JP4344333B2 - Packet transfer apparatus, packet transfer network system, and packet transfer method - Google Patents

Description

  The present invention relates to a redundant packet transfer apparatus, a packet transfer network system, and a packet transfer method for switching between an active system and a standby system.

  An IP network is widely used as a packet transfer network. A router that performs packet transfer processing between terminals in an IP network requires a routing table for determining a packet transfer destination. The routing method for generating this routing table can be classified into two types: static routing and dynamic routing.

  The static routing is a method in which a maintenance person sets routing information in a router in advance and always selects a fixed route. Normally, each router has information on a destination network (network subnet address). And the information (next hop router address) of the adjacent router to reach there is set as a set.

  The dynamic routing is a method for determining a route for packet transfer by exchanging routing protocol information between routers. Routing protocol information is changed between routers when the network configuration is changed or when a router is started. In addition to delivery, information is often exchanged at regular time intervals. Specific routing determination algorithms for dynamic routing include Routing Information Protocol (RIP), Open Shortest Path First (OSPF), Border Gateway Protocol (BGP), and the like.

  Hereinafter, in this specification, the routing table generated by the static routing is referred to as a static routing table, and the routing table generated by the dynamic routing is referred to as a dynamic routing table.

  Many routers use both static routing and dynamic routing, and generate a forwarding table to refer to the optimal output port of each input packet from the generated routing tables, and perform packet forwarding processing accordingly. ing.

  Recently, in order to improve router performance, it has been proposed to configure each router separately into a part for generating the routing table and forwarding table and a part for performing packet forwarding processing. Under such a configuration, packet transfer processing can be performed without being affected by the routing processing load. Hereinafter, in this specification, a part for generating a routing table and a forwarding table is called a control signal processing unit, and a part for performing packet transfer processing is called a data signal processing unit.

  Furthermore, a packet transfer device has been introduced which has improved reliability by making the control signal processing unit redundant. Such a packet transfer apparatus has a plurality of control signal processing units, one of which is operated as an active system, and the remaining control signal processing units are kept on standby as standby systems. If a failure occurs in the active control signal processing unit, the processing performed by the failed control signal processing unit is continued by switching the standby control signal processing unit to the active system.

  Here, depending on how much routing protocol information is synchronized between the active control signal processor and the standby control signal processor, the speed of router process restart and failure recovery is determined. come.

  In the cold backup method that has been widely used in the past, the routing protocol information is not synchronized between the active control signal processing unit and the standby control signal processing unit, and the active system is switched (hereinafter referred to as system switching). Is completed), the standby control signal processing unit is rebooted, and the routing table and forwarding table are regenerated from a completely blank state. Here, the static routing table needs to be reset by a maintenance engineer every time system switching occurs, which increases the human cost for failure recovery and takes a long time until failure recovery.

  On the other hand, as a technique for quickly performing the system switching, in the routing protocol information synchronization method disclosed in Non-Patent Document 1, a standby control signal processor for all routing protocol information held by the active control signal process Thus, the same state as that of the active control signal processing unit can be restored to the control signal processing unit switched from the standby system to the active system. As a result, the control signal processing unit switched from the standby system to the active system can immediately perform the same processing as the control signal processing unit that has been operating as the active system.

  However, this method consumes more processing resources than necessary, which may adversely affect network scalability and performance. Specifically, the amount of information notified from the active control signal processing unit to the standby control signal processing unit increases according to the number of other routers. Increase in the number of routers may increase traffic inside the router due to information notification from the active control signal processing unit to the standby control signal processing unit.

  And if the traffic inside the router increases, the processing of the control signal processing unit itself may be delayed, and the packet forwarding process may be hindered because the routing table and forwarding table are not immediately generated or updated. There is. This also means that the router device cannot accommodate many lines.

  Therefore, as an intermediate solution between the two methods, only a part of the routing protocol information held by the active control signal processing unit is synchronized with the standby control signal processing unit, thereby reducing the failure recovery time and internal synchronization. It is conceivable to reduce the processing load.

  For example, in the routing protocol information synchronization method disclosed in Patent Document 1, only routing protocol information collected from other routers by dynamic routing is reserved among routing protocol information held by a control signal processing unit operating as an active system. Notify the control signal processing unit waiting as a system. As a result, the control signal processing unit that has been switched from the standby system to the active system can immediately generate a dynamic routing table from the stored routing protocol information.

However, as described above, the routing protocol information is transferred and updated between routers when the network configuration is changed or when the router is activated. Therefore, every time the routing protocol information held by the control signal processing unit operating as the active system is updated, a process of notifying the control signal processing unit waiting as a standby system of the content occurs. Even in this system, there is a problem that traffic in the router may increase if state changes such as configuration changes frequently occur in the network.
Japanese Patent No. 3286854 (FIG. 2 etc.) Fujitsu Limited, “GeoStreamR900 Series Product Report Vo1.1 (High Reliability)”, [online], 2001, [February 2005 Search] Internet, <URL: http: // telecom. fujitsu. com / jp / products / report / geosestream_r900 / report_r900. pdf>, p. 9-12, FIG. 9-12, etc.

  In view of the above-mentioned problems in the prior art, in the present invention, in the router device in which the control signal processing unit is made redundant, the control signal processing unit operating as the active system notifies the control signal processing unit waiting as the standby system. It is an object of the present invention to reduce the amount of information to be transmitted and the frequency of information notification, and to prevent human cost generation and failure recovery time associated with system switching at the time of failure.

In order to solve the above-mentioned problem, in the present invention (Claim 1), a dynamic routing table for defining a dynamic route for packet forwarding is generated by routing protocol processing, and the dynamic routing table and a preset static route for packet forwarding are stored. a plurality of control signal processing unit for generating a forwarding table based on static routing table to determine, a packet transfer device and a plurality of data signal processing unit that performs packet transfer according to the forwarding table, the plurality of control signal processing The control signal processing unit selected from among the units operates as the active system, the remaining control signal processing units stand by as the standby system, and waits as the standby system when a failure occurs in the active control signal processing unit. Control signal Control signal processing unit selected from among the processing section operates as the active system, the control signal processor of an active system, and the static routing table set in advance, routing protocol information and the collected from other routers based on the the first database management unit control signal processor of an active system for holding the said dynamic routing table generated, the first routing protocol information held in the database management unit based on the routing protocol information A first routing protocol packet processing unit for executing routing protocol processing including collection of new routing protocol information held in the first database management unit and generation of a dynamic routing table; and the first database management unit In Based on the lifting has been static routing table and dynamic routing table, executes the generation processing of the forwarding table comprises a first forwarding table calculation unit for notifying the forwarding table thus generated to the data signal processing unit, wherein the routing protocol information control signal processor waiting as a spare system, which is holding the static routing table set prior Ki予 Me and second database management unit that holds, in the second database management unit Based on the second routing protocol packet processing for executing routing protocol processing including collection of new routing protocol information held in the second database management section and generation of a dynamic routing table. Based on the dynamic routing table generated by the management unit, the static routing table held in the second database management unit and the second routing protocol packet processing unit, the forwarding table generation processing is executed, and the generation It provided with a second forwarding table calculation unit for notifying the forwarding table in the data signal processing section has, and the data signal processing unit, that holds the forwarding table sent from the control signal processor of an active system serial comprising a憶means, before based on the forwarding table held in the crisis憶means, and a packet transmission and reception unit for performing inter-network transfer of packet.

According to this configuration, it is possible to provide a packet transfer apparatus having a redundant configuration that is highly available and that can switch the control signal processing unit seamlessly. Further, in the redundantly configured packet transfer apparatus, the control signal processing unit can be switched without any break.

In the present invention (Claim 2 ), the control signal processing unit of the active system sends the static routing table held in the first database management unit to the control signal processing unit waiting as the standby system. Notification means are further provided.

  According to this configuration, it is possible to prepare for the switching of the control signal processing unit with a small number of internal transfers in the redundantly configured packet transfer apparatus.

In the present invention (Claim 3 ), the control signal processing unit standing by as the standby system erroneously sends the second database management unit of the static routing table sent from the active control signal processing unit. A routing table write monitoring unit for preventing writing is further provided.

  According to this configuration, the availability of the packet transfer apparatus can be further increased.

Further, in the present invention (claim 4), wherein the data signal processing section, a forwarding table write monitoring portion for preventing erroneous writing Previous handed憶means of the forwarding table sent from the control signal processor of an active system Is further provided.

  According to this configuration, the availability of the packet transfer apparatus can be further increased from another viewpoint.

In the present invention (Claim 5 ), the control signal processing unit of the active system generates the forwarding table held in the first database management unit of the data signal processing unit, and generates An extraction unit that extracts a difference forwarding table that is a difference between the forwarding table and the forwarding table acquired from the data signal processing unit; and a notification unit that sends the difference forwarding table to a data signal processing unit. the signal processing unit further comprises updating means for updating the forwarding table held before Kiki憶unit based on the difference forwarding table sent from the control signal processor of an active system.

  According to this configuration, the forwarding table can be updated with a small amount of data transfer.

Further, in the present invention (claim 6 ), the control signal processing unit of the active system uses the routing protocol information newly collected in the routing protocol processing to hold the routing protocol information held in the first database management unit. And updating the dynamic routing table so as to be consistent with the updated routing protocol information, the static routing table held in the first database management unit and the updated dynamic routing table Based on the above, a process for regenerating the forwarding table is performed, and the regenerated forwarding table is notified to the data signal processing unit.

  According to this configuration, the forwarding table can be maintained at an appropriate level.

In the present invention (Claim 7 ), a packet transfer network system including a packet transfer device and a network to which the packet transfer device is connected is configured.

  According to this configuration, a highly available packet transfer network can be configured.

In the present invention (Claim 8 ), a dynamic routing table for defining a dynamic route for packet forwarding is generated by routing protocol processing, and the dynamic routing table and a static routing table for defining a static route for packet forwarding set in advance are used. A packet transfer method executed by a packet transfer device comprising a plurality of control signal processing units for generating a forwarding table and a plurality of data signal processing units for performing packet transfer according to the forwarding table, wherein the packet transfer device comprises: A procedure for operating a control signal processing unit selected from the plurality of control signal processing units as a working system, a procedure for waiting the remaining control signal processing units as a standby system, and a control signal processing unit for the working system A control signal processing unit selected from among the control signal processing units waiting as a standby system when a failure occurs is executed as an active system, and the control signal processing unit of the active system and set the static routing table, and procedures for holding said dynamic routing table control signal processing unit of the active system is generated based on the routing protocol information and the routing protocol information collected from other routers, the based on the routing protocol information held in the database management unit 1, the procedure for executing the routing protocol process including collection and generation of the dynamic routing table of new routing protocol information held in the first database management unit the first database Based on the static routing table and dynamic routing table held by the management unit, executes a procedure for executing the process of generating the forwarding table, and a procedure for notifying the forwarding table in the data signal processing section, as the standby system Based on the routing protocol information held in the second database management unit, the control signal processing unit that is waiting executes a procedure for holding the preset static routing table in the second database management unit A procedure for executing routing protocol processing including collection of new routing protocol information held in the second database management unit and generation of a dynamic routing table, and held in the second database management unit A procedure for executing a forwarding table generation process based on a dynamic routing table generated by a tatic routing table and the second routing protocol packet processing unit; and a procedure for notifying the data signal processing unit of the forwarding table; is executed, the data signal processing section, the procedure for holding the forwarding table sent from the control signal processor of an active system to memorize means, based on the forwarding table held before crisis憶means, And a procedure for transferring packets between networks.

According to this configuration, it is possible to provide a packet transfer apparatus having a redundant configuration that is highly available and that can switch the control signal processing unit seamlessly. Further, in the redundantly configured packet transfer apparatus, the control signal processing unit can be switched without any break.

Further, in the present invention (claim 9 ), the active control signal processing unit notifies the control signal processing unit standing by as the standby system of the static routing table held in the first database management unit. Perform further steps to

  According to this configuration, it is possible to prepare for the switching of the control signal processing unit with a small number of internal transfers in the redundantly configured packet transfer apparatus.

In the present invention (claim 10 ), the control signal processing unit waiting as the standby system erroneously sends the static routing table sent from the active control signal processing unit to the second database management unit . Further steps to prevent writing are performed.

  According to this configuration, the availability of the packet transfer apparatus can be further increased.

Further, in the present invention (Claim 11), the data signal processing unit is further steps to prevent erroneous writing Previous handed憶means of the forwarding table sent from the control signal processor of an active system .

  According to this configuration, the availability of the packet transfer apparatus can be further increased from another viewpoint.

In the present invention (Claim 12 ), the active control signal processing unit obtains the forwarding table held in the first database management unit of the data signal processing unit, and the generated A step of extracting a difference forwarding table that is a difference between the forwarding table and the forwarding table acquired from the data signal processing unit; and a step of notifying the data signal processing unit of the difference forwarding table; processing unit further executes a procedure for updating the forwarding table held before Kiki憶unit based on the difference forwarding table sent from the control signal processor of an active system.

  According to this configuration, the forwarding table can be updated with a small amount of data transfer.

Further, in the present invention (claim 13 ), the active control signal processing unit uses the routing protocol information newly collected in the routing protocol processing to hold the routing protocol information held in the first database management unit. When updating the dynamic routing table so as to match the updated routing protocol information, the static routing table held in the first database management unit , and the updated dynamic routing table. Based on the routing table, a procedure for regenerating the forwarding table and a procedure for notifying the data signal processing unit of the regenerated forwarding table are further executed.

  According to this configuration, the forwarding table can be maintained at an appropriate level.

  According to the present invention, in a packet transfer device, the amount of information notified from the control signal processing unit operating as the active system to the control signal processing unit waiting as the standby system and the frequency of information notification are reduced, and the system is switched at the time of failure. It is possible to prevent the associated human costs and shorten the failure recovery time.

<< first embodiment >>
Hereinafter, embodiments of the present invention will be described. First, the first embodiment will be described.

[Device configuration]
FIG. 1 is a diagram illustrating a configuration of a network device to which the router device according to the first embodiment is applied. As shown in FIG. 1, the packet transfer apparatus 10 includes redundant control signal processing units 11 a and 11 b and a plurality of data signal processing units 13. Note that the packet transfer apparatus 10 provided with the redundant control signal processing units 11a and 11b is also a router device, but thereafter, the router of the present invention including the redundant control signal processing units 11a and 11b. The device is called a packet transfer device 10 and another general router device is called a router 14 to be distinguished. (However, the router 14 may be substituted by the packet transfer device 10 of the present invention.) The packet transfer device 10 is connected to the network by the data signal processing unit 13. A router 14 and other communication terminals 15 are connected to the network. The packet transfer device 10 and the router 14 constitute a network.

  FIG. 2 is a diagram illustrating a more detailed configuration of the packet transfer apparatus. As shown in FIG. 2, the packet transfer apparatus 10 performs a packet transfer process with two redundant control signal processing units 11a and 11b that generate and distribute a routing table and a forwarding table used for packet transfer. The data signal processing unit 13 is connected to the internal bus 12 of the router. The connection inside the router is not limited to a bus connection, and a mesh connection or a connection via a network is also possible.

  Each control signal processing unit 11 (11a, 11b) includes a routing protocol packet processing unit 20 (20a, 20b), a forwarding table calculation unit 21 (21a, 21b), and a database management unit 22 (22a, 22b). The static routing table 23 (23a, 23b), the dynamic routing table 24 (24a), and the state monitoring unit 25 (25a, 25b) are provided. The dynamic routing table 24 is a standby control signal processing unit 11. Not. Each data signal processing unit 13 (13a, 13b) includes a forwarding table 26 (26a, 26b) and a packet transmitting / receiving unit 27 (27a, 27b). Of the two control signal processing units 11, one is used as an active system and the other as a standby system.

[Operation of packet transfer device]
Hereinafter, the operation of the packet transfer apparatus according to the present embodiment will be described with reference to FIG. 1 and FIG.
In FIG. 1 and FIG. 2, when the control signal processing unit 11a in the packet transfer device 10 operates as an active system and the control signal processing unit 11b is on standby as a standby system, the communication with the packet transfer device 10 is performed. The router 14 that is present transmits and receives packets via the data signal processing unit 13. The packet transmitting / receiving unit 27 of the data signal processing unit 13 transfers the packet to the routing protocol packet processing unit 20 (20a) when the packet is a routing protocol packet, and transfers the packet based on the forwarding table 26 when the packet is a data packet. I do. Then, the control signal processing unit 11a generates a dynamic routing table 24a from the collected routing protocol information.

  Further, the terminal 15 notifies the control signal processing unit 11 a and the control signal processing unit 11 b of the same static routing table through the data signal processing unit 13. The control signal processing unit 11a operating as the active system generates forwarding table information based on the retained static routing table 23a and dynamic routing table 24a, and sends the generated forwarding table information to the data signal processing unit 13. Send the packet according to this. Note that an example of processing for generating forwarding table information from the retained static routing table 23a and dynamic routing table 24a will be described later with reference to FIG.

  Here, when the control signal processing unit 11a becomes inoperable due to a failure or the like, the control signal processing unit 11b in the standby state detects the failure of the control signal processing unit 11a and replaces the control signal processing unit 11a. Switch to the active system. Thereafter, exchange of routing protocol packets with the router 14 is performed by the control signal processing unit 11 b via the data signal processing unit 13.

  Here, since the control signal processing unit 11b does not have a dynamic routing table at the time of switching to the working system, the control signal processing unit 11b newly collects routing protocol information from other routers 14 and operates as the working system. The same processing as when the processing unit 11a generates the dynamic routing table is performed.

  FIG. 3 is a diagram for explaining an example of constructing a forwarding table from a static routing table and a dynamic routing table. In this example, it is assumed that the static routing table 42 is manually set by a maintenance person, and the dynamic routing table 41 is set by OSPF (Open Shortest Path First) which is a routing protocol. Here, the cost described in the dynamic routing table 41 and the static routing table 42 refers to a cost for transferring a packet through the network, for example, the number of paths that pass through to reach the network. It may be.

  The forwarding table 43 is an example of generating the forwarding table from the static routing table 42 and the dynamic routing table 41 by combining the routing protocol information of both with cost priority. The routing to the network A in the forwarding table 43 is directed to the router having the address “192.168.10.1”, and the cost of 3 is adopted. The routing of the network A at the cost 3 in the static routing table 42 and the routing of the network A at the cost 4 in the static routing table 42 are compared, and the routing of the network A in the dynamic routing table 41 having a lower cost is determined.

  An example of a forwarding table generated by giving priority to manual setting without comparing costs is the forwarding table 44. In this example, the routing in the static routing table 42 is employed as it is. However, even when such generation is performed, if routing protocol information that does not appear in the static routing table 42 appears in the dynamic routing table 41, the routing protocol information from the dynamic routing table 41 is also forwarded to the forwarding table. 44 will be reflected.

  As shown in the example of FIG. 3, if there is routing protocol information in the static routing table 42, basic routing protocol information is included, so that it is possible to continue routing with this information alone. Recognize. Therefore, for example, even if the active control signal processing unit 11a destroys the forwarding table 26a of the data signal processing unit 13a at the time of the failure, the standby control signal processing unit 11b switched to the active system. Can quickly re-create the basic forwarding table 26a from the static routing table 23b having the same contents as the active control signal processing unit 11a before switching. Thereby, it is possible to guarantee the minimum packet transfer in the data signal processing unit 13a even immediately after switching.

  In this example, OSPF is taken as an example of the dynamic routing protocol, but the dynamic routing protocol is not limited to OSPF, and may be, for example, RIP (Routing Information Protocol).

  Hereinafter, returning to FIG. 1 and FIG. 2, the internal operation of the packet transfer apparatus 10 will be described. The status monitoring units 25a and 25b in the control signal processing units 11a and 11b of the packet transfer apparatus 10 hold status information of themselves and other control signal processing units 11, and monitor other control signal processing units 11. . When the control signal processing unit 11b standing by as the standby system detects that the control signal processing unit 11a operating as the active system cannot execute processing due to the occurrence of a failure or the like, its own control signal processing unit 11b Is switched to the active system, and the routing protocol packet processing unit 20b is activated.

  In the control signal processing unit 11 (11a in FIG. 2) operating as the active system, the routing protocol packet processing unit 20 (20a in FIG. 2) is connected to the other routers 14 connected to the packet forwarding apparatus 10. Routing protocol packets are transmitted and received, dynamic routing table information is generated based on the collected routing protocol information, and is sent to the database management unit 22 (22a in FIG. 2). The database management unit 22 (22a in FIG. 2) holds the dynamic routing table information received from the routing protocol packet processing unit 20 (20a in FIG. 2) in the dynamic routing table 24 (24a in FIG. 2). Note that the control signal processing unit 11 operating from the beginning as the active system and the control signal processing unit 11 switching from the standby system to the active system perform the operations described here in exactly the same manner.

  In the control signal processing unit 11 operating as the active system or waiting as the standby system, when the data management unit 22 receives the setting of the static routing table from the terminal 15 connected to the packet transfer apparatus 10, Is held as the static routing table 23.

  In the control signal processing unit 11a operating as the active system, when the static routing table 23a or the dynamic routing table 24a is updated, the forwarding table calculation unit 21a is activated. The forwarding table calculation unit 21 a generates forwarding table information based on the static routing table 23 a and the dynamic routing table 24 a and sends the information to all the data signal processing units 13 connected to the internal bus 12. Each data signal processing unit 13 holds the forwarding table information received from the forwarding table calculation unit 21 a in the forwarding table 26 as the forwarding table information for each data signal processing unit 13.

[Processing in control signal processor]
Hereinafter, details of processing performed by each unit of the control signal processing unit 11 will be described (see FIG. 2 as appropriate).
FIG. 4 is a diagram illustrating a processing procedure of the state monitoring unit of each control signal processing unit when the packet transfer apparatus is activated.

  When the packet transfer device 10 is activated, the packet transfer device 10 performs initialization processing of each processing unit (processing program) in each control signal processing unit 11 (step S101), and monitors whether the processing ends normally. When the initialization is completed, the control signal processing unit 11 is in an initial state. Next, when the initialization is completed, the system stands by as a standby system, and notifies the other control signal processing unit 11 that it is in a standby state (step S102).

  Then, the state of the other control signal processing unit 11 is monitored to check whether or not all others are standby systems (step S103). If there is no control signal processing unit operating as the active system (Yes in step S103). ) The content of the initial setting information provided in the control signal processing unit is checked in advance (step S104), and the process proceeds to step S105. If there is a control signal processing unit operating as an active system (No in step S103), the processing is terminated as it is.

  In step S105, it is determined whether or not the control signal processing unit 11 itself becomes the active system from the standby state notified from the other standby system and the initial setting information of the control signal processing unit 11 itself. (Yes in step S105), it switches itself to the active system and notifies the other control signal processing unit 11 (step S106). If the current system is not used (No in step S105), the process is terminated as it is.

  Thereafter, in step S107, the routing protocol packet processing unit 20 is activated and the processing is terminated.

FIG. 5 is a diagram illustrating the procedure of the monitoring process of the state monitoring unit that is subsequently executed after the process of FIG.
In this process, the status monitoring units 25 of both the active system and the standby system periodically notify the other control signal processing unit 11 of the status (step S111). Further, the state monitoring unit 25 checks whether there is a state notification from each control signal processing unit 11 (step S112). If there is a status notification (Yes in step S112), the process returns to step S111 to continue the monitoring process. If there is no status notification for a certain period of time (No in step S112), the status monitoring unit 25 notifies It is recognized that a failure has occurred in the control signal processing unit 11 having no failure, and it is checked whether or not the control signal processing unit 11 in which the failure has occurred is an active system (step S113). The status notification sent in the past includes information indicating whether the control signal processing unit 11 is the active system or the standby system, and this information is used to determine whether it is the active system or the standby system. Can do.

  If the control signal processing unit 11 in which the failure has occurred is the active system (Yes in step S113), if the control signal processing unit 11 itself including the state monitoring unit 25 is on standby as a corresponding standby system Then, it is determined whether or not it is the active system (step S114). If it is the active system (Yes in step S114), it is switched to the active system and is transferred to the other control signal processing unit 11 as the active system. A status notification indicating that the switch has been made is sent (step S115). Then, the routing protocol packet processing unit 20 is activated (step S116), and the monitoring process is continued. When the control signal processing unit 11 in which the failure has occurred is a standby system (No in step S113), the process returns to step S111 to continue the monitoring process. Further, even when the device itself does not become the active system in Step S114 (No in Step S114), the process returns to Step S111 and the monitoring process is continued.

  FIG. 6 is a diagram illustrating a processing procedure of the routing protocol packet processing unit 20 in the control signal processing unit 11 operating as an active system.

  When the routing protocol packet processing unit 20 is activated, first, the routing protocol packet is transmitted to the network directly connected to the packet transfer apparatus 10, and the routing protocol packet is received from another router (step S121). Then, it is checked whether or not new information is included in the received packet (step S122). If a packet containing new information is received (Yes in step S122), a dynamic routing table is generated so as to match this (step S123), and the process proceeds to step S124. If a packet containing new information has not been received (No in step S122), the process returns to step S121 and the process is repeated.

  In step S124, the generated dynamic routing table is sent to the database management unit 22, and the processing is repeated from step S121.

Next, FIG. 7 shows a processing procedure of the database management unit 22.
FIG. 7 is a diagram showing a processing procedure when the database management unit 22 newly receives a static routing table or a dynamic routing table.

  In this process, the database management unit 22 acquires the sent routing update information (routing table) (step S131), and whether or not the control signal processing unit 11 itself in which the database management unit 22 is operating is the active system. (Step S132). If the flag indicating the operation mode of the control signal processing unit 11 itself is examined, it can be determined whether or not the current system is in use. If it is operating as an active system (Yes in step S132), the forwarding table calculation unit 21 is notified of the update of the routing table (step S133), and the process is terminated. If it is not operating as the active system (No in step S132), the process is terminated without doing anything.

  FIG. 8 is a diagram illustrating a processing procedure of the forwarding table calculation unit 21 when an update notification is received from the database management unit 22.

  In this process, the updated static routing table 23 and dynamic routing table 24 are read (step S141), and forwarding table information is generated based on them (step S142). Then, the information of the generated forwarding table is sent to the data signal processing unit 13 (step S143), and the process is terminated. After that, the data signal processing unit 13 that has received the information rewrites the internal forwarding table 26 in accordance with the contents sent from the forwarding table calculation unit 21.

  Through the operations described above, even when there are a large number of router devices on the same network as the packet transfer device, failure monitoring and resetting of the static routing table by the maintainer at the time of system switching of the control signal processing unit in the packet transfer device The traffic inside the packet transfer apparatus can be suppressed while suppressing the cost required for recovery and the time required for failure recovery.

<< Second Embodiment >>
Hereinafter, a second embodiment of the present invention will be described (see FIGS. 1 and 2 as appropriate). Since the second embodiment has the same device configuration as the first embodiment, the description of the device configuration is omitted. In addition, since processes other than the static routing table setting process described later are the same as those in the first embodiment, the description thereof is omitted.
In the second embodiment, unlike the first embodiment, the setting of the static routing table by the maintenance person is performed only for the control signal processing unit 11a operating as the active system, and operating as the active system. A static routing table is sent from the control signal processing unit 11a to the control signal processing unit 11b standing by as a standby system. For this reason, in the second embodiment, the processing procedure of the database management unit 22 is different from that of the first embodiment.

  FIG. 9 is a diagram illustrating a processing procedure of the database management unit 22 according to the second embodiment. FIG. 9 shows a processing procedure when the database management unit 22 newly receives a static routing table or a dynamic routing table.

  In this process, the routing update information (routing table) sent from the network is acquired (step S151), and it is checked whether or not it is the active system (step S152). If it is not operating as an active system (No in step S152), the processing is terminated as it is. If it is operating as an active system (Yes in step S152), an update notification indicating that the routing table has been updated is sent to the forwarding table calculation unit 21 (step S153).

  Then, it is checked whether or not the updated routing table is a static routing table (step S154). If the updated routing table is not a static routing table (No in step S154), the process is terminated as it is. If the updated routing table is a static routing table (Yes in step S154), the static routing table is sent to the database management unit 22 of the control signal processing unit 11 waiting as a standby system (step S155), and the process is terminated. .

  Thus, the static routing table set in the control signal processing unit 11 operating as the active system by the maintenance person is equally reflected in the static routing table 23 of the control signal processing unit 11 waiting as another standby system. .

  According to the second embodiment, as in the first embodiment, even when a large number of routers exist on the same network as the packet transfer device, at the time of system switching of the control signal processing unit in the packet transfer device, It is possible to reduce traffic in the packet transfer apparatus while reducing the cost and trouble recovery time required for trouble monitoring and static routing table resetting by the maintenance person. In addition, according to the second embodiment, the labor of the maintenance person can be reduced.

<< Third Embodiment >>
Hereinafter, a third embodiment of the present invention will be described (see FIGS. 1 and 2 as appropriate). Since the apparatus configuration in the third embodiment is the same as that of the first embodiment and the second embodiment except for the configuration of the database management unit described later, the description of the same apparatus configuration is omitted. Other processing is also the same as that of the second embodiment, and the description thereof is omitted.

  FIG. 10 is a diagram illustrating the configuration of the database management unit in the third embodiment. As shown in FIG. 10, the third embodiment adds a routing table write monitoring unit 30 (corresponding to erroneous write prevention means in the claims) inside the database management unit 22 compared to the second embodiment. It is a thing.

  The routing table write monitoring unit 30 of the control signal processing unit 11b waiting as the standby system receives the static routing table sent from the control signal processing unit 11a operating as the active system, and completely acquires the static routing table. At this point, the standby static routing table 23b is updated according to the received contents.

  According to the third embodiment, while the control signal processing unit 11a operating as the active system is sending the static routing table to the control signal processing unit 11b waiting as the standby system, the active system When a failure occurs in the control signal processing unit 11a that operates as the above, the contents of the static routing table 23 can be protected from data corruption due to erroneous writing. This further improves the availability of the packet transfer apparatus.

<< Fourth Embodiment >>
A fourth embodiment of the present invention will be described (see FIGS. 1 and 2 as appropriate).
FIG. 11 is a diagram illustrating a configuration of a data signal processing unit in the fourth embodiment. The fourth embodiment is different from the first embodiment, the second embodiment, or the third embodiment in that the data signal processing unit 13 includes a forwarding table write monitoring unit 31 (a forwarding table in the claims). This corresponds to prevention means for preventing erroneous writing to the storage means). The apparatus configuration in the fourth embodiment is the same as that of the basic embodiment (the first embodiment, the second embodiment, or the third embodiment) except for the configuration of the data signal processing unit 13 described later. Since there is, description is abbreviate | omitted. Further, since the processing other than the forwarding table write monitoring unit 31 is also common to the first embodiment, the second embodiment, or the third embodiment, the description thereof is omitted.

  The forwarding table write monitoring unit 31 of the data signal processing unit 13 receives the forwarding table sent from the forwarding table calculation unit 21 of the control signal processing unit 11a operating as the active system, and when the forwarding table is completely acquired. The forwarding table 26 is updated according to the received contents.

  According to the fourth embodiment, while the control signal processing unit 11a operating as the active system is sending the forwarding table to the data signal processing unit 13, the control signal processing operating as the active system is performed. When a failure occurs in the unit 11a, the contents of the forwarding table 26 can be protected from data corruption due to erroneous writing.

<< Fifth Embodiment >>
Hereinafter, a fifth embodiment of the present invention will be described (see FIGS. 1 and 2 as appropriate).
FIG. 12 is a diagram illustrating a processing procedure when the forwarding table calculation unit 21 receives an update notification from the database management unit 22 in the fifth embodiment.
In the fifth embodiment, forwarding regenerated from the forwarding table calculation unit 21 to the data signal processing unit 13 with respect to the first embodiment, the second embodiment, the third embodiment, or the fourth embodiment. The processing procedure of the forwarding table calculation unit 21 is changed so as to send only the difference table of the forwarding table 26 held by the table and the data signal processing unit (extraction means for extracting the difference from the forwarding table in the claims and Corresponding to notification means for sending the difference forwarding table to the data signal processing unit). It should be noted that processes other than the configuration of the apparatus and the processing procedure of the forwarding table calculation unit 21 are based on the embodiment (the first embodiment, the second embodiment, the third embodiment, or the fourth embodiment). The explanation is omitted because it is the same.

  In the processing of the forwarding table calculation unit 21 in the fifth embodiment, the updated static routing table 23 and dynamic routing table 24 are read (step S161), and a forwarding table based on them is generated (step S162). Next, the contents of the forwarding table 26 held by the data signal processing unit 13 are read (step S163), and a difference table from the newly generated forwarding table is extracted (step S164). In step S164, if the information of the previous forwarding table is lost, the extracted difference table includes the information of the entire forwarding table.

  Next, it is checked whether or not a difference table has been extracted (step S165). When the difference table is extracted (Yes in step S165), the difference table is sent to the data signal processing unit 13 (step S166), and the process ends. If the difference table is not extracted (No in step S165), the process ends without sending anything.

  After this processing, the data signal processing unit 13 rewrites the internal forwarding table 26 in accordance with the contents of the difference table sent from the forwarding table calculation unit 21.

  According to the fifth embodiment, since the amount of information in the forwarding table sent to the data signal processing unit 13 by the forwarding table calculation unit 21 of the control signal processing unit 11 operating as the active system is suppressed, Can reduce traffic.

  So far, the embodiment of the present invention has been described, but according to this, there is no information sent from the control signal processing unit operating as the active system to the control signal processing unit waiting as the standby system, Or at most only the static routing table. Therefore, it is possible to reduce the traffic inside the router device as compared with the case of sending a dynamic routing table that is updated as the state in the network changes.

  In addition, since the control signal processing unit switched from the standby system to the active system holds the static routing table received while waiting as the standby system, it is necessary for the maintenance person to set the static routing table again. Absent. Therefore, compared with a case where the control signal processing unit waiting as a standby system does not hold any information, it is possible to reduce the failure recovery time without causing human costs.

  In addition, at least in the router device in which the control signal processing unit is made redundant, while reducing the amount of information notified from the control signal processing unit operating as the active system to the control signal processing unit waiting as the standby system and the frequency of information notification, It is possible to prevent human costs associated with system switching at the time of failure and shorten failure recovery time.

  If a packet transfer network system is configured using the packet transfer apparatus according to the present invention, a highly available packet transfer network that can be stably operated can be configured.

It is a figure which shows the structure of the packet transfer apparatus which concerns on 1st Embodiment. It is a figure which shows the detailed structure of a packet transfer apparatus. It is a figure explaining the example which comprises a forwarding table from a static routing table and a dynamic routing table. It is a figure which shows the process sequence of the state monitoring part of each control signal process part when a packet transfer apparatus starts. FIG. 5 is a diagram illustrating a procedure of a monitoring process of a state monitoring unit that is executed subsequently after the process of FIG. 4. It is a figure which shows the process sequence of the routing protocol packet process part in the control signal process part which is operate | moving as an active system. It is a figure which shows the procedure of a process when a database management part receives a static routing table or a dynamic routing table newly. It is a figure which shows the process sequence of the forwarding table calculation part when the update notification from a database management part is received. It is a figure which shows the process sequence of the database management part 22 in 2nd Embodiment. It is a figure which shows the structure of the database management part in 3rd Embodiment. It is a figure which shows the structure of the data signal processing part in 4th Embodiment. It is a figure which shows the process sequence when the forwarding table calculation part in 5th Embodiment receives the update notification from a database management part.

Explanation of symbols

10 packet transfer device 11, 11a, 11b control signal processor 12 internal bus 13, 13a, 13b data signal processor 14 router (ordinary router)
15 terminal 20, 20a, 20b routing protocol packet processing unit 21, 21a, 21b forwarding table calculation unit 22, 22a, 22b database management unit 23, 23a, 23b static routing table 24, 24a dynamic routing table 25, 25a, 25b state monitoring Unit 26, 26a, 26b forwarding table 27, 27a, 27b packet transmitting / receiving unit

Claims (13)

A plurality of control signal processes for generating a dynamic routing table for defining a dynamic route for packet forwarding by routing protocol processing, and generating a forwarding table based on the dynamic routing table and a static routing table for defining a static route for packet forwarding set in advance And a plurality of data signal processing units that perform packet transfer according to the forwarding table,
A control signal processor selected from the plurality of control signal processors operates as an active system,
The remaining control signal processing unit is on standby as a standby system,
When a failure occurs in the active control signal processing unit, the control signal processing unit selected from the control signal processing units waiting as a standby system operates as the active system,
The control signal processing unit of the active system,
It said static routing table set in advance, the first holding and said dynamic routing table control signal processing unit of the active system is generated based on the routing protocol information and the routing protocol information collected from other routers A database management unit ;
The executes on the basis of the first routing protocol information held in the database management unit, a routing protocol process including collection and generation of the dynamic routing table of new routing protocol information held in the first database management unit 1 routing protocol packet processing unit ;
A first forwarding table that executes a generation process of a forwarding table based on the static routing table and the dynamic routing table held in the first database management unit and notifies the data signal processing unit of the generated forwarding table A calculation unit ,
A control signal processing unit waiting as the standby system,
The static routing table set prior Ki予 Me and second database management unit that holds,
Based on the routing protocol information held in the second database management unit, a routing protocol process including collection of new routing protocol information held in the second database management unit and generation of a dynamic routing table is executed. Two routing protocol packet processing units;
Based on the static routing table held in the second database management unit and the dynamic routing table generated by the second routing protocol packet processing unit, the forwarding table generation processing is executed, and the generated forwarding table is A second forwarding table calculation unit for notifying the data signal processing unit ,
The data signal processor is
And SL憶unit that holds the forwarding table sent from the control signal processor of an active system,
Before handed憶based on forwarding table held in the unit, the packet transfer device, characterized in that it comprises a packet reception unit that performs inter-network transfer of packet. The packet transfer apparatus according to claim 1 ,
The control signal processing unit of the active system,
A packet transfer apparatus, further comprising: a notification unit configured to send a static routing table held in the first database management unit to a control signal processing unit waiting as the standby system. The packet transfer apparatus according to claim 1 or 2 , wherein
A control signal processing unit waiting as the standby system,
A packet transfer apparatus, further comprising: a routing table write monitoring unit that prevents erroneous writing to the second database management unit of the static routing table sent from an active control signal processing unit. The packet transfer apparatus according to any one of claims 1 to 3 , wherein
The data signal processor is
Packet transfer apparatus further comprising a forwarding table write monitoring portion for preventing erroneous writing Previous handed憶means of the forwarding table sent from the control signal processor of an active system. The packet transfer apparatus according to any one of claims 1 to 4 , wherein
The control signal processing unit of the active system,
Obtaining means for obtaining the forwarding table held in the first database management unit of the data signal processing unit;
Extraction means for extracting a difference forwarding table that is a difference between the generated forwarding table and the forwarding table acquired from the data signal processing unit;
Notification means for sending the difference forwarding table to a data signal processing unit,
The data signal processor is
Packet transfer apparatus further comprising updating means for updating the forwarding table held before Kiki憶unit based on the difference forwarding table sent from the control signal processor of an active system. The packet transfer apparatus according to any one of claims 1 to 5 , wherein
The control signal processing unit of the active system,
When the routing protocol information stored in the first database management unit is updated with the routing protocol information newly collected in the routing protocol processing,
Performing a process of updating the dynamic routing table to be consistent with the updated routing protocol information;
Based on the static routing table held in the first database management unit and the updated dynamic routing table, the forwarding table is regenerated,
A packet transfer apparatus that notifies the data signal processing unit of the regenerated forwarding table. The packet transfer apparatus according to any one of claims 1 to 6 ,
And a network to which the packet transfer apparatus is connected. A plurality of control signal processes for generating a dynamic routing table for defining a dynamic route for packet forwarding by routing protocol processing, and generating a forwarding table based on the dynamic routing table and a static routing table for defining a static route for packet forwarding set in advance A packet transfer method executed by a packet transfer apparatus comprising a plurality of data signal processing units that perform packet transfer according to the forwarding table,
The packet forwarding device is
A procedure for operating a control signal processing unit selected from the plurality of control signal processing units as an active system;
A procedure for waiting the remaining control signal processing unit as a standby system;
Executing a procedure for operating the control signal processing unit selected from the control signal processing units waiting as the standby system as the active system when a failure occurs in the control signal processing unit of the active system,
The control signal processing unit of the active system,
A step of holding said static routing table set in advance, and said dynamic routing table control signal processing unit of the active system is generated based on the routing protocol information and the routing protocol information collected from other routers,
Based on the routing protocol information stored in the first database manager, the procedure for executing the routing protocol process including collection and generation of the dynamic routing table of new routing protocol information held in the first database management unit When,
A procedure for executing a forwarding table generation process based on the static routing table and the dynamic routing table held in the first database management unit ;
Perform the procedure for notifying the forwarding table in the data signal processing unit,
A control signal processing unit waiting as the standby system,
Executing a procedure for retaining the preset static routing table in the second database management unit ;
Procedure for executing routing protocol processing including collection of new routing protocol information held in the second database management unit and generation of a dynamic routing table based on the routing protocol information held in the second database management unit When,
A procedure for executing a forwarding table generation process based on a static routing table held in the second database management unit and a dynamic routing table generated by the second routing protocol packet processing unit;
Executing the procedure of notifying the data signal processing unit of the forwarding table;
The data signal processor is
A step of holding the forwarding table sent from the control signal processor of an active system to memorize means,
Based on the forwarding table held before crisis憶means, packet transfer method characterized by performing a procedure for performing inter-network transfer of packet. The packet transfer method according to claim 8 , comprising:
The control signal processing unit of the active system,
A packet forwarding method further comprising a step of notifying a control signal processing unit waiting as the standby system of a static routing table held in the first database management unit . The packet transfer method according to claim 8 or 9 , wherein
A control signal processing unit waiting as the standby system,
A packet transfer method, further comprising a step of preventing erroneous writing of the static routing table sent from an active control signal processing unit to the second database management unit . The packet transfer method according to any one of claims 8 to 10 , comprising:
The data signal processor is
Packet transfer method characterized by further steps to prevent erroneous writing Previous handed憶means of the forwarding table sent from the control signal processor of an active system. The packet transfer method according to any one of claims 8 to 11 , wherein
The control signal processing unit of the active system,
A procedure for obtaining the forwarding table held in the first database management unit of the data signal processing unit;
A procedure for extracting a difference forwarding table that is a difference between the generated forwarding table and the forwarding table acquired from the data signal processing unit;
A step of notifying the data signal processing unit of the difference forwarding table;
The data signal processor is
Packet transfer method, characterized by further steps of updating the forwarding table held before Kiki憶unit based on the difference forwarding table sent from the control signal processor of an active system. The packet transfer method according to any one of claims 8 to 12 ,
The control signal processing unit of the active system,
When the routing protocol information stored in the first database management unit is updated with the routing protocol information newly collected in the routing protocol processing,
A procedure for performing a process of updating the dynamic routing table so as to be consistent with the updated routing protocol information;
A procedure for regenerating the forwarding table based on the static routing table and the updated dynamic routing table held in the first database management unit ;
And a step of notifying the data signal processing unit of the regenerated forwarding table.

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