JPH11341042A - Method and system for determining communication route in computer network and recording medium for programming and recording the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change a communication route due to a fault or the like without changing the internal processing of a communication program in a computer network multiplexing plural LANs or computers. SOLUTION: In the computer network system multiplexing plural LANs 11, 12 using a TCP/IP protocol or multiplexing plural computers, each equipment connected to the LANs 11, 12 has a logical IP address allocated independently of an IP address allocated to a network adaptor, executes communication between computers by the logical IP address and changes its communication route by updating the contents of a routing table 14c in accordance with states such as a fault in a route information updating program 13e or 14e by using the table 14c in accordance with the state of the communication route.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and system for determining a communication path in a computer network, and a recording medium on which the method is programmed and recorded.

[0002]

2. Description of the Related Art With the rapid development of computers from mainframes to personal computers, public packet switching networks,
Various computer networks such as a value-added communication network (VAN), a wide area network (WAN), and a local area network (LAN) have been constructed. In recent years, by mutually connecting these networks, it has become possible to exchange information and share computer resources beyond individual frames.

In a computer network in which a LAN is duplicated, peripheral devices such as a computer and a printer connected to the network are provided with a LAN.
A line management table for setting information on whether communication is possible or not is prepared. When communication is performed between devices connected to a network, data is transmitted by designating a LAN with which communication is possible based on information in each line table. The line management table is updated based on a communication result when communication is performed via any LAN or data for inspection is transmitted periodically, and based on the communication result of the inspection data.

[0004]

In the computer network system in which the LAN is duplicated,
A communication program transmits data by directly designating a communicable LAN. Therefore, the communication program is L
In order to support AN multiplexing, the LAN
It is necessary to add a process of directly specifying a communicable LAN so as to perform communication so that the switching is performed. As described above, it is necessary to always consider what path is used to connect to the other party, and to switch the communication path even when a failure or the like occurs, and this places a heavy burden on the programmer such as resetting the IP address. Was.

[0005] The present invention has been made in view of the above circumstances, and assigns a logical IP address, which is different from a normal IP address and whose communication path information is not explicit, to each device connected to the LAN, By dynamically changing the settings according to the state of the communication path,
It is an object of the present invention to provide a method and system for determining a communication path in a computer network in which the load on a programmer is reduced without changing the internal processing of the program, and a recording medium on which the method is programmed and recorded.

[0006]

A method of determining a communication path in a computer network according to the present invention comprises a plurality of computers in which communication lines are multiplexed and each of which is connected to the multiplexed lines via a network adapter. In the computer network system, for each of the network adapters, an address where a communication path to be allocated is different from an explicit address and a communication path which is not explicit is allocated, and communication between computers is performed using the non-explicit address. Thus, the communication path is dynamically determined according to the state.

In a computer network system in which computers are multiplexed and the multiplexed computers are connected via a communication line, communication paths allocated to the plurality of computers are different from explicit addresses. The same address whose communication path is not explicit is assigned to any set of the multiplexed computers, and communication between the computers is performed by using the non-explicit address to include the computer. It is also characterized in that the communication path is dynamically determined according to the state.

In a computer network system according to the present invention, in a computer network system including a plurality of computers in which communication lines are multiplexed and each of which is connected to the multiplexed line via a network adapter, the network adapter is used as a destination. Means for receiving, via the multiplexed communication line, a packet to which a logical address whose assigned communication path is not explicit is specified, reads and executes a server or client program as a user process, and each of the network adapters The communication path allocated to the computer is assigned an address where a communication path different from the explicit address is not explicit, and communication between the computers is performed using the non-explicit address, so that the communication path is changed according to the state. Characterized by comprising a path information updating means for dynamically determined.

Further, in a computer network system in which computers are multiplexed and the multiplexed computers are connected via a communication line, each of the computers includes a packet in which a logical address whose communication path is not explicit is designated as a destination. Via the network adapter, means for reading and executing a server or client program which is a user process, and a communication path assigned to the network adapter is not an explicit communication path other than an explicit address. The same logical address is allocated to the multiplexed computer, and the communication between the computers is performed using the non-explicit address, thereby providing a path information updating means for dynamically determining a communication path according to the state thereof. Having And it features.

[0010] The recording medium of the present invention comprises a plurality of devices in which communication lines are multiplexed, and each of the multiplexed lines is connected via a network adapter, and a normal address assigned to the network adapter. It is used in a computer network system that assigns a logical address for which communication path information other than the explicit one is not explicit to each device and changes the setting of the routing table according to the state of the communication path, and is multiplexed with the partner device A step of transmitting a packet for confirming whether or not the communication path is normal via the line, a step of judging a normal or abnormal state of the communication path based on which communication path a reply packet has been received, and a first communication When it is determined that the route is normal, the routing table is used as the logical address route information. A step of address of the first network adapter to register that the gateway,
Registering that the address of the second network adapter is a gateway as routing information of a logical address in the routing table when it is determined that the second communication path is normal; and referring to the routing table. The step of determining a communication path is programmed and recorded.

Further, the computer is multiplexed, the multiplexed computer is connected to a communication line via a network adapter, and communication path information different from a normal address assigned to the network adapter is not explicit. Used in a computer network system that assigns the same logical address to an appropriate computer and changes the setting of the routing table according to the state of the communication path. Transmitting a packet for confirming whether the first communication path is normal, determining a normal or abnormal state of the communication path based on which communication path a reply packet has been received, and determining that the first communication path is normal. When the routing information of the logical address is Registering that the address of the first network adapter is a gateway, and when it is determined that the second communication path is normal, the second network adapter is added to the routing table as path information of a logical address. The step of registering that the address is a gateway and the step of referring to a routing table to determine a communication path including the computer are programmed and recorded.

Thus, a program that communicates using a logical IP address does not need to be aware of what path is used to connect to the other party, and this program is also used when switching communication paths due to the occurrence of a failure or the like. If connection is performed by designating a logical IP address, it is not necessary to reset the IP address.

[0013]

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, reference numerals 11 and 12 denote multiplexed LAN lines, and computers 13 and 14 are connected to the LAN lines 11 and 12, respectively. Computers 3 and 4 are connected to network adapters 13a and 1 respectively.
4a to the LAN 11 via the network adapter 13
b and 14b to the LAN 12.

In the computer 13, a server program 13d, which is a user process, is running, and in the computer 14, its client program 14d is running. The computer 13 sends the logical IP address 1
3c are designated as LAN11 and LAN12
It is assumed that it is configured to be received via the Internet.
The logical address 13c includes LAN 11 and LAN
12 are assigned IP addresses having different addresses of the network unit. Therefore, from the viewpoint of the computer 14, since the route information to the logical address 13C is not explicit, the routing table 1 of the computer 14
If there is no route information to the logical IP address 11c in 4c,
The computer 14 cannot connect by designating the logical IP address 13c.

The connection operation between computers in the computer network system shown in FIG. 1 will be described with reference to the flowchart shown in FIG. When trying to connect to the server program 13d, the client program 14d specifies the logical IP address 13c of the computer 13 as the IP address of the partner device and starts the connection (step S21). In this system, the route information to the logical IP address 13c is transmitted to the LAN 1 which can communicate with the route information update programs 13e and 14e.
1 (12) is constantly updated to connect.

Here, in the routing table 14c,
If the IP address of the network adapter 13a is registered as the gateway as the route information of the logical IP address 13c, the connection is made using the LAN 11. On the other hand, if the IP address of the network adapter 13b is registered as a gateway, LAN1
2 are used (steps S22 and S2).
3).

The route information update program 13e shown in FIG.
In (14e), the processing is performed according to the procedure according to the flowchart shown in FIG. The route information update program 14e periodically sends a packet for confirming whether or not the communication path is normal to the LAN information update program 13e to the route information update program 13e.
The data is transmitted via the AN 12 (step S31). The route information update program 13e that has received the packet returns a reply to the route information update program 14e using the LAN 11 (12) to which the packet was sent (step S3).
2). Route information update program 14e that received the reply
Determines whether the communication path is normal based on which communication path the packet has been received from.

If the normal communication path is the LAN 11, the network adapter 13 is stored in the routing table 14c as the path information of the logical IP address 13c.
The IP address of a is registered as a gateway (step S33). On the other hand, if it is determined that the normal communication path is the LAN 12, the IP address of the network adapter 13b is registered in the routing table 14c as the path information of the logical IP address 13c (step S34). When it is determined that both the LANs 11 and 12 are normal, it is determined which LAN to use according to the priority specified in advance (step S35), and the route information using the determined LAN is registered. . If both LANs 11 and 12 are abnormal, nothing is done (step S36).

By controlling as described above, when the client program connects to the server program, by using the logical IP address, it is completely conscious of which of the multiplexed LANs is used for communication. Connection is possible.

FIG. 4 is a block diagram showing another embodiment of the computer network system of the present invention. In the figure, the computers 41 and 42 to which the same logical IP address 45 is assigned and the computer 43 as a client thereof are connected to a unit LAN 44 of the computer 43 to which another logical IP address is assigned. The computers 41, 52, and 43 connect to the LA via the network adapters 41a, 42a, and 43a, respectively.
N44. The computers 41 and 42 send the packet with the logical address 45 specified as the destination
It is assumed that it is configured to be received via N44.

The logical IP address 45 is assigned an IP address that is different from the address of the LAN 44 and the network section. Therefore, if there is no route information to either the computer 41 or 42 in the routing table 43e of the computer 43, the computer 43 cannot connect by designating the logical IP address 45. In the computers 41 and 42, server programs 41b and 42b, which are user processes, are running, and in the computer 43, their client programs 43b are running.

Using the flowchart shown in FIG.
The basic operation of the computer network system shown in FIG. When trying to connect to either the server program 41b or 42b, the client program 43b specifies the logical IP address 45 assigned to the computers 42 and 42 as the IP address of the partner device and starts the connection (step S51). . In this system, the route information of the logical IP address 45 is updated by the route information update programs 41c, 42c, and 43c so that the client program 43b can always connect to the communicable server program 41b (42b).

In the routing table 43e, a logical IP
Network adapter 4 as route information of address 45
1a is registered as a gateway, the client program 43b is connected to the server program 42b and the network adapter 42a
If the IP address is registered as a gateway, it is connected to the server program 42b (steps S52 and S53).

The processing procedure of the route information update programs 41c, 42c, 43c will be described with reference to the flowchart shown in FIG. The route information update program 43c
A packet for periodically confirming whether or not communication can be normally performed with the route information update programs 41c and 42c is transmitted (step S61). Route information update programs 41c and 42c that have received the packet
Sends back a reply to the route information update program 43c (step S62).

The route information change program 4 which received the reply
3c depends on whether a reply packet has been received or not.
It is determined whether the communication path and the computer are normal. If it is determined that communication with the computer 41 can be performed normally, the routing information of the logical IP address 45 is stored in the routing table 43e as the network adapter 41.
The IP address of a is registered as a gateway (step S63). If it is determined that communication with the computer 42 can be performed normally, the routing table 43e
Then, as the route information of the logical IP address 45, the IP address of the network adapter 42a is registered as a gateway (step S64). Computer 4
If the communication is normal in both the computers 1 and 42, it is determined which computer is to be connected according to the priority specified in advance (step S65), and the route information to the determined computer is registered in the routing table 43e. You. If both the computers 41 and 42 cannot communicate, nothing is done (step S66).

As described above, by using the logical IP address when the client program connects to the server program, it is not necessary to be aware of which of the multiplexed computers is connected, and When switching computers, the switching can be performed without resetting the IP address.

[0027]

As described above, according to the present invention, for example, TC
In a computer network system in which a LAN using the P / IP protocol is multiplexed, each device connected to the LAN has a logical IP address assigned separately from the IP address assigned to the network adapter, and the Communication is performed using this logical IP address, and the communication path is specified using the routing table, thereby dynamically updating the contents of the routing table in accordance with the state of a failure or the like. A program that communicates using an IP address does not need to consider what path is used to connect to the other party, and also specifies a logical IP address when switching communication paths due to the occurrence of a failure or the like. Eliminates cumbersome work such as resetting the IP address if connected That.

For example, in a LAN using the TCP / IP protocol, each device has a logical IP address assigned separately from an IP address assigned to each network adapter, and a plurality of devices have the same Having a logical IP address, using the logical IP address for communication between the devices, and specifying the communication path using the routing table, dynamically updating the contents of the routing table according to the state of a failure or the like. Therefore, a program that communicates using a logical IP address does not need to consider which of the devices having the same logical IP address is connected. When switching the connection destination device, if the connection is made by specifying the logical IP address, Scan does not require the hassle of re-setting of.

Therefore, in a computer network system in which LANs are multiplexed or computers are multiplexed, even if the communication program does not take the system configuration into consideration, the internal logic is not changed, and the logical IP is not changed. Multiplexing support can be realized only by specifying an address and making a connection.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a computer network system according to the present invention;

FIG. 2 is a flowchart showing a basic operation of the computer network system in FIG. 1,

FIG. 3 is a flowchart showing a processing procedure of a path information update program used in the embodiment of the present invention;

FIG. 4 is a block diagram showing another embodiment of the computer network system of the present invention;

FIG. 5 is a flowchart showing a basic operation of the computer network system in FIG. 4,

FIG. 6 is a flowchart showing a processing procedure of a route information update program used in the embodiment of the present invention;

[Explanation of symbols]

11 (12, 44) ... LAN, 13 (14, 41, 4)
2, 43) Computer, 13a (13b, 14a,
14b, 41a, 42a, 43a) ... network adapter, 13c (45) ... logical IP address, 13d (4
1b, 42b) ... server program, 14c (43e)
... Routing table, 14d (43b) ... Client program, 13e (14e, 41c, 42c, 4)
3c) ... route information update program,

Claims (13)

[Claims] In a computer network system comprising a plurality of computers connected to a multiplexed line via a network adapter, a communication path assigned to each network adapter is provided. An address that is different from the explicit address but is not explicit is assigned,
A method of determining a communication path in a computer network, wherein communication between computers is performed using the non-explicit address to dynamically determine a communication path according to the state of the communication path. 2. In a computer network system in which computers are multiplexed and the multiplexed computers are connected via a communication line, communication paths allocated to the plurality of computers are different from explicit addresses. The same address whose communication path is not explicit is assigned to any set of the multiplexed computers, and communication between the computers is performed by using the non-explicit address to include the computer. A method for determining a communication path in a computer network, wherein the communication path is dynamically determined according to a state of the communication path. 3. A plurality of computers connected via a network adapter perform inter-computer communication using the TCP / IP protocol, and dynamically change the contents of a routing table defining a communication path according to the state of the communication path. 3. The method for determining a communication route in a computer network according to claim 1, wherein the communication route is updated. 4. When a client connects to a server, an IP address assigned to a first network adapter is registered as a gateway in a routing table as route information of a logical address whose communication route is not explicit, 4. The computer network according to claim 3, wherein when the first communication line is used and the IP address assigned to the second network adapter is registered as a gateway, the second communication line is used. How to determine the communication path. 5. When a client connects to a server, an IP address assigned to the first network adapter is registered as a gateway in the routing table as route information of a logical address whose communication route is not explicit. Connecting to the server program in the second computer when the IP address assigned to the second network adapter is registered as a gateway in the server program in the first computer. A method for determining a communication path in the computer network according to the above. 6. In a computer network system comprising a plurality of computers multiplexed with communication lines and connected to the multiplexed lines via respective network adapters, a communication path allocated to the network adapter as a destination is provided. Means for receiving a packet to which a non-explicit logical address is specified via the multiplexed communication line, reading and executing a server or client program as a user process, and a communication path allocated to each of the network adapters Is assigned an address where a communication path different from the explicit address is not explicit, and performs communication between computers using the non-explicit address, thereby dynamically determining a communication path according to the state. Information updating means A computer network system, comprising: 7. The routing information updating means includes: a routing table in which routing information is defined; and routing information of a logical address for which a communication route is not explicit in the routing table; and an address assigned to the first network adapter as a gateway. Gateway for connecting computers by using the first communication line when registered and using the second communication line when the address assigned to the second network adapter is registered as a gateway 7. The computer network system according to claim 6, comprising: 8. In a computer network system in which computers are multiplexed and the multiplexed computers are connected via a communication line, each computer transmits a packet in which a logical address whose communication path is not explicit is designated as a destination. Via the network adapter, a means for reading and executing a server or client program as a user process, and a communication path assigned to the network adapter is explicitly different from an explicit address. And the same logical address is allocated between the multiplexed computers, and the communication between the computers is performed using the non-explicit address, thereby dynamically determining the communication path according to the state of the path information update. And means Characterized computer network system. 9. The routing information updating means includes: a routing table in which routing information is defined; and routing information of a logical address for which a communication route is not explicit in the routing table; and an address assigned to the first network adapter as a gateway. Computer by connecting to the server program in the first computer when registered and to the server program in the second computer when the IP address assigned to the second network adapter is registered as a gateway 9. A gateway for performing a connection between the gateways.
A computer network system as described. 10. A communication system in which a communication line is multiplexed and comprises a plurality of devices connected to each of the multiplexed lines via respective network adapters, the communication being different from a normal address assigned to the network adapter. Used in a computer network system that assigns a logical address for which route information is not explicit to each device and changes the setting of the routing table according to the status of the communication route. Transmitting a packet for confirming whether or not the communication path is normal; determining from which communication path a reply packet has been received to determine whether or not the communication path is normal; and the first communication path is normal. Is determined as the logical network route information in the routing table, the first network Registering that the address of the network adapter is a gateway, and when it is determined that the second communication path is normal, the address of the second network adapter is added to the routing table as path information of the logical address. And a step of determining a communication path by referring to a routing table. 11. A computer is multiplexed, the multiplexed computer is connected to a communication line via a network adapter, and communication path information different from a normal address assigned to the network adapter is not explicit. Used in a computer network system in which the same logical address is assigned to a plurality of computers and the setting of a routing table is changed according to the state of a communication path. Transmitting a packet for confirming whether the first communication path is normal, determining a normal or abnormal state of the communication path based on which communication path a reply packet has been received, and determining that the first communication path is normal. When the routing table uses A step of registering that the address of the first network adapter is a gateway; and, when it is determined that the second communication path is normal, a routing table of the second network adapter is added to the routing table as path information of a logical address. A computer-readable recording medium in which a step of registering that an address is a gateway and a step of determining a communication path including the computer with reference to a routing table are programmed and recorded. 12. A computer readable program which further comprises the step of selecting one of the communication paths in accordance with a predetermined priority when all the communication paths are determined to be normal. The recording medium according to the above. 13. The computer-readable recording medium according to claim 10, wherein a step of instructing not to do anything is further programmed and recorded when it is determined that any communication path is abnormal.