CN1863198A - Apparatus and method of real-time recovering service - Google Patents

Abstract

The invention relates to a device and method for real-time service restoration in the technical field of network communication. Based on BFD (Bidirectional Forwarding Detection) technology, the present invention provides a method for fast convergence of VRPP (Virtual Routing Redundancy Protocol). BFD detects the fault of the master router, constructs a VRRP message and transmits it to the VRRP module, and realizes the master Quick switchover of backup routers. The present invention realizes the combination of BFD and VRRP, detects faults through BFD, can realize fast standby router becoming master, and overcomes the defect of long convergence time of current VRRP.

Description

A device and method for real-time service recovery

technical field

The invention relates to the technical field of network communication, in particular to a device and method for real-time service recovery.

Background technique

In the existing network system, when the main router fails, in order to restore the service as soon as possible and ensure the continuity and reliability of the communication, the VRRP (Virtual Routing Redundancy Protocol) protocol is often used to realize the switching operation between the main and standby routers. . This protocol ensures that when the next-hop router of the host fails, it can be replaced by another router in the backup state in time, so that when the device fails, the service can be automatically restored as soon as possible.

The working principle of the VRRP protocol is as follows: a group of VRRP routers work together to form a virtual router. The virtual router appears externally as a logical router with a unique fixed IP address and MAC address. Routers in the same VRRP group have two mutually exclusive roles: active router and standby router. There is only one router in the active role in a VRRP group, and there can be one or more routers in the backup role. . The VRRP protocol uses a competition strategy to select a router from the router group as the master, responsible for ARP response and forwarding IP data packets, and other routers in the VRRP group are in the standby state as backup roles. When the active router fails for some reason, the backup router can be upgraded to the active router after a delay of several seconds.

A VRRP router group has a unique identifier: VRID, the range is 0-255. The router appears as a unique virtual MAC address to the outside world, and the format of the address is 00-00-5E-00-01-[VRID].

VRRP periodically sends control packets for fault detection. There is only one type of VRRP control packet: VRRP advertisement. It uses IP multicast data packets for encapsulation, the group address is 224.0.0.18, and the release range is limited to the same LAN. This ensures that the VRID can be reused in different networks. To reduce network bandwidth consumption, only the active router can periodically send VRRP advertisement messages. The backup router starts a new round of VRRP election when it fails to receive VRRP within three consecutive advertisement intervals or receives an advertisement with priority 0.

The VRRP is compatible with various network technologies and link layer technologies, and has been widely used in VPN (Virtual Private Network), traffic engineering, QoS (Quality of Service) and other fields.

As a fault-tolerant protocol, the main problem solved by VRRP is to realize the automatic backup and switching of multiple exits. As shown in Figure 1, a default router is usually set on the host side, and the next hop points to a router, so as to realize the communication between the host and the outside world. Communication.

Traditional VRRP uses the method of regularly sending HELLO packets for fault detection. The default interval for sending VRRP protocol packets is 1 second. To realize the switchover of master and backup. Since the minimum time granularity of the HELLO message is usually 1 second, it takes at least 3 seconds for the standby router to perceive the link failure status. This convergence time is too long for real-time services that need to quickly detect the link failure status. The sending of VRRP packets is processed on the control plane. Therefore, simply reducing the time interval for sending VRRP packets will waste a lot of system resources. On the other hand, in a distributed system, VRRP cannot be guaranteed to converge within 50ms Meet the requirements of real-time communication.

In order to ensure that when the active router fails on the network using the VRRP protocol, the standby router can quickly become the active one, so that the business can be restored quickly and the voice service can not be interrupted. protocol module.

Contents of the invention

The object of the present invention is to provide a kind of device and method of real-time recovery business, detect fault by BFD (bidirectional forwarding detection), management and control module constructs VRRP fault message and report to VRRP module according to the fault detected, all backup routers actively The master-changing competition is carried out, and the fast switching operation of the master and backup routers is realized.

The purpose of the present invention is achieved through the following technical solutions:

A method of restoring business in real time, including:

After bidirectional forwarding detection BFD detects the failure of the active router, it constructs a virtual routing redundancy protocol VRRP failure message and reports it to the VRRP module, which completes the switchover of the active and standby routers.

The failure of the active router includes:

A link failure between the active router and the backup router; or,

The control plane of the active router fails.

The information carried in the VRRP fault message includes message type information used to indicate that the message is for reporting a router fault.

The message type information specifically includes: message version number and message type.

The relationship between the message version number and the message type is:

When the value of the message version number is specified, it indicates that the message is a VRRP fault message, and the value of the message type is used to indicate specific fault type information.

The fault type information corresponds to the message type value.

A device for recovering services in real time, including a BFD module for detecting and judging a failure message of a master router, a VRRP module for processing the failure, and a management and control module.

The management and control module is associated with the BFD module and the VRRP module.

The management and control module is used to receive the fault message detected by the BFD module, construct a VRRP message according to the fault message, and send it to the VRRP module.

It can be seen from the above-mentioned technical solutions provided by the present invention that the present invention realizes the combination of BFD technology and VRRP, detects faults through BFD, can quickly detect faults, and overcomes the defect of long convergence time of current VRRP; After a fault occurs, a control module constructs a VRRP message and reports it to the VRRP module, realizing fast switchover of the active and standby routers.

Description of drawings

FIG. 1 is a prior art VRRP system architecture diagram;

Fig. 2 is the working principle diagram of BFD of the present invention;

Fig. 3 is a block diagram of the device of the present invention;

Fig. 4 is a flowchart of the operation of the method of the present invention.

Detailed ways

BFD (Bidirectional Forwarding Detection) is a router fault detection protocol gradually developed from the basic transmission technology. It can detect faults at all layers of the network, and can be used to detect Ethernet, Multi-Protocol Label Switching (MPLS) paths, Generic routing encapsulation and multiple types of transport correctness including IPSec (IP Internet Security Protocol) tunneling.

In essence, BFD is a high-speed independent HELLO protocol that can establish a peer-to-peer relationship with adjacent systems. Then, each system monitors the BFD rate from other systems at a negotiated rate, and the monitoring rate can be incremented in milliseconds. set up. When a peer system does not receive a preset number of packets, it infers that the software or hardware infrastructure protected by BFD has failed, whether that infrastructure is a label-switched path, another type of tunnel, or an Ethernet network.

The working principle of BFD is shown in Figure 2. By periodically sending fault detection packets based on the UDP (User Datagram Protocol) layer, BFD can not only detect and judge the interruption faults of transmission links, optical interfaces, and device ports, but also And judge soft faults such as bit errors and packet loss in the transport layer, link layer, IP layer and application layer, making up for the current fault detection based on SDH (Synchronous Digital Hierarchy) can only realize the fault detection of the transmission layer.

At present, the default BFD detection interval is 10ms. If a fault is detected three times in a row, it will be judged as a link fault. That is, the fault can be detected and judged within 30 ms. BFD technology does not depend on any other protocols or applications, and can be implemented by hardware without affecting device performance.

Therefore, the present invention proposes a real-time service recovery device and method, which combines BFD and VRRP to realize service flow switching in the shortest time, thereby meeting the needs of real-time services.

The core idea of the present invention is to provide a device and method for restoring services in real time. BFD detects a fault and reports it to the management and control module. The management and control module constructs a VRRP fault message and reports the fault message to the VRRP module. After the VRRP module receives this message, it immediately starts the competition for the backup router to become the master. Finally, the backup router with the highest priority or the same priority and a large IP address competes for the master, and takes over from the original failed master router to start forwarding. Fast switchover of primary and backup routers.

The present invention provides a device for real-time service recovery, the module diagram of the device is shown in Figure 3, the device includes a BFD module 1, a management and control module 2, and a VRRP module 3; wherein the BFD module 1 is used to detect and judge the The default detection interval is 10ms for the link failure between the router and the standby router and the control plane failure of the active router. If the failure is detected three times in a row, the link failure is judged, that is, the failure can be detected and judged within 30ms. ; The management and control module 2 is associated with the BFD module 1, and is used to receive the fault message sent by the BFD module 1, and construct a VRRP fault message according to the fault message, and the information carried by the VRRP fault message includes information used to represent the primary and backup routers Fault type information, such as the location and type of fault occurrence; the VRRP module 3 is associated with the control management module 2, and is used to receive the VRRP fault message sent by the control module 2, and perform fault detection according to the information carried in the message deal with.

The present invention also provides a method for resuming services in real time, as shown in Figure 4 is an operation flowchart of the method of the present invention, as can be seen from Figure 4, the method specifically includes the following steps:

Step 10: Enable BFD module detection and VRRP on all routers in the backup group;

Use BFD module 1 on all routers in the backup group to detect the working status of the active router, including detecting whether the link between the active router and the standby router fails, and whether the control plane of the active router fails.

Step 11: The BFD module 1 detects a fault, notifies the control module 2, and the control module 2 constructs a VRRP fault message and sends it to the VRRP module 3;

The faults detected by the BFD module 1 include: a link failure between the active router and the standby router, and a fault in the control plane of the active router. When the fault occurs, the BFD module 1 can quickly detect it, and send the fault information to the management and control module 2 in a certain format, and the management and control module 2 constructs a new VRRP fault message according to the fault information, and sends the constructed VRRP The fault message is reported to the VRRP module 3, and the version Version of the VRRP fault message is filled in as the desired version number; the type Type of the message is filled in as the agreed message type representing a router fault, and different types of faults are filled in with different Type values , each Type value represents a specific fault, which can be preset; the format of the message is as follows: 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 Version type Virtual Rtr ID priority Count IP Addrs AuthType Adver Int Checksum IP Address(1) IP Address(2) … IP Address(n) Authentication Data(1) Authentication Data(2)

in,

Version: version number, usually 2, the value of this version number can be changed as needed in the VRRP failure message;

Type: The type of the message, usually 1, which means a broadcast message. When the version is a value specified by the user in a VRRP fault message, different Type values represent different types of faults, and a Type value of 1 no longer means broadcast message, but a specific fault, that is to say, 1 is multiplexed, which will be described in detail later;

Virtual Rtr ID (VRID): The configured VRRP backup group number, 1 to 255, must be configured, and uniquely identifies the virtual group;

Priority: priority, 0-255 (among them, 0 and 255 are not configurable), optional, the larger the value, the higher the priority;

Count IP Addrs: The number of configured backup group virtual IP addresses. A backup group can correspond to multiple virtual addresses. It must be configured, and multiple virtual addresses can be configured, at least 1. The backup group must be consistent, and the order can be different;

Auth Type: authentication type, three authentication types are specified in the protocol, 0 means no authentication, 1 means simple text password, 2 means IP authentication header

Adver Int: The time interval for sending HELLO messages, the default is 1 second;

Checksum: checksum;

IP Address(es): the virtual IP address list of the configured backup group;

Authentication Data authentication word;

In the VRRP fault message constructed by the management and control module 2, when the version number changes, the Type value indicates various fault types, which are determined by the management and control module 2 based on the detection results of the BFD module 1 and filled in the new VRRP fault In the message, the specific mapping relationship can be as follows:

TYPE value Fault type

1 Link failure between master and backup;

2 Primary management failure;

3 A failure in the active uplink;

4 Reset the forwarding plane of the master router;

5 All uplinks of the active router fail;

The specific mapping relationship can be preset;

Step 12: The VRRP module 3 realizes the switching of the master and backup routers;

After the above operations are completed, if there is a failure between the active and standby routers or the control plane of the active router, the VRRP module 3 will start to control the competition for the standby router to become the active one. The backup router with the largest address performs master switching, and this process is realized by the VRRP module 3 according to the received new VRRP failure message.

To sum up, the present invention realizes the combination of BFD and VRRP, detects faults through BFD, realizes fast detection of faults and switching of active and standby routers, and overcomes the shortcoming of long convergence time of current VRRP.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present invention can easily think of changes or Replacement should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (9)

1, a kind of method of real-time recovering service is characterized in that, comprising:

After two-way forwarding detection BFD detected primary route device fault, constructing virtual route redundancy protocol VRRP fault message reported the VRRP module, finishes active and standby switching with router by the VRRP module.

2, the method for a kind of real-time recovering service as claimed in claim 1 is characterized in that, described primary route device fault comprises:

Link failure between primary route device and the standby router; Or,

The control plane of primary route device breaks down.

3, the method for a kind of real-time recovering service as claimed in claim 1 is characterized in that, loaded information comprises and is used to represent that this message is the type of message information that reports router failure in the described VRRP fault message.

4, the method for a kind of real-time recovering service as claimed in claim 3 is characterized in that, described type of message information specifically comprises: message version number, type of message.

5, the method for a kind of real-time recovering service as claimed in claim 4 is characterized in that, the pass of described message version number and type of message is:

When the value of message version number is this message of expression of appointment when being VRRP fault message, described type of message value is used to represent concrete fault type information.

6, the method for a kind of real-time recovering service as claimed in claim 5 is characterized in that, described fault type information is corresponding with the type of message value.

7, a kind of device of real-time recovering service comprises the BFD module and the VRRP module that is used to handle described fault that are used to detect and judge primary route device failure message, it is characterized in that, also comprises: the management and control module.

8, the device of a kind of real-time recovering service as claimed in claim 7 is characterized in that, described management and control module and BFD module and VRRP module connection.

As the device of claim 7 or 8 described a kind of real-time recovering services, it is characterized in that 9, described management and control module is used to receive the detected failure message of BFD module, and, send to the VRRP module according to described failure message structure VRRP message.

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