JPH06132959A - Routing control system - Google Patents

Abstract

PURPOSE:To ensure the dynamic change of the routing information in the small traffic as less as possible against the change of numbers of routers and LANs connected to a routing control system or against the faults. CONSTITUTION:A routing manager 101 is added to a public network 100 to attain the integrated network control and routing control. The manager 101 also contains a routing subject list 11 to show the routers 104-110 set at the relaying points of all LAN 120-130 that can be connected to each other via the network 100. The addition or deletion of routers, the switching of the relaying routes, the addition or deletion of LANs, etc., are all informed to the manager 101. Receiving these information, the manager 101 updates the list 11. Then the manager 101 informs each router of the necessary minimum information for the updating of the routing information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a local area network (LAN) connected through a public network (WAN).
The present invention relates to a routing management system that dynamically manages routing information when relaying data between networks at the network layer level of the OSI reference model by a router provided at a relay point.

[0002]

2. Description of the Related Art In a conventional large-scale local area network, a plurality of local area networks are connected via a router (relay device), and wide area information can be exchanged using a public network. . Figure 2
Figure 1 shows the network block diagram of the conventional system. In this system, the public network 200 is connected to the router 2
LANs 220 to 230 are connected via 04 to 210. In addition, a router 211 is appropriately provided between these LANs.
~ 216 for relay connection.

In such a system, each router 2
Each of 04 to 216 holds routing information for managing a route for transferring a signal in order to perform relay at the network layer level of the OSI reference model. For example, when the router 204 shown in FIG. 2 receives a request to transfer a signal input via the public network 200 to the LAN 221, the routing information is used to determine that the signal should be transferred to the router 211 via the LAN 220. Do it. The following methods have been conventionally proposed as means for acquiring such routing information.

First, the routers directly connected to each other via the LAN, for example, the routers 204, 205, 211 and 212 connected via the LAN 220 and the LAN 222, perform a general process for notifying the routing information of the LAN. The routing information is dynamically obtained by the routing protocol. That is, when the number of routers connected to the LAN increases or decreases or a new LAN is connected,
Detailed routing information is notified each time by the LAN routing protocol.

On the other hand, between the routers 204 to 210 connected to each other via the public network, since the public network itself does not have this kind of routing protocol, the network address of the LAN reachable by each router is fixed in advance. Register in advance. Therefore, for example, LANs that can be reached through the router 208 are registered in the router 204, such as LAN 229 and LAN 230. Then, a router is newly connected to each router, LA
When N is connected, its routing information is artificially updated at an appropriate timing.

[0006] It should be noted that the method of registering such routing information in a fixed manner and periodically updating its contents artificially cannot deal with the increase or decrease of the number of routers or the increase or decrease of the number of LANs. A method of updating routing information between routers connected to a public network using a protocol similar to the routing protocol has also been proposed.

[0007]

The conventional system as described above has the following problems to be solved. First, for example, in a system that communicates via a public network, if a failure occurs at any one place in the network, an alternative route for bypassing the failure must be set. However, usually, a router holds only one route, and it is impossible to dynamically change the route as needed. On the other hand, as described above, if the public network is notified of the routing information by the same routing protocol as the LAN, such a dynamic change becomes possible. However, in this case, L is also used in the public network for notifying the routing information.
It is necessary to perform the same broadcast communication as the AN.

FIG. 3 shows a comparative explanatory diagram of this type of broadcast communication. FIG. 3A is an explanatory diagram of broadcast communication using a LAN. As shown in this figure, for example, LAN
Three routers 251, 25 connected via 240
It is assumed that the routers 2, 253 receive the routing information change notification from the router 250. In this case, the router 250 transmits the broadcast packet to the LAN 240 only once. Each of the routers 251, 252, 253 receives the information as its own information and updates the respective routing information.

Further, FIG. 3B shows a broadcast communication explanatory diagram by the public network. As shown in the figure, when the public network is used, the same routing information as the routers 250 to 3 is used.
When sending to a single router 251, 252, 253, it is generally necessary to call each router individually, and in this example, perform individual communication in three times. That is, when using the public network,
If there are many routers that should notify the routing information, there is a problem that a large amount of individual communication is required and the traffic increases. In particular, when a router failure, LAN addition / deletion, router addition / deletion, etc. occur, new routing information is notified to all applicable routers each time, so this kind of traffic increase cannot be ignored. It was a thing. Moreover, the routing information executed by each router is managed based on the network address of the reachable LAN, and when the deletion or addition of the specific router occurs, the calculation processing for updating the routing information is performed. There was a problem that it became very complicated. The present invention has been made paying attention to the above points. Even when the number of routers or LANs connected to the system is increased or decreased or a failure occurs, the routing information can be dynamically changed with the lowest possible traffic, and the change can be made. It is an object of the present invention to provide a routing management system that can be efficiently performed.

[0010]

A routing management system of the present invention relays between a plurality of local area networks connected via a public network at a network layer level by a router provided at a relay point, When connecting, a routing manager is provided in the public network, the routing manager holds routing information indicating a connection route necessary for the relay connection at the network layer level, and monitors the connection route including the router. When the network joining request and the routing information change request are received from the router, the routing information held is updated and the minimum necessary update information is generated to notify each router. Is.

According to the second aspect of the invention, two routing managers having the same function are connected to the public network, and when one polls the other, if there is a predetermined response, the other is operated. One of them is operated as a standby system, and if there is no predetermined response, one of the polled systems is operated as an active system. Third
The invention stores, in the routing information, an optimal route specifying a router for relaying to all the respective local area networks to be connected together with its alternative route, and when a failure occurs in the optimal route, The feature is that each router cancels the optimum route and notifies the alternative route.

According to a fourth aspect of the present invention, a routing target list is provided in the routing information for each of all the local area networks to be connected, and a route specifying a router for relaying to the local area network is provided. For each router, provide a joining router list associated with the routing target list,
When a network joining request and a routing information change request are received from the router, the joining router list is referred to and the route for relaying is updated in router units.

According to a fifth aspect of the invention, a router provided at a relay point between a public network and a local area network executes routing information management on the local area network side, while the routing information management on the public network side is managed by the public. It is characterized by being executed by a routing manager connected to the network.

[0014]

In this system, a routing manager for centrally performing network management and routing management for the public network is provided. The routing manager has a routing target list indicating routers at relay points of all LANs that can be connected to each other via the public network. Notifications such as addition / deletion of routers, switching of relay routes, addition / deletion of LANs, etc. due to network failures are all sent to this routing manager. Upon receipt of this notification, the routing manager updates the routing target list. Then, each router is notified of the minimum necessary information for updating the routing information. This makes it possible to dynamically change routing information between LANs with low traffic.

In addition, the routing managers are duplicated so as to have a function of polling each other, the operation of the other party is constantly monitored, and if there is no response from the routing manager operating as an active system, it is considered that a failure has occurred. ,
Make sure that the standby system switches to the active system. This makes it possible to easily achieve duplexing. Also, if the routing manager pre-calculates and registers multiple routes as a routing target list, it is possible to immediately detect and notify an alternative route without a new recalculation process when a failure occurs. Becomes Furthermore, by providing a joining router list that manages router information for each router together with the routing target list, for example, when a failure occurs in any router, the relay route held by that router can be quickly changed. It will be possible. Also,
With this joining router list, the routers under management can be centrally managed, and the efficiency of network management can be improved. Also,
For the routing information management on the LAN side, the conventional LAN routing protocol is adopted, and on the public network side,
If the routing information management of the present invention is performed, more efficient routing management becomes possible.

[0016]

The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 is a block diagram of an embodiment of a routing management system of the present invention. In the figure, this system is
A plurality of routers 104 to 110 are connected to the public network 100, and LANs 120 to 130 are relayed to each other via each router. Such a configuration
There is no difference from the conventional system described in FIG.

Here, in the system of the present invention, with respect to the public network 100, the router 10 connected to this public network is used.
A routing manager 101 is connected to monitor 4 to 110 and manage the routing information. In this embodiment, in order to improve the management reliability, a routing manager 102 is connected in addition to the routing manager 101, and one of them is used as an active system (ACT),
The other is used as a backup system (SBY).

The routing manager 101
Manages routers directly connected to the public network 100, and manages routing information between routers directly connected to each LAN by using existing existing protocols. This is because the increase in traffic due to the notification of the routing information described above is a problem peculiar to the public network. Also, by limiting the jurisdiction of the Routing Manager,
This is because it is possible to reduce the burden and reduce the amount of information for notifying the routing information.

FIG. 4 is a diagram for explaining the routing information of the above routing manager. The routing manager has a function of monitoring the network of each router under its control, dynamically determining a relay route corresponding to the conversion of the network configuration, and transmitting it to each router. To realize this function, the routing manager is provided with the routing information as shown in the figure. Note that this information does not exist at all in the initial state. That is, the routing manager does not hold the routing information fixedly. In principle, all such information is created during operation.

First, the routing information is composed of a routing target list 11 and a joining router list 12. The routing target list 11 is information that is connected to this network and is collected in network address units for all reachable LANs. Also,
The joining router list 12 is information in which the addresses of the routers directly connected to the public network and the public network numbers are collected together. The LANs listed in the routing target list 11 are communicated via any of the routers listed in the joining router list 12.

It is the elements 303 to 305 shown on the right side of the figure that indicate which LAN should be used for communication through which router. This element is an L
One or more can be set for the AN, and the element indicating the optimum route is headed, and the elements indicating the alternative routes are sequentially connected and arranged. The reachable LAN network address and each element of the routing target list 11 are chained by a queue. For example, the LAN network address queue 302 of the reachable LAN network address 301 is a queue for chaining to the element 303. The LAN network address pointer 307 provided in the element 303 indicates the reachable LAN network address 301.

On the other hand, a router address queue 313 is also provided for the WAN direct connection router address 311 of the joining router list 12. The router address queue 313 is a queue for chaining to the element 303. The router address pointer 309 of the element 303 indicates the WAN direct connection router address 311. In this way, the elements, the routing target list 11, and the joining router list 12 are mutually chained so that data can be searched.

Further, the metric value 3 of the element 303
The number 10 represents the number of routers that pass through from the router directly connected to the WAN to the LAN that is actually trying to reach. If this metric value is large, it will pass through many routers to reach the target LAN. Therefore, a relay route that passes through as few routers as possible and reaches the target LAN is selected as the optimum route. Element 30
3, 304 and 305 are chained in such a manner that the smaller the metric value is, the earlier the head is.

FIG. 5 is an explanatory view showing a concrete example of the above routing information. Further, similar specific examples are illustrated in FIGS. 6 and 7. These are all the routing information for each router and LAN shown in FIG. For example, the routing information about the LANs 120, 121, 122 connected via the routers 104, 105 shown in FIG. 1 is as shown in FIG. That is, the routing target list includes LANs 120, 121, 12
2 is listed. Further, the routers 104 and 105 are listed in the joining router list. And
The LAN 120 is chained with the elements 320 and 321.

Element 320 indicates that the optimum route to reach LAN 120 is via router 104. The metric value is "1". That is, it means that the LAN 120 is reached via one router. Further, as shown in FIG. 1, the alternative route to this relay route is the router 105.
And the router 112. Therefore, as an alternative route, the element 321 is chained, which indicates that there is a relay route having the metric value of 2 via the router 105. Here, if there are no more alternative routes, the element 32
The network address queue of 1 becomes "0", indicating that there are no more elements to chain. The other elements are similarly created.

Thus, in the system shown in FIG.
As shown in FIGS. 6 and 7, a routing target list for 11 LANs in total and a joining router list for 7 routers in total are created. The NW address P of each element shown in FIGS. 5, 6 and 7 is
The router address P is a part of the network address, that is, the address of the corresponding LAN, and represents the address of the corresponding router. These match the contents of the routing target list or the joining router list. The generation function and management function of the routing target list and the joining router list as described above will be specifically described later.

FIG. 8 is a diagram for explaining information of the duplicated routing manager. When the routing managers are duplicated, information as shown in this figure is stored in order to recognize the other routing manager from each other and perform the polling function described later. That is, for example, the standby routing manager address 316 and its public network number 317 are written in the active routing manager, as shown in the figure. The format of this information is similar to the information for each router in the joining router list 12 shown in FIG. Therefore, the last part 31
A router address queue is entered in 8, but it is set to "0" because it does not chain with any element. In this way, information about other routing managers is handled in the same format as the joining router list.

FIG. 9 shows an explanatory view of management information in each router. Each router has its own router information 400, routing manager information 403, and LA as shown in this figure.
A routing table 410 on the N side and a routing table 415 on the public network side are provided. Own router information 4
00 is composed of an own router public network side address 401 and an own router public network number 402. This is fixed information set in advance. The routing manager information 403 is 2 when there are two routing managers.
Individually provided. This information consists of the routing manager address 404, the routing manager public number 405 and the status 406, respectively. The state 406 is data indicating whether the corresponding routing manager is the active system or the standby system.

Further, the LAN side routing table list 410 stores reachable LAN network addresses 411, metric values 412 and NextHop router addresses 413. This is data obtained by executing a conventional routing information management protocol on the LAN side. The routing table list 415 on the public network side has a reachable LAN network address 416, NextHop router address 417, N
The extHop router is composed of a public network number 418 and the like. In the system of the present invention, the part where the routing manager provides necessary information to each router is the routing table list on the public network side. Therefore, the optimum route of which router should be passed to another LAN connected via the public network is listed for each LAN. This is updated dynamically by the Routing Manager.

Now, the routing manager on the operation side has a registration function of newly registering a router in this system, a re-registration function of changing the contents of a once-registered router and registering it, and various kinds of routers. A redirect function that notifies you of routing information changes,
It has a polling function for monitoring the operation of each router. Further, when the routing manager is duplicated and one of them becomes the active system and the other becomes the standby system, the standby system needs the polling reception function and the redirect reception function.
Hereinafter, these functions will be described step by step.

FIG. 10 shows a flowchart of the registration operation of the routing manager. First, as explained earlier,
The routing manager has no fixed information about the routing for each router. Each router sends a registration request to the representative routing manager when it starts up. The registration function is a process executed by the representative routing manager each time it receives such a registration request.

The input parameters from each router are the newly added router address, the public network number of the router, and the LAN side routing table list of the router. The LAN side routing table list is composed of a LAN side network address reachable via the router and a sequence of metric values. This LAN side routing table list is created by each router using the routing protocol used in the LAN.

When starting the registration function, first, step S
In step 1, the parameters shown in the figure, that is, the new joining router address and the public network number are registered in the joining router list. Further, in step S2, for each reachable LAN address in the LAN side routing table list, an entry required for calculation is secured.

In steps S3 and S4, it is determined whether the processing has been completed by the number of routing table lists as described above. This is a process for determining whether or not all the registration processes have been completed. The registration operation repeats the processing from step S5 to step S11.
First, in step S5, a metric value is set in the element and a reachable network address pointer is set. Then, in step S6, the reachable network address queue is traced, and the metric value in each element is compared with the metric value set in this element. Then, in step S7, a new element is inserted at an appropriate position in the reachable network address queue. In this embodiment, the elements are arranged in ascending order of the metric value. Therefore, when a new element is inserted in the middle of the element,
Reset the queues of upstream and downstream and the own element.

In step S8, it is determined whether the inserted element is the head of the queue. If the element is the head of the queue, the relay route is the optimum route, so it is necessary to notify other routers. Therefore, the process moves from step S9 to step S10,
Prepare to execute the redirect function for the routers registered in the list of all participating routers. That is, this information is temporarily stored in order to notify the router that has been subscribed so far. The redirect function that is a process of notifying this information will be described later. If an alternate router exists, it sends whatever has changed, even if it's not the first one, for redirection to the alternate routing manager.

Then, in step S11, a router address queue is set in the element and a router pointer is set. This completes one element setting by joining a new router. When there are a plurality of LANs that can reach the element, the processes of steps S3 to S11 are repeated, and necessary elements are additionally updated. If it is determined in step S8 that the element is not the head of the queue, the process jumps from step S9 to step S11. That is,
In this case, even if the route is registered in the routing manager as an alternative route, the notification is not sent. That is, each router keeps only the optimum route as before.

If it is determined in step S3 that the processing has been completed by the number of routing table lists, which are the parameters supplied when the router is started up, the process proceeds from step S4 to step S12, and the newly added router is instructed. Create and send a routing table that shows the best routes. That is, the information stored in step S10 is transmitted to the router here. The information in this case is the best routing table,
That is, the reachable LAN network address, the router address indicated by the router pointer of the head element of the queue, and its public network number. As a result, each router stores the latest best route routing information base. The contents are as shown in the routing table 415 described in FIG.

This step S12 is the information transmitted to the newly added router. In step S13, the redirect function is executed for all the routers registered in the added router list if necessary. That is, the processing for updating the routing information of each router is executed.
In step S12, when the routing information base (RIB) is transmitted to the newly added router, this is used as the end response message of the registration operation, and the registration operation ends. The subsequent process of step S13 is based on the redirect function.

Next, the function of re-registering the routing configuration and the like of the already registered router will be described. FIG. 11 is a flowchart of the re-registration operation of the routing manager. Each router 1 as shown in FIG.
Each of 04 to 110 transmits a re-registration request to the representative routing manager when there is a change in the routing configuration on the LAN side. When the representative routing manager receives this, it executes this re-registration operation each time. First, in step S1, the re-registration request router address, the public network number of the re-registration request router, and the LAN side routing table list are input as parameters from the joining router list. The contents of this parameter are the same as those sent to the routing manager during the registration operation already described in FIG. In step S1, the joining router list is searched to find the same router address. Then, in step S2, the element that is chained with the router address is traced. Next, the following processing is executed for each element. Note that step S3 shows a branch when the queue is completed.

In step S4, the same address as the reachable LAN network address in the element is searched from the table of input parameters. And
If it is determined in step S4 that there is a corresponding item, the process proceeds to step S6 to compare the metric values. If the metric values are different, in order to change the contents, the process proceeds from step 7 to step S8, and the metric values are reset. This is the same operation as described in the description of the registration function. Then, in step S9, it is determined whether or not the position of the queue is changed due to the change of the metric value. If it is determined that there is a position change, the process proceeds to step S11, and it is determined whether or not the position of the cue before and after the movement is the head. All modified elements are sent as redirects to the alternate routing manager. If the element in the first queue is changed, it is necessary to issue a notification for changing the routing information. Therefore, in this case, the process moves to step S13 and the first element is stored for executing the redirect function.

By executing the processing and judgment as described above, only the changed portion is changed and the processing returns to step S2. When all the necessary changes are completed and the queue is completed, the process proceeds to step S14. Here, it is determined whether or not there is an unprocessed element in the routing table list (step S14). If there is, move from step S15 to S16,
A new element is secured and its registration is executed (step S17). When the registration of such elements is completed, the process proceeds to step S18 and step S13 is performed for all registered routers in the joining router list.
If you need redirect by processing like
Perform the redirect function. In this case, all the changed information is transmitted to the alternative routing manager.

FIG. 12 shows a flow chart of the redirect operation of the routing manager. This redirect function is executed as a response to the newly added router when the registration function is executed by the router newly added as described above, and is also executed as a route change notification to the other routers. Also, when a notification is received from each router when there is a route change on the LAN side, and when the re-registration function for this is executed, it is executed as a route change notification to other joining routers. Furthermore, when there is a change in the routing information as described above, the active routing manager always executes the same redirect processing for the standby routing manager.

The input parameter in this case is the reachable L
It is composed of the AN network address, the router address, the router public network number, and the element list of the metric value described in FIG. These parameters are collected in one packet data unit and transmitted to the intended partner. If the packet data units cannot be combined into one packet data unit, the data is divided and transmitted using the function conventionally provided in the network layer. As a flowchart, in step S1, it is determined whether or not an element list exists, and if it exists, one element is read and set in a redirect PDU, that is, a packet data unit. When all the elements are packetized, the process moves from step S2 to step S4 and one list is read from the joining router list. Next, the process proceeds from step S5 to step S6, and the redirect PDU is transmitted to the read data. After that, the process returns to step S4, and one list is read from the next joining router list. When the redirect processing for all the joining routers is executed, this function is exited.

FIG. 13 shows a polling operation flowchart of the routing manager. This function is used by the representative routing manager to poll each joining router at regular intervals to check whether they are operating normally. By executing this polling for the other routing manager, it can be used as a trigger for switching between the active system and the standby system. First, in step S1, one list is read from the joining router list. Then, in step S2, polling PDU transmission is executed. In this case, a retry or the like is also executed due to the circumstances of the line. Next, in step S3, it is determined whether or not there is a response from the corresponding router.

If there is a response, it means that the router is operating normally, and the process returns to step S1 to execute the polling for the next router. On the other hand, if there is no response, the process moves from step S4 to step S5, and the element of the joining router chain of the corresponding router is removed from the reachable network address chain. That is, the applicable router is searched from the joining router list, and all the elements chained to the router address queue are removed from the network address queue of each reachable LAN network address. Thus, if the head of the network address queue is changed, the element is stored in step S6 in order to notify the other router of the change. Then, in step S7,
Perform the redirect function.

By carrying out such processing, the routing manager positively confirms the operating state of each router without receiving notification from each router, and if there is no response from the router, it is immediately notified. To other routers to optimize the routing information. This function is always executed at an appropriate time after the routing manager is started.

FIG. 14 shows a flow chart of the initial operation of the routing manager. Here, the operation when the routing manager itself is started up will be described. In the embodiment shown in FIG. 1, two routing managers are connected to the public network, but when the routing managers are started up, each routing manager
They do not know which is the active system and which is the standby system. However, it is possible to automatically determine the active system or the standby system by the algorithm shown in this figure. That is, in step S1, when the routing manager is started up, a registration request of its own routing manager information is transmitted to the alternative routing manager, that is, the standby routing manager.
Then, in step S2, it is determined whether or not there is a response from the partner routing manager.

If there is a response, the process moves from step S3 to step S4, and the routing manager operates as an alternative mode, that is, a standby routing manager. After that, the standby routing manager executes the polling reception function and the redirect reception function. On the other hand, in step S2, when it is determined that there is no response from the partner routing manager, the process proceeds from step S3 to step S5, and the node itself operates as an active routing manager. In this case, the registration function, the re-registration function, the redirect function, the polling function, and the like described above are executed. In this way, a configuration in which the routing information of the active system and that of the standby system are matched and one is always switched to the other by making a response in which the required routing information base is returned from the active routing manager to the standby routing manager It is said that

FIG. 15 shows a polling reception operation flowchart of the standby routing manager. Already in Figure 1
By the polling function shown in 3, the active routing manager polls the standby routing manager, and if there is any abnormality in the active system, the standby routing manager switches to the active system. That is, in this embodiment, the standby routing manager recognizes that there is polling from the active routing manager at regular time intervals,
If it detects that the polling has stopped, it will automatically switch to the active system. Specifically, it is as follows.

First, in step S1, it is determined whether or not there is polling from the representative routing manager. If there is polling, step S
2, the polling response is sent to the representative routing manager. Then, when it is determined that there is no polling within a certain time using a timer or the like, the process proceeds from step S3 to step S4. Here, Figure 8 owned by me
For the routing manager information shown in, set your router address and public network number as the active routing manager. Then, the redirect is executed for all the joining routers. As a result, all the joining routers recognize that the routing manager of the standby system has been switched to the active system. Finally, in step S5, the operation transits to the active routing manager mode. This function is always valid after the routing manager starts up.

FIG. 16 shows a flowchart of the redirect receiving operation of the standby routing manager. This function is activated when the standby routing manager receives a redirect from the active routing manager. This is a process to create the same routing information base as the routing information base held by the active routing manager in the standby routing manager based on the information redirected from the active routing manager. is there. The input parameters in this case are the new route list 1101, the reachable network address 1102, and the router address 110.
3, router public network number 1104 and metric value 110
It is 5.

First, in step S1, the routing manager that has received the redirect executes the processing for each router address of the input parameter. And
In step S2, a list having one router address is extracted. If there is such a list, the process moves from step S3 to step S4, and the registration function already described with reference to FIG. 10 is executed. If all the lists are exhausted, the process ends. That is, the same process as the registration function performed by the active routing manager is executed for each list of input parameters, and the process of all input parameter lists is completed. In this way, the same routing information as that of the active routing manager is held, and the standby system is on standby so that the standby system can be switched to the active system at any time.

FIG. 17 shows a redirect receiving operation flowchart in each router. Various processing operations in each router will be described below. First, when each router receives a redirect, the processing shown in FIG. 17 is executed. This is a routing information base (RI) held by the routing manager based on the information redirected from the routing manager.
The purpose is to create the same as B). As described above, each router holds only the optimum route as the routing information, and the alternative route is held only by the routing manager. First, the input parameters are the new router list 1201, the reachable network address 1202, the router address 1203, and the router public network number 1204.

In step S1, such a list is read, and the process proceeds from step S2 to step S3 to search for a corresponding reachable network address from the routing table list on the public network side. If it is determined in step S4 that there is a corresponding item, the process proceeds to step S5, and the router address, router public network number, etc. are updated. If the list content is "0", it is deleted. On the other hand, if it is determined in step S4 that there is no corresponding network address, the process proceeds to step S6, and a table is added. As a result, a new list of reachable network addresses, router addresses, and public network numbers is registered. In this way, the routing table 415 shown in FIG. 9 is updated.

An example of the LAN side routing table shown in FIG. 9 for the network of FIG. 1 is as follows. Reachable LAN network address (411) + metric value (412) + NextHop router address (413) LAN (123) 0-LAN (124) 0-LAN (125) 1 router (113) LAN (126) 1 router (114) LAN (127) 2 router (113) LAN (128) 2 router (114)

The routing table list 415 on the public network side is as follows when generated for the network shown in FIG. Reachable LAN network address (416) + NextHop router address (417) + public network number (418) LAN (120) router (104) (104) number LAN (121) router (104) (104) number LAN (122) ) Router (105) (105) number LAN (123) Router (106) (106) number LAN (124) Router (106) (106) number LAN (125) Router (106) (106) number LAN (126) Router (106) (106) number LAN (127) Router (106) (106) number LAN (128) Router (107) (107) number LAN (129) Router (108) (108) number Number LAN (130) Router (108) (108) number

FIG. 18 is a flowchart of the initial operation in each router. At startup, each router executes the initial operation in the order shown in this figure. First, in step S1, a LAN side routing table is created by the LAN side routing protocol.
This is done using existing routing protocols. After that, a registration request is issued to the active routing manager using the sequence including the own router address, the own router public network number, and the reachable LAN network address and the metric value created from the LAN side routing table list described above as parameters. (Step S2).

Then, in step S3, it is determined whether or not there is a response from the routing manager. Since the router does not know which routing manager is the active system in the initial state, it sends such a registration request to either routing manager for the time being. If there is no response from the routing manager, the routing manager judges that it is the standby system, registers the state of the routing manager as the standby system in step S5, and returns to step S2.
Then, when there is a response from the routing manager in step S3, the process proceeds from step S4 to step S6, and the state of the routing manager is set to the active system. Then, the process proceeds to step S7, and a routing table on the public network side is created from the information in the response message. Thus, the router starts the relay operation,
In the router operation mode, the re-registration request function and the redirect reception function are required thereafter (step S
8).

FIG. 19 shows a re-registration request operation flowchart in each router. In each router, a routing table list on the LAN side is created by the routing protocol used in the LAN. This routing table list is dynamically updated by a routing protocol when a router is added, changed, or deleted thereafter. Then, when a change occurs in the routing information base, each router requests the routing manager to re-register in the same manner as described above. In this case, in step S1, it is first determined whether or not the LAN side routing table has been changed by the routing protocol.

When it is determined that there is no change, the determination of step S1 is repeated, and when there is a change, the process proceeds to step S3. At this time, a parameter list of the re-registration function to be sent to the routing manager is created. This content is as described above, and is a list of its own router public network side address, its own router public network number, reachable LAN network address and metric value. If the router is deleted, -1 is added to the metric value to distinguish it. In step S4, the routing manager is requested to perform the re-registration function. In this way, re-registration is executed in the manner described above.

When the redirect reception function is executed, the received message from the routing manager includes a list of new routes, reachable LAN network addresses, NextHop router addresses, and a list of NextHop router public network numbers. . In this function, the public network side routing table list is updated based on this input information list. In this case, a list having the same address as the reachable LAN network address is searched from the public network side routing table list, and if the corresponding list exists, the parameter is substituted in the NextHop router address part of the list and the NextHop router public network Substitute the parameter corresponding to the number part. In this case, when both are “0”, it means that the route is deleted. If the corresponding address does not exist in the public network side routing table list, the process is performed by adding a route. In this case, a new list is added to the public network side routing table list. In that case, the parameters corresponding to the reachable LAN network address part, the NextHop router address part, and the NextHop router public network number part of the list are substituted.

The function of each routing manager or router is as described above. Hereinafter, the cooperation operation between them will be described using a sequence chart. 20
It is a routing manager start-up sequence chart. R as shown in the figure
If M1 and RM2 are displayed, first, the routing manager RM1 starts up, makes a registration request to the RM2, measures a certain time, and when the time-out occurs, the routing manager RM1 serves as a representative mode, that is, an active routing manager stand up. On the other hand, when the routing manager RM2 is subsequently started up and a registration request is made to the RM1, the routing manager RM1 sends a RIB to the routing manager RM2. This requests the routing manager RM2 to create the same routing information. When receiving this, the routing manager RM2 sets itself as an alternative mode, that is, a standby routing manager, and generates necessary routing information. On the other hand, the routing manager RM1 performs polling at regular intervals thereafter, and the routing manager RM2 returns the response, thereby performing mutual failure detection.

FIG. 21 shows a system switching sequence chart of the routing manager. In this figure, in addition to the routing managers RM1 and RM2, four routers RT
1, RT2, RT3, and RT4 are related, the router RT1 and the router RT3 are not joined, and the router RT2 and the router RT are not joined.
4 is already subscribed. In this case, for example, when the routing manager RM1 executes polling and the process in which the routing manager RM2 returns a response is stopped due to the routing manager RM1 being down, the routing manager RM2 detects that it does not receive the polling for a certain period of time, and the routing manager RM2 Start up in the representative mode, that is, as the routing manager of the operation system. Then the routing manager RM2
Informs the already-joined routers RT2 and RT4 that the accident was in the active routing manager.

FIG. 22 shows a new router joining sequence chart. In this sequence chart, FIG.
Similarly, it is assumed that the routers RT1 and RT3 are not joined and the routers RT2 and RT4 are already joined. At this time,
After the router RT1 is started up and the RIB on the LAN side is created, a registration request is made to the routing manager RM2. In this case, the routing manager RM1
Is an active system, the router RT1 recognizes that there is no response due to a timeout. After that, RT1 makes a registration request to the routing manager RM1. Next, the routing manager RM1 sends an RI to the router RT1.
Send B. As a result, the router RT1 obtains necessary routing information and starts operation.

On the other hand, the routing manager RM1
Routing manager RM by redirect function
2 is redirected to update the routing information. In addition, the same redirect is performed for the routers RT2 and RT4. In this way, the routing information is dynamically updated in each router. After that, the routing manager RM1 periodically polls the router RT1, recognizes that the response is returned, and confirms and monitors whether it is operating normally.

FIG. 23 shows a sequence chart when the route is changed. In this example, it is assumed that the routers RT1, RT2, RT4 have already joined and the router RT3 has not joined. In this case, it is assumed that the LAN-side RIB of the router RT2 has changed. At this time, the router RT2 issues a re-registration request to the routing manager RM1. Upon receipt of this request, the routing manager RM1 executes the re-registration function and also executes the redirect operation for the routing manager RM2 and the routers RT1 and RT4. By these, router RT
The change of the LAN connected to 2 is dynamically notified, and the routing information of each router is updated.

FIG. 24 shows a route change sequence chart by network monitoring. In this example, the router RT
It is assumed that 1, RT2 and RT4 are already subscribed. First, in this case, the routing manager RM1 polls each router at regular intervals by the polling function and receives the response. If there is a response, the router determines that it is operating normally and polls the next router. Here, for example, when polling is performed on the router RT2, it is assumed that the RT2 is down immediately before. At this time, when the routing manager RM1 confirms that there is no response due to timeout, it redirects to the routing manager RM2 and further redirects to the other routers RT1 and RT4. In this way, the routing information of each router is updated.

By utilizing the above-mentioned registration function, re-registration function, redirect function, polling function, redirect reception function, re-registration request function, etc., the routing information base connected to the public network of each router is dynamically changed. Is changed to. In this case, the minimum amount of information required to change the routing information base is sent, so it is possible to dynamically change routing information at a lower cost than the conventional method of exchanging all routing information. Become.

Further, the polling function and the polling reception function allow the routing manager not only to monitor the operations of all the routers but also to monitor the mutual operations between the active and standby routing managers to duplicate each other. Can be easily realized. Furthermore, each router stores only the optimum route as routing information, but the routing manager stores alternative routes in addition to the optimum route as elements, which are arranged in priority order. When a failure occurs, it is possible to immediately determine a new route and notify other routers without complicated recalculation processing. In addition, since the joining router list is provided in the routing manager and the list for each router directly connected to the public network is provided, it is possible to quickly update the route of the corresponding router by following the router address queue. Become.

Further, the subordinate router list can centrally manage the routers under all management and can be used as a list for network monitoring on the public network. Further, a router directly connected to the public network manages the present invention, and a LAN side adopts an existing efficient routing protocol for routing, whereby a functional system can be realized at an appropriate scale. The present invention is not limited to the above embodiments. The configuration of the network, the detailed configuration of the routing information, and the like may be appropriately changed within the range in which the object of the present invention can be achieved. Further, the above-mentioned functions do not necessarily have to be provided in all the routing managers and routers, and increase / decrease settings can be freely set as necessary.

[0071]

The routing management system of the present invention described above is provided with a routing manager for monitoring the network and managing the routing information in the public network, and when receiving a network joining request or a routing information change request from each router, Since the routing information held is updated and the minimum necessary update information is notified to each router, the traffic for information exchange performed via the public network when changing this kind of routing information is performed. Can be minimized.

Further, two routing managers are connected to the public network, the standby system polls the active system, and if there is a response, it is regarded as the active system, and if there is no response, the standby system switches to the active system. If processing is performed, the duplication of the routing manager can be facilitated. Furthermore, if the optimal route that specifies the router for relaying to the local area network is stored in the routing information together with the alternative route, a new alternative route can be immediately determined and notified when a failure occurs. You can

Further, by providing a routing target list specifying a relay router for each local area network, and providing a joining router list associated with the routing target list for each router,
When changing the relay route for each specific router,
The routing target list can be modified while referring to the joining router list, and this kind of routing information update becomes easy. Further, if the local area network side executes the routing information management protocol conventionally adopted in the local area network and the public network side performs the routing management according to the present invention, the system as a whole becomes efficient. Can be operated and managed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a routing management system of the present invention.

FIG. 2 is a network block diagram of a conventional system.

3A and 3B are explanatory views of a broadcast communication comparison, in which FIG. 3A is a broadcast communication using a LAN, and FIG.

FIG. 4 is an explanatory diagram of routing information of a routing manager.

FIG. 5 is a diagram (part 1) for explaining a specific example of routing information.

FIG. 6 is a diagram (part 2) for explaining a specific example of routing information.

FIG. 7 is a diagram (part 3) for explaining a specific example of routing information.

FIG. 8 is an explanatory diagram of information of a duplicated routing manager.

FIG. 9 is an explanatory diagram of management information in each router.

FIG. 10 is a flow chart of a registration operation of a routing manager.

FIG. 11 is a flowchart of re-registration operation of a routing manager.

FIG. 12 is a flowchart of a redirect operation of a routing manager.

FIG. 13 is a flowchart of a polling operation of the routing manager.

FIG. 14 is a flowchart of an initial operation of a routing manager.

FIG. 15 is a flowchart of the polling reception operation of the standby routing manager.

FIG. 16 is a flowchart of a redirect receiving operation of the standby routing manager.

FIG. 17 is a flowchart of a redirect receiving operation in each router.

FIG. 18 is a flowchart of an initial operation in each router.

FIG. 19 is a flowchart of a reregistration request operation in each router.

FIG. 20 is a routing manager startup sequence chart.

FIG. 21 is a system switching sequence chart of the routing manager.

FIG. 22 is a new router joining sequence chart.

FIG. 23 is a sequence chart when a route is changed.

FIG. 24 is a route change sequence chart by network monitoring.

[Explanation of symbols]

 10 Routing Information 11 Routing Target List 12 Joined Router List 100 Public Network 101, 102 Routing Manager 104-117 Router 120-130 LAN

Claims (5)

[Claims] 1. When connecting between a plurality of local area networks connected via a public network by a router provided at a relay point at a network layer level, the routing manager is connected to the public network. The routing manager holds routing information indicating a connection route necessary for relay connection at the network layer level, monitors a connection route including the router, and requests a network joining request and a routing information change request from the router. A routing management system that updates the routing information it holds when it receives a request, generates the minimum necessary update information, and notifies each router. 2. When two routing managers having the same function are connected to a public network and one polls the other, if there is a predetermined response, the other is regarded as an active system and one 2. The routing management system according to claim 1, wherein the routing management system operates as a standby system, and if there is no predetermined response, one of the polling executions operates as an active system. 3. An optimal route specifying a router for relaying to each of the local area networks to be connected is stored in the routing information together with its alternative route, and a failure occurs in the optimal route. The routing management system according to claim 1, characterized in that the optimum route is canceled and the alternative route is notified to each router. 4. A routing target list is provided in the routing information for each of all the local area networks to be connected, and a route specifying a router for relaying to the local area network is provided, and for each of the routers. , A route for relaying in router units by providing a joining router list associated with the routing target list and referring to the joining router list when receiving a network joining request and a routing information change request from the router Is updated.
The described routing management system. 5. A router provided at a relay point between a public network and a local area network is made to execute routing information management on the local area network side, while routing information management on the public network side is connected to the public network. The routing management system according to claim 1, wherein the routing management system is executed by a specified routing manager.