JPH09186718A - Path controller controlling network path and its method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow the method to make countermeasure and restoration to a network fault by controlling automatically a path such as communication lines configured as a network. SOLUTION: Each router in a computer network has a path table in which adjacent destination routers are registered for each communication. In the case of communication by a work station 11 via routers 4, 1 with a main frame 13, when the router 4 is defective, the router 4 reports a fault to adjacent routers 1, 2, 3. Each router receiving the notice excludes the router 4 to update the path table and other adjacent router is registered as a substitute router. Thus, a substitute path via routers 2, 5, 3, 1 is automatically set.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a route control device and method for dynamically controlling a route such as a communication route or a traffic route configured in a network.

[0002]

2. Description of the Related Art In recent years, with the decentralization of computer resources, a global computer network in which a plurality of communication networks are connected has been constructed. In such a large-scale network, it is becoming more and more important to provide a smooth communication environment, and conventionally, communication control using route information has been performed.

The route information is important basic information for determining to which network a packet of data sent to a network is to be transferred and, if so, where to relay it. The route information is held in the form of a route table (routing table) in a device (gateway) that relays the network.

The routing table is a paired table of an end point address and an address of an adjacent gateway to be relayed to deliver a data packet to the end point address. Each gateway is
Each time a packet of data arrives, the address of the next gateway is obtained from the routing table and the packet is transferred to that gateway. In this way, the packet is delivered to the destination.

The route information is held by each gateway, and the contents thereof must be managed consistently throughout the network. In today's large-scale network environment, failures, construction, maintenance and inspections occur daily. Furthermore, the connection state of the network is constantly changing, such as new devices and terminals being connected to the network. The route information has to be updated according to this change, but it is practically impossible to manually set the route information or to centrally manage the entire route somewhere.

Therefore, a protocol for maintaining and distributing the route information has been decided, and a popular one is RIP (Routing Information Protocol) defined in RFC (Requests For Comments) 1058. RIP is used for the routing control of the IP protocol of the Internet, and Novell's network O
NetWare's IPX / SPX protocol that is S, Appl
Almost the same format is used for the routing control of the Apple Talk protocol adopted by e's Macintosh.

[0007]

However, the above-mentioned conventional route information control has the following problems. When a failure occurs in a network device that holds and distributes route information, a failure also occurs in the work of holding and distributing it.
In the worst case, the distribution of the route information may be stopped and the communication of the entire network may be stopped. At present, devices do not have the ability to recover autonomously, so the network will remain in a confused or suspended state until the administrator manually recovers the failed device.

At present, it is not possible to centrally manage route information at one location, and it is not possible to manually set it. For this reason, there is no effective method for automatically securing an alternative route by bypassing a failed device on the network or limiting the flow of packets on the network.

Therefore, when the network is temporarily overloaded, or when the network itself goes down due to a failure or the like, the administrator currently uses a management tool or device to manually check the network status. Often dealt with. At this time, the network is in an abnormal state, so even with a management tool or device that operates effectively during normal times, its operation is blocked by the load of abnormal communication on the network, and as a result Is likely to be delayed.

It is an object of the present invention to provide a route control device and method for automatically controlling a route such as a communication route configured in a network form to deal with and restore a network failure.

[0011]

FIG. 1 is a principle diagram of a route control device of the present invention. In FIG. 1, the information processing device 1
And 4 are provided on a communication network including a plurality of routes and operate as a route control device.

The information processing apparatus 1 comprises a detection means 2 and an instruction means 3. The detection means 2 is the first on the network.
To detect anomalies related to the route. When an abnormality occurs in the first route, the instructing unit 3 instructs the other information processing device 4 on the network to update the local route information regarding the first route, and becomes an alternative as soon as possible. The second route is searched.

The abnormality relating to the first path means a state in which normal communication is disturbed, such as an increase in communication load (congestion), communication failure, equipment failure on the path, and illegal communication. When the detecting means 2 which monitors the communication passing near the information processing device 1 detects such an abnormality, the detecting means 2 notifies it.
Tell

The instructing means 3 instructs the information processing device 4 via the network to search for a second route which is an alternative to the first route before the first route becomes completely unusable. In response to this instruction, the information processing device 4 updates the route information regarding the first route and checks whether there is an alternative route.

As the route information, for example, a route table based on RIP is used. The routing table does not contain the connection information of all the devices on the communication route. For example, when data is sent to a certain target device distant from the information processing device 4, which adjacent device (router) Etc.) is stored. Therefore, the route information describes a local transmission destination near the information processing device 4.

When the route table is used, the information can be updated by exchanging the information between the adjacent devices on the network based on the RIP. In the present invention, the information processing device 4 updates the route information according to the instruction from the instruction means 3.

At this time, if the adjacent device included in the first route is removed from the destination, another adjacent device may be automatically registered as a new destination. If such an alternative destination is found, the route including it is the alternative route.

The information processing device 4 comprises a receiving means 5, a searching means 6 and a storing means 7. The receiving means 5 receives the abnormality notification regarding the first route on the network. The search unit 6 updates the local route information regarding the first route stored in the storage unit 7 based on the abnormality notification, and searches for an alternative second route earlier.

When the information processing device 1 notifies the receiving means 5 that an abnormality has occurred on the first route, the receiving means 5 notifies the search means 6 of the abnormality. In response to this, the search means 6
RIPs the route information described in the above route table, for example.
Find an alternate destination based on your updates. Then, if an alternative transmission destination is found, it is registered as the route information regarding the second route.

The information processing device 4 can also manage the route information of any network other than the communication network, such as a transportation network. In this case, the information processing device 4 can be provided separately from the network, and the receiving means 5 is not always necessary. The storage means 7 stores local route information of the network. When an abnormality occurs in the first route on the network, the search means 6 changes the route information in the vicinity of the place where the abnormality has occurred, and searches for a second alternative route earlier.

As the route information in this case, local information is used as in the route table in the communication network.
For example, for each node on the network, the next adjacent destination node is stored as information on the route to the destination. Then, when an abnormality occurs in the first route, the search means 6 updates the route information corresponding to some nodes in the vicinity of the place, and searches for an alternative destination node. If such a destination node is found, it is registered as the route information regarding the second route.

By using such a route control device, the network itself can automatically set the detour route when the network is temporarily overloaded or when the network itself goes down. The administrator does not need to check the network status and set an alternative route, and also does not need to register the alternative route of each route in advance.

For example, the information processing device 1 in FIG. 1 corresponds to the router 4 in FIG.
Corresponds to Router 1, Router 2, and Router 3. Also,
For example, the detection unit 2 is the communication port control unit 4 in FIG.
2, the instructing unit 3 and the searching unit 6 correspond to the control agent unit 41, the receiving unit 5 corresponds to the communication port 58 in FIG. 11, and the storage unit 7 corresponds to the memory 57.

[0024]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 2 shows the computer network of the embodiment. The computer network of FIG. 2 includes four networks, net 1, net 2, net 3, and net 4. Net 1
And the net 2 are connected via the router 3, and the net 2 and the net 3 are connected via the router 4. The net 3 and the net 4 are connected via the router 2, and the net 4 and the net 1 are connected via the router 5.
These routers act as gateways between networks.

In addition, the workstation 1 is connected to the net 3.
1 is connected, and the management server 12 is connected to the net 2. Further, a mainframe 13 is connected to the net 2 via a router 1. It is assumed that a user uses the mainframe 13 from the workstation 11 in such a network.

In RIP and the like currently popular, a route is selected on the basis of the number of gateways (the number of relays) through which a data packet passes before reaching an end point. For example, as a communication path from the workstation 11 to the mainframe 13, the workstation 11 == net 3 == router 4 ==
The net 2 == router 1 == mainframe 13 1 is adopted.

It is assumed that the router 4 malfunctions during use in this state. At this time, in FIG. 2, the workstation 11 == net 3 == router 2 ==
There is a detour route called net 4 == router 5 == net 1 == router 3 == net 2 == router 1 == mainframe 13 In this case, the router 1, the router 2, the router 3, and the router 4 mainly function as the route control device, and automatically set the bypass route in the route table.

In addition to the route table, each router holds an emergency contact table for managing the notification destination router when a failure occurs, and issues an abnormality notification with reference to this. Upon receiving the notification, the router exchanges the route information with another router according to the RIP at a timing other than the normal route table update, and updates the route table of its own router. As a result, if a new router that replaces the abnormal router is registered in the routing table, it is set as an alternative route.

For example, the malfunctioning router 4 manages the adjacent routers 1, 2 and 3 on the network as notification destinations, and notifies each of these routers of abnormality. Upon receipt of the notification, each router excludes the router 4 and updates the routing table based on the RIP, and registers the router belonging to the route with the next smallest number of relays as the alternative router.

As a result, the router 3 is registered in the routing table of the router 1 instead of the router 4, and the routers 2 and 3 are registered.
The router 5 is registered in place of the router 4 in the routing table. Since the route table of the router 5 is originally set with the information connecting the routers 2 and 3, the above-mentioned detour route is automatically secured.

The router to which the alternative route is set notifies the router 4 of that fact, and the router 4 marks those routers in the emergency contact table. This distinguishes the router for which the alternative route has been set from the router for which the setting has failed. Further, the routing table of the router 4 is saved without being updated, and is used again when the router 4 is restored.

At the time of restoration, the router 4 refers to the emergency contact table and gives a restoration notice to the marked router. In response to this, the router 1, the router 2, and the router 3 reset their routing tables to the original state. In this way, the communication path that has passed through the router 4 before the abnormality occurs can be used again.

The transmission of the route control information between the routers as described above can be realized by an arbitrary communication process, but in the following embodiments, a method using Telescript, which is a language based on remote programming, is used as an example. I will use it.

In remote programming by telescript, an agent which is a kind of process for holding data is used. In this case, since it is possible for each agent to have the monitoring request information of each user, it is possible to process the requests of a plurality of users independently. In addition, the agent functions autonomously and automatically disappears when processing is completed,
It is suitable for processing on the network used by an unspecified number of users.

Regarding remote programming by telescript, "Implementation method of remote programming" (Japanese Patent Application No. 6-179767 and Japanese Patent Application Laid-Open No. 7-18217).
Although detailed in 4), the method will be described here.

This remote programming is a kind of method for describing processing on a communication network connecting a plurality of computer systems, and is an agent that is a movable process that walks across the network and a place that is a fixed process in which the agent enters. It is realized by (Place).

FIG. 3 shows the structure of the place. Places are telenames that can be distinguished from other processes.
name) and can have any finite number of child processes. The place has an arbitrary finite number of data that can be referred to by itself and other processes, and an arbitrary finite number of procedures that can be called by itself and other processes.

Furthermore, the procedure live is used as the main routine.
And the created place executes live. Places exist only while live is running, and l
It disappears when Ive ends. When the place disappears,
The child process also ends and disappears.

FIG. 4 shows the configuration of the agent. An agent has a telename that distinguishes it from other processes and exists only as a child process in a place. Further, the agent has an arbitrary finite number of data that can be referenced by itself and other processes, and an arbitrary finite number of procedures that can be called by itself and other processes.

Further, as the main routine, the procedure li
ve, and the created agent executes live. The agent exists only while the live is being executed, and disappears when the live ends. When the command go is executed in the agent's procedure live, the agent moves to the specified destination via the network.

FIG. 5 shows an example of the operation by the command go. In FIG. 5, the agent 22 in the place 21 is a ticket (Ticket) 2 that is data that specifies the destination place 24 by executing go.
Obtain 3 and move to the designated place 24.

At this time, the agent 22 suspends the execution of live by go, freezes (compresses) together with the held data, and packs it. Then, it is sent to the place 24 indicated by the ticket 23, and the place 24
Checked by acceptance. When it is accepted into place 24, it is placed in it as a child process,
It is decompressed (expanded), and execution of live is resumed from the command next to go.

In addition, the agent can call the command meet for another agent in the place where the agent is placed in the procedure live.
When the command meet is executed, the agent is a petition (Pe
tition).

FIG. 6 shows an example of operation by the command meet. In FIG. 6, place 31
The agent 32 inside specifies a petition by the command meet. The place 31 searches for agents that meet the conditions specified by the petition. Then, if there is no corresponding agent in the place 31, it waits until such an agent comes in.

If the agent 33 in the place 31 satisfies the petition condition, the place 31 informs the agent 33 that the agent 32 desires interaction. Then, when the agent 33 returns a return value indicating that the agent 32 accepts the wishes of the agent 32, the place 31 meets the pointer to the agent 33 by meeting.
Is returned to the agent 32. After that, the agent 32 can directly access the agent 33 to exchange information.

FIG. 7 shows a schematic configuration of each router when the remote programming method as described above is applied to the route control of the network of FIG. The router of FIG. 7 includes a control agent unit 41, a communication port control unit 42,
And a communication port unit 43.

The communication port control unit 42 creates / holds a route table required for communication and controls the communication port unit. The communication port unit 43 controls the communication port according to an instruction from the communication port control unit 42 or the control agent unit 41, and monitors the data flow. For example, the communication port control unit 4
From 2, an instruction such as filter setting for shielding communication and port monitoring is sent to the communication port unit 43, and the communication port unit 43 returns the setting result and filter information.

The control agent section 41 generates a control agent which is a control process for controlling the communication path of the network on behalf of the administrator and operates it in an appropriate place. The control agent can move to another device on the network and exchange information with the control agent in the device by the command meet. The control agent unit 41 is mounted on each network device such as a gateway device that holds and distributes route information on the network or a terminal hub.

The specific operation contents of the control agent are as follows. (1) Route control of a communication path is a basic operation such as creation of a bypass communication path (alternative path) at the time of failure. In such a case, the communication port control unit 42 and the communication port unit 43 are controlled.
Specifically, the communication port control unit 42 is instructed to initialize and set the route information, and receives the setting result and the route information. Further, the communication port unit 43 is instructed to set filters and monitor, and receives setting results and filter information. (2) During normal times, monitor the communication path to check the load status, and regularly communicate with the control agents of other communication devices to store the priority communication destination address in an emergency called the emergency contact list. Keep and update the table. (3) In order to prevent misconnection by the administrator or spoofed connection by a third party if the communication path is disconnected once, when the communication path is re-established, mutual authentication of the devices with other control agents I do. Then, after confirming the authentication, the communication path is restored.

The control agent unit 41 is independent of the hardware so that it can communicate with other devices even if the communication port control unit 42 or the communication port unit 43 fails. Is desirable.

Next, referring to FIGS. 8 to 10, the control agent unit 41, the communication port control unit 42,
The contents of data held by the communication port unit 43 will be described. The method of using these data will be described later.

FIG. 8 shows the data structures of the emergency contact table, control agent self-information, and authentication decryption key held in the control agent unit 41. The emergency contact table is created in a list format for the number of transmission targets, and includes the address of the transmission target router, the encryption key for the transmission target router, and the target flag.

The emergency contact table stores the address of the router that can reach the router with the minimum number of relays as the address of the transmission target router when a failure occurs in the router. In reality, since the number of relays to other routers belonging to the same net as the router itself should be the minimum, they are the transmission target routers to be notified.

That is, the routers belonging to the same net have mutual addresses as notification destinations for emergency contact. A router that is a candidate for setting an alternative route is selected from these transmission target routers. This makes it possible to quickly search for an alternative route even when a failure occurs.

The target flag is mainly used for managing the notification destination at the time of restoration. When the failure information is first sent to the transmission target router, data such as "transmission" is stored in the target flag.

The control agent self information includes the address of the self router, the latest routing table information of the self router, the encryption key required by the other party for transmission to the self router, and the control agent status flag. The control agent can move on the network with this self-information. The status flag stores data indicating the processing status of the control agent, such as “notification”, “completion”, and “illegal”.

Further, as the authentication decryption key, a decryption key required for authentication at the own router is stored. FIG. 9 shows the data structure of the routing table held in the communication port control unit 42. The routing table consists of the sending address (destination address) that represents the destination, the address of the router that is the route to the sending address (destination router address), the number of relays to the sending address, the substitution flag, and the router that made the substitution request Contains the address (alternate request router address). The substitute flag stores data representing the role of the destination router, such as “normal”, “substitute”, and “original”.

FIG. 10 shows the structure of data held in the communication port unit 43. The communication port unit 43 holds a communication port number, control information such as the type of shielding filter currently set, and an identification flag.

FIG. 11 shows a system configuration example of the router of FIG. The router shown in FIG.
5, communication port 58, and bus 54 connecting them
And is connected to the communication network 59 through the communication port 58. Here, the communication network 59 corresponds to, for example, the net 1, the net 2, the net 3, and the net 4 in FIG.

The processing unit 51 is a CPU (central processing unit).
52 and a memory 53, a control agent is generated by executing a program using the memory 53, and the function of the control agent unit 41 is realized.

Further, the processing device 55 is provided with a CPU 56 and a memory 57, and realizes the functions of the communication port control unit 42 and the communication port unit 43 by executing the program using the memory 57.

As described above, by making the control agent unit 41 hardware independent from the communication port control unit 42 and the communication port unit 43, it is possible to operate the control agent correctly even if the router main body fails. become.

Next, the route control processing and the restoration processing when the router 4 malfunctions will be described in detail with reference to FIGS. 12 to 19. FIG. 12 shows a route table in each router before an abnormality occurs in the router 4,
FIG. 13 shows a routing table in each router after the occurrence of an abnormality. 14 to 19 show the processing flow of the control agent of each router.

FIG. 14 is a flowchart of the processing of the communication port control unit 42 and the control agent of the router 4 which has become abnormal. When the process is started in FIG. 14, the communication port control unit 42 informs the control agent unit 41 on its own router of "abnormal" due to the malfunction of the router (step S1), and performs the process. To finish.

The control agent of the control agent unit 41 regularly watches the signal from the communication port control unit 42 and catches this abnormality notification (step S2). Next, the communication port unit 43 is instructed to filter (block) the communication communication protocol and the communication port used by the control agent itself for communication (step S).
3).

As a result, the router 4 is isolated from the normal communication route. At this time, the communication port unit 43
In the identification flag of the filtered port (see FIG. 10),
Set as "Router 4".

Next, the control agent searches the emergency contact table as shown in FIG. 8 stored in the control agent section 41 in order to find another router which becomes a candidate for an alternative route when the own router is abnormal. Yes (step S4). Then, it is checked whether or not the target router to be notified of the abnormality is registered (step S5).

In this example, the router 1 and the router 3 belonging to the net 2 to which the router 4 is connected, and the router 2 belonging to the net 3 are registered in the emergency contact table as transmission targets. Therefore, since the router to be notified is found in the emergency routing table, the control agent sends the command send.
Is executed, and its own copy is created by the number of transmission target routers (step S6). At this time, the control agent self information is also copied at the same time.

Send is an agent procedure liv.
command executed in e to make a copy of the agent and send it to another place. Here, send
By executing, the processing of steps S6, S7, and S8 is performed.

The control agent sets the status flag of the self-information of the created plurality of agents to "notification" (step S7). At this time, multiple agents are encrypted by using the encryption key for each notified router. Next, the replication agent is sent to the transmission target router (routers 1 to 3 in this example), and at the same time, the target flag of the emergency contact table is set to "transmission" (step S8).

The control agent of the router 4 which is the transmission source performs a standby procedure (step S9), and is in a standby state until all the transmitted replication agents have returned. If the replication agent does not return, some processing such as notifying the administrator, resending, stopping due to an error, etc. is performed as exception processing.

FIG. 15 is a flowchart of the waiting procedure of the control agent performed in step S9. FIG.
When the processing is started in 5, the control agent
An authentication procedure as shown in FIG. 16 is performed for each returned duplicate agent (step S21).

When the processing is started in FIG. 16, the control agent decrypts the agent sent back from another router with the decryption key held by itself (step S31). Next, the address of the own router in the self information of the agent is compared with the address of the router to be transmitted which is held in the emergency contact table (step S32), and the process is ended.

Next, in step S22 of FIG.
Authenticate whether the address of the incoming agent is correct. Since the address of the returned replication agent is rewritten to the address of the source router at the time of transmission, it should match with the address of one of the destination routers in the emergency contact table.

If the address of the transmission target router matches,
It is determined that the address is correct, and 1 is added to the counter value of the number of receiving agents (step S23). And
It is determined whether or not the counter value has reached the number of transmitted replication agents (step S24), and if reached, the processing ends.

If the addresses do not match in step S22, or if the counter value does not reach the number of transmitted replication agents in step S24, the processing from step S21 is repeated.

When it is confirmed that all the plurality of agents have returned, the status flags of them are checked (step S10). And the status flag is "out of route"
If it returns with, the setting of "transmission" in the target flag of the corresponding transmission target router of the emergency contact table is canceled. This means that the target router cannot be used as an alternative route.

When the status flag returns "invalid", some processing such as notifying the administrator, resending, stopping due to an error, etc. is performed as an exception processing. The multiple agents from the router to which the alternative route is set return with the status flag set to “complete”.

In this way, it is possible to know that the alternative routes have been set on some routers by returning the transmitted multiple agents. Therefore, the administrator is instructed to start the work (step S10), and the process is terminated. To do. afterwards,
The administrator restores the malfunctioning router 4. In step S5, when the notification destination router is not registered in the emergency contact table, the process of step S11 is immediately performed, and the process ends.

FIG. 17 is a flowchart of the process of the control agent of a normal router which has received a plurality of agents from the router 4. In this example, the router 1, the router 2, and the router 3 perform this processing. When the process is started in FIG. 17, the control agents of the routers 1 to 3 first perform the authentication procedure of the sent agent (step S41).

Here, the sent agent is decrypted (FIG. 16, step S31), and the address of the router to be sent which the local router has in the emergency contact table is compared with the address of the sent agent (step S31). S3
2). Then, it authenticates whether or not it is a replication agent from a correct transmission source (step S42).

Since the address of the router 4 is supposed to be registered in the emergency contact tables of the routers 1 to 3, the duplicate agent sent from it is authenticated as a correct agent.

If the sent address of the agent is not correct, the status flag is set to "invalid" (step S52), the agent is sent back to the source router (step S51), and the process is terminated. Alternatively, step S
Exception handling may be performed at 52.

If the address of the agent sent is correct, then the route table in the communication port control unit 42 of the router in which it is located is searched for a route containing the address of the router 4 owned by the duplicate agent. . Then, the substitute flag is set to "original" (step S4).
3).

For example, in the route table of the router 2 shown in FIG.
Since it is described that the destination router when transmitting to the net 2 is the router 4, the substitute flag of that route is set to "original" as shown in FIG. This means that the route cannot be used because an abnormality has occurred in the router 4.

Next, the communication port control unit 42 is instructed to update the routing table of its own router (step S4).
4). As a result, the communication port control unit 42 exchanges route information with other routers belonging to the same net, obtains a destination router other than the malfunctioning router 4, and updates the route table. However, in this updating process, the route in which the alternative flag is set to a value other than "normal" is not deleted.

Next, the latest routing table of the router 4 included in the self-information is received from the duplication agent coming from the router 4 (step S45), it is searched (step S46), and it is in the routing table. It is checked whether or not the destination address is the destination address in the routing table of the router itself (step S47).

If the destination address of the router 4 is not in the route table of the own router, the own router does not become the alternative route, so the status flag of the copy agent coming from the router 4 is set to "outside route" (step S47). ). Then, the data is encrypted with the encryption key for the router 4 and sent back to the router 4 (step S51), and the process ends.

If the destination address of the router 4 is in the route table of the own router, the substitute flag of that route is set to "substitute". As a result, the specific route including the router that received the duplicate agent is automatically set as the alternate route.

For example, in the route table of the router 2, as a result of the communication port control unit 42 exchanging the route information with the router 5 by the update process, the destination router when transmitting to the net 2 as shown in FIG. Is newly added as the router 5. Therefore, the alternative flag of the route is set to "alternative".

Next, the address of the router 4 which has sent the replication agent is set as the "address of the router which has made the substitution request" for that route (step S49). Here, the address of the router 4 is set as the alternative request router address in the route whose alternative flag in the route table of the router 2 is "alternative".

Next, the status flag of the copy agent coming from the router 4 is set to "complete", encrypted with the encryption key for the router 4 (step S50), and sent back to the router 4 (step S51) to perform the processing. finish. Thus, the setting of the alternative route is completed.

The routing tables of the router 1 and the router 3 of FIG. 12 are updated in the same manner as the router 2, and the substitution flag and the like are rewritten to become the routing table shown in FIG. As a result, the workstation 11 == net 3 == router 2 == net 4 == router 5 == net 1 == router 3
== Net 2 == Router 1 == An alternative route such as the mainframe 13 is set.

Incidentally, in FIG. 13, the routing table of the router 5 which has not received the copy agent from the router 4 is not changed. When the replication agent having the “completed” status flag returns from the router 1, the router 2, and the router 3 to the router 4, the administrator performs work such as repair of the router 4.
When the work is completed, the administrator instructs the control agent of each router to perform the process at the time of restoration.

FIG. 18 is a flow chart of processing when the control agent on the router 4 is restored. When the process starts in FIG. 18, the control agent first sets the pre-abnormal routing table held as self-information in the communication port control unit 42 (step S61). At this time, since the communication port unit 43 is still filtered, it does not disturb the route of the packet passing to another alternative router.

Next, referring to the emergency contact table, it is judged whether or not there is a router to be notified of the restoration (step S6).
2). The transmission target router whose target flag in the emergency contact table is set to "transmission" is the router to be notified.

If there is no router to be notified, the communication port unit 43 is instructed to cancel the filter having the identification flag of FIG. 10 set to "router 4" among the filters set to the communication port 58. (Step S67), the process ends.

If there is a router to be notified, the command se
nd is executed to perform the processing of steps S63, S64, and S65. First, duplicates are created as many as the number of notification target routers (step S63), and the status flags of the created multiple agents are set to "notification" (step S6).
4). At this time, use the encryption key for each router to notify,
Encrypt multiple agents.

Next, the replication agent is sent to the notification target router (routers 1 to 3 in this example) (step S6).
5) The standby procedure shown in FIG. 15 is performed, and the standby state is set until all the duplicate agents sent have returned (step S66). If the duplicate agent does not return, some exception processing is performed.

When the duplicate agents return, the authentication procedure as shown in FIG. 16 is performed for each (step S2).
1). If the status flag returns "invalid", some exception processing is performed.

When all the replication agents have returned, then the communication port unit 43 is instructed to cancel the filter whose identification flag is set to "router 4" (step S67), and the process is terminated.

Thus, the filter of the communication port 58 of the router 4 is released and the router 4 returns to the normal state. FIG. 19 is a flowchart of a process at the time of restoration of the control agents on the router 1, the router 2, and the router 3 which have received the duplicate agent. When the process is started in FIG. 19, the control agent first performs the authentication procedure as shown in FIG. 16 (step S71), decrypts the duplicate agent sent (step S31), and the own router sends the emergency contact table. The address of the router to be transmitted, which is included in the above, is compared with the address of the sent agent (step S32). Then, it authenticates whether or not it is a duplicate agent from the correct source (step S72).

If the sent address of the agent is not correct, the status flag is set to "invalid" (step S77), and it is sent back to the sender router (step S76), and the process is terminated. Alternatively, step S
Exception handling may be performed at 77.

If the agent's address sent is correct, then, in the routing table in the communication port control unit 42 of the router in which it is located, the alternative flag set to "original" is reset to "normal". It is set (step S73). For example, in the routing table of the router 2 in FIG. 13, the substitute flag of the transmission route to the net 2 via the router 4 is set to "original", and therefore it is reset to "normal".

Next, the route whose substitute flag is set to "substitute" is deleted in the route table of the own router. For example,
In the routing table of the router 2, the alternative flag of the transmission route to the net 2 via the router 5 is set to "alternative".
Delete this route from the routing table.

Next, the status flag of the copy agent coming from the router 4 is set to "complete" and encrypted with the encryption key for the router 4 (step S75). Then, it is sent back to the router 4 (step S76), and the process ends.

The routing tables of the router 1 and the router 3 of FIG. 13 are rewritten in the same manner as the router 2, and the routing table before the abnormality occurrence as shown in FIG. 12 is restored. As a result, the workstation 11 passing through the router 4 == net 3 == router 4 == net 2 == router 1 == mainframe 13
The route will be available again.

In this embodiment, when changing or switching the communication route, it is necessary to guarantee the data on the route at that moment. Fortunately, for communication on a packet-by-packet or cell-by-cell basis that requires route control, the currently used communication protocol basically has a technology called "retransmission when communication fails". Sex is guaranteed.

Even when this embodiment is used, it is impossible to switch the route in zero time, so it is expected that retransmitted packets will appear to some extent. However, the number of retransmitted packets can be expected to be considerably reduced by controlling the switching of routes by the control agent.

Further, in the present embodiment, the conventional route control protocol such as RIP can be utilized as it is.
The path control device can be realized relatively easily. According to the embodiment using remote programming as described above, by utilizing the autonomy of the control agent, each device on the network voluntarily discovers an abnormality and secures an alternative route. Therefore, the administrator can concentrate on the recovery work of the abnormal device by omitting the work of setting the alternative route.

In the present embodiment, the router has the function of the route control device, but the present invention is not limited to this, and the route control device can be provided in any device on the network. Further, the connection form of the network is not limited to that shown in FIG. 2 and can take any form.

If the duplicate agent created when an abnormality occurs cannot find an alternative router on the destination router, it may repeat self-copy until it can find it. In this case, by referring to the emergency contact table of each destination router, the duplicate agents as many as the number of the destination routers are created.

Further, it is not always necessary to use an agent when carrying out the present invention, and each control agent may be processed by an ordinary process. In this case, the communication via the network is, for example, RP.
It is executed by C (remote procedure call) or the like.

Another application example of the present invention is as follows. [1] Construction of a firewall (fire wall) to protect the security of the communication network When a communication to an access prohibited destination is found while monitoring the communication path, the communication path for that communication is dynamically filtered. [2] Line control during traffic concentration time of commercial communication network Depending on the load on the line, increase the number of communication channels for communication,
Temporarily suppress other communication. [3] Control of traffic routes during congestion or disaster Instead of controlling communication routes, control routes through which people and goods flow. For example, traffic light control is performed on a traffic route arranged in a network to adjust the traffic volume during congestion.

[0115]

According to the present invention, it is possible to dynamically control a route such as a communication route or a traffic route configured in a network and autonomously secure an alternative route when a failure occurs. Therefore, when the network is temporarily overloaded or when the network itself goes down, the network itself can automatically set the detour route.

Therefore, it is not necessary for the administrator to check the network condition and set an alternative route, and it is not necessary to register the alternative route in advance when a certain device becomes out of order.

[Brief description of the drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a diagram showing a computer network.

FIG. 3 is a diagram showing a configuration of a place.

FIG. 4 is a diagram showing a configuration of an agent.

FIG. 5 is a diagram showing an operation go.

FIG. 6 is a diagram showing an operation meet.

FIG. 7 is a schematic configuration diagram of a router.

FIG. 8 is a diagram showing a data structure in a control agent unit.

FIG. 9 is a diagram showing a data structure in a communication port control unit.

FIG. 10 is a diagram showing a data structure in a communication port unit.

FIG. 11 is a system configuration diagram of a router.

FIG. 12 is a diagram showing a route table before occurrence of an abnormality.

FIG. 13 is a diagram showing a route table after an abnormality has occurred.

FIG. 14 is a flowchart of processing of an abnormal router.

FIG. 15 is a flowchart of a waiting procedure of the control agent.

FIG. 16 is a flowchart of a control agent authentication procedure.

FIG. 17 is a flowchart of processing of a normal router.

FIG. 18 is a flowchart of processing of an abnormal router at the time of restoration.

FIG. 19 is a flowchart of processing of a normal router at the time of restoration.

[Explanation of symbols]

 1, 4 Information processing device 2 Detecting device 3 Instructing device 5 Receiving device 6 Searching device 7 Storage device 11 Workstation 12 Management server 13 Mainframe 21, 24, 31 Place 22, 32, 33 Agent 23 Ticket 41 Control agent part 42 Communication Port control unit 43 Communication port unit 51,55 Processor 52,56 CPU 53,57 Memory 54 Bus 58 Communication port 59 Communication network

Claims (13)

[Claims] 1. An information processing device, which is provided on a communication network including a plurality of routes and manages route information for communication control, comprising: detecting means for detecting an abnormality relating to a first route on the network; When an abnormality occurs in the first route, the other information processing device on the network is instructed to update the local route information regarding the first route, and the second route serving as an alternative is promptly selected. A route control device comprising: an instruction means for searching. 2. The route control device according to claim 1, wherein the instruction means holds an emergency contact table that stores address information of the other information processing device as a contact address. 3. The route control device according to claim 1, wherein the instruction means sends an agent process to the other information processing device to search for the second route. 4. An information processing device, which is provided on a communication network including a plurality of routes and manages route information for communication control, comprising: receiving means for receiving an abnormality notification regarding the first route on the network; A route control device comprising: a search unit that updates local route information about the first route based on the abnormality notification, and searches for an alternative second route earlier. 5. The route control device according to claim 4, further comprising a notifying unit that notifies another information processing device that the alternative route has been set when the second route is found. 6. The route control device according to claim 4, wherein the search means updates the route information regarding the first route by exchanging route information with another information processing device. 7. The receiving means receives an agent process informing of the abnormality, and the searching means refers to the identification information of the first path held by the agent process to refer to the second path. The route control device according to claim 4, wherein 8. The route according to claim 7, further comprising notifying means for setting information indicating whether or not the second route has been found in the agent process and sending the information back to the information processing device of the transmission source. Control device. 9. An information processing device for managing route information of a network including a plurality of routes, wherein an abnormality has occurred in a storage unit for storing local route information of the network and a first route on the network. Time,
A route control device comprising: a search unit that changes route information in the vicinity of a place where the abnormality has occurred and searches for an alternative second route earlier. 10. A function of detecting an abnormality related to a first route on the network when used by an information processing device provided on a communication network including a plurality of routes, and an abnormality of the first route. When it occurs, the information processing device has a function of instructing another device on the network to update the local route information regarding the first route and searching for a second route as an alternative as soon as possible. A readable medium for performing on. 11. A function of receiving an abnormality notification regarding a first route on the network when used by an information processing device provided on a communication network including a plurality of routes, and based on the abnormality notification, A readable medium for causing the information processing apparatus to perform a function of updating local route information about the first route and searching for an alternative second route earlier. 12. A function of creating local route information of the network when used by an information processing device for managing route information of a network including a plurality of routes, and an abnormality in a first route on the network. When occurs,
A readable medium for causing the information processing apparatus to perform a function of changing route information in the vicinity of a place where the abnormality has occurred and searching for a second alternative route earlier. 13. A method of managing route information of a network including a plurality of routes, wherein local route information of the network is created, and when an abnormality occurs in a first route on the network,
A route control method characterized by changing route information in the vicinity of a place where the abnormality has occurred to search for an alternative second route earlier.