JP6272264B2 - Information processing apparatus and network system - Google Patents

Description

  The present invention relates to an information processing apparatus and a network system, and more particularly, to a technology for preventing a loop in a network system including, for example, a switch apparatus of a backbone network and a switch apparatus arranged under the switch apparatus.

  Spanning trees such as STP (Spanning Tree Protocol) and RSTP (Rapid Spanning Tree Protocol) are known as loop suppression functions on the network, but these loop suppression functions are generally used in switch devices arranged in a backbone network. Is running. Spanning tree is a route selection algorithm for preventing frames from circulating infinitely (loop) in a network between a plurality of bridges connected in parallel. The spanning tree algorithm is standardized as IEEE 802.1d.

  In switch devices belonging to a backbone network, port expansion is frequently performed or devices are often installed for temporary purposes. When the STP or the like is started with such a simple switch device, topology change or the like frequently occurs and affects the backbone network. Therefore, a loop suppression function such as STP may not be started. In such an environment, when a loop failure occurs under the backbone network, the effect spreads over the entire network, so the loop detection function is activated in each switch device under the backbone network.

  For example, as a conventional loop detection function, a loop detection frame is transmitted from a port of a switch device of a backbone network at a fixed period, and the loop detection frame is received by the switch device, thereby detecting that a loop configuration has been established. There is technology to do.

  Patent Document 1 describes a switch device having a loop detection function, in which port identification is set for a port that activates the loop detection function. In this loop detection function, on the basis of the set port identification, the upper port of the switch device connected to the backbone network or the upper switch device only receives the loop detection frame and does not transmit it. In addition, when a loop detection frame is received by the upper port of the switch device, blocking control is performed on the lower port of the transmission source that has transmitted the loop detection frame of the switch device.

JP 2009-207028 A

  However, in a switch device with the loop detection function enabled, when a port detection frame is transmitted from multiple ports at regular intervals, if a loop occurs, the loop detection frame is received by the multiple ports and the corresponding port is blocked . When a plurality of ports are blocked as described above, the number of ports that can communicate is reduced, and the communication range (the number of communication paths) of the network is greatly reduced.

  Further, in Patent Document 1, it is difficult for a general user to set port identification, and when a loop injury occurs, a portion having a loop configuration may not be immediately cut off.

  The present invention has been made in consideration of the above situation, and does not require complicated port identification settings, and performs port blocking to prevent a loop while maintaining the communication range of the network as much as possible. Objective.

An information processing device of one embodiment of the present invention includes a plurality of ports that transmit and receive data, a transmission unit, a determination unit, and a port control unit.
The transmission unit transmits loop detection data including transmission source port information for detecting the loop configuration from each of the plurality of ports.
The determination unit determines whether or not the other port receiving the loop detection data is in a blocked state when the loop detection data transmitted from one of the plurality of ports is received by the other port. .
The port control unit performs the process of setting one port to the blocked state when the other port that has received the loop detection data is not blocked during the determination process by the determining unit, and when the other port is in the blocked state. Does not process one port.

A network system of one embodiment of the present invention is a network system including at least a first information processing device, a second information processing device, and a third information processing device.
The first information processing device has a port connected to the second information processing device and a port connected to the third information processing device, a plurality of ports for transmitting and receiving data, the transmission unit, A determination unit and the port control unit are provided.

According to at least one aspect of the present invention, it is possible to prevent a plurality of ports that have received loop detection data from being blocked, and to maintain a wide range (number of communication paths) in which network communication can be maintained.
Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is a block diagram which shows the structural example of the network system which concerns on the 1st Embodiment of this invention. It is a figure which shows the motion of a loop detection frame when a loop generate | occur | produces in the network system of FIG. It is a block diagram which shows the internal structural example of a switch apparatus provided with a loop detection function. It is explanatory drawing which shows the example of the frame format of a loop detection frame. It is a flowchart which shows the loop detection determination process which concerns on the 1st Embodiment of this invention. It is a sequence diagram which shows the outline | summary of the loop generation | occurrence | production at the time of the network incorrect connection which concerns on the 1st Embodiment of this invention. It is a figure which shows the state before the blocking state of a switch apparatus changes. It is a figure which shows the state after the blocking state of a switch apparatus changed. It is a flowchart which shows the port state change monitoring process which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows the structural example of the network system which concerns on the 3rd Embodiment of this invention.

Hereinafter, an example of an embodiment for carrying out the present invention will be described with reference to the accompanying drawings. The description will be given in the following order. In addition, in each figure, about the component which has the substantially same function or structure, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.
1. First Embodiment (Example of loop detection determination processing)
2. Second embodiment (example of port state change monitoring processing)
3. Third embodiment (example in which the number of ports of the switch device is four)

<1. First Embodiment>
The present embodiment prevents an infinite circulation of a frame (broadcast frame) transmitted to an unspecified number of transmission destinations without specifying a port from the switch device due to an erroneous connection of the network system. This prevents the entire system from going down.

  FIG. 1 is a block diagram showing a configuration example of a network system according to the first embodiment of the present invention.

  In the network system 1 illustrated in FIG. 1, a switch device 101 (an example of an information processing device) is connected to a backbone network 100 via a communication line 201. The switch device 101 is a switch device having a loop detection function, and is a so-called intelligence type switching hub. For example, an Ethernet (registered trademark) category 5e UTP (Unshielded Twist Pair) cable can be used as the communication line of the network system 1, but the cable is not limited to this example.

  A first port of the switch device 101 is connected to the switch device 102 via a communication line 202. Further, the second port of the switch device 101 is connected to the switch device 103 via the communication line 203. That is, the switch device 102 and the switch device 103 are arranged under the switch device 101 arranged in the backbone network 100. The switch device 102 and the switch device 103 do not have a loop detection function. Hereinafter, a network composed of the switch device 102 and the switch device 103 arranged under the switch device 101 connected to the backbone network 100 is referred to as a “lower network”.

  Three communication devices 111 to 113 are connected to the switch device 102 via communication lines 211 to 213. In addition, three communication devices 114 to 116 are connected to the switch device 103 via communication lines 214 to 216.

  The switch device 101 transmits loop detection frames 221 and 222 (an example of loop detection data) that are L2 control frames for loop detection from the first port and the second port at regular intervals (for example, at intervals of 5 seconds).

FIG. 2 is a diagram illustrating the movement of the loop detection frame when a loop occurs in the network system of FIG.
As shown in FIG. 2, when the switch device 102 under the switch device 101 and the switch device 103 are mistakenly connected directly by the communication line 210, the loop detection transmitted from the first port of the switch device 101 to the switch device 102 is detected. A loop 231 is formed in which the frame 221 is input to the second port of the switch device 101 that is the transmission source via the switch devices 102 and 103. That is, a loop failure occurs in which the loop detection frame 221 transmitted from the first port of the switch device 101 is received by the second port of the switch device 101 that is the transmission source through the loop 231 path.

  Similarly, when the switch device 102 and the switch device 103 are erroneously connected via the communication line 210, the loop detection frame 222 transmitted from the second port of the switch device 101 to the switch device 103 passes through the switch devices 103 and 102. Thus, a loop 232 for inputting to the first port of the switch device 101 as the transmission source is formed. That is, a loop failure occurs in which the loop detection frame 222 transmitted from the second port of the switch device 101 is received by the first port of the switch device 101 that is the transmission source through the loop 232 path.

  In a conventional switch device, a blocking process (port blocking) is performed on a port that has received a loop detection frame. Therefore, when the switch device connected to the backbone network has two ports that can communicate with the lower network as shown in FIG. 2, these two ports are blocked. Therefore, the backbone network and the lower network are completely separated. Thus, when a loop occurs, there is a possibility that the network damage will be serious. Therefore, it is required to prevent network damage by detecting a loop at an early stage.

  In this embodiment, transmission source port information is added to the loop detection frame, and when the loop detection frame is received by any one of the ports 301 of the switch device 101, the switch device 101 checks the blocking state of the reception port. As a result of the check, if the reception port is in the non-blocking state, the switch apparatus 101 transitions the transmission source port to the blocking state based on the transmission source port information acquired from the loop detection frame.

  1 and 2, an example in which a loop is configured in the switch devices 101 to 103 via the communication line 210 that is erroneously connected between the switch device 102 and the switch device 103 has been described. Of course, it is not limited to. As an example, the following loop configuration can be considered.

(1) Case of connecting one port of the switch device 101 to another port (incorrect cable connection in the same switch device)
(2) When the ports are misconnected in the switch device 102 or 103 under the switch device 101, the frame transmitted from the switch device 101 to the switch device 102 or 103 is transferred between the ports in the switch device 102 or 103. A case in which a loop is formed that is transmitted to the switch device 101 due to an erroneous connection (3) A frame transmitted from the switch device 101 to the switch device 102 or 103 is a switch device under the switch device 102 and the switch device 103 (see FIG. (4) A case in which a loop is formed from the switch device 103 or the switch device 102 to the switch device 101 via the switch device 103 or the switch device 102 via the switch device 101 or the switch device 102. Essential from device 103 Case received by the switch apparatus 101 which is the transmission source via the Ttowaku 100

  FIG. 3 is a block diagram illustrating an internal configuration example of the switch device 101 having a loop detection function, and illustrates a path through which a loop detection frame, which is an example of loop detection data, is transmitted through the switch device 101.

  The switch device 101 includes a plurality of ports 301-1 to 301-3 and a plurality of physical layers 302-1 to 302-3 for inputting / outputting data to / from the outside. The switch device 101 also includes a frame transfer / port control unit 303, a loop detection frame reception control unit 304-1, a loop detection frame transmission control unit 304-2, and a loop detection control unit 305. Hereinafter, the port 301-1, the port 301-2, and the port 301-3 are referred to as a port 301 when they are not particularly distinguished or collectively referred to. Similarly, when the physical layer 302-1, the physical layer 302-2, and the physical layer 302-3 are not particularly distinguished or collectively referred to as the physical layer 302.

  The physical layer 302 corresponds to the first layer that defines the physical connection and transmission method of the network in the OSI reference model established by, for example, the International Organization for Standardization (OSI: Open Systems Interconnection).

  The frame transfer / port control unit 303 (an example of a transmission unit and a port control unit) includes a frame transfer function that performs transfer (input / output processing) of all frames processed by the switch device 101 including a loop detection frame, and a port 301 It has a port control function for performing blocking processing and opening (non-blocking) processing. When the port is blocked, the frame transfer / port control unit 303 does not link up (communicable) with the port 301 to be blocked. In other words, the frame transfer / port control unit 303 performs link-down (communication impossible state) with the blocking target port 301 by blocking the physical layer 302 connected to the blocking target port 301. Thus, even when the physical layer 302 receives a frame at any of the ports 301, the received frame is not transferred to the frame transfer / port control unit 303.

  The loop detection frame reception control unit 304-1 receives only the loop detection frame from all the frames processed by the switch device 101 from the frame transfer / port control unit 303 and transmits it to the loop detection control unit 305.

  The loop detection frame transmission control unit 304-2 receives from the loop detection control unit 305 only the loop detection frame among all the frames processed by the switch device 101, and transmits it to the frame transfer / port control unit 303.

  The loop detection control unit 305 (an example of a determination unit) receives a loop detection frame from the loop detection frame reception control unit 304-1 and transmits the loop detection frame to the loop detection frame transmission control unit 304-2.

  When the loop detection frame is received at the port 301-1 (an example of one port), the loop detection frame is transmitted to the physical layer 302-1 through the signal line 312. The loop detection frame is transmitted from the physical layer 302-1 through the signal line 322 to the frame transfer / port control unit 303 that controls transmission / reception of all frames in the switch device 101. Thereafter, the loop detection frame is transmitted to the loop detection frame reception control unit 304-1 via the signal line 331, and further transmitted to the loop detection control unit 305 via the signal line 341.

  When a loop detection frame is transmitted from the port 301-1, the loop detection frame is transmitted from the loop detection control unit 305 to the loop detection frame transmission control unit 304-2 via the signal line 342, and further the signal. The data is transmitted to the frame transfer / port control unit 303 via the line 332. Thereafter, the loop detection frame is transmitted to the physical layer 302-1 through the signal line 321 and is transmitted to the port 301-1 through the signal line 311.

  Similarly, when transmitting and receiving a frame at the port 301-2 (an example of another port), the frame is transmitted between the port 301-2 and the physical layer 302-2 via the signal lines 313 and 314. And receive. In addition, transmission and reception of frames are performed between the physical layer 302-2 and the frame transfer / port control unit 303 via the signal lines 323 and 324.

The frame transmission path is the same for the port 301-3 connected to the backbone network 100 via the communication line 201. Via the signal line 315, to transmit and receive the frames between the port 301-3 and the physical layer 302-3. In addition, transmission and reception of frames are performed between the physical layer 302-3 and the frame transfer / port control unit 303 via the signal lines 325 and 326.

  When closing the port 301, a port close instruction 350 is issued from the loop detection control unit 305, and the frame transfer / port control unit 303 receives the port close instruction. The frame transfer / port control unit 303 performs port close control on the corresponding physical layer 302 to block the corresponding port 301.

  Note that the information may be notified to the user or the terminal at the time of loop detection or when the port is closed by loop detection. For example, the information about loop detection or port blockage may be written to MIB (Management Information Base) so that it can be viewed by the user. Or you may display on LED provided in the applicable port, or you may display on the terminal connected to the switch apparatus 101, and the means to perform notification is not ask | required.

  In the following description, when explaining the transmission and reception of a frame between the loop detection control unit 305 and the port 301, the physical layer 302, the frame transfer / port control unit 303, the loop existing between the two. Description of the detection frame reception control unit 304-1 and the loop detection frame transmission control unit 304-2 is omitted as appropriate.

[Frame format of loop detection frame]
Here, the frame format of the loop detection frame transmitted and received by the switch apparatus 101 will be described.
FIG. 4 is an explanatory diagram showing an example of the frame format of the loop detection frame.
The loop detection frame uses an L2 control frame, and includes DA 401, SA 402, first fixed value 403, second fixed value 404, transmission time 405, MAC address 406, third fixed value 407, transmission source port number 408, as fields. It has a fourth fixed value 409, padding 410, and FCS (Frame Check Sequence) 411. The fields from the second fixed value 404 to the fourth fixed value 409 are information unique to the loop detection frame.

  DA 401 is a destination MAC address, and uses a unique MAC address reserved in advance. SA 402 is a source MAC address, and uses the MAC address of its own device. The first fixed value 403, the second fixed value 404, the third fixed value 407, and the fourth fixed value 409 are bit strings inserted to make the data length of the loop detection frame a fixed data length.

  The transmission time 405 is the time when the loop detection frame is transmitted from the own device. The MAC address 406 is the MAC address of the transmission source port that transmitted the loop detection frame. The transmission source port number 408 is the port number of the transmission source port that transmitted the loop detection frame.

  Further, padding 410 is a field of an arbitrary data length (10 bytes in FIG. 4) inserted for padding processing in which the loop detection frame is set to a fixed data length (for example, 64 bytes). The FCS 411 is a field added to check whether there is an error in the received frame. For example, CRC (Cyclic Redundancy Code) is used as the FCS.

  In the present embodiment, the transmission source port number 408 in the loop detection frame is used as transmission source port information, and when the reception port is not blocked, processing for blocking the transmission source port is performed.

[Loop detection judgment processing]
FIG. 5 is a flowchart showing loop detection determination processing according to the first embodiment of the present invention. Here, a case where a loop detection frame is received by two ports (for example, ports 301-1 and 301-2) connected to the lower network of the switch device 101 will be described as an example.

  As a premise, the loop detection control unit 305 of the switch device 101 defaults the ports 301-1 to 301-3 to the non-blocking state (enabled) and enables communication by the ports 301-1 to 301-3 ( Link up).

  The loop detection control unit 305 periodically transmits a loop detection frame from the ports 301-1 to 301-3 to a plurality of unspecified transmission destinations (multicast transmission) at regular intervals by the frame transfer / port control unit 303. Control. Actually, the loop detection frames are sequentially transmitted from the ports 301-1 to 301-3 with a slight time difference for convenience of processing of the frame transfer / port control unit 303. Each of the loop detection frames transmitted at this time includes information on the transmission source port number as information (transmission source port information) regarding the port transmitting the loop detection frame (see FIG. 4). Note that the DA 401 (destination MAC address) of the loop detection frame (FIG. 4) includes information indicating multicast.

  In an actual network system, a loop is formed by a more complicated path. Sending loop detection frames from all the ports of the switch device 101 without fixing the transmission and reception ports eliminates check omissions. It is desirable to transmit loop detection frames from at least more ports.

  When a frame is received at any port 301, the loop detection control unit 305 determines whether the received frame is a loop detection frame, that is, whether a loop detection frame is received (step S1). . When the loop detection frame is not received (NO in step S1), the loop detection control unit 305 continues to monitor the loop detection frame. If the loop detection frame is not detected for a certain period of time, the loop detection determination process may be terminated.

  On the other hand, when the loop detection frame is received in the determination process of step S1 (YES in step S1), the loop detection control unit 305 indicates that the loop detection frame has been received at any of the ports 301 and the corresponding port 301. Port number (reception port number) is acquired (step S2).

  Next, the loop detection control unit 305 acquires the transmission source port number 408 from the received loop detection frame (step S3).

  Thereafter, the loop detection control unit 305 acquires port close on / off information of the port 301 corresponding to the reception port number, that is, status information indicating whether or not the port is closed (step S4). When port close is on, the port is blocked, and when it is off, the port is not blocked.

  Next, the loop detection control unit 305 determines whether or not the port close of the port 301 corresponding to the reception port number is off (step S5). The loop detection control unit 305 sequentially performs this determination process from the port that received the loop detection frame. If the port close of the port 301 is OFF during the determination process (YES in step S5), the loop detection control unit 305 performs a process of closing the transmission source port by the frame transfer / port control unit 303. Execute (Step S6). After this process ends, the loop detection control unit 305 ends the loop detection determination process.

  When the port close of the port 301 corresponding to the reception port number is ON in the determination process in step S5 (NO in step S5), the loop detection control unit 305 does not perform any process on the port 301. Finally, the loop detection determination process ends.

[Specific example of loop detection judgment processing]
A specific example of the loop detection determination process will be described with reference to FIG.
FIG. 6 is a sequence diagram showing an outline of loop generation when a network is erroneously connected according to the first embodiment of the present invention. Here, a case where a loop detection frame is transmitted from the ports 301-1 and 301-2 of the switch device 101 will be described as an example.

  First, the loop detection control unit 305 of the switch device 101 transmits a plurality of unspecified transmissions from the port 301-1 (hereinafter referred to as “first port”) and the port 301-2 (hereinafter referred to as “second port”). A loop detection frame is transmitted (multicast) toward the destination (steps S11 and S12). At this time, source port information is added to the loop detection frames transmitted from the first port and the second port, respectively.

  Then, the loop detection control unit 305 of the switch device 101 receives the loop detection frame transmitted from the first port at the second port (step S13). Subsequently, the switch device 101 receives the loop detection frame transmitted from the second port at the first port (step S14).

  The switch apparatus 101 performs a determination process on the state of the second port that received the loop detection frame first after a predetermined time lag (time shift) has elapsed since the second port received the loop detection frame. The time lag varies depending on the processing speed of the loop detection control unit 305 and the like. Then, the loop detection control unit 305 of the switch device 101 performs processing for blocking the first port that is the transmission source of the loop detection frame by the frame transfer / port control unit 303 when the second port is not blocked ( Port close) is performed (step S15).

  Next, the loop detection control unit 305 of the switch device 101 also executes determination processing for the state of the first port that has received the loop detection frame with a delay from the second port (step S16). Here, there is a time lag from when the loop detection control unit 305 detects that the loop detection frame has been received at the first port to when the state of the first port is determined. Therefore, when this determination process is executed, the first port is already closed, and the loop detection control unit 305 determines that the first port is closed. Then, the loop detection control unit 305 ends the loop detection determination process without blocking the second port that is the transmission source of the loop detection frame received at the first port.

  In the first embodiment configured as described above, the transmission source port number is included in the loop detection frame transmitted from the port of the switch device 101 connected to the backbone network 100. Then, when the switch device 101 detects the loop detection frame, if the reception port that received the loop detection frame is not in the blocked state, the processing is performed to block the transmission source port, and the reception port is in the blocked state. Sometimes, the process of blocking the transmission source port is not performed. This loop detection determination process can prevent a situation in which all the ports that have received the loop detection frame are blocked. Therefore, it is possible to maintain a wide range in which network communication can be maintained during operation of the loop configuration prevention function using the loop detection frame without requiring complicated settings as in the past, and without reducing the communication range. A loop configuration can be prevented.

  By such a loop detection determination process, when a loop occurs in the network, it is possible to quickly close the corresponding port and prevent a broadcast frame loop (infinite circulation). Therefore, it is possible to prevent the entire network system from being down due to a broadcast frame loop.

<2. Second Embodiment>
Next, a second embodiment of the present invention will be described with reference to FIGS.
In a spanning tree (route selection algorithm) such as STP or RSTP (Rapid STP), control information called BPDU (Bridge Protocol Data Unit) is exchanged between bridges based on a given priority, and a route usually used is changed. One is set, and the other routes are set as detour routes at the time of failure. In the spanning tree, the path of the frame is set by switching between a blocking state in which no frame is transferred for each port and a non-blocking state in which the frame is transferred (hereinafter referred to as a “forwarding state”), thereby logically preventing a loop configuration. To do. RSTP is an improvement of STP that shortens the time until a path is completely switched when there is a topology change.

  In the blocking state, even if a loop is formed in the configuration of the network system, the loop detection control unit 305 is configured not to receive the loop detection frame by setting a route by software. Therefore, a loop may be formed when the blocking state of the port changes to the forwarding state for some reason. Therefore, in the second embodiment, a change in the blocking state of the port of the switch device is monitored, and the loop detection determination process (FIG. 5) in the first embodiment is executed according to the result.

FIG. 7 is a diagram illustrating a state before the blocking state of the switch device is changed.
FIG. 8 is a diagram illustrating a state after the blocking state of the switch device is changed.
FIG. 9 is a flowchart showing a port state change monitoring process according to the second embodiment of the present invention.

  The configuration of the network system 1A shown in FIGS. 7 and 8 is the same as the configuration of the network system 1 in FIG. That is, the port of the switch device 102 and the port of the switch device 103 are misconnected. The configuration of the switch device 101A of the network system 1A is the same as the configuration of the switch device 101 in FIG. However, in the switch apparatus 101A of the network system 1A, a spanning tree (for example, STP or RSTP) which is a kind of loop suppression function is activated. The port 301-1 of the switch device 101A is a first port, and the port 301-2 is a second port.

  The second port of the switch device 101A shown in FIG. 7 is set to a blocking state by setting such as STP / RSTP. When the second port of the switch device 101A is in the blocking state, it is assumed that the blocking state of the second port is canceled due to some failure, and the second port has changed to the non-blocking state (forwarding state) as shown in FIG. To do. When the second port of the switch device 101A transitions to the forwarding state, a loop having the switch devices 101A, 102, and 103 as a route is formed, and the broadcast frame may circulate indefinitely. In order to prevent this, the port state change monitoring process shown in FIG. 9 is executed in the switch device 101A.

[Port status change monitoring processing]
First, the loop detection control unit 305 of the switch device 101A acquires the blocking state information (a) of each port (step S21).

  Furthermore, the loop detection control unit 305 acquires the blocking state information (b) of each port again after a delay (waiting time) of a predetermined time (for example, 1 second) has elapsed after performing the process of step S21 (step S22). (Step S23).

  Thereafter, the loop detection control unit 305 determines whether the state of the second port is based on the blocking state information (a) of each port acquired in step S21 and the blocking state information (b) of each port acquired in step S23. It is determined whether or not a transition is made from the blocking state to the forwarding state (step S24). When the state of each port has not transitioned from the blocking state to the forwarding state (NO in step S24), the loop detection control unit 305 ends the port state change monitoring process.

  When the state of the port has changed from the blocking state to the forwarding state in the determination process of step S24 (YES in step S24), the loop detection control unit 305 changes the port (second port) that has changed from the blocking state to the forwarding state. ) To transmit a loop detection frame (step S25).

  Thereafter, since the loop configuration is generated by the misconnected communication line 210, the loop detection frame is received by another port (first port) of the switch device 101A, and the loop detection determination process of FIG. S26).

  In the loop detection determination process, if the port (first port) that received the loop detection frame is not in the blocked state, the blocking process is performed on the second port that is the transmission source of the loop detection frame. Therefore, transmission and reception of frames cannot be performed between the second port of the switch apparatus 101A and the switch apparatus 103, and the network system returns to the original state (FIG. 7) where no frames are looped.

  According to the second embodiment having the above-described configuration, it is possible to prevent the loop more reliably by combining the loop suppression function such as the conventional spanning tree and the loop detection determination process according to the first embodiment. is there.

In the second embodiment, the port state changes superintendent Misho management shown in FIG. 9, the state of the port when the transition from the blocking state to the forwarding state, the loop detection determining process of FIG. 5 is executed. Therefore, a transition state of the port of the switch equipment from the blocking state to a forwarding state, when the loop of the loop detection frame is generated, immediately the corresponding port closed process, the broadcast frames loop (infinite circulation) is Is prevented. Therefore, it is possible to prevent the entire network system from being down due to a broadcast frame loop.

<3. Third Embodiment>
Next, a third embodiment of the present invention will be described with reference to FIG.
The number of ports of the switch device connected to the backbone network may be four or more. The third embodiment shows an example in which the number of ports of the switch device connected to the backbone network is 4 or more.

  FIG. 10 is a block diagram illustrating a configuration example of a network system according to the third embodiment of the present invention. In the network system 1B shown in FIG. 10, the switch device 101B connected to the backbone network 100 further includes a port 301-4 in addition to the ports 301-1 to 301-3. The port 301-4 of the switch device 101B is connected to the switch device 104 of the lower level network via the communication line 204. Three communication devices 117 to 119 are connected to the switch device 104 via communication lines 217 to 219.

  The port 301-4 transmits and receives a loop detection frame to and from the frame transfer / port control unit 303 via the signal lines 317 and 318, the physical layer 302-4, and the signal lines 327 and 328.

  Furthermore, the present invention is not limited to the above-described embodiments, and various other application examples and modifications can be taken without departing from the gist of the present invention described in the claims. is there.

  For example, the above-described exemplary embodiments are detailed and specific descriptions of the configuration of the apparatus and the system in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described above. . Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment. In addition, the configuration of another embodiment can be added to the configuration of a certain embodiment. Moreover, it is also possible to add, delete, and replace other configurations for a part of the configuration of each exemplary embodiment.

  Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files for realizing each function can be stored in a recording device such as a memory, a hard disk, or an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.

  In addition, control lines, information lines, and the like are those that are considered necessary for the explanation, and not all control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

  Further, in this specification, the processing steps describing time-series processing are not limited to processing performed in time series according to the described order, but are not necessarily performed in time series, either in parallel or individually. The processing (for example, parallel processing or object processing) is also included.

  DESCRIPTION OF SYMBOLS 1,1A, 1B ... Network system 101, 101A, 101B, 102-104 ... Switch apparatus, 210 ... Communication line, 221, 222 ... Loop detection frame, 301-1 to 301-4 ... Port, 302-1 to 302 -4 ... Physical layer, 303 ... Frame transfer / port control unit, 304-1 ... Loop detection frame reception control unit, 304-2 ... Loop detection frame transmission control unit, 305 ... Loop detection control unit, 408 ... Source port number

Claims (5)

Multiple ports to send and receive data;
A transmitting unit for transmitting loop detection data including source port information for detecting a loop configuration from each of the plurality of ports;
Determination of whether or not the other port that has received the loop detection data is blocked when the loop detection data transmitted from one of the plurality of ports is received by another port And
When the other port that has received the loop detection data is not in the blocked state during the determination process by the determination unit, the one port that has transmitted the loop detection data is processed to be blocked, and the other port A port control unit that does not perform processing for the one port when
An information processing apparatus comprising: 2. There is a time lag between receiving the loop detection data at the other port and determining whether or not the other port that has received the loop detection data is blocked by the determination unit. The information processing apparatus described. When a loop suppression function using a route selection algorithm is activated, the port control unit monitors a state of the plurality of ports, and from a blocking state in which data transfer is not performed by the loop suppression function to a non-blocking state The information processing apparatus according to claim 1, wherein when there is a port that has transitioned to, the loop detection data is transmitted from the corresponding port. The information processing apparatus according to claim 1, wherein the transmission unit multicasts the loop detection data from all of the plurality of ports. A network system comprising at least a first information processing device, a second information processing device, and a third information processing device,
The first information processing apparatus includes a port for connecting to the second information processing apparatus and a port for connecting to the third information processing apparatus, and a plurality of ports for transmitting and receiving data,
A transmitting unit for transmitting loop detection data including source port information for detecting a loop configuration from each of the plurality of ports;
Determination of whether or not the other port that has received the loop detection data is blocked when the loop detection data transmitted from one of the plurality of ports is received by another port And
When the other port that has received the loop detection data is not in the blocked state during the determination process by the determination unit, the one port that has transmitted the loop detection data is processed to be blocked, and the other port A port control unit that does not perform processing for the one port when
A network system comprising:

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