JPH0799533A - Bridge monitor equipment - Google Patents

Abstract

PURPOSE:To improve the reliability of a network system by detecting a fault operation such as FCS data incorrectly processed generated in the inside of the bridge equipment. CONSTITUTION:The same packet as a packet on LANs 10a, 10b received by a bridge equipment 11 is received and latched by a bridge monitor equipment 12, whether or not the same packet as that sent by the bridge equipment 11 is in existence in a group of packets received by the bridge monitor equipment 12 is checked. When data processed incorrectly take place in the inside of the bridge equipment 11, the same packet as the packet sent by the bridge equipment 11 is not in existence in the group of the received packets. Thus, the occurrence of a fault of the bridge equipment 11 is detected depending whether or not the same packet as the packet sent by the bridge equipment 11 is in existence.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bridge monitoring device for monitoring the operation of a bridge device connecting a plurality of networks.

[0002]

2. Description of the Related Art Generally, a plurality of LANs (local area networks) and WANs (wide area networks).
A network device such as a bridge, a router, and a gateway is known as a method for mutually connecting the two.

Among them, the bridge device analyzes the data packet up to the MAC (media access control) frame level and controls the transfer.
The C-bridge method is standardized by IEEE802.1D.

This MAC bridge method uses only the source address and the destination address of a packet to be transferred as transfer control information, and does not depend on the upper layer protocol as long as the MAC level packet format is matched. There is a feature that can connect between LANs.

The conventional bridge device employing such a system controls transfer of data packets using a transfer database. In particular, the transparent bridge device receives all packets on the LAN for data transfer from one LAN to the other LAN, and then uses the transfer database as shown in FIG. A process called filtering is performed to determine whether or not to transfer the packet.

The conventional transfer database is constructed as shown in FIG. That is, in the transfer database, the MAC address of each data station and the port number of the bridge device to which each data station is connected are registered. Here, it is assumed that the data stations with the MAC addresses A1 to A3 are connected to the port number 1 side and the data stations with the MAC addresses A4 and A5 are connected to the port number 2 side.

The filtering process using this transfer database is performed as follows. For example, when the bridge device receives a packet at the first port (port number 1), it is checked whether the destination MAC address of the received packet is registered in the transfer database,
If registered, the received packet is transmitted to the port to which the data station having the destination MAC address is connected.

On the other hand, if the data station of the destination MAC address is connected to the same port as the receiving port, for example, the first port, it means that the data station of the transmission source and the data station of the destination are on the same LAN. Therefore, in this case, the packet is not transferred,
The received packet is discarded.

In the bridge device, the packet determined to be transferred by the filtering process is the FCS.
The (frame check sequence) is normally transmitted unchanged to the data station having the destination MAC address. Therefore, even if the data in the packet is corrupted in the bridge device, the data station can detect the error by using the FCS and discard the packet if necessary.

However, when connecting LANs having different types of MACs, the FCS must be recalculated inside the bridge device, and in this case, the data station side performs accurate error detection. I can't
A packet containing incorrect data may be received as a correct packet. This is because the processing inside the bridge device may cause data corruption in the FCS itself.

Further, even in a bridge device for connecting LANs having the same kind of MAC, LAN transmission / reception LS
Due to the functional restriction of I, there is a case where the FCS is recalculated and the packet is transmitted. Also in this case, it becomes difficult to perform accurate error detection on the data station side.

As described above, if the error detection cannot be performed correctly, the communication between the end nodes, that is, the data stations is hindered. However, in this case, since it is unknown whether or not the data is garbled inside the bridge device, much labor is required to investigate the cause even during maintenance.

[0013]

Conventionally, even if a problem occurs in communication between end nodes, it is difficult to find the cause, and there is a drawback that the reliability of a network system using a bridge device cannot be improved. It was

The present invention has been made in view of the above circumstances, and it is possible to accurately detect an operation failure that occurs inside a bridge device such as garbled data of a packet, and to trust a network system using the bridge device. It is an object of the present invention to provide a bridge monitoring device that can improve the performance.

[0015]

Means and Actions for Solving the Problems
A bridge monitoring device that monitors the operation of a bridge device that couples a plurality of networks, and means for separately receiving and holding packets on a plurality of networks to which the bridge device is connected for each network, Whether a packet transmitted from the bridge device to the network is received, and the same packet transmitted from the bridge device exists in the packet group received and held from other networks other than the network. It is characterized by further comprising a packet detecting means for detecting whether or not, and a monitoring means for detecting an operation failure of the bridge device according to a detection result by the packet detecting means.

In this bridge monitoring device, the same packet as the packet on the network received by the bridge device is received and held, and the same packet as the packet transmitted by the bridge device is included in the received packet group. It is checked whether it exists. When data corruption occurs inside the bridge device, the same packet as the packet transmitted by the bridge device does not exist in the received and held packet group. Therefore, it is possible to detect the occurrence of an abnormal operation such as garbled data inside the bridge device depending on whether or not the same packet as the packet transmitted by the bridge device exists.

Therefore, by connecting this bridge monitoring device to the network to which the bridge device to be monitored is connected, it becomes possible to accurately detect an abnormal operation occurring inside the bridge device such as garbled packet data. The reliability of the network system using the bridge device can be improved.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of a network system using a bridge monitoring apparatus according to an embodiment of the present invention.

This network system has two LAs.
It includes N (or WAN) 10a, 10b and a transparent bridge device 11 for interconnecting these two LANs 10a, 10b. The bridge device 11 has first and second ports P1 and P2, which are connected to the LAN 10 via transceivers (T / R) 20a and 20b, respectively.
a, 10b.

After all the packets on the LAN 10a are received via the first port P1 of the bridge device 11, they are discarded by the filtering process or transferred to the LAN 10b via the second port P2. Similarly, LAN10
All the packets on b are also received via the second port P1 of the bridge device 11 and then discarded by the filtering process or transferred to the LAN 10a via the first port P1.

The bridge device 11 is provided with a CPU, a buffer memory, and a transfer database. The CPU of the bridge device 11 executes a filtering process using the transfer database and a process of discarding a packet waiting to be transmitted when the buffer memory overflows. In the process of discarding a packet waiting to be transmitted, the transfer priority information in the transfer database is referred to, and the packet from the data station having the lowest priority is discarded first according to the priority information.

The transfer database is used when the filtering process is executed by the CPU. As described in FIG. 6, the transfer database contains the MAC addresses of the respective data stations to be communication-controlled and the respective data. The port number indicating the port on the side to which the station is connected is registered.

For example, as shown in the drawing, the data stations 301 and 302 are connected to the LAN 10a, and the LAN 1
Assume that the data station 303 is connected to 0b. In this case, the MAC address is “00-01
The first data station 301 of "-01-01-01-01" and the MAC address of "00-02-02-02"
Since the second data station 302 of “-02-02” is connected to the LAN on the first port side of the bridge device 11, those data stations 301,
“1” is registered as the port number of 302. on the other hand,
The MAC address is "00-03-03-03-03-0"
Since the third data station 303 of 3 ″ is connected to the LAN on the first port side of the bridge device 204, “2” is registered as its port number.

By the filtering process using this transfer database, for example, L received from the port P1
The packet on the AN 10a is the data station 301.
In the case of the packet transmitted from the packet No. to 302, the packet is discarded, and only the data packet addressed to the data station 303 is transmitted to the port P2.

When the received packet is transmitted to another port, the frame check sequence added to the received packet is recalculated inside the bridge device 11 as necessary, and the recalculated frame check sequence is received. It is added to the packet and sent to another port. The recalculation of the frame check sequence is executed when the LAN of the packet reception source and the LAN of the packet transmission destination are different, and the frame check sequence is replaced with a frame check sequence suitable for the LAN of the transmission destination.

The bridge monitoring device 12 is the bridge device 1.
1 is an independent device for monitoring the operation, and like the bridge device 11, is connected to two LANs 10a and 10b via transceivers (T / R) 21a and 21b.

The bridge monitoring device 12 includes a processor 13, a program memory 14, and a packet receiving section 15.
a, 15b and a buffer memory 16 are provided. The processor 13 is for controlling the bridge monitoring device 12 as a whole, and executes a program stored in the program memory 14. In the program memory 14,
A program for monitoring the operation of the bridge device 11 is stored.

The packet receiver 15a receives all packets on the LAN 10a via the transceiver (T / R) 21a. In this case, the data station 30
Bridge device 1 as well as packets from 1,302
Packets output from 1 to the LAN 10a are also received.
Similarly, the packet receiving unit 15b also has a transceiver (T /
R) receives all packets on LAN 10b via 21b. In this case, not only the packet from the data station 303 but also the bridge device 11 to the LAN1
The packet output to 0b is also received.

The packets received by the packet receivers 15a and 15b are stored in the buffer memory 16. In this case, the received packet group from the LAN 10a and the received packet group from the LAN 10b are stored separately, and the packet from the data station and the packet from the bridge device 11 are also stored separately.

The packet from the data station and the packet from the bridge device 11 are identified by using the packet transmission signals Tx1 and Tx2 output from the bridge device 11. The packet transmission signal Tx1 is output when the bridge device 11 transmits a packet to the LAN 10a via the port P1. Similarly, the packet transmission signal Tx2 is transmitted by the bridge device 11 via the port P2 to L level.
It is output when transmitting a packet to the AN 10b.

Next, referring to FIG. 2, the buffer memory 1
An example of the storage format of packets in 6 will be described. As shown, the buffer memory 16 includes a buffer area 161 for the LAN 10a and a buffer area 16 for the LAN 10b.
2, the packet received by the packet receiving unit 15a is written in the buffer area 161, and the packet received by the packet receiving unit 15b is written in the buffer area 162.

The buffer area 161 is further divided into two areas 161a and 161b. The packet receiving unit 15a normally stores the packet in the first area 161a, but the packet transmission signal Tx1 is transmitted to the bridge device 1
When it is output from 1, the packet received at that time is a transmission packet from the bridge device 11, so that it is stored in the second area 161b.

Similarly, the buffer area 162 is further divided into two areas 162a and 162b. The packet receiving unit 15b normally stores the packet in the first area 162a, but when the packet transmission signal Tx2 is output from the bridge device 11, the packet received at that time is a transmission packet from the bridge device 11, It is stored in the second area 162b.

The first area 161 of the buffer area 161
The packet group stored in a is stored in the buffer area 16
The packets stored in the second second area 162b are sequentially compared with each other, and it is checked whether the same packet as the packet stored in the second area 162b is included. Similarly, the packet group stored in the first area 162 a of the buffer area 162 is the second area 1 of the buffer area 161.
It is sequentially compared with the packet stored in 61b, and it is checked whether or not it includes the same packet as the packet stored in the second area 161b.

The packet search processing for such a packet is executed by the processor 13 every time a packet from the bridge device 11 is received. The packet search process will be described below with reference to FIG.

When the packet transmitted by the bridge device 11 is received by the packet receiver 15a or 15b (step S11), the packet search process of the processor 13 is executed and the packet group received from the LAN on the other port side is included. , It is checked whether the same thing as the packet transmitted by the bridge device 11 exists (step S1).
2). For example, when the packet receiving unit 15a receives a packet from the bridge device 11, the packet group stored in the first area 162a of the buffer area 162 becomes a search target.

If the same packet as the packet from the bridge device 11 exists, the processor 13 determines that the relay operation (including the filtering operation, the FCS recalculation operation, etc.) of the bridge device 11 is normally performed. To do. On the other hand, if the same packet as the packet from the bridge device 11 does not exist, the processor 13 determines that a failure such as data corruption has occurred in the relay operation of the bridge device 11,
It is detected that an error has occurred in the bridge device 11 and the error is detected in some form, for example, the network management node 40.
The network administrator is notified by, for example, transferring a packet indicating the occurrence of an error to 1 or 402, displaying an error on the display device provided in the bridge monitoring device 12, or the like (steps S13 and S14). The detected status of the error, that is, the error occurrence time, the packet data from the bridge device 11 related to the error, the FCS, the destination address, the source address, etc.
Collected in the internal memory of. This is used by the management node 401 or 402 at the time of network maintenance or the like later to investigate the cause of the failure occurrence.

As described above, in this embodiment, the same packet received by the bridge device 11 on the LANs 10a and 10b is received and held by the bridge monitor device 12, and is the same as the packet transmitted by the bridge device 11. Packet of the bridge monitoring device 12
To see if it is in the packet group being received by. When data corruption occurs inside the bridge device 11, the same packet as the packet transmitted by the bridge device 11 does not exist in the received packet group. Therefore, the occurrence of the abnormal operation of the bridge device 11 can be detected depending on whether or not the same packet as the packet transmitted by the bridge device 11 exists.

Therefore, this bridge monitoring device 12
By connecting to the network to which the bridge device 11 to be monitored is connected as shown in FIG. 1, it becomes possible to accurately detect an abnormal operation that occurs inside the bridge device 11 such as garbled packet data. The reliability of the network system using the bridge device 11 can be improved.

In this embodiment, the transmission signals Tx1 and Tx2 output from the bridge device 11 are used to identify the packet from the data station and the packet from the bridge device 11, but this is shown in FIG. like,
It is also possible to make it possible to receive the signal T indicating that the bridge device 11 is transmitting from the transceiver 20a to which the bridge device 11 is connected, and to identify the packet by the signal T.

Since the bridge monitoring device 12 may be connected to the same LAN as the bridge device 11 to be monitored,
As shown in FIG. 5, it is preferable to install the management node 401 together with the management node 401 in a place (a first area) where a system administrator can easily enter and exit, such as one room in an office building. By doing so, even if the bridge device 11 is installed in a place (second area) where it is relatively difficult for system managers and workers to enter and exit, such as under the floor of a warehouse or building, the operation of the bridge device 11 can be easily performed. Can be monitored.

In this case, the operation error of the bridge device 11 is changed to the display unit 1 without going through the network.
Since it is possible to directly notify the system administrator by means of 21, it is possible to obtain accurate failure information of the bridge device 11 even if a failure occurs in the network itself.

[0043]

As described above, according to the present invention, by comparing the transmission packet and the reception packet of the bridge device by the bridge monitoring device, it is possible to accurately detect an abnormal operation such as garbled data in the bridge device. Therefore, the reliability of the network system using the bridge device can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a network system using a bridge monitoring device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a packet storage format in a buffer memory 16 provided in the bridge monitoring device shown in FIG.

FIG. 3 is a flowchart illustrating a packet search operation of the bridge monitoring device illustrated in FIG.

FIG. 4 is a block diagram showing a configuration example of a packet receiving unit and its vicinity provided in the bridge monitoring apparatus shown in FIG.

5 is a diagram showing another configuration of a network system using the bridge monitoring device shown in FIG.

FIG. 6 is a diagram showing a configuration example of a transfer database provided in a conventional bridge device.

[Explanation of symbols]

10a, 10b ... LAN, 11 ... Bridge device, 12 ...
Bridge monitoring device, 13 ... Processor, 14 ... Program memory, 15a, 15b ... Packet receiving unit, 16 ... Buffer memory.

Claims (2)

[Claims] 1. A bridge monitoring device for monitoring the operation of a bridge device connecting between a plurality of networks, wherein packets on a plurality of networks to which the bridge device is connected are classified and received for each network. A means for holding and a packet which is the same as the packet transmitted from the bridge device in the packet group received and held from the network other than the network that receives the packet transmitted from the bridge device to the network A bridge monitoring device comprising: a packet detecting means for detecting whether or not there is a packet; and a monitoring means for detecting an operation failure of the bridge device according to a detection result by the packet detecting means. 2. The bridge device according to claim 1, further comprising means for recalculating a frame check sequence added to the received packet and adding the recalculated frame check sequence to the received packet. Bridge monitoring equipment.