CN113098768A

CN113098768A - Equipment management method and related device

Info

Publication number: CN113098768A
Application number: CN201911345172.1A
Authority: CN
Inventors: 刘国梁
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-12-23
Filing date: 2019-12-23
Publication date: 2021-07-09
Anticipated expiration: 2039-12-23
Also published as: CN113098768B

Abstract

A device management method and device can realize the flow switching among links, avoid manual link switching operation and improve operation and maintenance efficiency. The method includes generating, by an operator edge (PE) device, a first message including first indication information for indicating that a network device receiving the first message quarantines the PE device from a Designated Forwarder (DF) election list; the PE equipment respectively sends the first message to one or more PE equipment, and the PE equipment and the one or more PE equipment are multi-homing equipment of the CE equipment at the edge of the user, so that the PE equipment except the PE equipment is ensured to act as DF, and the switching of flow forwarding is realized.

Description

Equipment management method and related device

Technical Field

The present application relates to the field of communications technologies, and in particular, to a device management method and a related apparatus.

Background

In an Ethernet Virtual Private Network (EVPN) multi-homing networking, a Customer Edge (CE) device may be connected to a plurality of Provider Edge (PE) devices in an EVPN Network through a plurality of links. In the single-alive mode of the EVPN multi-homing networking, only a Designated Forwarder (DF) is responsible for forwarding messages from or to the CE device. Therefore, in an EVPN multihoming networking, one PE device is usually selected from a plurality of PE devices as a DF, and a link where the DF is located is a primary link.

At present, when equipment in a main link needs to be maintained, operation and maintenance personnel are often required to disconnect the link between the PE equipment serving as a DF and the CE equipment on site, then maintain the equipment, and connect the link between the PE equipment and the CE equipment after the operation and maintenance are finished, so that the operation and maintenance efficiency is low due to the fact that the whole process is complicated in operation.

Disclosure of Invention

When a first PE device serving as a DF receives a first message, the first PE device sends a second message to a third PE device, so that the third PE device can isolate the first PE device from a DF election list according to the second message and then perform DF election, flow forwarding by devices except the first PE device is guaranteed, flow switching is achieved, manual link switching operation is avoided, and operation and maintenance efficiency is improved.

A first aspect of the present application provides an apparatus management method, including: when a link needs to be switched, a PE device serving as a main DF generates a first message, wherein the first message comprises first indication information, and the first indication information is used for indicating a network device receiving the first message to isolate the PE device from a designated forwarder DF election list; and the PE equipment respectively sends the first message to one or more PE equipment, wherein the PE equipment and the one or more PE equipment are multi-homing equipment of the CE equipment at the edge of the user. That is to say, the PE device sets its own DF from the primary DF to the standby DF, that is, does not forward the traffic any more, and sends a first message to the third PE device to instruct the third PE device to perform DF election enhancement, so that the one or more PE devices can perform DF elections after isolating the PE devices in the election list, and finally, the traffic is switched from the first PE device to another PE device.

In the scheme, the PE device serving as the DF sends the first message to other PE devices which form a multi-homing with the PE device, so that the other PE devices can isolate the PE device from the DF election list and then carry out DF election again according to the first identifier which is carried in the first message and indicates that the PE device quits DF election, flow forwarding by devices except the PE device is guaranteed, flow switching is realized, and operation and maintenance efficiency is improved. The PE device enables the first message to indicate other PE devices to perform DF election after isolating the PE device from the DF election list by carrying the first identifier for indicating that the PE device exits DF election in the first message, and flexibility of achieving flow switching is improved.

Optionally, in a possible implementation manner, the PE device receives a second message before generating the one or more first messages; and the PE equipment sets the DF of the PE equipment set as a standby according to the second message.

In the scheme, the DF election enhancement aiming at the PE equipment can be automatically triggered by receiving the first message from other network equipment, such as remote PE equipment or network control equipment, so that the manual link switching operation is avoided, the stability and the robustness of network operation are improved, and the operation efficiency of the network is improved.

Optionally, in a possible implementation manner, the second message is from a far-end PE device, and the far-end PE device establishes a connection with the multihoming device of the CE, respectively.

Optionally, in a possible implementation manner, the second message carries an ethernet segment identifier ESI, and the sending, by the PE device, the first message to the one or more PE devices respectively includes: said PE device determining said one or more PE devices based on said ESI, said first one or more PE devices having said ESI; the PE device sends the first message to the determined one or more PE devices respectively. That is to say, the PE device determines, according to the ESI in the second message, another PE device that belongs to the multi-homing device, so that the first message is sent to another PE device capable of performing traffic switching, thereby improving flexibility of implementation of the scheme.

Optionally, in a possible implementation manner, after the PE device sends the first message to the one or more PE devices, the PE device receives a third message from the far-end PE; the PE equipment sets the PE equipment as a main DF according to the third message; and the PE equipment respectively sends fourth messages to the one or more PE equipment, wherein the fourth messages comprise second indication information, and the second indication information is used for indicating the network equipment receiving the fourth messages to add the PE equipment into the DF election list. Therefore, the PE device can quickly realize that the PE device joins in DF election to become the main DF device again by sending the fourth message carrying the second indication information to other PE devices, and the switching of the flow forwarding device is completed.

Optionally, in a possible implementation manner, before the PE device generates the first message, the method further includes: and the PE equipment respectively receives fifth messages sent by the one or more PE equipment, wherein the fifth messages comprise identification information, and the identification information is used for identifying that the one or more PE equipment support DF election isolation operation. That is, before performing the traffic switching, a DF election enhancement negotiation may be performed between the PE device and the other PE devices, and in a case that the PE device determines that the other PE devices are capable of supporting DF election enhancement, the PE device sends a first message to the other PE devices to perform the traffic switching.

In the scheme, before flow switching, DF election enhancement negotiation can be performed among the devices, and when the PE device determines that other PE devices all support DF election enhancement, the PE device sends the first message to trigger DF election enhancement, so that the feasibility of the scheme is effectively ensured.

Optionally, in a possible implementation manner, the first message is a Border Gateway Protocol (BGP) message, and the first indication information is located in an extended community attribute field of the BGP message.

A first PE device receives a first message sent by a second PE device, where the first message includes first indication information, and the first indication information is used to indicate a network device that receives the first message, and isolate the second PE device from a DF election list; and the first PE equipment isolates the second PE equipment from a DF election list according to the first indication information, wherein the first PE equipment and the second PE equipment are multi-homing equipment of the CE equipment at the edge of the user.

The first PE device in the present solution may be, for example, one of the one or more PE devices referred to in the first aspect, and is configured to perform a DF election enhancement operation according to an instruction message sent by the first PE device in the first aspect. Therefore, the scheme realizes the flow switching, avoids manual link switching operation and improves the operation and maintenance efficiency.

Optionally, in a possible implementation manner, after the first PE device isolates the second PE device from the DF election list, the first PE device receives a second message sent by the second PE device, where the second message includes second indication information, and the first indication information is used to indicate a network device that receives the second message, and add the second PE device to the DF election list; and the first PE equipment adds the second PE equipment into the DF election list according to the second indication information. Therefore, the scheme ensures that the traffic forwarding equipment can be switched again as required after operations such as operation and maintenance are finished.

Optionally, in a possible implementation manner, before receiving the first message sent by the second PE device, the method further includes: and the first PE equipment sends a third message to the second PE equipment, wherein the third message comprises identification information, and the identification information is used for identifying that the first PE equipment supports DF election isolation operation.

In the scheme, before flow switching, DF election enhancement negotiation can be performed among the devices, and under the condition that the first PE device determines that other PE devices all support DF election enhancement, the first PE device sends the first message to trigger DF election enhancement, so that the feasibility of the scheme is effectively ensured.

A third aspect of the present application provides a network device, where the network device is a PE device, and the network device includes:

a generating unit, configured to generate a first message, where the first message includes first indication information, and the first indication information is used to indicate that a network device receiving the first message isolates the PE device from a designated forwarder DF election list; a sending unit, configured to send the first message to one or more PE devices by the PE device, where the PE device and the one or more PE devices are multi-homing devices of a customer edge CE device.

Optionally, in a possible implementation manner, the receiving unit is configured to receive a second message before generating the one or more first messages; and the first setting unit is used for setting the DF of the first PE device as a standby according to the second message.

Optionally, in a possible implementation manner, the second message carries an ethernet segment identifier ESI, and the apparatus further includes: a determining unit, wherein the PE device determines the one or more PE devices according to the ESI, and the first one or more PE devices have the ESI; the sending unit is configured to send the first message to the determined one or more PE devices, respectively.

Optionally, in a possible implementation manner, the receiving unit is further configured to receive a third message from the far-end PE; the apparatus further comprises: the second setting unit is used for setting the PE equipment as the main DF according to the third message; the sending unit is further configured to send a fourth message to the one or more PE devices, where the fourth message includes second indication information, and the second indication information is used to indicate, to the network device that receives the fourth message, that the first PE device adds the first PE device to the DF election list.

Optionally, in a possible implementation manner, before the generating unit generates the first message, the receiving unit is further configured to receive fifth messages sent by the one or more PE devices, respectively, where the fifth messages include identification information, and the identification information is used to identify that the one or more PE devices support DF election isolation operation.

Optionally, in a possible implementation manner, the first message is a border gateway protocol BGP message, and the first indication information is located in an extended community attribute field of the BGP message.

A fourth aspect of the present application provides a network device, where the network device is a first PE device, and the network device includes: a receiving unit, configured to receive a first message sent by a second PE device, where the first message includes first indication information, and the first indication information is used to indicate a network device that receives the first message, and isolate the second PE device from a DF election list; an operation unit, configured to isolate the second PE device from a DF election list according to the first indication information, where the first PE device and the second PE device are multihomed devices of a customer edge CE device.

In this scenario, the first PE device may be, for example, one of the one or more PE devices in the third aspect for receiving a message to perform DF enhancement elections.

Optionally, in a possible implementation manner, the receiving unit is further configured to receive a second message sent by the second PE device after the first PE device isolates the second PE device from a DF election list, where the second message includes second indication information, and the first indication information is used to indicate a network device that receives the second message, and join the second PE device in the DF election list; the operation unit is further configured to add the second PE device to the DF election list according to the second indication information.

Optionally, in a possible implementation manner, the network device further includes a sending unit, configured to send a third message to the second PE device, where the third message includes identification information, and the identification information is used to identify that the first PE device supports DF election isolation operation.

A fifth aspect of the present application provides a network device, including: a processor, a memory; the memory is used for storing instructions; the processor is configured to execute the instructions in the memory to cause the network device to perform the method of any of the preceding first or second aspects.

A sixth aspect of the present application provides a computer storage medium, which may be non-volatile; the computer storage medium has stored therein computer readable instructions which, when executed by a processor, implement the method of any of the first or second aspects.

A seventh aspect of the present application provides a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method as in any one of the first or second aspects.

An eighth aspect of the present application provides a chip system comprising a processor for enabling a network device to implement the functions referred to in the above aspects, e.g. to send or process data and/or information referred to in the above methods. In one possible design, the system-on-chip further includes a memory, which stores program instructions and data necessary for the network device. The chip system may be formed by a chip, or may include a chip and other discrete devices.

A ninth aspect of the present application provides a network system including a first network device and a second network device. The first network device may be, for example, a PE device used for sending the first message in any implementation of the first aspect, or a network device provided in any implementation of the third aspect. The second network device may be, for example, a PE device used for receiving the first message in any implementation manner of the second aspect, or a network device provided in any implementation manner of the fourth aspect.

The first network device generates a first message, where the first message includes first indication information, where the first indication information is used to indicate that a network device receiving the first message isolates the first network device from a Designated Forwarder (DF) election list, the first network device sends the first message to a second network device, and the first network device and the second network device are multihomed devices of a Customer Edge (CE) device. And the second network equipment receives the first message sent by the first network equipment, and isolates the first network equipment from a DF election list according to the first message.

Optionally, in a possible implementation manner, the first network device receives a second message, and the first network device sets the first network device as the active DF according to the second message; and the first network equipment sends a third message to the second network equipment, wherein the third message comprises second indication information, and the second indication information is used for indicating the network equipment receiving the third message to add the first network equipment into the DF election list. And the second network equipment receives the third message sent by the first network equipment, and isolates the first network equipment from a DF election list according to the third message.

Optionally, in a possible implementation manner, the second network device further includes a sending unit, configured to send a third message to the first network device, where the third message includes identification information, and the identification information is used to identify that the second network device supports DF election isolation operation.

According to the technical scheme, the embodiment of the application has the following advantages:

when PE equipment serving as DF receives a first message, the PE equipment sends the first message to one or more PE equipment, so that the one or more PE equipment can isolate the PE equipment from a DF election list according to the first message and then carry out DF election again, the forwarding of flow by equipment except the PE equipment is ensured, the flow switching is realized, the manual link switching operation is avoided, and the operation and maintenance efficiency is improved.

Drawings

Fig. 1 is a schematic view of an application scenario of a device management method according to an embodiment of the present application;

fig. 2 is a schematic flowchart of a device management method according to an embodiment of the present application;

fig. 3 is a schematic structural diagram of a two-layer extended community attribute provided in an embodiment of the present application;

fig. 4 is a schematic structural diagram of an EVPN multihoming networking provided in an embodiment of the present application;

fig. 5A is a schematic diagram of device management according to an embodiment of the present application;

fig. 5B is another schematic diagram of device management according to an embodiment of the present application

Fig. 6 is a schematic structural diagram of a network device according to an embodiment of the present application;

fig. 7 is a schematic structural diagram of a network device according to an embodiment of the present application;

fig. 8 is a schematic structural diagram of a network device according to an embodiment of the present application;

fig. 9 is a schematic structural diagram of a network system according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the embodiments of the present application are described below with reference to the accompanying drawings, and it is obvious that the described embodiments are only some embodiments of the present application, but not all embodiments. As can be known to those skilled in the art, with the advent of new application scenarios, the technical solution provided in the embodiments of the present application is also applicable to similar technical problems.

The terms "first," "second," and the like in the description and in the claims of the present application and in the above-described drawings are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that the embodiments described herein may be practiced otherwise than as specifically illustrated or described herein. Moreover, the terms "comprises," "comprising," and any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or modules is not necessarily limited to those steps or modules explicitly listed, but may include other steps or modules not expressly listed or inherent to such process, method, article, or apparatus. The naming or numbering of the steps appearing in the present application does not mean that the steps in the method flow have to be executed in the chronological/logical order indicated by the naming or numbering, and the named or numbered process steps may be executed in a modified order depending on the technical purpose to be achieved, as long as the same or similar technical effects are achieved. The division of the units presented in this application is a logical division, and in practical applications, there may be another division, for example, multiple units may be combined or integrated into another system, or some features may be omitted, or not executed, and in addition, the shown or discussed coupling or direct coupling or communication connection between each other may be through some interfaces, and the indirect coupling or communication connection between the units may be in an electrical or other similar form, which is not limited in this application. Furthermore, the units or sub-units described as the separate parts may or may not be physically separate, may or may not be physical units, or may be distributed in a plurality of circuit units, and some or all of the units may be selected according to actual needs to achieve the purpose of the present disclosure.

At present, when maintenance needs to be performed on equipment of a main link in an EVPN multi-homing networking, an operation and maintenance worker often needs to go to a site where a CE device is located, accurately extract a main link between the CE device and a PE device serving as a DF from a plurality of links connected to the CE device, manually disconnect the main link (for example, pull a connection line of the main link off the CE device), perform maintenance on the main link device, and finally connect a link between the PE device and the CE device after the operation and maintenance are completed.

In view of this, an embodiment of the present application provides an apparatus management method, in which a far-end PE device opposite to a CE device sends a first message to a first PE device serving as a DF, so that the first PE device sets itself as a standby DF and sends DF update information indicating that a second PE device performs DF election enhancement to the second PE device, thereby implementing switching of traffic forwarding from the first PE device to the other PE devices, without manually performing cut-off and connection of a main link on site, improving operation and maintenance efficiency, and ensuring stability of network operation. The traffic is traffic on the CE device or the user equipment connected to the CE device, and the other PE devices and the first PE device together form a multi-homing device of the CE device. The remote PE device may be a PE device that is not directly connected to a CE device. The remote PE device may establish connections with the multi-homed PE devices of the CE devices, respectively.

Referring to fig. 1, fig. 1 is a schematic view of an application scenario of a device management method according to an embodiment of the present application. As shown in fig. 1, the application scenario specifically includes a PE device and a CE device, where the CE device 21 is connected to the PE device 11 and the PE device 13, that is, the CE device 21 is accessed to the EVPN network through two links, and the PE device 11 and the PE device 13 are dual-homing devices of the CE device 21. The PE device 11 and the PE device 13 are also connected to the PE device 12, and the PE device 12 is connected to the CE device 22; the PE device 11 is a DF, the PE device 13 is a standby DF, and the traffic sent from the CE device 22 to the CE device 21 is sent to the PE device 11 via the PE device 12 and then to the CE device 21, that is, the PE device 11 is responsible for forwarding the traffic. When the PE device 11 needs to switch the traffic from the PE device 11 to another PE device for forwarding, for example, when the PE device 11 needs to be maintained or a link between the PE device 11 and the CE device 21 needs to be maintained, the PE device 12 sends a first message to the PE device 11, and after receiving the first message, the PE device 11 sets itself as a standby DF and sends a second message to the PE device 13, so that the PE device 13 performs DF election enhancement, and finally, the traffic forwarding is switched from the PE device 11 to the PE device 13.

Referring to fig. 2, fig. 2 is a schematic flowchart of a device management method according to an embodiment of the present disclosure; as shown in fig. 2, an apparatus management method provided in an embodiment of the present application includes:

201. the second PE equipment sends a first message to the first PE equipment;

the first PE device is a PE device connected with the CE device in the multi-homing networking, and the CE device can be accessed into the EVPN in a multi-homing mode. The first PE device is currently a DF device, and is responsible for forwarding a message from or to a CE device connected thereto. The DF role of the first PE device may be determined, for example, by DF elections, or may be initially determined manually. The second PE device is a PE device connected to the first PE device, and is responsible for sending the packet sent to the CE device to the first PE device, or receiving the packet from the CE device forwarded by the first PE device. In short, the first PE device is located between the second PE device and the CE device, and is responsible for forwarding the packet between the second PE device and the CE device.

Generally, when maintenance needs to be performed on the first PE device or a link between the first PE device and the CE device, the first message may be sent to the first PE device by the second PE device. The first message includes traffic switching information, where the traffic switching information is used to instruct the first PE device to forward traffic for switching, that is, the second PE device sends traffic switching information to the first PE device to instruct the first PE device to forward traffic of the CE device or the user equipment connected to the CE device to another PE device, where the another PE device and the first PE device form a multi-homing device of the CE device.

In a possible implementation manner, the traffic switching information sent by the second PE device to the first PE device may carry an identifier for instructing the first PE device to forward traffic for switching, so that when the first PE device receives the traffic switching information and detects the identifier in the traffic switching information, the subsequent traffic forwarding switching step can be performed.

In a possible implementation manner, the first message sent by the second PE device to the first PE device may be a Border Gateway Protocol (BGP) message carrying an extended community attribute. For example, the second PE device may send a BGP-based ethernet virtual instance-auto discovery (EVI-AD) route to the first PE device, where the EVI-AD route carries an extended community attribute, and the extended community attribute carries a specific field to instruct the first PE device to switch traffic forwarding. For example, the EVI-AD route carries a two-layer extended community attribute, where an M bit (bit) in a reserved (reserved) field in the two-layer extended community attribute is 0, that is, the M bit (0) in the two-layer extended community attribute in the EVI-AD route is an identifier indicating that the first PE device switches traffic forwarding.

Referring to fig. 3, fig. 3 is a schematic structural diagram of a two-layer extended community attribute according to an embodiment of the present disclosure. As shown in fig. 3, the two-layer extended community attribute includes a type (type) field, a sub-type (sub-type) field, a control flag (control flag) field, a two-layer maximum transmission unit (L2 maximum transmission unit, L2 MTU) field, and a reserved field. Wherein, the type field may be used to indicate a usage range of the two-layer extended community attribute, and the sub-type field may be used to indicate a subtype of the two-layer extended community attribute. In this embodiment, it may be defined that M bit in the Reserved field is 0 as an identifier indicating that the first PE device performs traffic forwarding switching, so that when the first PE device receives the EVI-AD route in which M bit in the two-layer extended community attribute Reserved field is 0, the first PE device can automatically perform a process of traffic forwarding switching. In other possible implementation manners, other fields may also be defined as an identification field for instructing the first PE device to perform traffic forwarding switching as needed.

In other possible implementations, the first PE device may not receive the first message, but directly configure to trigger the first PE device to directly execute 202, such as by a local administrator; alternatively, the first message is not sent by the second PE device to the first PE device, but is sent by a network control device such as a controller or a management device, and so on.

202. The first PE equipment sets itself as a standby DF according to the first message;

since the first PE device is responsible for forwarding the traffic as a DF before the traffic switching, in order to switch the traffic from the first PE device to another PE device for forwarding, the first PE device may set itself as a standby DF after receiving the first message, that is, the first PE device does not perform forwarding of the traffic corresponding to the corresponding CE device any more.

203. The first PE equipment sends a second message to third PE equipment;

after receiving the first message, the first PE device, in addition to setting itself as a standby DF, further sends a second message to a third PE device, where the second message includes, for example, first DF update information for instructing the third PE device to perform DF election enhancement, where DF election enhancement refers to DF elections performed by the third PE device after isolating the first PE device in a DF election list. In an actual application scenario, the isolating may be, for example, to temporarily delete the first PE device in the DF election list, or may not delete the first PE device, but temporarily mask the first PE device in the DF election list by setting an identification bit, and the like.

The third PE device may be one or more PE devices in the EVPN multihoming networking, and is connected with the same CE device as the first PE device, and is used for the CE device to access the EVPN networking in a multihoming manner, that is, the first PE device and the third PE device together form a multihoming device of the same CE device.

Optionally, in some implementation manners, the second message may carry an identifier indicating that the first PE device exits DF election, so that when the third PE device receives the second message and detects the identifier indicating that the first PE device exits DF election, the third PE device performs DF election enhancement.

In one possible implementation, the first PE device may send an Ethernet Segment (ES) route to the third PE device, where the ES route carries an extended community attribute, and the extended community attribute carries a specific field to identify that the first PE device exits DF election. For example, the ES route carries a two-layer extended community attribute, where a B bit in a reserved field in the two-layer extended community attribute is 1, that is, a B bit in the two-layer extended community attribute in the ES route is 1, which indicates that the first PE device exits DF election, and when the B bit is 0 or in some cases, the ES route sent by the first PE device does not carry a corresponding identification bit in the extended community attribute, it may indicate that the first PE device still participates in DF election.

The EVPN network defines a unique Ethernet Segment Identifier (ESI) for the connection between a PE and a CE, and ESI values on PEs connected to the same CE are the same, while ESI values connected to different CEs are different. When routing transmission is performed between PEs, ESI values are carried in the routing, so that other PE devices connected to the same CE can be sensed between PEs. Optionally, in some embodiments, the first message sent by the second PE device to the first PE device includes the ESI. The first PE device can determine a transmission object of the second message (i.e., a third PE device) according to the ESI. In a possible implementation manner, the ESI is carried in the EVI-AD route sent by the second PE device, and after receiving the EVI-AD route, the first PE device may extract the corresponding ESI from the EVI-AD route.

It should be noted that 202 and 203 in the above method are not limited in execution sequence, and the first PE device may execute 202 first and then execute 203, may execute 203 first and then execute 202, and may also execute 202 and 203 simultaneously, which is not limited herein.

204. And the third PE equipment performs DF election enhancement according to the second message.

And the third PE device performs DF election enhancement according to the second message, which means that the third PE device isolates the first PE device from a DF election list and then performs DF election. Specifically, the same DF election list is configured on both the first PE device and the third PE device that are mutually multi-homed, and during DF election, the first PE device and the third PE device may obtain the same election result according to the same DF election algorithm based on the same DF election list. Therefore, after the first PE device exits DF election, in order to ensure that a new DF can be elected in PE devices other than the first PE device, the third PE device that receives the second message may isolate the first PE device from the current DF election list, then elect to obtain a new DF according to a given DF election algorithm, and execute forwarding of traffic corresponding to the corresponding CE device by the new DF, that is, take the newly elected other PE devices as a DF to replace the first PE device to forward traffic, thereby implementing switching of traffic forwarding.

For example, when the first PE device and the third PE device are dual-homed to each other, that is, the CE device is dual-homed to the first PE device and the third PE device, the third PE device isolates the first PE device from the DF election list, and then elects itself as the DF.

For another example, when the first PE device and the third PE device are mutually multi-homed, that is, when the first PE device, the third PE device, and the other one or more PE devices together form a multi-homed device of the same CE device, the first PE device sends the second message to the third PE device and the other one or more PE devices forming multi-homed with the first PE device, and after the first PE device is isolated from the DF election list by the plurality of PE devices receiving the second message, one of the remaining plurality of PE devices is elected as the DF according to the corresponding election rule.

It should be noted that, when the first PE device and a plurality of PE devices including a third PE device jointly form a multihomed device of a CE device, the first PE device may send the first message to the plurality of PE devices. It is to be understood that, in the above situation, the plurality of first messages respectively sent to the plurality of PE devices are actually messages of the same type, and should not be understood as messages having exactly the same content. The plurality of first messages each include indication information for indicating that the network device receiving the first message isolates the first PE device from a designated forwarder, DF, election list.

As shown in fig. 4, fig. 4 is a schematic structural diagram of an EVPN multihoming networking system according to an embodiment of the present application. In fig. 4, the PE device 31, the PE device 33, and the PE device 34 are mutually multi-homed, and are all used for accessing the CE device 41 to the EVPN networking in multi-homed mode, where the PE device 31 is the first PE device, the PE device 33 is the third PE device, and the PE device 34 is the other PE devices. The PE device 31 receives the first message sent by the PE device 32 to perform flow switching, and sends second messages to the PE device 33 and the PE device 34 respectively to instruct the corresponding PE devices to perform DF updating operation, so that the PE device 33 and the PE device 34 isolate the PE device 31 from the DF election list after receiving the second messages, that is, the DF election list only includes the PE device 33 and the PE device 34, and then performs DF election based on the new DF election list, and acquires a new DF by election. For example, the PE device 33 is selected as the new DF by the PE device 33 and the PE device 34.

Optionally, in some embodiments, the first PE device may already know that the third PE device is DF election enhancement capable prior to the first PE device sending the second message to the third PE device. In a possible implementation manner, the way in which the first PE device learns that the third PE device supports DF election enhancement may be: and the first PE device receives a third message sent by a third PE device, wherein the third message carries an identifier for indicating that the third PE device supports DF election enhancement, so that the first PE device knows that the third PE device has DF election enhancement capability, and sends the second message to the third PE device on the premise of the DF handoff. In other possible implementation manners, the first PE device may further confirm that the first PE device itself supports DF election enhancement capability and enables DF election enhancement capability, that is, when the first PE device determines that the third PE device supports DF election enhancement and the first PE device itself also enables DF election enhancement, send the second message to the third PE device. Alternatively, the first PE device may initially support only DF election enhancement but not enable, and after confirming that the third PE device supports DF election enhancement, then enable the election enhancement of the first PE device.

In other possible implementations, the first PE device may also send a message to the third PE device. The message sent by the first PE device carries an identifier indicating that the first PE device supports DF election enhancement, so that after the third PE device receives the message, it is determined that the first PE device supports DF election enhancement.

As one possible example, the first PE device may send the ES route to the third PE device. The extended community attribute in the ES route carries an identifier for indicating that the first PE device supports DF election enhancement, for example, an S bit in a reserved field of a two-layer extended community attribute of the ES route is set (that is, the S bit is 1); similarly, the third PE device may also send the ES route to the first PE device, and also indicate that the third PE device supports DF election enhancement according to the S bit being set in the extended community attribute reserved field.

For the first PE device, after it is known that the first PE device supports DF election enhancement and receives the third message sent by the third PE device, it may be considered that both of them support DF election enhancement. The first network device may send the second message to the third PE device, so that the third PE device performs DF election enhancement according to the second message.

Optionally, in some possible implementations, the operation and maintenance personnel may configure the DF election enhancement enabling parameter for the first PE device and the third PE device under corresponding interfaces of the first PE device and the third PE device, so that the DF election enhancement capability is enabled by the first PE device and the third PE device. Illustratively, the configuration information of the DF election enhancement enabling parameter is specifically as follows:

interface gi1/0/1

(- -interface gi1/0/1)

esi 0011.1001.1001.1001.1002enhanced-df-selection

(- -ESI 0011.1001.1001.1001.1002DF election enhancement)

Wherein interface represents an interface, 0011.1001.1001.1001.1002 represents corresponding ESI, enhanced-DF-selection represents DF election enhancement, and the configuration information specifically represents DF election enhancement enabling for PE equipment with ESI of 0011.1001.1001.1001.1002 under gi1/0/1 interface.

Optionally, in some possible implementations, the second PE device may be triggered to send the first message for performing the traffic switching to the first PE device by sending a traffic forwarding switching instruction to the second PE device. In a possible implementation manner, an operation and maintenance person may configure, to the second PE device, indication information carrying a specific field to trigger the second PE device to send the first message to the first PE device. Illustratively, the specific configuration information may be as follows:

Evpn instance evpn_maintenance

(- -EVPN instance type EVPN maintenance)

peer 1.1.1.1

(- -neighbor ID: 1.1.1)

maintenance switch

(-maintenance instruction: switch)

Wherein, the peer in the configuration information represents a PE device (i.e., a neighbor device) adjacent to the second PE device, and 1.1.1.1 represents an identifier of the PE device (i.e., an identifier of the first PE device) adjacent to the second PE device; the switch indicates traffic switching, and in combination with the peer 1.1.1.1 and maintence switch, the configuration information is specifically used to instruct the second PE device to send the first message to the PE device with the identifier of 1.1.1.1.

Optionally, in some embodiments, after the first PE device sends the second message for re-election and updating the DF to the third PE device, the first PE device receives a fourth message sent by the second PE device, where the fourth message is used to instruct the first PE device to resume forwarding of the traffic. And the first PE equipment restores to set the first PE equipment as DF according to the fourth message and sends a fifth message to the third PE equipment. The fifth message is used to instruct the third PE device to perform DF elections after the first PE device is added to the DF election list. That is to say, when the forwarding of the traffic needs to be resumed to the execution of the first PE device, for example, when the maintenance of the first PE device is completed, the second PE device may send the traffic resumption information to the first PE device, so that the first PE device sets itself as the DF, and sends DF update information for instructing the third PE device to reselect the DF to the third PE device. The traffic may be, for example, traffic of a CE device connected to the first PE device, or traffic of a user device connected to the CE device. In this way, the first PE device may set itself as the DF, and the third PE device adds the first PE device to the DF election list and then performs DF election, and the first PE device is also referred to as the DF, that is, the traffic forwarding is restored from the third PE device to the first PE device.

In a possible implementation manner, the second PE device may be triggered to send the fourth message indicating to resume forwarding of the traffic to the first PE device by sending a traffic forwarding recovery instruction to the second PE device. Specifically, the operation and maintenance personnel may trigger the second PE device to send information for traffic restoration to the first PE device by sending configuration information carrying a specific field to the second PE device. Illustratively, the specific configuration information may be as follows:

Evpn instance evpn_maintenance

(- -EVPN instance type EVPN maintenance)

peer 1.1.1.1

(- -neighbor ID: 1.1.1)

maintenance recovery

(-maintenance instruction: resume)

Wherein, recovery indicates traffic switching, and in combination with peer 1.1.1.1 and mainenance recovery, the configuration information is specifically used to instruct the second PE device to send traffic recovery information to the PE device identified as 1.1.1.1.

In a possible implementation manner, the fourth message sent by the second PE device to the first PE device may carry an identifier for indicating the first PE device to resume traffic forwarding. As a possible implementation manner, the second PE device may send an EVI-AD route to the first PE device, where the EVI-AD route carries the extended community attribute. The extended community attribute carries a specific field indicating that the first PE device resumes traffic forwarding. For example, the EVI-AD route carries a two-layer extended community attribute, where a value of an M bit (bit) in a reserved field in the two-layer extended community attribute is 1, that is, the M bit in the two-layer extended community attribute in the EVI-AD route is 1, which is an identifier indicating that the first PE device resumes forwarding traffic.

In a possible implementation manner, the first PE device may send a fifth message to a third PE device, where the fifth message may carry an identifier for indicating to resume the DF election of the first PE device. As a possible implementation manner, the first PE device may send an ES route to the third PE device, where the ES route carries an extended community attribute, and the extended community attribute carries a specific field indicating that the first PE device is restored to participate in DF election. For example, the ES route carries a two-layer extended community attribute, and a value of B bit in a reserved field in the two-layer extended community attribute is 0, that is, the condition that B bit in the two-layer extended community attribute in the ES route is 0 indicates that the first PE device is resumed to participate in DF election.

For convenience of understanding, the device management method provided in the embodiments of the present application will be described in detail below with reference to specific application scenarios. Referring to fig. 5A, fig. 5A is a schematic diagram of device management provided in the embodiment of the present application, where a PE device 51 and a PE device 53 form a dual-homing device of a CE device 61, and a PE device 52 is a remote device of the CE device 61.

S1, PE device 53 sends a second ES route to PE device 51, and the S bit in the reserved field in the two-layer extended community attribute of the second ES route is set, which indicates that PE device 53 supports DF election enhancement;

s2, PE device 52 sends a first EVI-AD route to PE device 51, where an M bit in a reserved field in a two-layer extended community attribute of the first EVI-AD route is 0, and is used to instruct PE device 51 to switch a traffic forwarding device;

s3, the PE device 51 sets itself as a standby DF according to the first EVI-AD route, that is, the PE device 51 no longer forwards the traffic corresponding to the CE device 61;

the traffic corresponding to the CE device 61 may be, for example, traffic to or from the CE device 61 itself, or traffic to or from a user device connected to the CE device 61.

S4, the PE device 51 extracts ESI from the first EVI-AD route, and sends a third ES route to the PE device 53 corresponding to the ESI, where a B bit in the two-layer extended community attribute of the third ES route is 1, which indicates that the PE device 51 exits DF election;

s5, after the PE device 51 is isolated from the DF election list according to the third ES route, the PE device 53 performs DF election, and elects itself as DF, and switches the traffic corresponding to the CE device 61 to the PE device 53.

In one possible embodiment, the PE device 51 may perform S1' in addition to the above-described S1-S5 as follows:

s1', PE device 51 sends the first ES route to PE device 53, where the S bit in the reserved field in the two-layer extended community attribute of the first ES route is set, indicating that PE device 51 supports DF election enhancement.

PE device 53 determines that PE device 51 supports DF election enhancement upon receiving the first ES route. For example, if there is a case where PE device 51 and PE device 53 constitute a dual homing device for another CE device 61, and PE device 53 is a DF, PE device 53, upon receiving the message indicating switching of traffic, may set itself as a standby DF for the another CE device 61, and send a DF update message to PE device 51 to instruct PE device 51 to re-perform DF elections after isolating PE device 53, the result of the re-performing DF elections will be determined as PE1 in the above case. It should be noted that S1' may be performed at any time, for example, before S1, at any stage of S1-S5 execution or after S5, or at other possible times.

Referring to fig. 5B, fig. 5B is another schematic diagram of device management provided in the embodiment of the present application, configured to enable a recovery device to participate in DF election, where PE device 51 and PE device 53 form a dual-homing device of CE device 61, and PE device 52 is a remote device of CE device 61.

S6, PE device 52 sends a second EVI-AD route to PE device 51, where an M bit in a reserved field in a two-layer extended community attribute of the second EVI-AD route is 1, and is used to instruct PE device 51 to resume traffic forwarding;

s7, PE device 51 sets itself to be DF according to the second EVI-AD route, that is, PE device 51 resumes forwarding the traffic corresponding to CE device 61; the traffic corresponding to the CE device 61 may be, for example, traffic to or from the CE device 61 itself, or traffic to or from a user device connected to the CE device 61.

S8, the PE device 51 extracts ESI from the second EVI-AD route, and sends a fourth ES route to the PE device 53 corresponding to the ESI, where a B bit in the two-layer extended community attribute of the fourth ES route is 0, which indicates that the PE device 51 participates in DF election;

s9, the PE device 53 adds the PE device 51 to the DF election list according to the fourth ES route, performs DF election, elects the PE device 51 as a DF, and forwards and switches the traffic corresponding to the CE device 61 to the PE device 51.

Fig. 6 is a schematic structural diagram of a network device according to an embodiment of the present application, and the network device 60 according to the embodiment of the present application may be, for example, a first PE device in the foregoing method embodiments. Network device 60 may include, for example: a generating unit 601, configured to generate a first message, where the first message includes first indication information, and the first indication information is used to indicate that a network device receiving the first message isolates the first PE device from a designated forwarder DF election list; a sending unit 602, configured to send the first message to one or more PE devices by the first PE device, where the first PE device and the one or more PE devices are multihomed devices of a customer edge CE device.

Optionally, in a possible implementation manner, the network device 60 further includes: a receiving unit 603, configured to receive a second message before generating the one or more first messages; a first setting unit 604, configured to set, according to the second message, a DF for the first PE device to be set as a standby.

Optionally, in a possible implementation manner, the second message carries an ethernet segment identifier ESI, and the network device 60 further includes: a determining unit 605, configured to determine the one or more PE devices according to the ESI, where the first one or more PE devices have the ESI; a sending unit 602, further configured to send the first message to the determined one or more PE devices, respectively.

Optionally, in a possible implementation manner, the receiving unit 603 is further configured to receive a third message from the far-end PE; the network device 60 further includes: a second setting unit 606, configured to set the first PE device as the primary DF according to the third message; the sending unit 602 is further configured to send a fourth message to the one or more PE devices, where the fourth message includes second indication information, and the second indication information is used to indicate that the network device that receives the fourth message adds the first PE device to the DF election list.

Optionally, in a possible implementation manner, before the generating unit 601 generates the first message, the receiving unit 603 is further configured to receive fifth messages sent by the one or more PE devices, respectively, where the fifth messages include identification information, and the identification information is used to identify that the one or more PE devices support DF election isolation operation.

Fig. 7 is a schematic structural diagram of a network device according to an embodiment of the present application, and the network device 70 according to the embodiment of the present application may be, for example, a third PE device in the foregoing method embodiments. Network device 70 may include, for example: a receiving unit 701, configured to receive a first message sent by a second PE device, where the first message includes first indication information, and the first indication information is used to indicate a network device that receives the first message, and isolate the second PE device from a DF election list; an operation unit 702, configured to isolate the second PE device from a DF election list according to the first indication information, where the first PE device and the second PE device are multihomed devices of a customer edge CE device.

Optionally, in a possible implementation manner, the receiving unit 701 is further configured to receive a second message sent by the second PE device after the first PE device isolates the second PE device from the DF election list, where the second message includes second indication information, and the first indication information is used to indicate a network device that receives the second message, and add the second PE device to the DF election list; an operation unit 702 is further configured to add the second PE device to the DF election list according to the second indication information.

Optionally, in a possible implementation manner, before the receiving unit 701 receives the first message sent by the second PE device, the network device further includes a sending unit 703 configured to send a third message to the second PE device, where the third message includes identification information, and the identification information is used to identify that the first PE device supports DF election isolation operation.

The network device in the above embodiments may have some units (or devices) implemented by hardware circuits and some other units (or devices) implemented by software, may also have all units (or devices) implemented by hardware circuits, and may also have all units (or devices) implemented by software.

Fig. 8 is a schematic structural diagram of a network device according to an embodiment of the present application, and as shown in fig. 8, a network device 80 is provided. The network device 80 may be, for example, the first PE device in the foregoing method embodiments. The network device 80 includes: a processor 801. The processor 801 is coupled to a memory 802. The Memory 802 may be independent of the processor 801 or independent of the network device 80, such as Memory #3, or may be within the processor 801 or the network device 80 (Memory #1 and Memory # 2). The memory 802 may be a physically independent unit, or may be a storage space on a cloud server or a network hard disk. Optionally, the memory 802 may be one or more. When the number of the memories 802 is plural, they may be located at the same or different positions, and may be used independently or cooperatively.

The memory 802 is used to store computer-readable instructions (alternatively referred to as a computer program).

The processor 801 is configured to read the computer readable instructions to implement the method provided in the foregoing aspects related to the network device and any implementation thereof.

Optionally, the network device 80 further comprises a transceiver 803 for receiving and transmitting data.

Additionally, the processor 801 may be a central processing unit, general purpose processor, digital signal processor, application specific integrated circuit, field programmable gate array or other programmable logic device, transistor logic device, hardware component, or any combination thereof. Which may implement or perform the various illustrative logical blocks, modules, and circuits described in connection with the disclosure. A processor may also be a combination of computing functions, e.g., a combination of one or more microprocessors, a digital signal processor and a microprocessor, or the like. Additionally, the memory 802 may include: volatile memory (volatile memory), such as random-access memory (RAM); the memory may also include a non-volatile memory (non-volatile memory), such as a flash memory (flash memory), a hard disk (HDD) or a solid-state drive (SSD), a cloud storage (cloud storage), a network attached storage (network attached storage), a network disk (network drive), and the like; the memory may also comprise a combination of the above types of memory or any other form of medium or article having a memory function.

The embodiment of the present application further provides a network system 90, where the network system 90 includes a first network device 901 and a second network device 902. The first network device 901 may be, for example, a network device for sending the first message in the foregoing embodiments, or the like. The second network device 902 may be, for example, the network device for receiving the first message in the above embodiments, or the like.

A first network device 901 generates a first message, where the first message includes first indication information, where the first indication information is used to indicate that a network device receiving the first message isolates the first network device 901 from a designated forwarder DF election list, the first network device 901 sends the first message to a second network device 902, and the first network device 901 and the second network device 902 are multi-homing devices of a customer edge CE device. The second network device 902 receives the first message sent by the first network device, and the second network device 902 isolates the first network device 901 from the DF election list according to the first message.

Optionally, in a possible implementation manner, the first network device 901 receives a second message, and the first network device 901 sets the first network device 901 as the active DF according to the second message; the first network device 901 sends a third message to the second network device 902, where the third message includes second indication information, and the second indication information is used to indicate the network device that receives the third message to add the first network device 901 to the DF election list. The second network device 902 receives the third message sent by the first network device, and the second network device 902 isolates the first network device 901 from the DF election list according to the third message.

Optionally, in a possible implementation manner, the second network device 902 further includes a sending unit, configured to send a third message to the first network device 901, where the third message includes identification information, and the identification information is used to identify that the second network device 902 supports DF election isolation operation.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be substantially implemented or contributed to by the prior art, or all or part of the technical solution may be embodied in a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. The computer readable storage medium includes: u disk, removable hard disk, read only memory, random access memory, magnetic or optical disk, etc. for storing program codes.

Claims

1. A method for device management, the method comprising:

generating a first message by an operator edge (PE) device, wherein the first message comprises first indication information, and the first indication information is used for indicating a network device receiving the first message to isolate the PE device from a Designated Forwarder (DF) election list;

and the PE equipment respectively sends the first message to one or more PE equipment, wherein the PE equipment and the one or more PE equipment are multi-homing equipment of the CE equipment at the edge of the user.

2. The method of claim 1, further comprising:

the PE device receives a second message before generating the first message;

and the PE equipment sets the DF set as the standby by the PE equipment according to the second message.

3. The method of claim 2,

the second message is from a far-end PE device, and the far-end PE device and the multi-homing device of the CE are respectively connected.

4. The method according to claim 2 or 3, wherein the second message carries an ethernet segment identity ESI, and the sending, by the PE device, the first message to the one or more PE devices respectively comprises:

said PE device determining said one or more PE devices based on said ESI, said one or more PE devices having said ESI;

the PE device sends the first message to the determined one or more PE devices respectively.

5. The method according to any one of claims 1 to 4, wherein after the PE device sends the first message to the one or more PE devices, respectively, the method further comprises:

the PE device receives a third message from the far-end PE;

the PE equipment sets the PE equipment as a main DF according to the third message;

and the PE equipment respectively sends fourth messages to the one or more PE equipment, wherein the fourth messages comprise second indication information, and the second indication information is used for indicating the network equipment receiving the fourth messages to add the PE equipment into the DF election list.

6. The method according to any of claims 1 to 5, wherein before the PE device generates the first message, the method further comprises:

and the PE equipment respectively receives fifth messages sent by the one or more PE equipment, wherein the fifth messages comprise identification information, and the identification information is used for identifying that the one or more PE equipment support DF election isolation operation.

7. The method according to any of claims 1 to 6, wherein said first message is a Border Gateway Protocol (BGP) message, and said first indication information is located in an extended community attribute field of said BGP message.

8. A method for device management, the method comprising:

a first Provider Edge (PE) device receives a first message sent by a second PE device, wherein the first message comprises first indication information, and the first indication information is used for indicating a network device receiving the first message and isolating the second PE device from a DF election list;

and the first PE equipment isolates the second PE equipment from a DF election list according to the first indication information, wherein the first PE equipment and the second PE equipment are multi-homing equipment of the CE equipment at the edge of the user.

9. The method of claim 8, further comprising:

after the first PE device isolates the second PE device from the DF election list, the first PE device receives a second message sent by the second PE device, where the second message includes second indication information, and the first indication information is used to indicate a network device that receives the second message, and join the second PE device in the DF election list;

and the first PE equipment adds the second PE equipment into the DF election list according to the second indication information.

10. The method according to claim 8 or 9, wherein before the first PE device receives the first message sent by the second PE device, the method further comprises:

and the first PE equipment sends a third message to the second PE equipment, wherein the third message comprises identification information, and the identification information is used for identifying that the first PE equipment supports DF election isolation operation.

11. A network device, wherein the network device is a provider edge PE device, comprising:

a generating unit, configured to generate a first message, where the first message includes first indication information, and the first indication information is used to indicate that a network device receiving the first message isolates the PE device from a designated forwarder DF election list;

a sending unit, configured to send the first message to one or more PE devices by the PE device, where the PE device and the one or more PE devices are multi-homing devices of a customer edge CE device.

12. The network device of claim 11, wherein the device further comprises:

a receiving unit, configured to receive a second message before generating the first message;

and the first setting unit is used for setting the DF set as the standby by the PE equipment according to the second message.

13. The network device of claim 12, wherein the second message is from a remote PE device, and wherein the remote PE device establishes a connection with a multihoming device of the CE, respectively.

14. The network device according to claim 11 or 12, wherein the second message carries an ethernet segment identity ESI, the device further comprising:

a determining unit, wherein the PE device determines the one or more PE devices according to the ESI, and the one or more PE devices have the ESI;

the sending unit is configured to send the first message to the determined one or more PE devices, respectively.

15. The network device of any of claims 11 to 14,

the receiving unit is further configured to receive a third message from the far-end PE;

the apparatus further comprises:

the second setting unit is used for setting the PE equipment as the main DF according to the third message;

the sending unit is further configured to send a fourth message to the one or more PE devices, where the fourth message includes second indication information, and the second indication information is used to indicate that the network device that receives the fourth message adds the PE device to the DF election list.

16. The network device according to any one of claims 11 to 15, wherein before the generating unit generates the first message, the receiving unit is further configured to receive fifth messages sent by the one or more PE devices, respectively, where the fifth messages include identification information for identifying that the one or more PE devices support DF election quarantine operation.

17. The network device according to any of claims 11 to 16, wherein said first message is a Border Gateway Protocol (BGP) message, and said first indication information is located in an extended community attribute field of said BGP message.

18. A network device, wherein the network device is a first carrier edge, PE, device, comprising:

a receiving unit, configured to receive a first message sent by a second PE device, where the first message includes first indication information, and the first indication information is used to indicate a network device that receives the first message, and isolate the second PE device from a DF election list;

an operation unit, configured to isolate the second PE device from a DF election list according to the first indication information, where the first PE device and the second PE device are multihomed devices of a customer edge CE device.

19. The network device of claim 18,

the receiving unit is further configured to receive a second message sent by the second PE device after the first PE device isolates the second PE device from a DF election list, where the second message includes second indication information, and the first indication information is used to indicate a network device that receives the second message, and join the second PE device in the DF election list;

the operation unit is further configured to add the second PE device to the DF election list according to the second indication information.

20. The network device according to claim 18 or 19, wherein before the receiving unit receives the first message sent by the second PE device, the network device further comprises:

a sending unit, configured to send a third message to the second PE device, where the third message includes identification information, and the identification information is used to identify that the first PE device supports DF election isolation operation.

21. A network device, comprising: a processor, a memory; the memory is used for storing instructions; a processor is configured to execute instructions in a memory to cause the network device to perform the method of any of claims 1 to 10.

22. A computer-readable storage medium having computer-readable instructions stored thereon which, when executed by a processor, implement the method of any one of claims 1 to 10.