JP2002252625A - Network failure monitoring method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a network failure monitoring device which enables to separate an abnormal part rapidly by directly detecting the part where a packet is actually interrupted. SOLUTION: A network failure monitoring device in the layer 2 network which is constituted of multiple layer 2 switches comprises a first method by which a filtering database of each layer 2 switch is detected and a port corresponding to the designated MAC address is required, using the designated MAC address and the construction information table which stores the network construction information showing connecting relations between ports of the layer 2 switch, and a second method by which a transferring path for packets based on the construction information table and the said layer 2 switch ports obtained by the first method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network fault monitoring method and apparatus, and more particularly, to a fault location occurring on a network and an erroneous setting of an administrator in a layer 2 network constituted by a plurality of layer 2 switches. It relates to technology that is effective in detecting.

[0002]

2. Description of the Related Art At present, in a LAN (Local Area Network), communication devices in the same subnet are connected by a layer 2 network composed of a layer 2 switch that performs layer 2 switching in two layers in an OSI protocol model. You. Conventionally, when a failure occurs on a network, a network administrator indirectly estimates a location causing a communication error by isolating a failure location by observing a state that can be monitored by each layer 2 switch. Was.

[0003]

Generally, a spanning tree protocol used as a failure switching protocol for a layer 2 switch of a LAN prevents a loop from occurring and automatically avoids a failure in the event of a network failure. The route is switched as follows. However, in the spanning tree protocol, it is difficult to determine in advance a switching destination of a path when a failure occurs. In a wide area network service, etc., it is necessary to guarantee the lowest communication quality to the user, and it is necessary to be able to systematically specify the switching destination of the communication path in the event of a network failure. May be operated. Therefore, when the network administrator makes an incorrect setting in the layer 2 switch, there is a possibility that the packet is not transferred to a predetermined place or a loop-like path is formed on a packet transfer path and the packet is circulated indefinitely. There is. Conventionally, in the network, there is no means to know the arrival status of the packet on the way of the packet, so if the network administrator makes an incorrect setting or if a failure occurs on the network and the packet does not reach the communication The network administrator does not know how far it has reached or where it has been disconnected, so the network administrator has checked the status of each layer 2 switch on the network and the set values to determine the problem location. It took a long time to separate.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a method and apparatus for monitoring a network fault, which directly detects where a packet is actually interrupted. It is an object of the present invention to provide a technique that enables an abnormal part to be quickly identified. Another object of the present invention is to provide a method and apparatus for monitoring a network fault, wherein a loop-like path exists on a packet transfer path, packets circulate indefinitely, and the bandwidth of the network is compressed by useless traffic. It is an object of the present invention to provide a technology capable of detecting a state in which a network is operating and ensuring efficient and stable operation of a network. The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0005]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows. A network failure monitoring method according to the present invention includes a filtering database, and learns a destination port of a packet based on a source address of a received packet and registers a plurality of layer 2 switches for registering the filtering port in the filtering database. In the present invention, the network fault monitoring device includes a configuration information table for storing network configuration information indicating a connection relationship between ports of each of the layer 2 switches. The network failure monitoring method of the present invention searches the filtering database of the specified layer 2 switch with the specified MAC address, starting from the specified layer 2 switch on the above-described system, and Step 1 for obtaining a port corresponding to the above, Step 2 for obtaining a Layer 2 switch connected to the port obtained in Step 1 from the configuration information table, and Step 3 of searching a filtering database by the specified MAC address to find a port corresponding to the specified MAC address;
Determining from the configuration information table the layer 2 switch connected to the port determined in step 4;
A step 5 of repeating the steps 3 and 4 until there are no more layer 2 switches registered in the configuration information table, and obtaining a transfer route of a packet addressed to the specified MAC address. It is characterized by.

In a preferred embodiment of the present invention, it is detected that the same layer 2 switch exists in the transfer path obtained in step 5 and it is determined that a loop exists in the packet transfer path. The method further comprises the step of detecting. In the network fault monitoring method of the present invention, the filtering database of all the layer 2 switches belonging to the layer 2 network is searched by a designated MAC address to find a corresponding port, and Determining a transfer route of a packet addressed to the specified MAC address based on the specified port and the configuration information table.

[0007] The network failure monitoring method according to the present invention further comprises the steps of: using the filtering database of all the layer 2 switches belonging to the layer 2 network,
Step 1 of deleting an entry in which the specified MAC address is registered, and specifying a packet having the specified MAC address as a source address and describing a MAC address for which a transfer route is to be obtained in a destination MAC address. Transmitting from a specific port of a layer 2 switch, searching a filtering database of all the layer 2 switches in the layer 2 network, and obtaining a port corresponding to the specified MAC address; A step of obtaining a transfer path of a packet whose destination MAC address is the MAC address whose transfer path is to be obtained based on the port obtained in step 3 and the configuration information table. .

The network failure monitoring method according to the present invention further comprises a step 1 of transmitting a packet having a specified MAC address as a destination MAC address to a specific port of a specific layer 2 switch. Step 2 for counting the number of received packets only having the specified MAC address as the destination MAC address; Step 3 for identifying the layer 2 switch whose count value has been increased in Step 2; A step of obtaining a transfer route of a packet having the specified MAC address as a destination MAC address based on the layer 2 switch and the configuration information table.

Further, according to the network failure monitoring method of the present invention, the V set to each port of each layer 2 switch is set.
A step of obtaining a LAN number, and a step of obtaining a VLAN path corresponding to the same VLAN number based on the VLAN number obtained in step 1 and the configuration information table. . The network failure monitoring method according to the present invention further comprises a step 1 for detecting a state of each port of each of the layer 2 switches determined by the failure time switching protocol, and a step of detecting each port of the layer 2 switch detected in step 1 And a step 2 of obtaining a logical path configured by the failure time switching protocol based on the state of (1) and the configuration information table.

The network fault monitoring method according to the present invention further comprises a step 1 of transmitting a packet having a specified MAC address as a destination MAC address to a specific port of a specific layer 2 switch. Step 2 for counting the number of packets received having only the designated MAC address as the destination MAC address, Step 3 for identifying the layer 2 switch whose count value has increased in Step 2, and determined by the failure switching protocol Detecting the state of each port of each of the layer 2 switches, the state of each port of each of the layer 2 switches detected in step 4, and the configuration information table, based on the failure switching protocol. Step 5 for finding the configured logical path
And a step 6 of obtaining a transfer path of a packet having the specified MAC address as a destination MAC address on the logical path determined in the step 5 based on the layer 2 switch identified in the step 3. It is characterized by doing.

The network fault monitoring method according to the present invention is provided with a filtering database, and is configured using a plurality of layer 2 switches for learning a destination port of a packet based on a source address of a received packet and registering the port in the filtering database. Port V is a layer 2 network between VLANs with different VLAN numbers.
The present invention is applied to a layer 2 network in which one connected VLAN is configured by being connected by a LAN, and a unique connected VLAN number is assigned to the specified connected VLAN. A configuration information table is provided for storing network configuration information indicating a connection relationship between ports of each of the layer 2 switches. The network fault monitoring method according to the present invention provides a network fault monitoring method according to the present invention, in which the V set in each port of each layer 2 switch in the layer 2 network is used.
Step 1 of obtaining a LAN number;
Step 2 of identifying a port to which a VLAN number belonging to the number is set and obtaining a route of the connected VLAN based on the identified port and the configuration information table; Step 3 of detecting that the layer 2 switch is obtained a plurality of times and detecting that a loop-like path exists in the path of the packet connection VLAN.

Further, the present invention is a network fault monitoring apparatus for executing the above-described network fault monitoring method, which stores network configuration information indicating a connection relationship between ports of each of the layer 2 switches. First means for searching a filtering database of each of the layer 2 switches based on an information table and a specified MAC address, and obtaining a port of each of the layer 2 switches corresponding to the specified MAC address; and the configuration information table And second means for obtaining a packet transfer route based on the port of each of the layer 2 switches obtained by the first means. In a preferred embodiment of the present invention, each layer 2
M specified from the filtering database of the switch
Third to delete the entry where the AC address is registered
Means is further provided. In a preferred embodiment of the present invention, each of the layer 2 switches includes:
A counter for reading the count value of the counter of each of the layer 2 switches, and a fourth unit for identifying a layer 2 switch whose count value is increasing, wherein the second unit includes the configuration information. A packet transfer route is obtained based on a table and the respective layer 2 switches obtained by the fourth means.

The network fault monitoring device of the present invention further comprises a configuration information table for storing network configuration information indicating a connection relationship between each port of each of the layer 2 switches, and a configuration information table for setting each of the ports of each of the layer 2 switches. First means for obtaining a VLAN number which has been set, and second means for obtaining a route of a VLAN corresponding to the same VLAN number based on the VLAN number obtained by the first means and the configuration information table. It is characterized by having.
In addition, the network fault monitoring device of the present invention includes a configuration information table storing network configuration information indicating a connection relationship between each port of each of the layer 2 switches, and a configuration information table for each of the layer 2 switches determined by the failure switching protocol. First means for detecting a state of a port, a state of each port of the layer 2 switch detected by the first means, and a path configured by a failure switching protocol based on the configuration information table. It is characterized by comprising two means.

The network fault monitoring device of the present invention further comprises a configuration information table for storing network configuration information indicating a connection relationship between each port of each of the layer 2 switches, and a configuration information table for setting each of the ports of each of the layer 2 switches. First means for acquiring the VLAN number being connected,
A second unit for identifying a port for which a VLAN number belonging to the N number is set; a port identified by the second unit; and a connection VLA based on the configuration information table.
And third means for determining the path of N. ADVANTAGE OF THE INVENTION According to this invention, the range which a packet can reach on a network can be calculated | required, and also it becomes possible to detect whether the loop exists on the transfer path of a packet.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. In all the drawings for describing the embodiments, components having the same functions are denoted by the same reference numerals, and repeated description thereof will be omitted. [First Embodiment] FIG. 1 is a block diagram showing a schematic configuration of a network system to which a network fault monitoring device according to a first embodiment of the present invention is applied. In the figure,
Reference numerals 1 to 3 denote layer 2 switches (hereinafter, simply referred to as switches). These switches (1 to 3) exchange packets transmitted from users and transfer the packets to destinations. 4 ~
Reference numeral 6 denotes a link, which is a transmission path connecting the switches. Reference numeral 7 denotes a failure monitoring device which remotely monitors a failure of a network device such as a switch. Reference numeral 8 denotes a management network, and the fault monitoring device 7 remotely monitors the switch through the network. In the present embodiment, the management network 8 is provided separately from the network constituted by the switches (1 to 3), but can be realized as the same network. Terminals 9 and 10 are used by users of the network, and transmit and receive packets in communication between users. Ports 11 to 18 are portions where the switches (1 to 3) transmit and receive packets.

FIG. 2 is a diagram for explaining a configuration information table 30 which stores configuration information indicating a connection relationship between each port of each switch in the network system shown in FIG. In the figure, reference numeral 31 denotes a link field which stores a link number corresponding to an entry in the configuration information table 30. 32 is switch 1
This is a field for storing the name of a switch connected to one of the links connecting the switches. A port 1 field 33 stores a port number connected to one of the links connecting the switches. Reference numeral 34 denotes a switch 2 field, which is a field for storing a name of a switch connected to the other of the links connecting the switches. A port 2 field 35 stores a port number of a switch connected to the other of the links connecting the switches. Reference numeral 36 denotes an entry of the configuration information table 30, in which connection information of a specific link is registered.

FIG. 3 is a block diagram showing a schematic configuration of the switches (1 to 3) shown in FIG. In FIG.
Is a packet switch, which transfers the received packet to the port specified by the control unit 41. Reference numeral 42 denotes a filtering database (hereinafter, referred to as FDB), which is a table for designating a transfer destination port based on a destination MAC address of a packet. 41 is a control unit,
The switch is controlled to transfer the packet to a predetermined port based on the received packet header and the FDB. Reference numeral 43 denotes a packet counter, which counts the number of received packets that satisfy the conditions specified by the switch.

FIG. 4 is a diagram showing a configuration of a packet to be transferred in the network system shown in FIG.
In the figure, reference numeral 50 denotes a packet, which is an information unit in which a header for designating a data transfer destination is added to information communicated between users. A destination MAC address 51 designates the destination of the packet 50, and the switches (1 to 51)
3) determines the destination port based on the destination MAC address 51. Reference numeral 52 denotes a source MAC address, and the switches (1 to 3) determine the source M of the received packet 50.
The registration information of the FDB 42 is learned from the AC address 52. Reference numeral 53 denotes a payload in which information to be communicated between users is stored.

FIG. 5 is a diagram showing the structure of the FDB 42 shown in FIG. In the figure, reference numeral 61 denotes a MAC address field which stores a destination MAC address.
A port number field 62 stores a destination port for the destination MAC address. Reference numeral 63 denotes an FDB entry for registering a combination of a transmission port with respect to a destination MAC address.

In the network system shown in FIG. 1, a method for obtaining a logical route in the network will be described by taking as an example a case where a packet is transmitted from the terminal 9 to the terminal 10. Switch 1, switch 2 and switch 3
Although connected in a loop as shown in FIG.
First, a case where a logical path without a loop is formed by the spanning tree protocol specified in E802.1D will be described. Each of the switches (1 to 3) executes a spanning tree protocol, and blocks the port 14 of the switch 2 connected to the link 6 between the switch 2 and the switch 3 and the port 15 of the switch 3 in a blocking state. The other ports are in the forwarding state to prevent the occurrence of loops. The fault monitoring device 7 checks whether each port of each switch (1 to 3) is in the forwarding state in the spanning tree protocol,
Alternatively, it is detected whether the state is a blocking state. In the example shown in FIG. 1, the ports 17, 13, 11, 12, 16, and 18 are in the forwarding state, and the port 14 and the port 15
Is in a blocking state. The failure monitoring device 7 can obtain a logical path configured by the spanning tree protocol based on the information and the information in the configuration information table 30.

Next, a method for obtaining a transfer route of a packet transmitted from the terminal 9 to the terminal 10 using the packet counter 43 of the switches (1 to 3) will be described. The failure monitoring device 7 increases the number of the packet counter 43 by one in the switch 1, the switch 2 and the switch 3 when the address described in the destination MAC address 51 of the received packet is the MAC address of the terminal 10. Set to Packet 50 from terminal 9 to terminal 10
, The switch 2 first receives the packet 50. Since the switch 2 describes the MAC address of the terminal 10 in the destination address of the packet 50,
The control unit 41 of the switch 2 increases the number of the packet counter 43 by one. As described above, the packet is transferred to the terminal 10 via the switch 1 after the switch 2 and the switch 3 after the switch 2. At this time, the numbers of the packet counters 43 of the switches 1 and 3 are each increased by one. Switch with increased counter and configuration information table 3
By using 0, the transfer route of the packet can be obtained. Further, the actual transfer path on the logical path of the packet can be obtained from the switch with the increased counter and the logical path obtained by the spanning tree protocol by the above-described processing.

Next, a description will be given of a method of obtaining a packet transfer route in the case where the Spanning Tree Protocol is stopped so that a switching destination of a communication route can be systematically designated when a failure occurs. Each of the switches (1 to 3) sets the MAC address described in the source address 52 of the received packet 50 in the MAC address field 61 of the FDB 42.
Then, the reception port number of the packet is registered in the port number field 62 of the FDB 42. This FDB
For details of the learning process of No. 42, refer to pages 301 to 302 of Document 1 below. Reference 1: Haruki Kotomo, "VPN / VLAN Textbook", ASCII Publishing Bureau In the fault monitoring device 7, a configuration information table 30 indicating a connection relationship between the switch 1, the switch 2, and the switch 3 is set in advance. The fault monitoring device 7 acquires information of the FDB 42 from the switches 1, 2 and 3 through the management network 8.

The FD acquired by the fault monitoring device 7 will be described below.
An example of a method for obtaining a transfer route of a packet transmitted from the terminal 9 to the terminal 10 based on the information in B42 and the information in the configuration information table 30 will be described. First, FD of switch 2
B42 is searched for by the MAC address of the terminal 10, and port 1 is searched.
3 is obtained. Since the connection destination of the port 13 is the port 11 of the switch 1 according to the configuration information table 30, the FDB 42 of the switch 1
The port number of the port 12 is obtained by searching with the C address. The configuration information table 30 indicates that the connection destination of the port 12 is the port 16 of the switch 3, and then searches the FDB 42 of the switch 3 with the MAC address of the terminal 10 to obtain the port number of the port 18. According to the configuration information table 30, the port 18 of the switch 3
It is found that the switch is not connected. At that point, the search for the route ends, and the transfer route of the packet transmitted from the terminal 9 to the terminal 10 is obtained. In the process of searching for a packet transfer route, the same switch is
If the packet has passed more than once, it is detected that a loop-like path exists in the packet transfer path.

In the following, another example of a method in which the fault monitoring device 7 obtains a transfer route of a packet transmitted from the terminal 9 to the terminal 10 will be described. The fault monitoring device 7 obtains the MAC of the terminal 9 from the FDBs 42 of all the switches in the network.
The FDB entry 63 of the address is deleted. The terminal 9
The MAC address of the terminal 9 is described in the source MAC address 52, and the packet 50 in which the MAC address of the terminal 10 is described in the destination MAC address 52 is transmitted. The packet passes through the switches in the order of the switch 2, the switch 1, and the switch 3 as described above. When passing through each switch, the MAC address described in the source MAC address 52 of the packet is learned, and the FDB 42 of the passing switch is learned.
Registered in. After the packet arrives at the terminal 10, the fault monitoring device 7 checks all the switches (1
3), and acquires the FDB into the M of the terminal 9.
A search is performed using the AC address, and the path through which the packet has passed can be determined from the switch in which the MAC address is registered and the configuration information table 30.

FIG. 6 is a diagram showing the structure of a packet in the tag VLAN. In the figure, 70 is a tag VLA
N, a header for designating a data transfer destination and a VLAN number for identifying a VLAN are added to information communicated between users. 71 is the destination MA
The C address is used to specify the destination of the packet 70, and the switches (1 to 3) determine the destination port based on the destination MAC address 71. Reference numeral 72 denotes a source MAC address. The switches (1 to 3) look at the source MAC address 72 of the received packet and learn the port that is the destination of the MAC address. Reference numeral 73 denotes a VLAN number, information for identifying which VLAN the packet is a packet of, and 74, a payload, which stores information for communication between users.

FIG. 7 is a block diagram showing an example of a network system in which a VLAN is set. 80 is VL
AN, and ports 13, 14, 11, 1 of the switch
The VLAN of the VLAN is assigned to 2, 15, 16, 17 and 18
Number is set. In the example shown in FIG. 7, 10 is set as the VLAN number. The fault monitoring device 7 acquires the VLAN number set for each port of the switches (1 to 3) in the network, specifies the port to which the VLAN number of 10 is set, and sets the port number of the switch (1 to 3). Ports 13, 14, 11, 12, 15, 16, 17 and 1
It can be seen that 10 is set to 8 as the VLAN number. The fault monitoring device 7 can obtain the route of the VLAN 80 from the result and the configuration information table 30.

That is, in the switch 2, the ports for which the VLAN number 10 is set include the port 14 and the port 13. According to the configuration information table 30, the switch 14 is connected to the port 14 and the switch 1 is connected to the port 13, so that the VLAN 80 is connected between the switch 2 and the switch 1, and between the switch 2 and the switch 3
It can be seen that a path exists between the links. In the switch 1, the VLAN number 10 is set to the port 12, and the configuration information table 30 indicates that the port 12 is connected to the switch 3. Similarly, in the switch 3, the VLAN number 10 is set to the port 15, the port 16, and the port 18. From the configuration information table 30, the switch 1 is connected to the port 16, and the switch 2 is connected to the port 15. It can be seen that no switch is connected to port 18. In the above-described process of searching for a route of the VLAN 80, the switch 3 has been redundantly searched.
It can be seen that a loop exists on the route of the LAN 80.

[Second Embodiment] FIG. 8 is a block diagram showing a schematic configuration of a network system to which a network fault monitoring apparatus according to a second embodiment of the present invention is applied, and a setting state of a VLAN. In the drawing, switches 90 to 93 exchange packets transmitted from a user and transfer the packets to a destination. Reference numerals 94 to 97 denote links, which are transmission paths connecting the switches. Reference numerals 98 to 108 denote ports, which are portions where switches 90 to 93 transmit and receive packets. Reference numerals 109 and 110 are terminals used by users of the network. Reference numerals 111 to 112 denote VLANs, and VLs to which the same VLAN numbers are set, respectively.
AN. VLAN 111 is connected to port 9 of the switch.
8, 108, 107 and 105 have VLAN numbers of 10
Is set. In the VLAN 112, 11 is set as a VLAN number in the ports 100, 101, 102, and 103 of the switch. Port 99, port 100,
The port 103 and the port 104 have a port VLAN
Are set respectively. The port VLAN is a VLAN system in which a VLAN set for one port on a switch is associated with the port as one group. VLAN 111 and VLAN 112 are port V
The link 94 and the link 96 are connected through the LAN at two places. Although the VLAN 111 and the VLAN 112 are apparently two tag VLANs, they are connected by the port VLAN and logically operate as one VLAN. This VLAN is hereinafter referred to as a connected VLAN.

Hereinafter, in the present embodiment, the connection VL
A method for obtaining the route of the AN will be described. First, VL
Connected VL configured by AN 111 and VLAN 112
Assign a connected VLAN number to the AN. The connection VLAN includes VLAN 111 and VLAN 112, and the connection VLAN number corresponds to the VLAN.
10 which is the VLAN number of 111 and V of the VLAN 112
The LAN number 11 is associated therewith. As in the first embodiment, the fault monitoring device 7 has a configuration information table for storing network configuration information in FIG.
A VLAN number set for each port of each switch on the network is obtained, and a port including VLAN numbers 10 and 11 corresponding to the connected VLAN number is obtained. As a result, ports 98, 99, 100, 10
1, 102, 103, 104, 105, 107, 108
Is required. From this result and the network configuration information table, as in the first embodiment, when a route search for a connected VLAN is performed and the same switch is searched a plurality of times, a loop-shaped route exists on the route of the connected VLAN. Is detected.

The above-described processing is executed at the time of occurrence of a failure, at the time specified by an administrator, or periodically. According to each of the above-described embodiments, the following effects can be obtained. In the conventional network, since it was not possible to specify the transfer route of the packet, the portion where the packet was disconnected was indirectly determined by checking the abnormal state of the device. By using the form, it is possible to directly detect where a packet is actually interrupted, so that an abnormal part can be quickly identified. In addition, by being able to discover the existence of a loop-like path on the packet transfer path, it is possible to detect a state in which packets circulate indefinitely and overwhelm the network bandwidth with useless traffic, and efficiently stabilize the network Operation can be secured. In addition, the setting route of the VLAN can be automatically searched, and it is easy to find a setting error.
Can be obtained for the route of the connected VLAN constituted by As described above, the invention made by the inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and can be variously modified without departing from the gist of the invention. Of course, it is.

[0031]

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows. (1) According to the present invention, where a packet is actually interrupted can be directly detected, so that an abnormal portion can be quickly identified. (2) According to the present invention, it is possible to detect a state in which a packet circulates indefinitely and presses the network bandwidth with useless traffic, and it is possible to secure efficient and stable operation of the network. (3) According to the present invention, it is possible to automatically search for a setting route of a VLAN, to easily find a setting error, and to obtain a route of a connected VLAN constituted by a plurality of VLANs.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a network system to which a network fault monitoring device according to a first embodiment of the present invention is applied.

FIG. 2 is a diagram illustrating a configuration information table that stores configuration information indicating a connection relationship between ports of each layer 2 switch in the network system illustrated in FIG. 1;

FIG. 3 is a block diagram showing a schematic configuration of each layer 2 switch shown in FIG. 1;

FIG. 4 is a diagram showing a configuration of a packet to be transferred in the network system shown in FIG. 1;

FIG. 5 is a diagram showing a structure of a filtering database shown in FIG. 3;

FIG. 6 is a diagram showing a structure of a packet in a tag VLAN.

FIG. 7 is a block diagram illustrating an example of a network system in which a VLAN is set.

FIG. 8 is a schematic configuration of a network system to which a network fault monitoring device according to a second embodiment of the present invention is applied;
5 is a block diagram illustrating a setting state of a VLAN.

[Explanation of symbols]

1-3,90-93 ... Layer 2 switch, 4-6,94
-97: link, 7: fault monitoring device, 8: management network, 9, 10, 109, 110: terminal, 11-1
8, 98 to 108: port, 30: configuration information table,
31 ... Link field, 32 ... Switch 1 field, 33 ... Port 1 field, 34 ... Switch 2 field, 35 ... Port 2 field, 36,63 ... Entry, 40 ... Packet switch, 41 ... Control unit, 42 ...
Filtering database, 43: packet counter, 50, 70: packet, 51, 71: destination MAC address, 52, 72: source MAC address, 53, 7
4 ... payload, 61 ... MAC address field, 6
2 ... port number field, 73 ... VLAN tag, 8
0, 111, 112... VLAN.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiyuki Hirano 2-3-1 Otemachi, Chiyoda-ku, Tokyo Inside of Nippon Telegraph and Telephone Corporation (72) Inventor Toshinobu Inazuka 2-3-3, Otemachi, Chiyoda-ku, Tokyo No. 1 Inside Nippon Telegraph and Telephone Corporation (72) Shinya Matsumoto Inventor 2-3-1 Otemachi, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Ryoichi Suzuki Otemachi 2, Chiyoda-ku, Tokyo No.3-1, Nippon Telegraph and Telephone Corporation (72) Hirohide Mikami, Inventor 2-3-1, Otemachi, Chiyoda-ku, Tokyo F-Term, Nippon Telegraph and Telephone Corporation 5K033 AA05 CB01 CB08 CC01 DA01 DA05 DB17 DB19 DB20 EA04 EA07 EC04 5K035 AA03 BB03 DD02 EE01 GG13 JJ06 KK01 MM03 5K042 DA32 EA11

Claims (15)

[Claims] 1. A network fault monitor in a layer 2 network comprising a filtering database, learning a destination port of a packet based on a source address of a received packet, and registering the port in the filtering database. In the method, there is provided a configuration information table for storing network configuration information indicating a connection relationship between each port of each of the layer 2 switches in the system.
Step 1 of searching the filtering database of the designated Layer 2 switch by the C address to find a port corresponding to the designated MAC address, Layer 2 switch connected to the port found in Step 1 From the configuration information table; and filtering the filtering database of the layer 2 switch determined in step 2 with the designated MA
A step 3 of searching by a C address to obtain a port corresponding to the specified MAC address; a step 4 of obtaining a layer 2 switch connected to the port obtained in the step 3 from the configuration information table; A step 5 of repeating the steps 3 and 4 until there are no more layer 2 switches registered in the configuration information table, and obtaining a transfer route of a packet addressed to the specified MAC address. A network fault monitoring method characterized by the following. 2. Detecting that the same layer 2 switch exists in the transfer path obtained in step 5;
2. The network fault monitoring method according to claim 1, further comprising a step of detecting that a loop exists in a packet transfer path. 3. A network fault monitor in a layer 2 network comprising a filtering database, learning a destination port of a packet based on a source address of a received packet, and registering the packet in the filtering database. The method, further comprising a configuration information table for storing network configuration information indicating a connection relationship between each port of each of the layer 2 switches in the system, wherein all the layer 2 belonging to the layer 2 network are provided.
Searching the filtering database of the switch with a specified MAC address to obtain a corresponding port; and sending the specified MAC address to the destination based on the port obtained in the step and the configuration information table. 2. A network fault monitoring method, comprising: a step 2 of obtaining a transfer route of a packet to be set. 4. A network fault monitor in a layer 2 network comprising a filtering database, learning a destination port of a packet based on a source address of a received packet, and registering the port in the filtering database. The method, further comprising a configuration information table for storing network configuration information indicating a connection relationship between each port of each of the layer 2 switches in the system, wherein all the layer 2 belonging to the layer 2 network are provided.
Step 1 of deleting an entry in which a specified MAC address is registered from the filtering database of the switch; M having the specified MAC address as a source address and seeking a transfer route from a destination MAC address
Transmitting a packet describing an AC address from a specific port of a specific layer 2 switch, searching a filtering database of all the layer 2 switches in the layer 2 network, and corresponding to the specified MAC address Step 3 for obtaining a port to be transferred, and MA for obtaining the transfer path based on the port obtained in Step 3 and the configuration information table.
A step 4 of obtaining a transfer route of a packet whose C address is a destination MAC address. 5. A network fault monitor for a layer 2 network comprising a filtering database, learning a destination port of a packet based on a source address of a received packet, and registering the port in the filtering database. The method comprises a configuration information table for storing network configuration information indicating a connection relationship between each port of each of the layer 2 switches in a system, wherein a packet having a specified MAC address as a destination MAC address is stored in a specific layer 2 switch. Step 1 of transmitting a packet to a specific port of the switch; Step 2 of counting each packet received by each of the layer 2 switches having the specified MAC address as a destination MAC address; Increase Step 3 for identifying the layer 2 switch that performs the operation, and based on the layer 2 switch identified in step 3 and the configuration information table, obtains a transfer route of a packet having the specified MAC address as a destination MAC address. A network fault monitoring method, comprising: 6. A network failure monitor in a layer 2 network comprising a filtering database, learning a destination port of a packet based on a source address of a received packet, and registering the port in the filtering database. In the method, the system comprises a configuration information table for storing network configuration information indicating a connection relationship between each port of each of the layer 2 switches, and a VLA set for each port of each layer 2 switch.
A step of obtaining an N number; and a step of obtaining a VLAN path corresponding to the same VLAN number based on the VLAN number obtained in the step and the configuration information table. Network fault monitoring method. 7. A network fault monitor in a layer 2 network comprising a filtering database, learning a destination port of a packet based on a source address of a received packet, and registering the port in the filtering database. The method further comprises a configuration information table for storing network configuration information indicating a connection relationship between each port of each of the layer 2 switches in the system, wherein each of the layer 2 switches determined by a failure switching protocol is provided.
Step 1 for detecting the state of each port of the switch; and based on the state of each port of each of the layer 2 switches detected in Step 1 and the configuration information table, a logical path configured by a failure switching protocol. 2. A network fault monitoring method, comprising: 8. A network failure monitor in a layer 2 network comprising a filtering database, learning a destination port of a packet based on a source address of a received packet, and registering the port in the filtering database. The method comprises a configuration information table for storing network configuration information indicating a connection relationship between each port of each of the layer 2 switches in a system, wherein a packet having a specified MAC address as a destination MAC address is stored in a specific layer 2 switch. Step 1 of transmitting to the port having the characteristic of the switch, Step 2 of counting the number of receptions of only the packets each having the specified MAC address as the destination MAC address by each of the layer 2 switches, Increase Step 3 identifies the Layer 2 switch that, each layer is determined by the fault at the time of switching protocol 2
A step 4 of detecting the state of each port of the switch; a state of each port of each of the layer 2 switches detected in the step 4; and a logical path configured by the failure switching protocol based on the configuration information table. Determining step 5; and determining a transfer path of a packet having the specified MAC address as a destination MAC address on the logical path determined in step 5 based on the layer 2 switch identified in step 3 above. A network fault monitoring method, comprising: 9. A layer 2 network comprising a filtering database, comprising a plurality of layer 2 switches for learning a destination port of a packet based on a source address of a received packet and registering the destination port in the filtering database. VL with different VLAN number
AN is connected by port VLAN and one connected VL
Configuring the AN and the specified connected VLAN
A network fault monitoring method in a layer 2 network in which a unique connection VLAN number is assigned to a network, wherein a configuration information table storing network configuration information indicating a connection relationship between ports of each of the layer 2 switches in the system Obtaining a VLAN number set for each port of each layer 2 switch in the layer 2 network; and identifying a port for which a VLAN number belonging to the connection VLAN number is set, Step 2 for obtaining a route of the connection VLAN based on the obtained port and the configuration information table;
A step of detecting that a switch is required a plurality of times, and detecting the presence of a loop-like path in the path of the packet-connected VLAN. 10. A system comprising a filtering database,
In a network fault monitoring apparatus in a layer 2 network configured by using a plurality of layer 2 switches for learning a destination port of a packet based on a source address of a received packet and registering the packet in the filtering database, each of the layer 2 switches A configuration information table that stores network configuration information indicating a connection relationship between ports, and a filtering database of each of the layer 2 switches is searched by using a specified MAC address, and the layer 2 corresponding to the specified MAC address is searched. First means for obtaining a switch port; and second means for obtaining a packet transfer route based on the configuration information table and the port of each of the layer 2 switches obtained by the first means. Network failure characterized by Visual apparatus. 11. The network fault monitoring according to claim 10, further comprising third means for deleting an entry in which a designated MAC address is registered from a filtering database of each of the layer 2 switches. apparatus. 12. Each of the layer 2 switches has a counter, and has a fourth means for reading the count value of the counter of each of the layer 2 switches and identifying a layer 2 switch whose count value is increasing. The second means may include the configuration information table and the fourth
11. The network fault monitoring device according to claim 10, wherein a packet transfer route is obtained based on each of the layer 2 switches obtained by the means. 13. A system comprising: a filtering database;
In a network fault monitoring apparatus in a layer 2 network configured by using a plurality of layer 2 switches for learning a destination port of a packet based on a source address of a received packet and registering the packet in the filtering database, each of the layer 2 switches A configuration information table storing network configuration information indicating a connection relationship between ports; and a V set in each port of each of the layer 2 switches.
A first unit for obtaining a LAN number; and a second unit for obtaining a route of a VLAN corresponding to the same VLAN number based on the VLAN number obtained by the first unit and the configuration information table. A network fault monitoring device, characterized in that: 14. A system comprising: a filtering database;
In a network fault monitoring apparatus in a layer 2 network configured by using a plurality of layer 2 switches for learning a destination port of a packet based on a source address of a received packet and registering the packet in the filtering database, each of the layer 2 switches A configuration information table for storing network configuration information indicating a connection relationship between ports; a first unit for detecting a state of each port of the layer 2 switch determined by the failure switching protocol; A network fault monitoring device comprising: a second unit that obtains a route configured by a failure time switching protocol based on a detected state of each port of the layer 2 switch and the configuration information table. 15. A system comprising: a filtering database;
A layer 2 network comprising a plurality of layer 2 switches for learning a destination port of a packet based on a source address of a received packet and registering the destination port of the packet in the filtering database.
LANs are connected by port VLAN and one connection V
Configures the LAN, and specifies the specified connection VLA.
A network failure monitoring device in a layer 2 network in which a unique connection VLAN number is assigned to N; a configuration information table storing network configuration information indicating a connection relationship between ports of each of the layer 2 switches; V set for each port of each layer 2 switch
A first means for acquiring a LAN number; a second means for identifying a port to which a VLAN number belonging to a connected VLAN number is set; a port identified by the second means; And a third means for obtaining a route of the connected VLAN based on the network failure monitoring apparatus.