JP2000299696A - Abnormality diagnostic method for network system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discover fault or abnormality in a terminal connected to a network, especially, the abnormality of hardware without directly touching the terminal by using a terminal provided with an Ethernet(R) interface having a test function for the terminal in a network system. SOLUTION: A terminal 13 provided with the I/F of the network having the test function transmits the character of a previously specified error to a terminal 11 by generating a test packet 12. When the test packet 12 is recognized, the terminal 11 recognizes the information in the kind of the error on the test packet 12 and compares this information with the kind of error actually shown by the test packet 12 and on the basis of the information of this result or the like, a reply packet is generated and returned to the terminal 13. When the reply packet is received, on the basis of this information, the terminal 13 detects the fault or abnormality of the terminal 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for diagnosing abnormalities in a network system related to an interface function of a network such as Ethernet.

[0002]

2. Description of the Related Art Conventionally, when a failure such as a failure or abnormality occurs in a terminal device connected to a network, if the failure is a software failure, the failure is caused by accessing from another terminal using the network. It could be detected and the cause of failure recovery was easy to grasp.

[0003] However, if the failure is hardware-related, it is difficult to grasp the cause.

[0004]

As described above, in a network system, a software failure is easy to detect and determine the cause of failure recovery. However, if the failure is a hardware failure, It was hard to grasp the cause.

[0005] For example, in the case of an Ethernet interface failure, particularly in the case of a fault in which an abnormal packet is erroneously recognized as a normal packet, that is, in the case of a fault in which an error cannot be recognized, software appears to be operating correctly. Met. Actually, even if an abnormal packet is received, it is discarded as an “unnecessary packet” at a higher level of the Ethernet, and thus there is a possibility that it is difficult to recognize the packet as an error. In this case, it seems that there is no problem in function, but since the error packet processing originally performed by hardware is performed by software, a state where the processing performance of the CPU is reduced occurs.

Further, in the case of a physical abnormality of the network (for example, when N bits are always added and transmitted), the abnormality may not be noticed. This means that in the case of Ethernet, the addition of n bits is n = 1,. . . , 7
In other words, even if 1 to 7 bits of meaningless bits are added to the normal packet, the packet does not become an abnormal packet and is not recognized as an error on the terminal side.

However, since this phenomenon occurs when the Ethernet cable is in a physically bad state (for example, a bad cable or a line that is significantly affected by electrical influences), the line is in an unstable state. . Since such a physical abnormality of the network is not recognized as an error, the above physically bad state is not improved, and the physical state may be further deteriorated. Further, the line may have a high error rate.

Therefore, the present invention has been made in view of the above circumstances, and in order to solve the above-mentioned problems, an Ethernet having a test function disclosed in Japanese Patent Application No. 11-57818, which is a prior application of the present applicant. By using a terminal equipped with an interface device as a terminal of the network system, a system for detecting failures such as failures and abnormalities of each terminal is constructed, and failures such as failures and abnormalities of terminals connected to the network, particularly hardware. It is an object of the present invention to provide an abnormality diagnosis method in a network system that can easily and surely find a fault related to the above without directly touching each terminal.

[0009]

In order to achieve the above object, the present invention provides a network system for recognizing a failure such as a failure or abnormality of a network or a terminal device connected to the network. The apparatus is connected to the network, outputs various error packets, and includes error packet information indicating a type of the error packet, source address information of the error packet, and test packet information indicating a test packet. A test function holding terminal having an interface having a function of generating a test packet having the property of an error packet based on the error packet information, transmitting the test packet to the terminal on the network and performing a test, is provided. , The interface of the terminal equipment is When the test packet is received from the holding terminal, whether or not the test packet is a test packet is recognized based on the test packet information. If the test packet is recognized, the type of the error packet is recognized based on the error packet information. It is determined whether or not the type of the packet and the type of the actual error packet indicated by the test packet match, and if the information of the determination result, the address information of the terminal and the type of the error packet do not match, Generates a reply packet including information on the type of the recognized error packet and returns the reply packet to the test function holding terminal.The interface of the test function holding terminal uses the terminal device or Failure or abnormality of the network between the terminal device and the test function holding terminal Configured to detect a fault.

According to such a configuration, in the terminal equipment on the network, no failure occurs, the terminal equipment on the network does not drop an abnormally large number of packets, or the network environment generates an error packet. Are you in a situation that is easy to do (eg, is the physical environment in adverse conditions)?
Can be detected and recognized. In addition, since there is no need to perform any special maintenance, it is possible to remain connected to the network.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a diagram showing a schematic configuration of a network system according to a first embodiment of the present invention.
The configuration necessary for the description of the present embodiment is shown, and other configurations are omitted.

The network 10 is a network for connecting a plurality of terminal devices and communicating data and the like in the network system of the present embodiment.

The terminal 11 is a normal network terminal device connected to the network system of the present embodiment. This terminal 11 is the same as Japanese Patent Application No. Hei.
No. 1-57818 discloses an interface function for recognizing a test packet from a terminal provided with an Ethernet interface device having a test function.
Then, the following functions are provided to the terminal 11 of this ordinary network.

1. Recognizing whether or not it is a test packet.

2. A function to read the error and nature of the test packet from the test packet data.

3. The test packet is 2. A function that recognizes that an error or property has been recognized.

The above 1 and 2 can be recognized by providing the test packet with a pattern indicating the test packet and information indicating which test was performed. The above 3 is a function existing in a normal interface.

The terminal 13 is provided with a terminal device provided with a network I / F (interface) having a test function (referred to as a terminal 13 provided with a test function I / F), as in the above-mentioned Japanese Patent Application No. 11-57818. (1) A terminal provided with an Ethernet interface device having a function of testing a terminal for abnormality on a network disclosed in the above publication.

The test packet 12 is a packet for testing an interface, and has a unique pattern for each test. Here, the definition of the test packet is as follows.

That is, the terminal 11 of the ordinary network is
If an error packet is received, a test function I /
It is necessary to be able to recognize whether or not the test packet 12 is output from the terminal 13 provided with F. Therefore, the test packet has the following information.

A pattern indicating a test packet.

Information indicating which of the above tests 1 to 3 was performed (the alignment test packet and the bit addition test packet are different test packets depending on the number of added bits).

The address of the source that transmitted the test packet.

In the interface having the test function of Japanese Patent Application No. 11-57818, error packets that can be output include: an alignment error (addition of a half N-bit FCS error (N = 1, 2,..., 7)) ・ FCS error (CRC error) ・ Long frame error (packet longer than specified by network) ・ Short frame error (packet shorter than specified by network) ・ Packet with N bits added (N = 1, 2,...) ., 7)
(This is not an error packet, but will be included in the error packet for the following description.)

As a result, the following types of test packets can be generated.

Alignment test packet 31 FCS error test packet 32 Long frame test packet 33 Short frame test packet 34 Bit addition test packet 35 Next, in this embodiment, the normal network terminal 1
The process performed when the test packet 1 receives the test packet 12 will be described with reference to the flowchart in FIG.

From the terminal 13 provided with the test function I / F,
It outputs various test packets 12. When the normal network terminal 11 receives the test packet 12 (step S202), the type of the received packet is the test packet 1 from the terminal 13 provided with the test function I / F.
2 is recognized (step S204).

Here, the terminal 1 provided with the test function I / F
In the case of a normal error packet or a packet is dropped, instead of the test packet 12 from 3, the following processing is not performed.

The ordinary network terminal 1 recognizes, for the received test packet 12, information indicating which test was performed by the terminal 13 having the test function I / F based on the definition of the test packet in advance (step S1). S
206). Next, the normal network terminal 11 recognizes the nature of an error or the like actually indicated by the received test packet 12 (step S208).

The ordinary network terminal 11 compares the definition of the test packet 12 recognized in step S206 with the nature of an error or the like actually indicated by the test packet 12 recognized in step S208 (step S21).
0).

If the results recognized in step S206 and step S208 are the same, that is, if the error and the nature are the same (YES in step S210), a packet is generated which means that the error has been correctly recognized (step S210). Step S212).

If the results recognized in steps S206 and S208 are not the same, that is, if the error and the nature are different (NO in step S210), a packet is generated which means that another error has been recognized (step S210). Step S214).

The normal network terminal 11 outputs the created packet to the terminal 13 provided with the test function I / F (step S216).

As described above, the terminal 1 of the ordinary network
By performing the process in step S210, the user 1 can recognize whether an error has occurred in the interface of the terminal 11 of the normal network or whether an error has occurred in the packet while the packet is being transferred from the transmission source.

The reply packet includes the following information.

The terminal 1 of the normal network that is the reply source
1 MAC address information.

When the error is correctly recognized, the information is included.

If another error is recognized, include that information.

For example, if an alignment error packet is actually recognized as an FCS error packet, it is considered that a physical problem has occurred on the network.

The reply packet has the following properties.

In the case of a normally occurring error packet, no reply packet is output.

If a packet is missed, no reply packet is output.

The terminal 13 provided with the test function I / F can confirm the following status from the reply packet.

Detection of a failure of the interface of the terminal 11 of the normal network to which the test packet has been transmitted,
That is, whether or not the error has been correctly recognized.

Poor physical condition of the network between the terminal 13 provided with the test function I / F and the terminal 11 of the normal network to which the data is transmitted (when an FCS error is recognized as an alignment error or vice versa) Case).

The probability of dropping the packet of the terminal 11 from the normal packet to which the test packet was transmitted (the number of returned packets / the number of output test packets).

In the following, a description will be given of a process for confirming the above three states.

First, the terminal 13 provided with the test function I / F
However, a process when detecting a failure of the interface of the terminal 11 of the normal network will be described with reference to the flowchart of FIG.

The terminal 13 provided with the test function I / F transmits various test packets 12 to the terminal 11 of the ordinary network.
(Step S302). The terminal 13 provided with the test function I / F waits for a reply packet to the test packet 12 to be transmitted from the terminal 11 of the normal network that has transmitted the test packet 12. The terminal 11 of the normal network creates a reply packet by the processing of the flowchart of FIG. 2 and transmits it to the terminal 13 provided with the test function I / F.

Upon receiving the reply packet (step S304), the terminal 13 provided with the test function I / F determines whether or not the content of the definition of the transmitted test packet 12 is the same as the content indicated by the reply packet. (Step SS3
06).

If the contents of the error and the nature of the transmitted test packet 12 are the same as the contents indicated by the reply packet (YES in step S306), there is no problem in the interface of the normal network terminal 11 that transmitted the test packet 12. Can be confirmed (step S308).

If the content of the definition of the transmitted test packet 12 is different from the content indicated by the reply packet (NO in step S306), the error recognition function of the interface of the terminal 11 of the normal network to which the test packet 12 has been transmitted. It can be confirmed that there is a failure or a problem that this interface is locked (step S310).

Next, the terminal 13 provided with the test function I / F
However, the process when the physical environment of the network is investigated will be described with reference to the flowchart of FIG.

The terminal 13 provided with the test function I / F
A CS error test packet is transmitted to the terminal 11 in a normal network. Terminal 13 provided with test function I / F
Waits for a reply packet to the test packet 12 to be transmitted from the terminal 11 of the normal network that has transmitted the test packet 12. Normal network terminal 1
1 generates a reply packet and transmits it to the terminal 13 provided with the test function I / F by the processing of the flowchart of FIG. 2 (step S402).

Upon receiving the reply packet (step S404), the terminal 13 provided with the test function I / F compares the content indicated by the reply packet. Here, it is determined whether an FCS error packet, which is an error or a property of the transmitted test packet 12, has been recognized as an alignment error packet (step S406).

If the packet is recognized as an alignment error packet (YES in step S406), this is because the network from the terminal 13 having the test function I / F to the terminal 11 of the normal network is in a physically bad state. Or that a bit has been added to the FCS error due to the failure of the router or hub (step S41).
0).

Thus, the following problems can be confirmed.

The possibility that the network is in a physically bad environment.

Similarly, if the bit addition test packet 35 is transmitted, similarly to the possibility of the failure of the router and the hub, 7 bits,
The same check can be made by checking whether the packet added with 6 bits is recognized as an FCS error packet.

If the packet is not recognized as an alignment error packet (NO in step S406), here F
It is assumed that the packet is recognized as a CS error packet, whereby it can be confirmed that no physical problem has occurred in the network environment from the terminal 13 provided with the test function I / F to the terminal 11 of the normal network (step). S
408).

Finally, the terminal 1 provided with the test function I / F
The process in which the terminal 3 investigates the probability of dropping the test packet of the terminal 11 in the normal network will be described with reference to the flowchart of FIG.

The terminal 13 provided with the test function I / F transmits m test packets to the terminal 11 on the normal network (step S502). The terminal 11 of the normal network returns one return packet (n pieces) for each one of the test packets 12 received by the processing of the flowchart of FIG. 2 to the terminal 13 provided with the test function I / F (step). S504). However, when the test packet 12 is dropped as described with reference to FIG. 2, no reply packet is created and no reply is made.

The terminal 13 provided with the test function I / F compares the number m of the transmitted test packets 12 with the number n of the received reply packets (step S5).
06).

If m = n (YE in step S506)
S), it can be confirmed that there is no problem such as packet loss in the terminal 11 of the normal network of the transmission destination (step S508).

On the other hand, when m = n is not satisfied (step S5)
(NO in 06), (mn) / (m) is calculated (step S510). This value is the probability of dropping the test packet of the terminal 11 of the normal destination network.

As a result, the following problems can be confirmed.

The probability of dropping of the test packet of the terminal 11 of the normal network.

It is possible to determine whether or not the terminal 11 of the ordinary network is locked. (Second Embodiment) FIG. 6 is a block diagram showing a schematic configuration of a network system according to a second embodiment of the present invention.

It is assumed that the terminal 21 of the normal network has the same function as the terminal 11 of the normal network in FIG. The test packet 22 has the same function as the test packet 12 in FIG. A terminal 23 provided with a network I / F having a test function (referred to as a terminal provided with a test function I / F) has a function similar to that of the terminal 13 provided with a test function I / F in FIG. And

The test packet compatible hub and router 24 are
When the test packet 22 is transmitted, it has a function of transmitting the test packet 22 to the terminal 21 of a predetermined ordinary network without deteriorating its properties. Depending on the router or hub, when an error packet is recognized, transmission of the packet is interrupted at that point (eg, a switching hub). If an error occurs, the error factor is removed and transmitted. Although there are some packets (addition of bits, modification of the length of the preamble, etc.), the network system of the present embodiment transmits an error packet as a test packet 22 consciously.
In order to test the function of the interface of the terminal 21 of the ordinary network, if the test packet 22 can be recognized as a test packet, the nature of the error is left as it is and the test packet 22 is transmitted to the terminal of the ordinary network. Send to

The network system of the present embodiment is obtained by changing the network 10 of the network system of the first embodiment described above to a test packet compatible hub and router 24 (other structures are the same as those of the first embodiment. With).

Therefore, the processing operation for investigating a failure such as a failure or abnormality of the terminal 21 of the normal network in the network system according to the present embodiment is the processing operation (FIG. 2) in the network system according to the first embodiment. 5 to FIG. 5), and the details are omitted.

[0073]

As described above in detail, according to the present invention, whether a failure has occurred in a terminal on a network,
Alternatively, it is possible to detect whether an abnormally large number of packets are dropped by terminals on the network, or whether the network environment is in a state where error packets are likely to occur (whether the physical environment is under unfavorable conditions). is there. In addition, each terminal test can be connected to the network without any special maintenance. Furthermore, since this function itself uses an error packet, it can be processed in the lower layer (MAC layer), and does not affect the upper layer. Even if the terminal does not have a function of recognizing the test packet, the error packet is merely an error packet and is discarded in the lower layer, so that the upper layer is not affected.

[Brief description of the drawings]

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

FIG. 2 is a flowchart showing a processing operation in a normal network terminal according to the embodiment of the present invention.

FIG. 3 is an exemplary flowchart showing a processing operation of interface failure detection according to the embodiment;

FIG. 4 is a flowchart showing a processing operation of a physical investigation of the network according to the embodiment;

FIG. 5 is a flowchart showing a processing operation of investigating a probability of missing packets according to the embodiment;

FIG. 6 is a block diagram showing a schematic configuration of a network system according to a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Network, 11 ... Normal network terminal, 12 ... Test packet, 13 ... Terminal provided with network I / F provided with test function, 21 ... Normal network terminal, 22 ... Test packet, 23 ... Test A terminal provided with a network I / F with functions.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) HH07 JJ01 MM03

Claims (5)

[Claims] In a network system configured to detect a failure or abnormality of a network and a terminal device connected to the network, the network system is connected to the network, outputs various error packets, and determines the type of the error packet. And generating a test packet having the nature of the error packet based on the error packet information, the test packet including the error packet information indicating the error packet, the source address information of the error packet, and the test packet information indicating the test packet. Providing a test function holding terminal having an interface with a function of transmitting a packet to the terminal device on the network and testing, the interface of the terminal device, when receiving the test packet from the test function holding terminal, The above test packet information Based on whether the packet is a test packet or not, if the packet is recognized as a test packet, the type of the error packet is recognized based on the error packet information. The type of the recognized error packet and the type of the actual error packet indicated by the test packet are recognized. Is determined, and whether or not the determination result information, the address information of the terminal device,
If the type of the error packet does not match, a reply packet including the information of the type of the actually recognized error packet is generated, and the reply packet is returned to the test function holding terminal. Based on the information of the reply packet, a failure / failure of the terminal device or a network between the terminal device and the test function holding terminal.
An abnormality diagnosis method in a network system, wherein an abnormality is detected. 2. In a network system for detecting a failure or abnormality of a hub or a router and a terminal device connected to the hub or the router, the error packet is connected to the hub or the router and outputs various error packets. And generating a test packet including the error packet information indicating the type of the error packet, the source address information of the error packet, and the test packet information indicating that the packet is a test packet, and having the characteristics of the error packet based on the error packet information. A test function holding terminal provided with an interface having a function of transmitting a test packet to the terminal device connected to the hub or the router and performing a test, the hub or the router, when receiving the test packet, This test packet is sent to the above terminal equipment without impairing the properties. When receiving the test packet from the test function holding terminal, the interface of the terminal device recognizes whether or not the test packet is a test packet based on the test packet information. The type of the error packet is recognized based on the error packet, and it is determined whether the type of the recognized error packet matches the type of the actual error packet indicated by the test packet. The information of the determination result and the address of the terminal device are determined. If the information and the type of the error packet do not match, a reply packet including the information of the type of the actually recognized error packet is generated, and the reply packet is returned to the test function holding terminal. The interface communicates with the terminal device or the terminal device based on the information of the reply packet. Network failure between the tester and the test function holding terminal
An abnormality diagnosis method in a network system, comprising detecting an abnormality. 3. The interface of the test function holding terminal compares the number m of the test packets transmitted with the number n of the return packets, and when m = n is not satisfied, the interface is determined by (mn) / m. 3. The abnormality diagnosis method according to claim 1, wherein the terminal device calculates a probability of dropping a packet. 4. The error packet according to claim 1, wherein the type of the error packet is one of an alignment error, a long frame error, an FCS error, and a short frame error. For diagnosing abnormalities in network systems. 5. The test packet does not include the error packet information, but includes bit additional information indicating that N bits are added to the test packet. The terminal device interface includes the test packet Is recognized, based on the bit addition information, it is determined whether or not the recognized bit addition information and the actual number of bit additions indicated by the test packet match, and the information of the determination result and the information of the terminal device When the address information does not match the number of added bits, a reply packet including the information of the actually recognized number of added bits is generated, and the reply packet is returned to the test function holding terminal. The method for diagnosing an abnormality in a network system according to claim 1, 2 or 3, wherein: