JPH0427239A - Control method for lan connecting device - Google Patents

Abstract

PURPOSE:To reduce the load of a data processor by executing periodically state monitoring of an existing system LAN connecting device independently from operations of the data processor and the existing system LAN connecting device by a stand-by system LAN connecting device. CONSTITUTION:An LAN cable 5 to which an existing system LAN connecting device 3 and a stand-by system LAN connecting device 4 are both connected is utilized as a state monitoring path, and the device 4 executes periodically state monitoring of the device 3 independently from operations of a data processor 1 and the device 3. In that case, by sending back monitoring data transmitted to the device 3 from the device 4 as it is from the device 3, its response is checked by the device 4 and whether the device 3 is faulty or not is decided. In such a way, an exclusive state monitoring path becomes unnecessary and a dual system can be formed by an existing adaptor. Also, in the case the device 3 becomes faulty, an MAC address of the device 3 is transferred to the device 4 in advance and held therein so that transmission and reception of data to and from the opposite device can be continued without changing the MAC address of the device 4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is a method of controlling a LAN connection device for improving the reliability of the connection by using one of the two LAN connection devices as a standby device.

[Conventional technology]

In the office, L A N (Local Ae
The reasons for introducing reaNeLwork are (a) to combine existing personal computers (CPUs) and share resources, and (b) to develop a new business system and combine it with the existing system. , and (c) in order to simplify the wiring of the host system when accessing multiple host machines from one personal computer.

When systems are connected via a LAN, it is extremely convenient to manage common resources used by each system in one place, and for this purpose the shared data is stored in a file server machine. Therefore, when increasing the reliability of a LAN, it is particularly important to improve the reliability of the file server machine.

Conventionally, measures to improve LAN reliability include (])
As described in JP-A-164146, there is a method of duplicating the transmission path itself.

In this method, as shown in FIG. 7, a LAN connection device 71 connected to a server 74 or a file 75 has two transmission paths (ring-shaped) 72.7 (one of which is a standby).
3, so that even if the working transmission line 72 becomes disconnected due to a failure, communication can be performed by switching to the backup transmission line 73.

(ij) Although not a LAN connection device, there is a method in which a data processing device or the like is configured in a dual system. In this method, as shown in FIG. 8, one of the data processing devices 81 and 82 is used as a working device and the other is used as a backup, so that if the current device fails, it can be switched to the backup and continue processing. However, it is necessary to provide a monitoring device 84 for monitoring the status of the two systems of devices, and a switching control device 83 for switching from active to standby.

(ni) For example, as described in JP-A-1-217523 and JP-A-1-162942,
There is a method of mutual status monitoring between active and backup. In this method, as shown in FIG. 9, when one of the adapters 91 and 92 connected to the CPU 93 and the bus 90 is in use and the other is in reserve, a special A route 94 was provided. The standby device must constantly monitor the active device via path 94 and determine whether a failure has occurred.

[Problem to be solved by the invention]

When connecting a communication control device to a LAN, it is connected to a common bus via a LAN connection device (connection adapter).
In preparation for this failure of the LAN connection device, a method of creating a dual system of connection devices is conceivable.

In that case, the following problems arise.

(b) In order to use the existing LAN connection adapter as a working system and a standby system, it is necessary to implement and modify it.

In other words, a special path for status monitoring is provided between the active and standby devices, and a dedicated LAN connection device for the dual system is prepared with circuits, connectors, connection cables, etc. to configure this path. This results in an increase in costs.

(b) LAN connection devices have a unique MAC (Media Access Control) for each device.
ol) address must be assigned when setting up or changing the system, but since this MAC address is also changed when switching from the active system to the standby system, the MAC address of the other device (
It becomes impossible to receive data from the computer (workstation, etc.). Note that the frames used for communication within the LAN include:
Since the destination address and source address are stored in the header or in each packet, if the MAC address changes, the other device must also be notified.

The purpose of the present invention is to solve these conventional problems and to
A method for controlling a LAN connection device that uses only a normal connection device without using an AN connection device, eliminates the need to change the MAC address when switching between LAN connection devices, and continues data transmission and reception with a partner device. [Means for Solving the Problems] In order to achieve the above object, a method for controlling a LAN connection device according to the present invention provides a method for controlling LAN connection devices having the same configuration, one of which is used as an active system and the other as a standby system. First, the MAC address used by the active LAN connection device is transferred to the backup LAN connection device, the MAC address is retained in the backup LAN connection device, and the MAC address is transferred from the backup LAN connection device via the LAN cable. By periodically sending test data to the active LAN connection device, status monitoring is performed and the active L
A feature of this system is that when a failure in the AN connection device is detected, the active system operation is started using the MAC address held by the backup LAN connection device.

[For production]

In the present invention, ■the active LAN connection device and the standby L
The LAN cable to which the AN connection devices are connected is used as a path for status monitoring, and the standby LAN connection device periodically connects to the active LAN, independently of the operation of the data processing device and the active LAN connection device. Monitors the status of connected devices,
In this case, the monitoring data sent from the backup device to the active device is returned as is from the active device, and the response is checked by the backup device to determine whether or not the active device is out of order. This eliminates the need for a dedicated state monitoring path and also eliminates the need for a dedicated dual system LAN connection device, making it possible to form a dual system using existing adapters.

In addition, if the active LAN connection device fails, the MAC address of the active LAN connection device can be changed so that data transmission and reception with the other device can be continued without changing to the MAC address of the backup LAN connection device. The data is transferred to the standby LAN connection device in advance and held there.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to one drawing.

FIG. 6 is a block diagram of a LAN system to which the present invention is applied.

Shared data shared in a LAN system is a file
It is stored in the server device 61. Along with the CPUs 62 to 65 that make up each workstation, file
The servers 61 are coupled to the bus 60 via LAN connections fi66-70, respectively. As shared data,
For example, it includes top management information, sales data, technical data, personnel data, general affairs data, accounting data, planning data, etc. A person in charge of file management is determined for each data file, and the file tI! Only the person in question updates the data.

Therefore, the person in charge of the other workstations
The shared data on the server side can only be referenced using program modules 2 to 65, and updates are not allowed. Therefore, the LAN connection device 66 connected to the server device 61
Since this is particularly important, in the present invention, only this connection device 66 is made into a dual system, one of which is used as an active system and the other as a standby system, and is connected to the bus 60, respectively. Note that if there is a workstation that plays a fairly important role among the CPUs 62 to 65 other than the server device 61, that CPU
Of course, the LAN connection device that connects the PU to the bus 60 may also be a dual system.

FIG. 1 is a block diagram of a dual LAN connection device showing an embodiment of the present invention.

In FIG. 1, a data processing device 1 and an associated input/output processor 2 are coupled to a LAN cable 5 via an active LAN connection device 3 and a backup LAN connection device 4. In FIG. The input/output processor 2 and the dual-system LAN connection devices 3 and 4 are connected to each other by a channel bus 6, and both LAN connection devices 3 and 4 are connected to each other by a cable 12.
It is connected to the LAN cable 5 via. As mentioned above, the data processing device l is a file server device of a LAN system or a processing device forming a particular workstation. Although not shown, it is assumed that a plurality of workstations are connected to the LAN cable 5.

The active system device 3 and the standby system device 4 are both dedicated L
It is not an AN connection device, but an existing LA-N connection device, and has the same configuration. That is, channel bus 6
A channel control unit 7 is provided on the side, and a LAN control unit 11 is provided on the LAN cable 5 side, and the channel control unit 7 and the LA
Between the N control units 11, there is an RA that can read and write from them.
M8 and RAM9. and ROM10a,b are arranged. The RAM 9 is a memory that stores the transferred MAC address, and the ROMs 10a and 10b each store their own readable MAC address.

ROM10a contains the MAC address of the active system device 3, R
The MAC addresses of the standby devices are registered in each OMI Ob.

The data processing bag [1] issues a command requesting a MAC address to the active device 3 before transmitting and receiving data via the LAN. When the channel control unit 7 of the active system W13 receives the command, the channel control unit 7 of the current system W13
The data processing device 1 reads the contents of the ROM and transfers it to the data processing bag [1.
The contents of 10a are transferred to the standby device 4 using the MAC address transfer command. The channel control unit 7 of the standby system device 4 determines the command and transmits the contents of the data (ROM) Oa accompanying the command to the active system device 3.
MAC address) is stored in the MAC address storage M9 in the own device 4. Next, the data processing device 1 issues a command to the standby system device 4 to instruct the start of standby system operation. The channel control unit 7 of the standby system device 4, which has received this command, writes a command code indicating the start of standby system operation into a predetermined area in the RAMB.

On the other hand, the LAN control section 11 of the standby system device 4 waits for an instruction from the channel control section 7 by continuously monitoring the above-mentioned area within the RANS. When the LAN control unit 11 detects that a command code for instructing the start of backup system operation is written in that area, it transmits test data to the active system device 3. The test data is normal L
It is transmitted as a data frame that is sent and received within the AN system, and includes a command, destination address, source address, etc. The test data is then transferred from the LAN control unit 11 of the standby system device 4 to the LAN control Ill of the active system device 3 via the cable 12, LAN cable 5, and cable 12.

On the other hand, when the LAN control unit 1 of the active device 3 receives this test data, it returns the test data as is to the backup device 4 via the cable 12, the LAN cable 5, and the cable 12. do.

After transmitting this test data, the LAN control unit 11 of the standby system device 4 waits for a response, and if there is a response within a certain predetermined time, it determines that it is operating normally, but if there is no response within that time, the LAN control unit 11 waits for the response. In this case, it is determined that there is a failure in the active system device 3. Furthermore, even if there is a response within the time, if the response content is different from what was expected, it is determined that there is a failure in the active system device 3.

When the LAN control unit 11 of the standby system device 4 detects a failure in the active system device 3, it writes data to a predetermined area of the RAM 8 in its own device 4 to convey the fact.

The channel control unit 7 in the standby system device 4 first instructs the LAN control unit 11 to perform standby system operation, and then continuously monitors that area, and data indicating a failure in the active system device 3 is written. When detecting this, it sends an interrupt signal and data indicating a fault in the active device 3 to the data processing device 1.

The data processing device l starts interrupt processing in response to this interrupt, and when it determines that the interrupt is due to a failure in the active device 3, it issues a stop command to the active device 3, and A command is issued to the device 4 to instruct it to start operating the active system. When the channel control unit 7 of the standby system device 4 receives the active system operation start command,
At the same time as instructing the LAN control unit 11 to start the active system operation via the RAM 8, it also starts the active system operation.

Based on the instruction, the LAN control unit 11 of the standby system device 4
Using the MAC address of the active system device 3 held in the MAC address storage RAM 9 in the own device 4, the operation of the active system is started.

On the other hand, when the active device 3 receives a stop command from the data processing device 1, it enters a halt state.

Note that if the standby system device 4 does not detect a failure in the active system device 3, the test data is repeatedly transmitted from the standby system device 4 to the active system device 3 at fixed time intervals.

Further, as another embodiment of the present invention, the ROM 10 for storing MAC addresses of the active system device 3 and the standby system bag W14 shown in FIG.
It is possible to write the same MAC address in a and fob in advance, and omit the process of transferring the MAC address from the active system W13 to the standby system 4 among the processes of the data processing device 1.

Further, regarding the MAC address, a method may be used in which the MAC address storage ROM 10a, lOb is removed and the data is loaded from the data processing device l to the active system device 3 and the standby system device 4.

Further, the status of the active system device 3 may be monitored by monitoring the status from the data processing bag [1 or the input/output processor 2], or by combining the test data from the standby system device 4 and the above status monitoring. No problem.

FIG. 2 is a processing flowchart 1 of the control program of the data processing device in FIG.

First, the data processing device 1 performs MA for the active system device 3.
Step 201: Issue a C address report request command.
), upon receiving the MAC address from the active device 3 (step 202), the MAC address of the device 3 is sent to the backup device 4.
Transfer the address (step 203). Next, regarding the standby system device 4.

A command to start monitoring the status of the active device 3 is issued (step 204). Then, it continuously waits for an interrupt from the standby system device 4 (step 205), and if there is an interrupt, it is determined whether or not it is caused by a failure in the active system device 3 (step 206).

If so, issue an operation stop command to the active system device 3 (step 207), then issue an active system operation start command to the standby system device 4 (step 207).
08).

FIG. 3 is a processing flowchart of the control program of the LAN control unit in the active system device in FIG. 1.

The LAN control unit 11 in the active device 3 always determines whether or not data is received (step 301), and if received, determines whether the received data is test data (step 301). 302).

If it is test data, it is sent back as is to the data transmission source (step 303).

Also, if the received data is not test data, the RA
The data is written to M8 and a processing request is issued to the channel control unit 7 (step 304).

FIG. 4 is a processing flowchart 1 of the control program of the 1=AN control section in the standby system device in FIG.

When the command to start the status monitoring operation is issued, the LAN control unit 11 of the standby system device 4 transmits test data to the active system device 4 (step 401). Then, it is determined whether there is a response from the active device 3 within a predetermined time (step 402), and if so, it is determined whether the response data is normal (step 403). If it is normal, the process returns to the original state and resumes sending the test data to the device 3 (step 401).

If there is no response from the active device 3, it is determined whether or not the response waiting time has expired (step 404). If it has timed out, the channel controller 7 is notified of abnormality detection in the active device 3. It instructs the processing device L to report (step 405), and determines whether there is an instruction to start the active system operation (step 406), and if so, the R
Using the MAC address stored in AM9, it starts operating as an active device (step 407).

FIG. 5 is a processing flowchart of the control program of the channel control units of the active system device and the standby system device in FIG. 1.

The channel control unit 7 waits for a command from the data processing device 1 (step 501), and if there is a command, if it is a MAC address request command (in the case of the channel control unit 7 of the active device 3, the command is sent to step 502). ), the MAC address is sent to the data processing device 1 (step 508), and if the command is a MAC address transfer command (in the case of the channel control unit 7 of the standby system device 4, step 503)
), stores the MAC address in RAM9 within the own device (
Step 509). If it is a standby system operation start command (step 504 in the case of the channel control unit 7 of the standby system device 4), monitoring of the status of the active system device indicated by the MAC address in RAMQ is started (step 510). If it is an operation stop command (step 505 in the case of the channel control unit 7 of the active device 3), the operation is stopped (step 511). In addition, if it is an active system operation start instruction command (in the case of the channel control unit 7 of the standby system device 4,
Step 506), the MAC address in RAMQ is set as the own MAC address, and the active system operation is started (Step 512). If neither of these is the case, other normal commands are processed (step 507).

In this manner, in this embodiment, the data processing device 1 is freed from the burden of monitoring the status of the active bag W3.

Even after switching from the active system to the standby system, the LAN
data processing device 1 via device 4 with the same MAC address as before switching.
Since it is possible to communicate with the other party, there is no need to notify the other party of the switch. Further, there is no need for a special monitoring path between the active system device 3 and the standby system device 4, and everything can be realized at the level of the control program of each device.

[Effects of the Invention] As explained above, according to the present invention, it is possible to create a special monitoring route without adding or changing hardware for active and standby LAN connection devices. By simply adding processing functions to the control programs of LAN connection devices and data processing devices, you can create a standby LAN.
Since the status of the active LAN connection device can be monitored from the connection device, the load on the data processing device is reduced and a highly reliable LAN connection device can be realized at low cost.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a LAN connection device showing an embodiment of the present invention, FIG. 2 is a processing flowchart of the data processing device in FIG. 1, and FIG. 3 is a LA of the active system device in FIG.
FIG. 4 is a processing flowchart of the N control unit 1. of the standby system device in FIG. Processing flowchart of AN control unit,
5 is a processing flowchart of the active channel and protection channel control units in FIG. 1, FIG. 6 is a block diagram of a LAN system to which the present invention is applied, and FIGS. 7, 8, and 9 are is an explanatory diagram showing a countermeasure method for a conventional highly reliable LAN system. I: data processing device, 2: input/output processor, 3: active LAN connection device, 4: standby LAN connection device, 5:
LAN cable, 6: Channel bus, 7: Channel control unit, 8: RAM, 9: RA for storing MAC address
M, 10a, 10b: R for storing MAC address
OM% 11: LAN control section, 12+LAN access cable. Figure Figure Figure Figure Figure

Claims (1)

[Claims] 1. Connect two LANs between the data processing device and the LAN cable.
In a LAN system connected via a connection device, one of the LAN connection devices with the same configuration is used as the active system and the other as the backup system, and the MAC address used in the active LAN connection device is first transferred to the backup LAN connection device. transfer,
By retaining the MAC address in the backup LAN connection device and periodically transmitting test data from the backup LAN connection device to the active LAN connection device via the LAN cable, the status can be determined. A LAN connection device characterized in that when a failure of the active LAN connection device is detected by monitoring, the protection LAN connection device starts operating the active system using a MAC address held by the backup LAN connection device. Control method.