JP4637755B2 - Network failure avoidance device for LAN switch and network failure avoidance method using the same - Google Patents

Description

  The present invention relates to a network failure avoidance device useful for avoiding a network failure caused by the occurrence of a broadcast storm caused by connecting lower-order concentrators in an L2 network, and a network failure avoidance method using the same.

  In an L2 (layer 2) network such as an in-house LAN, if the hub and hub that are the concentrators are misconnected and the lower ports are connected to each other as shown by the broken line in FIG. Broadcast is sent to the loop network, and the network goes down due to the occurrence of a broadcast storm.

Such a network failure occurs due to a simple cause of a mistake in inserting a LAN cable. However, once it occurs, communication becomes impossible, and conventionally, in order to prevent a mistake in inserting a LAN cable. Attach a tag with identification information to the end of the LAN cable, etc. (see Patent Document 1), and perform a connection operation while collating with the design drawing, or a loop with an L2 level protocol such as the spanning tree protocol The mechanism etc. which detect this and prevent a failure are considered (refer patent documents 2 and 3).
JP 2002-245865 A JP 2005-295209 A JP 2004-222106 A

  However, even if a method of attaching a tag or the like and performing a connection operation by collating with a design drawing, it is not possible to avoid an erroneous connection due to an operator's confirmation error or assumption, and a loop failure cannot be prevented. On the other hand, the method of detecting a loop by the protocol at the L2 level and preventing a failure is processed by software, so that a human error can be avoided, but this is a process by software. Therefore, the load on the network becomes heavy during the processing operation, and in some cases, the switch may be shifted to the reboot of the switch. In addition, the function itself does not operate, and it has actually occurred that leads to a large-scale network failure.

  Also, once the network goes down, in order to identify the wrong place of the cable, an expert engineer logs in to the switch and analyzes it, or captures the packet and analyzes it. It takes considerable technical skill, time, and labor.

  The present invention has been made in view of such circumstances, and even if a LAN cable is mistakenly inserted, a network failure avoidance device for a LAN switch capable of recognizing an erroneous connection before communication is started. The main object is to provide a network failure avoidance method using the same.

  The present inventors have found that a loop failure due to erroneous connection occurs by connecting lower-order ports (downlink ports) of LAN switches with a LAN cable, and generally used LAN cables are: As shown in Fig. 5, it is a 4 to 8 core "RJ45" type, and it uses only 2 to 4 cores for data transmission and reception, whether it is a straight cable or a cross cable. Focusing on the fact that the remaining 2 to 4 cores are not used, at least one unused core is used as a judgment core for determining whether or not the loop connection is used, and the voltage between the judgment cores is determined. The present inventors have found that it is possible to determine the port connection form based on the presence or absence, and have completed the present invention.

  That is, in order to achieve the above object, a network failure avoidance device for a LAN switch according to the present invention determines whether or not the connector is inserted in a lower port to which a LAN cable connector used in the network is inserted. And a voltage detection circuit that detects the presence or absence of a voltage using at least one unused core of the LAN cable when the insertion detection unit determines that the connector is inserted. A voltage application circuit that applies a voltage to the at least one core when the voltage detection circuit detects that there is no voltage, and the lower port when the voltage detection circuit detects that there is a voltage And alarm means for operating an alarm mechanism corresponding to the above.

  Therefore, it is determined whether or not the LAN cable connector is connected to the lower port by the insertion detection means. When the LAN cable connector is inserted into the lower port, the voltage detection circuit does not connect the LAN cable. The presence or absence of voltage is detected using at least one core in use, and when it is detected that there is no voltage, a voltage is applied to the at least one core by a voltage application circuit, and it is detected that there is a voltage. In this case, the alarm mechanism corresponding to the port is activated by the alarm means, so that by providing such a configuration in each lower port, voltage application is performed if one end of the LAN cable is already connected to the lower port. A voltage is applied to at least one unused core by the circuit, and the other end of this LAN cable is connected to another lower port. , Are detected and there is a voltage by the voltage detection circuit, alarm mechanism will operate.

  Here, the voltage detection circuit for detecting the presence / absence of a voltage using at least one unused core of the LAN cable detects the presence / absence of a voltage between the unused one core of the LAN cable and the ground. Alternatively, the presence or absence of a voltage between a pair of core wires that are not used in the LAN cable may be detected, and a voltage application circuit that applies a voltage to the at least one core is not used in the LAN cable. A voltage may be applied between one core of the cable and the ground, or a voltage may be applied between a pair of unused core cables of the LAN cable.

  For this reason, the operator can recognize that the both ends of the LAN cable are connected to the lower port by the activation of the alarm mechanism, and the loop connection state is mistakenly inserted. Even if an insertion error occurs, the insertion error can be confirmed at the L1 level, and it is possible to prevent the network from being affected by releasing the connection at this stage.

  Even if the alarm mechanism is configured by an LED installed in the vicinity of the port, and the alarm means is configured to turn on the LED when a voltage is detected by the voltage detection circuit, the alarm mechanism is configured by a buzzer and an alarm is provided. The means may be configured to sound the buzzer when a voltage is detected by the voltage detection circuit.

  Therefore, as a network failure avoidance method using the network failure avoidance apparatus described above, the insertion detection step of determining whether or not the LAN cable connector is inserted by the insertion detection means, and the insertion detection step A voltage detection step of detecting the presence or absence of a voltage by the voltage detection circuit when it is determined that a connector is inserted, and a step of operating the alarm mechanism by the alarm means when a voltage is detected by the voltage detection step And when the voltage detection step does not detect the voltage, the voltage application circuit applies a voltage to at least one core of the LAN cable to open the communication core circuit. do it.

As described above, according to the present invention, the insertion detection means for determining whether or not the LAN cable connector is inserted into each of the lower ports of the LAN switch, and the insertion of the connector by the insertion detection means. A voltage detection circuit that detects the presence or absence of voltage using at least one unused core of the LAN cable when it is determined that there is a voltage, and at least one core when the voltage detection circuit detects that there is no voltage A voltage applying circuit for applying a voltage and an alarm means for activating an alarm mechanism corresponding to the lower port when the voltage detecting circuit detects that there is a voltage. Even if it occurs, it is possible to make a determination at the L1 level before communication is started, and to recognize whether or not it is a misconnection, thus affecting the network. Theft is not.
In addition, since the operator can confirm the presence or absence of incorrect connection on the spot where the connection work was performed, it is possible to respond quickly, and to identify and remove the erroneous connection, special technical skills, time, and Does not require labor.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, the best embodiment of the invention will be described with reference to the accompanying drawings.

In FIG. 1, an example of a front panel 1 of a LAN switch is shown.
In the figure, a plurality of connectors 2 (2a to 2i) constituting a port are arranged in parallel on the lower side of the front panel 1, and an LED 3 for displaying the status of each port above each connector 2a to 2i. (3a-3i), 4 (4a-4i), 5 (5a-5i) are provided.

  The connector 2 has a connector 2a corresponding to the upper port (uplink port) and connectors 2b to 2i corresponding to the lower port (downlink port), and the LEDs 3, 4 and 5 indicate the link state. LEDs 3a to 3i, LEDs 4a to 4i for displaying a transmission speed, and LEDs 5a to 5i for displaying a collision state and full / half duplex communication.

  Here, the LEDs 3a to 3i are lit when, for example, a link is established with a network device connected via a cable to a port corresponding to each connector, and communication is possible between them, It blinks during data communication and turns off when the cable is not connected. The LEDs 4a to 4i are, for example, turned on when the transmission speed of the port corresponding to each connector is 100 Mbps, and turned off when the transmission speed is 10 Mbps. For example, the LEDs 5a to 5i are turned on when communication between a port corresponding to each connector and a network device is performed in full duplex, and are turned off when performed in half duplex, and collision (data collision) occurs. It flashes when it occurs.

  In addition to the LEDs 3, 4, 5, alarm LEDs 6 (6 b to 6 i) are provided above the connectors 2 b to 2 i corresponding to the lower ports of the front panel 1. The alarm LED 6 is not provided in the upper port.

  FIG. 2 shows a configuration example of a network failure avoidance apparatus provided at the lower port of the LAN switch. In this example, the configuration of the original switching control of the LAN switch is omitted, and only the configuration according to the present invention that avoids the connection between the lower ports is shown.

  This network failure avoidance apparatus has a connector insertion detection circuit 10 configured using a microswitch or the like that detects whether or not a LAN cable connector is physically inserted into the connector 2 constituting the port. And a pair of unused core wires (determination core wires 15a and 15b) of the inserted LAN cable, for example, in this example, a voltage applying circuit for applying a voltage between the core wires corresponding to the pin numbers 7 and 8 11, a voltage detection circuit 12 that detects the presence or absence of a voltage between the pair of core wires, and a control circuit 13 that is connected to each of these circuits and includes a display circuit that controls the display of the alarm LED 6. The control circuit 13 is configured to control the voltage application circuit 11 and the voltage detection circuit 12 based on information detected by the connector insertion detection circuit 10 and the voltage detection circuit 12. So as to control the display of alarm for LED6.

  Even if the control circuit 13 is shared by the connector insertion detection circuit 10, the voltage application circuit 11, the voltage detection circuit 12, and the alarm LED 6 provided in each lower port, each control circuit 13 is provided for each port. It may be provided.

  An example of the control operation by the network failure avoidance apparatus described above is shown in FIG. 3 as a flowchart. Hereinafter, the control operation example will be described based on this flowchart. First, the connector 2 constituting the lower port by the connector insertion detection circuit 10 is shown. It is determined whether or not the LAN cable connector is inserted in (2b to 2i) (step 50), and the connector insertion detection circuit 10 inserts the LAN cable connector into the connector 2 constituting the lower port. If it is determined, the voltage between the determination core wires 15a and 15b is measured by the voltage detection circuit 12 (step 52).

  As a result of the voltage measurement by the voltage detection circuit 12, the control circuit 13 determines whether or not the determination core wires 15a and 15b have a voltage (step 54). If it is determined that there is no voltage, the other end of the LAN cable is connected. Because it is connected to the upper port of another switch, connected to a terminal such as a personal computer, or is not connected at all, one end of this LAN cable is already connected to the lower port In order to recognize the state, the voltage application circuit 11 applies a voltage to the determination core wires 15a and 15b (step 56), and corresponds to the communication core wires (pin numbers 1, 2, 3 and 6 in the figure). The core wire to be opened is released (step 58), and L2 communication is started (step 60).

Thereafter, when connector removal is detected by the connector insertion detection circuit 10 (step 62), the communication core wire circuit is closed to stop the L2 communication (step 64), and the voltage application circuit 11 applies the voltage. Is stopped (step 66).
In the above description, the specific means for starting or stopping the L2 communication may be one that electrically turns the circuit on and off, or one that is realized by a communication control processing flow step.

  On the other hand, if it is determined in step 54 that the determination core wires 15a and 15b have a voltage, one end of the LAN cable is already connected to the lower port, and the voltage application circuit 11 performs the determination in step 56. Since voltage is applied to the core wires 15a and 15b, if L2 communication is performed with the other end of this LAN cable connected to another lower port, the network goes down due to the occurrence of a broadcast storm. Since there is a fear, the signal of the signal line connected to the alarm LED 6 is set to LOW to light the alarm LED 6 (step 70), and the communication core circuit is kept closed (step 72).

  Thereafter, when the worker who has seen the alarm LED 6 lit removes the connector of the LAN cable from the connector 2 and the connector insertion detection circuit 10 detects the removal of the connector (step 74), the alarm LED 6 is turned on. The light is turned off (step 76).

  Therefore, according to the above-described configuration, the connector insertion detection circuit 10, the voltage application circuit 11, the voltage detection circuit 12, and the alarm LED 6 are provided in each lower side port, so that one end of the LAN cable is at the lower level. If it is connected to the side port, a voltage is applied to the determination core wires 15a and 15b by the voltage application circuit 11. When the other end of this LAN cable is connected to another lower side port, the voltage detection circuit 12 The voltage between the determination core wires 15a and 15b is detected, and the alarm LED 6 is turned on to indicate that the lower ports are connected.

For this reason, the operator can recognize the wrong insertion of the LAN cable by visually confirming that the alarm LED 6 is lit, and can confirm the wrong insertion at the L1 level. At this stage, since L2 communication has not yet started, even if a mistake is made, a network failure due to the occurrence of a broadcast storm will not occur.
Moreover, by removing the erroneously connected cable while observing the lighting of the alarm LED, it is possible to quickly remove the erroneously connected portion, so that no special technical skill, time, and labor are required.

  In the above configuration, the alarm mechanism is configured by the alarm LED 6 installed in the vicinity of the port, and the alarm LED 6 is turned on when the voltage detection circuit 12 detects the voltage between the determination core wires. However, the alarm mechanism is configured by a buzzer provided in the LAN switch, and the buzzer is sounded when the voltage detection circuit 12 detects the voltage between the determination core wires. These configurations may be used in combination.

  In the above-described configuration, the presence or absence of voltage between the pair of core wires is detected by the voltage detection circuit 12 using a pair of unused core wires (determination core wires 15a and 15b), and voltage application is performed. Although the configuration in which the voltage is applied between the pair of core wires by the circuit 11 is shown, the voltage detection circuit 12 is configured to detect the presence or absence of a voltage between one unused line of the LAN cable and the ground, and the voltage application circuit 11 may be configured to apply a voltage between one unused line of the LAN cable and the ground.

FIG. 1 is a diagram illustrating an example of a front panel of a LAN switch as a line concentrator. FIG. 2 is a block diagram showing a network failure avoidance apparatus according to the present invention. FIG. 3 is a flowchart illustrating an example of a control operation performed by the network failure avoidance apparatus of FIG. FIG. 4 is a diagram for explaining a network failure in the network. FIG. 5 is a diagram showing a conceptual diagram of the existing LAN switch ports and LAN cable wiring.

Explanation of symbols

6 Alarm LED
10 Connector insertion detection circuit 11 Voltage application circuit 12 Voltage detection circuit

Claims (5)

In the lower port where the connector of the LAN cable used for the network is inserted,
Insertion detecting means for determining whether or not the connector is inserted;
A voltage detection circuit that detects the presence or absence of a voltage using at least one core unused of the LAN cable when the insertion detection means determines that the connector is inserted; and
A voltage application circuit for applying a voltage to the at least one core when the voltage detection circuit detects that there is no voltage;
An LAN switch network failure avoidance device comprising: alarm means for activating an alarm mechanism corresponding to the lower port when the voltage detection circuit detects that there is a voltage. The voltage detection circuit is configured to detect the presence or absence of a voltage between a pair of unused core cables of the LAN cable when the insertion detection unit determines that the connector is inserted. 2. The LAN switch according to claim 1, wherein the application circuit applies a voltage between the pair of core wires when the voltage detection circuit detects that there is no voltage between the pair of core wires. Network failure avoidance device. 2. The alarm mechanism is an LED installed in the vicinity of the port, and the alarm means turns on the LED when a voltage is detected by the voltage detection circuit. LAN switch network failure avoidance device. A network failure avoidance method using the network failure avoidance device for a LAN switch according to claim 1,
An insertion detection step for determining whether or not the LAN cable connector is inserted by the insertion detection means;
A voltage detection step of detecting the presence or absence of a voltage by the voltage detection circuit when it is determined by the insertion detection step that the connector is inserted;
A network fault avoidance method for a LAN switch, comprising: a step of operating the alarm mechanism by the alarm means when a voltage is detected by the voltage detection step. 5. The method according to claim 4, further comprising the step of applying a voltage to the at least one core by the voltage application circuit when the voltage is not detected by the voltage detection step and opening a circuit of the communication core wire. Network switch avoidance method of the LAN switch.

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