JP2000049818A - Router device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the router device where a router having a redundant constitution using the label switching technology is easily realized and a high- level effect is obtained. SOLUTION: The router device is provided with an ATM switch 12 that assigns information of 2 layers or below to each communication port and transfers inputted data by using the information of 2 layers or below, and IP routers 10, 11 either of which acts like an active system and the other of which acts like a standby system. Each of the IP routers 10, 11 has information of 3 layers or over for intercommunication and has common routing information for communication with other devices connected to the ATM switch 12. The IP router selected as the active system validates the common routing information and corresponds the information of 3 layers or over to the information of 2 layers or below assigned to each port of the ATM switch 12, acquires the information of 3 layers or over from the IP router assigned as the standby system and registers the information of 3 layers or over to its own routing information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a router device.

[0002]

2. Description of the Related Art Conventionally, in a network layer structure, a hardware switch for exchanging packets using information of layer 2 or lower and a router for routing using information of layer 3 or higher are combined. Label switching technology that realizes high-speed transfer has attracted attention.

As an example of the above hardware switch,
There are IP switches and cell switch routers using ATM switches. These are a combination of an ATM switch having a plurality of ATM ports and an IP router.
The router is connected to one of the ports of the ATM switch.
Also, in order to communicate with an adjacent device connected to the ATM port of another ATM switch, the IP router and the IP address of the adjacent device and the VPI to be assigned to each ATM port
The VPI / VCI is set for each ATM port by actually operating the ATM switch.

The IP router sets VPI / VCI as default information so that communication between the neighboring device and itself can be performed. However, information such as the IP address of an input packet or exchange with the neighboring device is performed. The VPI / VCI setting for directly connecting the input / output port of the ATM switch without the intervention of the IP router is performed according to the routing information or the like. Using this VPI / VCI makes it possible to transfer IP packets at high speed. A router device applying the label switching technology by a combination of an IP router and an ATM switch performing such operations has been established.

By the way, in the above router device, the IP router plays an important role such as associating and assigning VPI / VCI with an IP address and installing an ATM switch, thereby improving the fault tolerance of the router device. Therefore, it is necessary to make the IP router redundant.

[0006] In the conventional system for realizing the redundant configuration, the operating system has realized all the information regarding the redundant configuration. Specifically, the active system communicated with the standby system as needed, and obtained all information on the redundant configuration, for example, information on how many standby systems existed and the status of each standby system. . In this method, for example, a request for data of the standby system by the maintenance staff is issued to the operation system, and the operation system notifies the maintenance staff of the data of the standby system owned by the maintenance system or the data obtained by communication with the standby system. I was

[0007]

In the above-described system for realizing the redundant configuration, the standby system and the active system exchange information in a dense manner, so that the redundant system can be finely controlled, but the information of the standby system is transmitted to the active system. There is a drawback that the configuration for realization becomes complicated, for example, it is necessary to implement a function for management.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a router device which can be easily realized as a redundant configuration of a router in a label switching technique and which can obtain a high effect. Is to provide.

[0009]

To achieve the above object, a first aspect of the present invention has a plurality of communication ports, and each communication port is assigned information of layer 2 or lower. A first communication device that transfers input data using information of layer 2 or lower, and a plurality of second communication devices connected to the first communication device by one or more communication ports. And one of the plurality of second communication devices.
In a router device in which one is an operation system and another is a standby communication system, each of a plurality of second communication devices has information of layer 3 or more for mutual communication and a second communication device. The second communication device selected as the active system has common routing information for communicating with another device connected to the first communication device other than the device, and has enabled the common routing information. Means for associating the information of layer 3 or higher with the information of layer 2 or lower assigned to each port of the first communication device; and transmitting the information of layer 3 or higher from the second communication device in the standby system. Get it,
By providing means for registering the obtained information of layer 3 or higher in its own routing information, communication is performed between the other device connected to the first communication device and the second communication device in the standby system. .

In a second aspect based on the first aspect, communication between the plurality of second communication devices is performed using a communication port other than the communication port connected to the first communication device. The third invention is the first invention wherein the second
Prior to allocating information of layer 2 or lower to the first communication device of the communication device, a plurality of second communication devices establish communication paths for mutually communicating with the first communication device,
The second communication device that has been successfully established operates as the active system.

In a fourth aspect based on the first aspect, the plurality of second communication devices are mutually connected before the second communication device assigns information of layer 2 or lower to the first communication device. Layer 2 of each second communication device
The above information is exchanged with each other, and the operation system is determined by comparing the information of the layer 3 or higher.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. First, an outline of the present embodiment will be described. The router device of this embodiment has a plurality of communication ports, each communication port is assigned information of layer 2 or lower, and the data input from the communication port is transferred using the information of layer 2 or lower. One communication device and a plurality of second communication devices connected to the first communication device by one or more communication ports, and one of the plurality of second communication devices is operated. The system and other second communication devices operate as a standby system. The second communication device is configured to store information of layer 3 or more of data input from a communication port connected to the first communication device and information of layer 2 or less to be assigned to each communication port of the first communication device. It has a function of performing association and assigning information of layer 2 or less to each communication port of the first communication device using communication means with the first communication device, and transmitting information of layer 3 or more of input data. The transfer is performed using an appropriate communication port of the first communication device based on the routing information of the second communication device itself.

Each of the plurality of second communication devices has information of layer 3 or more for communicating with each other using a means for communicating with each other, and is connected to a first communication device other than the second communication device. And have common routing information to communicate with other devices. After validating the common routing information, the second communication device selected as the active system transmits the information of layer 3 or higher and the information of layer 2 or lower allocated to each port of the first communication device. A connection is made to the first communication device by performing association, obtaining information of layer 3 or more from the second communication device of the standby system, and registering the obtained information of layer 3 or more in its own routing information. The communication between the other device and the second communication device in the standby system is performed.

In this embodiment, an ATM VPI / VCI is assumed as the information of the layer 2 or lower, and therefore, an ATM switch is taken as an example of the first communication device.
Further, an IP address is assumed as information of layer 3 or higher.
Although a router will be described as an example, the present invention is not limited to these configurations. For example, as information of layer 2 or lower, DLCI of frame relay may be used,
IPX address, telephone number,
A unique number or the like can also be used.

FIG. 1 shows a first embodiment to which the router of the present invention is applied.
FIG. 2 is a diagram illustrating a redundant configuration of the IP router according to the embodiment. Although only two IP routers are shown in FIG. 1 for simplification of the description, the present invention is not limited to this configuration.

As shown in FIG. 1, the IP router 1 (10)
Is connected to the P0 port of the ATM switch 12, and the IP router (11) is connected to the P1 port of the ATM switch 12. Other ports P2 to P2 of the ATM switch 12
Reference numeral 6 is connected to other devices, but a port P2 is directly connected to a network management terminal (NMS) 14 for performing network management. However,
For example, another router device or the like may be connected between them. Further, two IP routers 1 (1
0) and 2 (11) are connected by an Ethernet 13 as a means for performing mutual communication. This configuration is also for the purpose of simplifying the description.
If two IP routers can communicate with each other using IP, a network other than Ethernet, such as FDDI or token ring, may be used.

FIG. 2 is a diagram for explaining the sequence of determining the active system and the standby system according to the first embodiment. In this example, as will be understood from the following description, the IP router 1 (10) operates as the active system and the IP router 2 (11) operates as the standby system.

When the IP router 1 (10) starts up, it notifies the ATM switch 12 of a start-up notice A, and then the IP router 2 (11) notifies the ATM switch 12 of a start-up notice B. The ATM switch 12 selects an appropriate partner from the notified ones and returns an activation notification response. Normally, this response is returned in the order of earliest. In this case, the startup notification response C is returned to the IP router 1 (10). An IP router other than the one that responded the startup notification response (here, IP router 2
In (11)), a standby system activation notification D is returned. As a result, the active system and the standby system are determined.

An IP router (here, I
The P router 1 (10)) uses the ATM switch 1 based on the VPI / VCI information to be assigned to each port of the P router 1 (10).
The setting E of 2 is performed. On the other hand, the ATM switch 12 returns an ATM switch setting response F. The ATM switch setting E and the ATM switch setting response F are repeated as necessary. The standby IP router (here, I
The P router 1 (10) notifies the routing information without setting the ATM switch 12, but in this case, the Ethernet port connected to the Ethernet 13 is used.

Thereafter, routing information notices G and H are periodically repeated between the IP router 1 (10) and the IP router 2 (11). FIG. 3 shows a table in which information held by each IP router is stored. FIG. 3 (a)
Is a table including, as information common to IP routers, an IP address assigned to each Px port, and a VPI / VCI list as switch information to be set.

The VPI / VCI list also includes the port information of the connection destination. Normally, Px is the port number to which the adjacent node is connected, and the IP address is assigned to the port number Px for communicating with the adjacent node. It is a self IP address. Since the actual IP packet is transferred to the IP router and processed and exchanged by the IP router, the VPI / V
VPI / V for communicating with the adjacent node is included in the CI list.
In addition to the CI value, a VPI / VCI value exchanged by the ATM switch 12 and used by the IP router to transmit and receive IP packets is also written.

FIG. 3B is a table having information specific to the IP router. An IP address is held as individual information, which is assigned to the Ethernet port in FIG.

FIG. 4 is a diagram showing an operation flow of the IP router according to the first embodiment. As shown in the sequence of FIG. 3, the IP router first transmits a startup notification to the ATM switch 12 (step S1). Based on the response from the ATM switch 12, it is determined whether the IP router is an active system or a standby system (step S2). In the case of the active system, after setting its own IP address in the Ethernet port (step S3), information such as VPI / VCI is set in the ATM switch 12 (step S4) and the routing protocol is started (step S5). .

In the case of a standby system, the ATM switch 12
The basic operation is the same as that of the active system, except that there is no data set in the operation system. That is, immediately after setting its own IP address in the Ethernet port (step S6), the routing protocol is started (step S7).

When the routing protocol is started, the router starts to notify its own routing information. However, the standby IP router notifies only that it is the active adjacent device through the Ethernet 13. Operating system is ATM
The information of the device connected via the switch 12 and its own routing information are notified to the standby IP router through the Ethernet 13.

FIG. 5 shows a network configuration display on the network management terminal relating to the redundant configuration. For simplicity, a display example of the simple configuration example shown in FIG. 1 is shown. The PC in the figure is a network management terminal (NMS) 14, which can perform the main display by obtaining the routing information of the adjacent node notified by the IP router 1 (10) and the IP router 2 (11). Where IP router 2
If (11) does not start due to some kind of failure, or if it goes down during operation, it is not displayed on the network configuration diagram, or is displayed as a diagram, but the status is displayed as abnormal. Incidentally, a circle in the figure means a network, which is set when an active IP router (IP router 1 (10) in this example) is activated and an IP address of each port is set. It is always displayed only for the port.

FIG. 6 shows a sequence for determining the active system and the standby system according to the second embodiment. The device configuration has the same configuration as that of FIG. In this sequence, each of the IP routers 1 (10) and 2 (11) first activates a routing protocol and notifies the other party of routing information notifications I and J. Here, it is assumed that the OSPF is operated. In this case, each router has a router ID as described below, and the representative router is determined by comparing the router IDs. Here, it recognizes that the IP router 1 (10) is the representative router and sends a start-up notification A to the ATM switch 12.
Subsequent activation notification response C, ATM switch setting E, ATM
The processes of the switch setting response F and the routing information notifications G and H are the same as those in FIG. As described above, this sequence is characterized in that the representative router determined by the standard routine is operated as the active system.

FIG. 7 shows an IP in the second embodiment of the present invention.
FIG. 6 is a diagram illustrating an operation flow of a router. IP routers activate a routing protocol and exchange individual information. One of the information at this time is a router ID. Normally, the router ID selects the youngest IP address among its own IP addresses, but as the IP address, the IP address assigned to the Ethernet port of any IP router is selected.

In general, OSPF, which is one of the routing protocols, selects the one with the youngest router ID as the representative router. After setting data to the Ethernet port in step S10 and activating the routing protocol in step S11, the IP router checks whether or not itself is selected as the representative router (step S1).
2) If it is recognized that the router is selected as the representative router, the data is set to the ATM switch 12 (step S13) and the ATM switch 12 operates as the active system. The difference between the case of operating as the active system and the case of not operating is basically the same as in the first embodiment described above, but in the second embodiment, in the case of the active system, the data setting of the ATM-SW (step S1)
The difference is that after 3), the routing protocol is restarted (step S14), and in the case of the standby system, the routing protocol is restarted immediately (step S15).

This is because there is only one port for exchanging packets at the start of the first routing protocol (step S11), and when operating OSPF, it is necessary to operate as a stub (Stub). When operating as an active system, since there are a plurality of ports, the stub setting is removed and OSPF operates as a normal router. The standby system operates the routing protocol as a stub as it is, but since the configuration of the active system is changed, the routing protocol is restarted once. The information to be shared in this case is the same as in FIG. 3 shown in the first embodiment, and the network management terminal (NMS) 14
The above network configuration diagram is also the same as FIG. 5 shown in the first embodiment.

FIG. 8 is a diagram showing a redundant configuration of an IP router according to a third embodiment of the present invention, wherein a plurality of IP routers (here, IP router 1 (10), IP router 2 (1
1)) is a configuration example in the case where the connection is not made by Ethernet. In this case, the IP via the ATM switch 12
By setting the path between the routers 1 (10) and 2 (11) by default, the ATM switch 1 between the IP routers
2 can be performed, but in this case, a path is set as necessary by using the following sequence.

FIG. 9 shows a sequence for determining such an active system and a standby system. The difference from the sequence of FIG. 2 is that the active IP router 1 (10) and the standby IP router 2
(11) means that the ATM switch 12
The M switch 12 receives the registration information of the member that has received the activation notification (member registration notification S, T), and sets a multicast path based on the notified information (multicast path setting U, W). It is to be. In response, the ATM switch 12 returns multicast path setting responses Y and X.

FIG. 10 shows the configuration of a path that is formed immediately before the active IP router performs the ATM switch setting E in the sequence of FIG. At this time, each of the IP routers and the ATM switch exchanges a start notification and the like. The two-way paths 1 and 2 are set by default, and the IP routers 1 (10) to 2 (11)
One-way path 3 and IP router 2 to IP router 1
A one-way path 4 is set. These one-way passes 3,
Reference numeral 4 denotes a point-to-point in the present embodiment. For example, when an IP router 3 (not shown) is added, a multicast path to the IP router 3 is added to the path 3 by the IP router 3. When a new member registration notification is received from the ATM switch 12, the IP router 1 and the I
The P router 2 sets a path for receiving a multicast packet transmitted by the IP router 3. This multicast path is a one-way path. This is used to exchange routing information with each other.

According to the above-described embodiment, a router device which can be easily realized as a redundant configuration of a router in the label switching technique and which can obtain a high effect can be provided by the following three conditions required for realizing the redundant function. Can be provided with satisfaction.

(1) A plurality of IP routers can be connected to an ATM switch to perform redundant operation. One of multiple IP routers
If a failure occurs, information can be collected from the network management terminal by detecting the failure. Further, when one of the currently operating systems becomes inoperable, the job of the operating system which cannot be operated by another IP router can be taken over.

(2) The protection system of the IP router can be disconnected and maintained during operation. At this time, there is no effect on the operation system. (3) The operation system of the IP router can be switched to the non-operation system by manual operation such as command input.
In addition, it is possible to select which of the plurality of protection systems is to be the working system after switching.

[0037]

According to the present invention, it is possible to provide a router device which can be easily realized as a redundant configuration of a router in the label switching technology and which can obtain a high effect.

[Brief description of the drawings]

FIG. 1 is a diagram showing a redundant configuration of an IP router according to a first embodiment to which a router device of the present invention is applied.

FIG. 2 is a diagram illustrating a sequence of determining an active system and a standby system according to the first embodiment.

FIG. 3 is a diagram showing a table in which information held by each IP router is stored.

FIG. 4 is a diagram showing an operation flow of the IP router according to the first embodiment.

FIG. 5 is a diagram showing a network configuration display on a network management terminal relating to a redundant configuration.

FIG. 6 is a diagram illustrating a sequence of determining an active system and a standby system according to the second embodiment.

FIG. 7 is a diagram illustrating an operation flow of an IP router according to a second embodiment of the present invention.

FIG. 8 is a diagram showing a redundant configuration of an IP router according to a third embodiment of the present invention.

FIG. 9 is a diagram for explaining a determination sequence of an active system and a standby system according to the third embodiment.

FIG. 10 is a diagram showing a configuration of a path configured immediately before an active IP router performs an ATM switch setting in the sequence of FIG. 9;

[Explanation of symbols]

 10: IP router, 11: IP router, 12: ATM switch, 13: Ethernet, 14: Network management terminal (NMS).

Claims (4)

[Claims] 1. A first communication system having a plurality of communication ports, wherein information of a layer 2 or lower is assigned to each communication port, and data input from the communication port is transferred using the information of the layer 2 or lower. Device, and the first communication device includes a plurality of second communication devices connected by one or more communication ports, and one of the plurality of second communication devices is an operation system, The second communication device operates as a standby system, wherein each of the plurality of second communication devices has information of layer 3 or more for communicating with each other, and the first communication device other than the second communication device The second communication device selected as the active system has common routing information for communicating with another device connected to the other communication device, and the second communication device selected as the active system has the common routing information enabled. The above information and the first communication Means for associating with the information of layer 2 or less assigned to each port of the device, and information of layer 3 or more obtained from the second communication device of the standby system, and the obtained layer 3 information is added to its own routing information. A router device comprising means for registering the above information, so that the other device connected to the first communication device communicates with the second communication device in the standby system. . 2. The router device according to claim 1, wherein communication between the plurality of second communication devices is performed using a communication port other than a communication port connected to the first communication device. 3. A communication path through which a plurality of second communication devices mutually communicate with the first communication device prior to the assignment of information of layer 2 or lower to the first communication device by the second communication device. 2. The router device according to claim 1, wherein the second communication device that succeeds in establishing is operated as an active system. 4. A plurality of second communication devices communicate with each other prior to the assignment of information of layer 2 or lower to the first communication device by the second communication device, and each of the second communication devices has 2. The router device according to claim 1, wherein information of layer 3 or higher is exchanged with each other, and the operation system is determined by comparing the information of layer 3 or higher.