procedure S131, the relay device reception unit 31 receives a loop detection frame.

  In the loop detection frame transfer procedure S132, the recording unit 33 identifies the port ID of the transmission / reception port 36 that has received the loop detection frame and the transmission edge device IDs of the edge devices 1021 and 1022 that have transmitted the loop detection frame. Record in association. Then, the relay device transmission unit 32 transmits the loop detection frame received by the relay device reception unit 31 from the transmission / reception port 37 different from the transmission / reception port 36.

  In the loop configuration information output procedure S133, the loop configuration device determination unit 34 includes a plurality of transmission edge device IDs recorded in association with a plurality of port IDs of the port ID and transmission edge device ID recorded in the recording unit 33. It is determined whether or not there is. When the loop configuration information output unit 35 determines that there are a plurality of transmission edge device IDs extracted by the loop configuration device determination unit 34, the loop configuration information output unit 35 outputs loop configuration information indicating that a loop is configured.

  In the loop elimination procedure S134, a transmission / reception port having a port ID recorded in association with a transmission edge device ID recorded in association with a plurality of port IDs among the port ID and transmission edge device ID recorded in the recording unit 33. For any of 36, transmission / reception is restricted. Thereby, a loop can be eliminated.

  For example, in the loop elimination procedure S134, a port blocking procedure, a transmission / reception stop procedure, or a transmission / reception flow rate restriction procedure is executed. The port control unit 38 acquires port control information indicating that the port is controlled. The acquisition destination may be another relay device or a control device that manages the L2 network 101. The port control unit 38 functions as a port blocking unit, a transmission / reception stop unit, or a transmission / reception amount limiting unit. When the port control unit 38 functions as a port blocking unit, the port control unit 38 executes a port blocking procedure. In this case, the port control unit 38 restricts transmission / reception by closing the port.

  When the port control unit 38 functions as a transmission / reception stop unit, the port control unit 38 executes a transmission / reception stop procedure. In this case, the port control unit 38 limits transmission / reception by logically stopping transmission / reception of frames. Thereby, a loop can be eliminated.

  When the port control unit 38 functions as a transmission / reception amount limiting unit, the port control unit 38 executes a transmission / reception flow rate limiting procedure. In this case, the port control unit 38 limits transmission / reception by limiting the frame transmission / reception flow rate. Thereby, the influence of a loop can be reduced.

  In the present invention, in the L2 network 101, loop detection frames are transmitted from two or more edge devices 1021 and 1022, and the ports where the loop detection frames are received are recorded in the relay devices 1031, 1032, 1033, 1034, 1035 and 1036. After that, the relay devices 1032, 1033, 1034, and 1035 that have received the loop detection frames from the plurality of edge devices 1021 and 1022 at the plurality of ports in the L2 network 101 are detected. As a result, it is possible to accurately extract the relay devices 1032, 1033, 1034, and 1035 in which a loop failure has occurred and the shape of the loop. Since this function does not need to be specially implemented on hardware, an L2 network capable of economical loop detection can be realized.

(Embodiment 2)
FIG. 7 shows a more specific configuration of the relay device. The relay apparatus 401 includes a plurality of transmission / reception ports 4021 to 4024, a frame transmission / reception unit 403 connected to each transmission / reception port, a loop detection frame reception unit 404, a recording table writing unit 405, and a loop information recording table 406. A loop configuration device determination unit 407 and a loop configuration information output unit 408.

  The plurality of transmission / reception ports 4021 to 4024 function as the transmission / reception port 36 or the transmission / reception port 37. The loop detection frame receiving unit 404 functions as the relay device receiving unit 31. The recording table writing unit 405 and the loop information recording table 406 function as the recording unit 33. The loop constituent device determination unit 407 functions as the loop constituent device determination unit 34. The loop configuration information output unit 408 functions as the loop configuration information output unit 35.

  The operation of the relay device 401 will be described. A loop detection frame transmitted from a certain edge device is received by each transmission / reception port 4021-4024. The frame transmission / reception unit 403 transfers or copies the frame to the destination transmission / reception port. At this time, the data is simultaneously transferred to the loop detection frame receiving unit 404, and the transmission edge device ID of the loop detection frame, the port ID of the received transmission / reception port, and the reception time are extracted. Here, the transmission edge device ID is, for example, a transmission edge device ID, and the port ID is, for example, a port ID. Thereafter, the information is transmitted to the recording table writing unit 405, and writing is performed in the loop information recording table 406.

  Based on the information in the loop information recording table 406, the loop constituent device determination unit 407 indicates that a state in which a loop detection frame transmitted from a certain edge device is received at a plurality of transmission / reception ports from a plurality of edge devices. When the error occurs in the loop detection frame, it is determined that the relay apparatus forms a loop. In this case, the loop configuration information output unit 408 outputs loop configuration information indicating that the relay apparatus forms a loop.

  Although the relay apparatus 401 described above includes four transmission / reception ports 4021, 4022, 4023, and 4024 and a frame transmission / reception unit 403, the number is not particularly limited.

  Furthermore, the function of the edge device and the function of the relay device according to the first embodiment may exist in a single device. FIG. 8 is a flowchart illustrating an example of the relay method according to the second embodiment. An example of the relay method according to the second embodiment is characterized in that it is determined whether or not the relay device 401 is a device constituting a loop.

  The procedure S111 is executed in the loop detection frame receiving procedure S131 described in the first embodiment. Step S112, step S113, step S114, step S115, and step S116 are executed in the loop detection frame transfer step S132 described in the first embodiment. Step S117, step S118, and step S119 are executed in the loop configuration information output step S133 described in the first embodiment.

  In step S111, the loop detection frame receiving unit 404 receives a loop detection frame. In step S112, when the loop detection frame receiving unit 404 receives the loop detection frame, the loop detection frame extraction unit extracts the transmission edge device ID that transmitted the frame, the received port ID, and the reception time from the loop detection frame. In step S113, the recording table writing unit 405 records the transmission edge device ID, the port ID, and the reception time in the loop information recording table 406. At this time, step S114 is executed.

  In step S114, it is determined whether or not a loop detection frame is received by two or more transmission / reception ports. If received, the process proceeds to step S115. If not received, the process proceeds to step 116. In step S115, the recording table writing unit 405 writes “1” in the multi-port reception flag of the loop information recording table, and proceeds to step S117. In step S116, the recording table writing unit 405 writes “0” in the multi-port reception flag of the loop information recording table, and proceeds to step S111.

  FIG. 9 shows an example of a loop information recording table when no loop has occurred. FIG. 10 shows an example of a loop information recording table when a loop has occurred. For example, when no loop has occurred, as shown in FIG. 9, “0” is recorded in the multi-port reception flag in all the transmission edge device IDs. However, when a loop has occurred, as shown in FIG. 10, there is a portion where the multi-port reception flag is “1” in any transmission edge device ID.

  In step S117, the loop constituent device determination unit 407 determines whether there is another edge device ID for which the multiple port reception flag is “1”. If there is, the process proceeds to step S118, and if not, the process proceeds to step S111. In step S118, the loop constituent device determination unit 407 determines that the device constitutes a loop. In step S119, the loop configuration information output unit 408 outputs loop configuration information.

  For example, as shown in FIG. 10, when there are a plurality of locations where the multi-port reception flag is “1”, it is determined that the device constitutes a loop, and loop configuration information is output. As in the above example, it is possible to determine whether or not the device constitutes a loop.

(Embodiment 3)
FIG. 11 is a configuration diagram illustrating an example of a loop detection system according to the third embodiment. The L2 network 801 according to the present embodiment identifies edge devices 8021 and 8022 having means for transmitting a loop detection frame, and a port received when the loop detection frame is received, and records transmission / reception ports in the device. Relay devices 8031 to 8036 having the function of

  After accurately extracting the shape of the loop using the method of the first embodiment, in order to eliminate the influence of the loop, by blocking any one port 804 among the relay devices 8032 to 8035 constituting the loop, Cancel the loop condition. One arbitrary port is selected from the ports that have received the loop detection frames from the plurality of edge devices among the transmission / reception ports recorded in the second embodiment in the relay device constituting the loop. As the selection method, a random number, a method selected by an administrator of the L2 network 801, a port that is preferentially blocked, or the like is conceivable.

(Embodiment 4)
FIG. 12 is a configuration diagram illustrating an example of a loop detection system according to the fourth embodiment. The L2 network 901 according to the present embodiment identifies edge devices 9021 and 9022 having means for transmitting a loop detection frame, and a port received when the loop detection frame is received, and records transmission / reception ports in the device. Relay devices 9031 to 9036 having the function of

  After accurately extracting the loop shape using the method of the first embodiment, in order to eliminate the influence of the loop, frame transmission / reception of any one port 904 among the relay devices 9032 to 9035 constituting the loop is stopped. By doing so, the loop state is canceled. One arbitrary port is selected from the ports that have received the loop detection frames from the plurality of edge devices among the transmission / reception ports recorded in the second embodiment in the relay device constituting the loop. As a selection method, a random number, a method selected by an administrator of the L2 network 901, a port that is preferentially blocked, or the like is conceivable.

  A major difference between this method and the third embodiment is that when there is a VLAN (Virtual Local Area Network) setting that may be used when constructing the L2 network 901, a certain VLAN has a loop depending on how the VLAN is set. There is a case where a VLAN that has occurred does not have a loop. Unlike the case where the port is blocked by logically stopping only the transmission / reception of the VLAN frame in which a loop has occurred at that time, the influence of the loop is eliminated while the transmission / reception of the VLAN frame without the loop continues. Will be able to.

(Embodiment 5)
FIG. 13 is a diagram illustrating a configuration of an L2 network according to the fifth embodiment. The L2 network 1001 according to the present embodiment identifies edge devices 10021 and 10022 having means for transmitting a loop detection frame, and a port received when the loop detection frame is received, and records transmission / reception ports in the device. Relay devices 10031 to 10036 having the function of

  After accurately extracting the shape of the loop using the method of the first embodiment, in order to reduce the influence of the loop, the frame of any one port 1004 among the relay devices 10032 to 10033 constituting the loop is transmitted / received. This is achieved by limiting the bandwidth. One arbitrary port is selected from the ports that have received the loop detection frames from the plurality of edge devices in the transmission / reception port records created in the first embodiment in the relay device constituting the loop. As the selection method, a random number, a method selected by the administrator of the L2 network 1001, a port preferentially blocked, etc. are conceivable.

  In the present embodiment, communication is not completely blocked. For this reason, even when a false detection of a loop due to an erroneous detection or an erroneous setting occurs, the communication can be continued without completely interrupting the communication.

(Embodiment 6)
FIG. 14 is a diagram illustrating a configuration of an L2 network according to the sixth embodiment. The L2 network 1101 according to the present embodiment identifies edge devices 11021 to 11023 having means for transmitting a loop detection frame, and a port received when the loop detection frame is received, and records transmission / reception ports in the device. Relay devices 11031 to 11036 having the function of

  FIG. 15 is an example of a loop information recording table according to the sixth embodiment. When the method of the first embodiment is used to transmit a loop detection frame from the edge devices 11021 and 11023 and it is determined that the relay device received at a plurality of transmission / reception ports is a relay device constituting the loop, the relay device 11031 Therefore, it is determined that the device is configured as a loop even though the loop is not configured. Therefore, for an L2 network such as 1101 in which edge devices exist at multiple points, loop detection frames are transmitted from all edge devices existing in the L2 network, and all loop detection frames are received by a plurality of transmission / reception ports. It is possible to accurately detect the loop shape by determining that the relay device is a relay device constituting a loop. By this method, it is possible to further improve the accuracy of detecting the loop shape.

  In the loop information recording table, as shown in FIG. 15, it is determined that a loop is formed when the multiple port reception flag is 1 in all transmission edge device IDs. Thus, when there is a transmission edge device ID whose multi-port reception flag is not 1, it is not determined that a loop is configured.

(Embodiment 7)
In the loop detection system according to the seventh embodiment, for the information of the same transmission edge device ID and the same port ID, the information of the same transmission edge device ID and different port IDs is present between the previously received information and the newly received information. If it is recorded, 1 is written to the multi-port reception flag. FIG. 16 is a flowchart illustrating an example of a loop detection method according to the seventh embodiment.

  The procedure S1111 is executed in the loop detection frame receiving procedure S131 described in the first embodiment. Step S1112, step S1113, step S1114, step S1115, step S1116, and step S1117 are executed in the loop detection frame transfer step S132 described in the first embodiment. Step S1118, step S1119, and step S1120 are executed in the loop configuration information output step S133 described in the first embodiment.

  In step S1111, a loop detection frame is received. In step S1112, the transmission edge device ID, the port ID, and the reception time are extracted. In step S1113, the transmission edge device ID, the port ID, and the reception time are written in the loop information recording table. FIG. 17 shows an example of a loop information recording table according to the seventh embodiment.

  In step S1114, the loop information recording table is referred to and it is determined whether or not a loop detection frame is received by two or more transmission / reception ports. If a loop detection frame is received at two or more transmission / reception ports, the process proceeds to step S1115. If a loop detection frame is not received at two or more transmission / reception ports, the process proceeds to step S1116.

  In step S1115, with reference to the loop information recording table, whether there is a reception record of the same transmission edge device ID and different port ID between the reception time of the same transmission edge device ID and the same port ID and the current reception time. Determine. If there is a reception record, the process proceeds to step S1117. If there is no reception record, the process proceeds to step S1116. For example, in the loop information recording table shown in FIG. 17, there is a reception record of the transmission edge device ID1 and the port ID 4023 between the reception time 1:00 of the transmission edge device ID1 and the port ID 4021 and the reception time 7:00. In this case, the process proceeds to step S1117.

  In step S1116, “0” is written in the multi-port reception flag of the loop information recording table, and the process proceeds to step S1111. In step S1117, “1” is written in the multi-port reception flag of the loop information recording table, and the process proceeds to step S1118.

  In step S <b> 1118, it is determined whether there is another transmission edge device ID in which the multi-port reception flag is “1”. If there is, the process proceeds to step S1119, and if not, the process proceeds to step S1111. In step S1119, it is determined that the device constitutes a loop. In step S1120, loop configuration information is output.

  By performing the above operation, the multiple port reception flag is set to 1 only when the loop detection frames from the same edge device are alternately received by a plurality of transmission / reception ports. For example, on the L2 network 1101 When path switching occurs, it is no longer determined that the loop has occurred. For this reason, in the case where route redundancy is taken, the cases of the first to fifth embodiments may be judged as a loop in the case of route switching that is not a loop, whereas It is possible to eliminate such cases.

  At this time, as described in the sixth embodiment, the loop shape is more accurately determined by determining that the loop is configured when the multiple port reception flag is 1 in all the transmission edge device IDs. It is also possible to use a combination of detection methods.

  Since the loop detection system of the present invention can be applied to the L2 network, it can be used in the information communication industry.

101: L2 networks 1021, 1022, 1023: edge devices 1031, 1032, 1033, 1034, 1035, 1036: relay device 301: edge device 302: transmission / reception port 303: loop detection frame generation unit 304: loop detection frame transmission unit 305: Frame transmission / reception unit 30: Relay device 31: Relay device reception unit 32: Relay device transmission unit 33: Recording unit 34: Loop configuration information determination unit 35: Loop configuration information output unit 36: Transmission / reception port 37: Transmission / reception port 38: Port Control unit 401: Relay device 4021, 4022, 4023, 4024: Transmission / reception port 403: Frame transmission / reception unit 404: Loop detection frame reception unit 405: Recording table writing unit 406: Loop information recording table 407: Loop constituent device determination unit 408: Loop configuration Report output unit 801: L2 network 804: transmission / reception ports 8021, 8022: edge devices 8031, 8032, 8033, 8034, 8035, 8036: relay device 901: L2 network 904: transmission / reception ports 9021, 9022: edge devices 9031, 9032, 9033 , 9034, 9035, 9036: Relay device 1001: L2 network 1004: Transmission / reception port 10021, 10022: Edge device 10031, 1003, 10033, 10034, 10035, 10036: Relay device 1101: L2 network 11021, 11022, 11023: Edge device 11031 , 11032, 11033, 11034, 11035, 11036: Relay device

Claims (8)

A plurality of edge devices that are connected to an end of a communication network configured by connecting devices having a plurality of transmission / reception ports, and that mutually transmit a loop detection frame including a specific bit string used for loop detection;
Connected between the edge devices of the communication network, receiving the loop detection frame, transmitting a port ID (identification) of a transmission / reception port that has received the loop detection frame and the loop detection frame The transmission edge device ID of the edge device is identified and recorded in association with each other, the loop detection frame is transmitted from a transmission / reception port different from the transmission / reception port that received the loop detection frame, and the recorded port ID and transmission A relay device that determines whether or not there are a plurality of transmission edge device IDs recorded in association with a plurality of the port IDs of an edge device ID ;
A loop detection system comprising: For any of the transmission / reception ports having the port ID recorded in association with the same transmission edge device ID that is a transmission / reception port of one of the relay devices determined to be the plurality of relay devices, The loop detection system according to claim 1 , wherein transmission / reception is restricted. A plurality of edge devices connected to an end of a communication network configured by connecting devices having a plurality of transmission / reception ports, a plurality of edges of the communication network including a loop detection frame including a specific bit string used for loop detection. A transmission procedure to send to the device;
The relay device connected between the edge devices of the communication network receives the loop detection frame, and transmits the port ID of the transmission / reception port that has received the loop detection frame and the loop detection frame. A relay procedure for identifying the transmission edge device ID of the edge device, associating it with each other, recording it for each relay device, and transmitting the loop detection frame from a transmission / reception port different from the transmission / reception port that received the loop detection frame;
A specifying procedure for specifying the relay device in which there are a plurality of the transmission edge device IDs recorded in association with a plurality of the port IDs of the port ID and the transmission edge device ID recorded in the relay procedure;
A loop detection method comprising: Transmission / reception is performed for any of the transmission / reception ports which are the transmission / reception ports of one of the relay apparatuses identified in the identification procedure and have the port ID recorded in association with the same transmission edge apparatus ID. The loop detection method according to claim 3 , further comprising a loop elimination procedure for restricting the frequency after the specific procedure. A relay device receiving unit that receives a loop detection frame including a specific bit string used for loop detection;
A recording unit that identifies and records a port ID of a transmission / reception port that has received the loop detection frame and a transmission edge device ID of an edge device that has transmitted the loop detection frame in association with each other;
A relay device transmission unit that transmits the loop detection frame received by the relay device reception unit from a transmission / reception port different from the transmission / reception port that received the loop detection frame;
A loop configuration device determination unit that determines whether there are a plurality of transmission edge device IDs recorded in association with a plurality of the port IDs among the port ID and the transmission edge device ID recorded in the recording unit. When,
A loop configuration information output unit that outputs that a loop is configured when the loop configuration device determination unit determines that there are a plurality of the loop configuration device determination unit;
A relay device comprising: A transmission / reception port having the port ID recorded in association with the transmission edge device ID recorded in association with a plurality of the port IDs of the port ID and the transmission edge device ID recorded in the recording unit. The relay apparatus according to claim 5 , further comprising a port control unit that restricts transmission / reception for any of the above. Loop detection frame reception for receiving a loop detection frame including a specific bit string used for loop detection from a plurality of edge devices connected to the end of a communication network configured by connecting devices having a plurality of transmission / reception ports Procedure and
A port ID of a transmission / reception port that has received the loop detection frame and a transmission edge device ID of the edge device that has transmitted the loop detection frame are identified and recorded in association with each other, and the received loop detection frame is A loop detection frame transfer procedure for transmitting from a transmission / reception port different from the transmission / reception port that received the loop detection frame;
Determining whether there are a plurality of transmission edge device IDs recorded in association with a plurality of the port IDs of the port ID and the transmission edge device ID recorded in the loop detection frame transfer procedure; When it is determined that there are a plurality of transmission edge device IDs, a loop configuration information output procedure for outputting that a loop is configured;
The relay method which has in order. The port ID recorded in association with the transmission edge device ID recorded in association with a plurality of the port IDs of the port ID and the transmission edge device ID recorded in the loop detection frame transfer procedure. The relay method according to claim 7 , further comprising a loop elimination procedure for restricting transmission / reception for any one of the transmission / reception ports having the loop configuration information output procedure.

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