JP2007258855A - Virtual router system for realizing logical redundant configuration in router apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a router whose routing function is not interrupted by executing switching through allocation of a routing table without awaiting an automatic switching time in several minutes for the routing table at switching between an active system routing system and a standby system routing system in a router system for forming a redundant configuration comprising the active system and the standby system. <P>SOLUTION: In a couple of the router systems configuring the active system and the standby systems, on the occurrence of a fault in the active system router system, setting of a Trap message to monitored terminals is established. The monitored terminal receiving the message applies allocation (provisioning) to the standby system routing table in order to validate the routing table of the standby system router and uses the standby system routing table with first priority. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  In a router system that forms a redundant configuration of an active system and a standby system, it takes several minutes of automatic switching time of the routing table when switching from the active system to the standby system by the routing method.

  For this reason, there has been a drawback that the routing process is delayed for several minutes and communication cannot be performed.

JP 2002-84313 A

  The present invention is to solve the drawbacks of the prior art.

  In order to achieve the above object, the present invention (feature corresponding to claim 1) is configured to send a Trap message to a monitoring terminal when a failure occurs in a working router system in a pair of router systems constituting a working system and a standby system. Set as listed. The monitoring device that receives the message interrupts routing by assigning (provisioning) the standby routing table to enable the routing table of the standby router and using the standby routing table with the first priority. The communication is continued without being performed.

  According to the present invention (Claim 1), at the time of a failure, when switching from the active system to the standby system router, the routing is instantaneously switched and exhibits the routing function without being interrupted (several minutes). This makes it possible to continue providing communication without interruption.

  According to the present invention (Claim 2), since a plurality of logical routers are formed in one casing, a reduction in installation space of 1/2 is realized as compared with the case where two routers are physically installed. As a result, TCO reduction is realized.

  According to the present invention (Claim 3), in order to realize the allocation method at the time of switching the routing table, an additional measure for incorporating provisioning software in the router is not required. As a result, the current router can be used and no additional development costs can be incurred.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows one system configuration example of a virtual router configuration that realizes instantaneous switching (continuation of routing processing without interruption) by the redundant router of the present invention. This system includes a physical router 10, an active virtual router 11, a standby virtual router 12, an active communication network 13, a standby communication network 14, a physical router 15, an active virtual router 16, a standby virtual router 17, and a monitoring device terminal. 18, a center LAN 19, and a base LAN 20.

  The normal communication path follows the working path of “20-16-13-11-19” and performs communication. If a failure of 16 or 13 or 11 occurs in this communication path, the communication is continued by following the backup path of “20-17-14-12-19”.

  Between the routers “11-16” on the active communication path, a table is set by applying a dynamic routing protocol to dynamically update the routing table periodically, and between the routers “12-17” on the standby communication path. Uses a static routing protocol to set the table in a fixed manner.

  Normally, the switching method from the active communication path “20-16-13-11-19” to the standby communication path “20-17-14-12-19” at the time of failure is switched by the routing method.

  Specifically, in the event of a failure, information for updating the communication route between the active routers “11-16” that is dynamically set is stagnant, and the routing table cannot be updated, so the communication route disappears from the routing table. Then, the communication path that has been fixedly determined in advance is selected, and the communication is continued on the backup path “20-17-14-12-19”.

  The routing table of the above active router disappears and communication becomes impossible, and it takes several minutes to switch to the standby routing table, and communication is interrupted.

  In the present invention, in order to continue this communication without interruption, a failure of “16, 13 or 11” occurred during communication on the working communication path “20-16-13-11-19”. In this case, the monitoring terminal 18 is notified of the SNMP Trap of the failure message. The monitoring terminal that has received the notification assigns the routing table of the virtual router 12 to be used preferentially by switching (provisioning) from the routing table of the virtual router 11 in the physical router 10 to the routing table of the virtual router 12. . Further, by switching (provisioning) the virtual router 16 in the physical router 15 to the routing table, the virtual router 17 is assigned so that the routing table is preferentially used. As a result, the system continues the communication on the standby path “20-17-14-12-19” without interruption.

  FIG. 2 is a block diagram showing the internal configuration of the virtual router of the present invention. This router includes a transmission / reception unit (WAN) 21 in the physical router 10, a transmission / reception unit (WAN) 22 in the physical router 10, a memory unit 23 in the physical router 10, an active control unit 24 in the physical router 10, and a physical router 10. Active system CPU unit 25, active system routing table unit 26 in physical router 10, standby system control unit 27 in physical router 10, standby system CPU unit 28 in physical router 10, and standby system routing in physical router 10 A table unit 29, a transmission / reception unit (LAN) 30 in the physical router 10, and a transmission / reception unit (LAN) 31 in the physical router 10 are configured. During normal communication, communication is performed using the active routers “21, 24, 25, 26, 30”. When a failure occurs on the working path, communication is performed using the spare routers “22, 27, 28, 29, 31”. At the time of the specific switching described above, even if the 26 active routing table has not yet disappeared and has communication information, the 29 standby routing table is assigned with priority according to the instruction from the monitoring terminal. By performing (provisioning), the system instantly switches from the active system to the standby system.

  FIG. 3 is a block diagram showing how the routing table in the memory of the virtual router of the present invention is updated when a failure occurs. In normal switching, as shown in the upper diagram of FIG. 3, when the dynamic table cannot be updated and the communication path disappears from the table, communication is continued with reference to the static routing table. This switching requires several minutes until the communication path disappears from the dynamic routing table. In the present invention, as shown in the lower diagram of FIG. 3, when the dynamic table cannot be updated, the monitoring terminal instructs to use the static table route preferentially even when the route remains on the dynamic table. Make an assignment. As a result, the communication path is directed to the standby system and communication is continued without interruption.

  FIG. 4 shows a switching operation (active system → standby system) when a failure occurs in the active / standby redundant configuration system using the virtual router of the present invention. FIG.

  When a failure occurs in the active system, an SNMP Trap message is notified from the active virtual router 16 to the monitoring device terminal 18. In the case of the corresponding message, the monitoring terminal that has received the notification designates and assigns it so that the routing unit in which static routing is set in advance in the memory of the standby virtual router 17 is used preferentially. Similarly, the backup virtual router 12 on the opposite side is designated and assigned so that the routing unit for which static routing is set in advance is used preferentially. Thereafter, communication continues without interruption using the standby virtual router 17 and the standby virtual router 12.

It is a system logic block diagram of the router redundancy structure which concerns on this invention. 1 is a block diagram schematically showing a router structure according to the present invention. FIG. It is a block diagram which shows the routing table in a memory of the router which concerns on this invention shown in FIG. 2 is a flowchart for switching to a standby system when a failure occurs in the working system of the configuration diagram system shown in FIG. 1 according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Physical router, 11 ... Active virtual router, 12 ... Standby virtual router, 13 ... Active communication network, 14 ... Standby communication network, 15 ... Physical router, 16 ... Active virtual router, 17 ... Standby virtual Router 18: Monitoring device terminal 19 Center LAN 20 Base LAN 21 Transmission / reception unit (WAN) in physical router 10 22 Transmission / reception unit (WAN) in physical router 10 23 In physical router 10 24 ... active system control unit in the physical router 10, 25 ... active system CPU unit in the physical router 10, 26 ... active system routing table unit in the physical router 10, 27 ... standby system in the physical router 10 Control unit 28... Backup CPU in physical router 10 29. Backup routing table in physical router 10 30 Transmission and reception in physical router 10 (LAN), 31 ... transceiver unit (LAN) of the physical routers 10, 32 ... working system dynamic routing table example in the routing table section 26, 33 ... protection system static routing table example in the routing table unit 29.

Claims (3)

  In a conventional communication path redundancy configuration using routers, two active and standby routers are physically installed, and one system is used for switching to the standby system using the routing method when the active system fails. Two routers are logically configured in the chassis (specifically, a configuration in which a plurality of physical interface boards are mounted on one chassis and the memory, control unit, and routing mechanism unit are shared and logically separated). When the active system fails, the shared routing table in the memory is changed from the active system to the standby system (specifically, if the monitoring terminal detects a Trap message that occurs in the event of a failure, the monitoring terminal sends a routing table to the router. A router that performs communication without interrupting the routing function by switching the allocation to the standby system.   The router according to claim 1, wherein the redundant configuration can reduce installation space by forming a plurality of logical router configurations in one casing. 2. The router according to claim 1, wherein in the switching method, routing table allocation (provisioning) is changed by using an SNMP Trap message as a trigger.

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