JP3999353B2 - Method and system for determining communication path in computer network, and recording medium on which program is recorded - Google Patents

Description

[0001]
BACKGROUND 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]
[Prior art]
With the dramatic development of computers from mainframes to personal computers, various computer networks such as public packet switching networks, value added communication networks (VAN), wide area dedicated networks (WAN), local area networks (LAN) have been constructed. It was. In recent years, it has become possible to exchange information and share computer resources beyond individual boundaries by interconnecting these networks.
[0003]
By the way, in a computer network in which a LAN is duplicated, a line management table for setting information on whether or not communication for each LAN is possible is prepared for each computer and peripheral device such as a printer connected to the network. When communication is performed between devices connected to a network, data is transmitted by designating a LAN capable of communication based on information in each line table. The line management table is updated based on the communication result when communication is performed via any one of the LANs or periodically transmitting inspection data, and the communication result of the inspection data.
[0004]
[Problems to be solved by the invention]
In the above-described computer network system in which the LAN is duplicated, a program for performing communication directly designates a communicable LAN and transmits data. Therefore, in order to make the communication program compatible with LAN multiplexing, it is necessary to add a process for performing communication by directly specifying a LAN capable of communication so that the LAN is switched when a LAN failure occurs. In this way, it is necessary to always consider what route is used to connect to the other party, and it is necessary to switch the communication route even if a failure occurs, which places a heavy burden on the programmer, such as resetting the IP address. It was.
[0005]
The present invention has been made in view of the above circumstances, and assigns a logical IP address whose communication path information is not explicit different from a normal IP address to each device connected to the LAN, and sets a routing table. A method and system for determining a communication path in a computer network that reduces the burden on the programmer without changing the internal processing of the program by dynamically changing according to the state of the communication path, and the same method are programmed and recorded. An object is to provide a recording medium.
[0006]
[Means for Solving the Problems]
A method for determining a communication path in a computer network according to the present invention is a method for determining a communication path in a computer network comprising a plurality of devices in which communication lines are multiplexed and connected via respective network adapters for each of the multiplexed lines. The network adapter is assigned an explicit address as a communication path, and the plurality of devices are individually assigned logical addresses whose communication path information other than the address is not explicit, Send a packet to the partner device to check whether the communication path is normal via the multiplexed line,
Based on which communication path the reply packet can be received from the counterpart device for this transmission packet, it is determined whether the communication path is normal or abnormal, and when it is determined that the first communication path is normal, Register that the address of the first network adapter is a gateway as route information of the logical address,
When it is determined that the second communication route is normal, the fact that the address of the second network adapter is a gateway is registered as route information of the logical address in the routing table, and any one of the network adapters The communication path is determined with reference to a routing table registered that the address of the address is a gateway .
[0007]
In the method of the present invention , when a client computer that is one of a plurality of devices connected via each network adapter for each multiplexed line connects to a server computer that is a counterpart device, a communication is made in the routing table. When the IP address assigned to the first network adapter is registered as a gateway as route information of a logical address whose route is not explicit, it is assigned to the second network adapter using the first communication line. When the IP address is registered as a gateway, the second communication line is used.
[0008]
A computer network system according to the present invention is a computer network system comprising a plurality of devices in which communication lines are multiplexed and connected via respective network adapters for each of the multiplexed lines. An explicit address is assigned to the communication path, and a logical address whose communication path information different from the address is not explicitly assigned to each of the plurality of devices is individually assigned, and one of the plurality of devices has the logical address. A routing table that can register route information to the address is provided, and a packet is sent from one device to the other device via the multiplexed line to check whether the communication path is normal. The received packet is received by receiving a reply packet from the partner device for the packet. When the first communication path is determined to be normal, the address of the first network adapter is the gateway as the logical address path information with respect to the routing table. And when the second communication path is determined to be normal, path information update means for registering that the address of the second network adapter is a gateway as path information of the logical address with respect to the routing table. The one device determines a communication path with the counterpart device by referring to a registered routing table that the address of any one of the network adapters is a gateway.
[0010]
The recording medium of the present invention comprises a plurality of devices in which communication lines are multiplexed and connected via the respective network adapters for each of the multiplexed lines, and is different from the normal addresses assigned to the network adapters. Used in a computer network system that assigns logical addresses whose communication path information is not explicit to individual devices and changes the setting of the routing table according to the state of the communication path. A step of transmitting a packet for confirming whether or not the communication path is normal, a step of determining whether the communication path is normal or not based on which communication path has been received, and the first communication path is normal If the first network is determined as route information of the logical address with respect to the routing table. The step of registering that the address of the work adapter is a gateway, and when the second communication path is determined to be normal, the address of the second network adapter is the gateway information as the logical address path information with respect to the routing table. And the step of referring to the routing table to determine the communication path are programmed and recorded.
[0012]
As a result, a program that communicates using a logical IP address does not need to be aware of what route is used to connect to the other party, and this logical IP address is also used when a communication route is switched due to the occurrence of a failure or the like. If you specify and connect, there is no need to re-set the IP address.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
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. The computers 3 and 4 are connected to the LAN 11 via the network adapters 13a and 14a, respectively, and to the LAN 12 via the network adapters 13b and 14b.
[0014]
A server program 13d, which is a user process, runs on the computer 13, and a client program 14d runs on the computer 14. Assume that the computer 13 is configured so that a packet in which the logical IP address 13c is specified as a destination is received via the LAN 11 and the LAN 12. The logical address 13c is assigned an IP address having a different network address for both the LAN 11 and the LAN 12. Therefore, when viewed from the computer 14, for routing information to the logical addresses 13C is not explicit, without the path information to the logical IP address 1 3 c in the routing table 14c of the computer 14, the logical IP address 13c of the computer 14 Cannot connect by specifying.
[0015]
An inter-computer coupling operation in the computer network system shown in FIG. 1 will be described with reference to the flowchart shown in FIG. When the client program 14d tries to connect to the server program 13d, the logical IP address 13c of the computer 13 is designated as the IP address of the partner apparatus and connection is started (step S21). In this system, the route information to the logical IP address 13c, are constantly updated so that to connect using the LAN 11 (12) which can communicate by routing information update program 13e and 14e.
[0016]
Here, if the IP address of the network adapter 13a is registered as a gateway as route information of the logical IP address 13c in the routing table 14c, the LAN 11 is used for connection. On the other hand, if the IP address of the network adapter 13b is registered as a gateway, the LAN 12 is used (steps S22 and S23).
[0017]
The route information update program 13e (14e) shown in FIG. 1 performs processing according to the procedure according to the flowchart shown in FIG. The route information update program 14e periodically transmits a packet for confirming whether the communication path is normal to the route information update program 13e via the LAN 11 and the LAN 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 has been sent (step S32). The path information update program 14e that has received the reply determines whether or not the communication path is normal depending on from which communication path the packet has been received.
[0018]
Here, if the normal communication path is the LAN 11, the IP address of the network adapter 13a is registered as the gateway as the path information of the logical IP address 13c in the routing table 14c (step S33). On the other hand, when it is determined that the normal communication path is the LAN 12, the IP address of the network adapter 13b is registered as a gateway 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 is to be used in accordance with the priorities specified in advance (step S35), and route information using the determined LAN is registered. . If both the LANs 11 and 12 are abnormal, nothing is done (step S36).
[0019]
By controlling as described above, when a client program connects to a server program, it uses a logical IP address to connect without being aware of which of the multiplexed LANs is used for communication. Is possible.
[0020]
FIG. 4 is a block diagram showing another embodiment of the computer network system of the present invention. In the figure, computers 41 and 42 to which the same logical IP address 45 is assigned and a computer 43 as a client thereof are connected to a LAN 44 in units of computers 43 to which other logical IP addresses are assigned. The computers 41, 52, and 43 are connected to the LAN 44 via network adapters 41a, 42a, and 43a, respectively. It is assumed that the computers 41 and 42 are configured so that a packet having a logical address 45 specified as a destination can be received via the LAN 44.
[0021]
The logical IP address 45 is assigned an IP address having a different address from the LAN 44 and the network unit. Therefore, if the routing table 43e of the computer 43 does not have route information to either the computer 41 or 42, the computer 43 cannot specify and connect to the logical IP address 45. In the computers 41 and 42, server programs 41b and 42b, which are user processes, operate, and in the computer 43, the client program 43b operates.
[0022]
The basic operation of the computer network system shown in FIG. 4 will be described using the flowchart shown in FIG. When the client program 43b tries to connect to either the server program 41b or 42b, the logical IP address 45 assigned to the computers 42 and 42 is designated as the IP address of the counterpart device and connection is started (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 server program 41b (42b) that can communicate.
[0023]
If the IP address of the network adapter 41a is registered as the gateway as the route information of the logical IP address 45 in the routing table 43e, the client program 43b is connected to the server program 42b, and the IP address of the network adapter 42a is the gateway. Are registered to the server program 42b (steps S52 and S53).
[0024]
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 periodically transmits a packet for confirming whether or not normal communication with the route information update programs 41c and 42c can be performed (step S61). The route information update programs 41c and 42c that have received the packet send a reply back to the route information update program 43c (step S62).
[0025]
The route information change program 43c that received the reply determines whether or not the communication path and the computer are normal depending on whether or not the reply packet has been received. If it is determined that communication with the computer 41 can be normally performed, the IP address of the network adapter 41a is registered as the gateway in the routing table 43e as the route information of the logical IP address 45 (step S63). If it is determined that communication with the computer 42 can be normally performed, the IP address of the network adapter 42a is registered as a gateway in the routing table 43e as route information of the logical IP address 45 (step S64). If both the computers 41 and 42 communicate normally, it is determined which computer to connect to according to the priority specified in advance (step S65), and the route information to the determined computer is registered in the routing table 43e. Is done. If the computers 41 and 42 cannot communicate with each other, nothing is done (step S66).
[0026]
In this way, by using the logical IP address when the client program connects to the server program, there is no need to be aware of which of the multiplexed computers is connected, and the connection destination computer is switched. Even in this case, switching is possible without resetting the IP address.
[0027]
【The invention's effect】
As described above, according to the present invention, in a computer network system in which, for example, a LAN using the TCP / IP protocol is multiplexed, each device connected to the LAN is assigned separately from the IP address assigned to the network adapter. By using this logical IP address for communication between devices and specifying the communication path using the routing table, the contents of the routing table are dynamically updated according to the state of failure, etc. As a result, a program that communicates using a logical IP address does not need to consider what route is used to connect to the other party, and switches the communication route when a failure occurs. If a logical IP address is specified and connected, the IP address Troublesome work such as re-setting of the scan is not required.
[0029]
Therefore, LAN is in multiplexed computer network system, without the need to change the internal logic be a communication program that does not consider the system configuration, set up to connect by specifying the logical IP address Multiplexing support can be realized simply by
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of a computer network system of the present invention;
FIG. 2 is a flowchart showing basic operations of the computer network system in FIG.
FIG. 3 is a flowchart showing a processing procedure of a route 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 the 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, 42, 43) ... Computer, 13a (13b, 14a, 14b, 41a, 42a, 43a) ... Network adapter, 13c (45) ... Logical IP address, 13d (41b, 42b) ... server program, 14c (43e) ... routing table, 14d (43b) ... client program, 13e (14e, 41c, 42c, 43c) ... route information update program,

Claims (6)

A method for determining a communication path in a computer network comprising a plurality of devices in which communication lines are multiplexed and connected via respective network adapters for each of the multiplexed lines ,
The network adapter is assigned an explicit address as a communication path, and the plurality of devices are individually assigned logical addresses whose communication path information other than the address is not explicit,
Send a packet to the partner device to check whether the communication path is normal via the multiplexed line,
Determine whether the communication path is normal or abnormal depending on which communication path the reply packet has been received from the counterpart device for this transmission packet,
When it is determined that the first communication path is normal, the fact that the address of the first network adapter is a gateway is registered as the logical address path information in the routing table;
When it is determined that the second communication path is normal, the fact that the address of the second network adapter is a gateway as the logical address path information is registered in the routing table;
A communication path determination method in a computer network, wherein a communication path is determined by referring to a routing table in which the address of any one of the network adapters is registered as a gateway . When a client computer that is one of multiple devices connected via each network adapter for each multiplexed line connects to a server computer that is a partner device, a logical address whose communication path is not explicit in the routing table As the routing information, when the IP address assigned to the first network adapter is registered as a gateway, the IP address assigned to the second network adapter is registered as a gateway using the first communication line. 2. A method for determining a communication path in a computer network according to claim 1, wherein the second communication line is used when the communication network is connected. A computer network system comprising a plurality of devices in which communication lines are multiplexed and connected via respective network adapters for each of the multiplexed lines,
  The network adapter is assigned an explicit address as a communication path, and the plurality of devices are individually assigned logical addresses whose communication path information other than the address is not explicit,
  One of the plurality of devices is provided with a routing table capable of registering route information to the logical address,
  By transmitting a packet for confirming whether or not the communication path is normal via a multiplexed line from one device to the other device, and receiving a reply packet from the other device for this transmission packet, When the communication path through which the received packet is sent is determined to be normal and the first communication path is determined to be normal, the address of the first network adapter is stored as the logical address path information with respect to the routing table. A route for registering that the address of the second network adapter is a gateway as the logical address route information with respect to the routing table when it is determined that the second communication route is normal when it is registered as a gateway With information update means,
  The one device determines a communication path with the counterpart device by referring to the registered routing table that the address of one of the network adapters is a gateway.
  A computer network system characterized by the above.   The communication line is multiplexed, and consists of a plurality of devices connected via the respective network adapters for each of the multiplexed lines. The communication path information different from the normal address assigned to the network adapter is explicitly shown. Is used in a computer network system that assigns non-logical addresses to individual devices and changes the setting of the routing table according to the status of the communication path. Whether the communication path is normal to the other device via the multiplexed line A step of transmitting a packet for confirming the communication, a step of determining normality / abnormality of the communication channel according to which communication channel has been received, and when the first communication channel is determined to be normal In the routing table, the address of the first network adapter is used as the logical address route information. If the second communication path is determined to be normal, and the step of registering that the second network adapter is normal, the address of the second network adapter is the gateway as the logical address path information with respect to the routing table. A computer-readable recording medium in which a step of registering and a step of determining a communication path with reference to a routing table are programmed and recorded. 5. The computer-readable recording medium according to claim 4 , wherein when any communication path is determined to be normal, a step of selecting one of the communication paths according to a predetermined priority is further programmed and recorded. 5. The computer-readable recording medium according to claim 4, wherein a step of instructing to do nothing is further programmed and recorded when it is determined that any communication path is abnormal.

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