CN106936682B

CN106936682B - Processing method and controller for appointed forwarder and provider edge device

Info

Publication number: CN106936682B
Application number: CN201511029051.8A
Authority: CN
Inventors: 郝卫国; 张晓益; 阴元斌; 庄顺万
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2015-12-31
Filing date: 2015-12-31
Publication date: 2021-09-14
Anticipated expiration: 2035-12-31
Also published as: CN106936682A; CN113923092A

Abstract

The invention discloses a processing method and a controller for a designated forwarder and provider edge equipment, which are used for realizing the centralized control of DF election so as to effectively realize the unified management of DF election. The embodiment of the invention provides a processing method for an appointed forwarder, which comprises the following steps: the method comprises the steps that a controller receives DF request information sent by a plurality of provider edge PE devices in the same core network; the controller elects a PE device from the PE devices as a DF according to DF request information sent by each PE device in the PE devices to obtain DF election information; the controller sends the DF election information to each of the PE devices, respectively.

Description

Processing method and controller for appointed forwarder and provider edge device

Technical Field

The invention relates to the technical field of computers, in particular to a processing method and a controller for a Designated Forwarder (DF), and Provider Edge (PE).

Background

An Ethernet Virtual Private Network (EVPN) is a two-layer VPN technology, and the basic protocol is defined in RFC 7432. The PE device may learn, in a Media Access Control (MAC) learning manner on a data plane, an MAC of a locally accessed Customer Edge (CE). And then, MAC learned locally is diffused and synchronized between the PE devices through a Border Gateway Protocol (BGP), MAC learning is not performed between the PE devices and the PE devices through a data layer broadcasting and flooding mechanism, unknown unicast message flooding in the VPN can be reduced through an EVPN Protocol, and network bandwidth is saved. Compared with the traditional Virtual Private Local Area Network Service (VPLS) technology, the EVPN can also realize multi-active access and improve the bandwidth of an access link.

In a scenario where multiple PE devices are connected in a core network (english name: core network), for example, two CE devices (CE 1 and CE2, respectively) are connected through the core network, a CE1 is connected to multiple PE devices, and when a CE2 sends a message to the CE1, the message is transmitted to a CE1 through the multiple PE devices. To prevent a CE1 from receiving multiple duplicate messages, only one PE device is allowed to send the message to the locally accessed CE 1. There is a DF election mechanism in EVPN, which can be used to elect a DF among multiple PE devices that are accessed, and only the DF can forward a message received from the core network to the locally connected CE 1.

After the existing multi-homed accessed PE devices can automatically discover among multi-homed members through BGP EVPN Ethernet Segment routing (English name: Ethernet Segment route), the existing EVPN basic protocol provides that all PE devices adopt the same algorithm to calculate DF, and because each PE device can independently carry out DF election through the same algorithm, the independent operation of each PE device can not effectively realize the unified management of DF election, for example, DF election load sharing is uneven, or unnecessary service flow is lost when a certain multi-homed PE fails. It is therefore necessary to alter the existing DF election mechanism.

Disclosure of Invention

The embodiment of the invention provides a processing method and a controller for a designated forwarder and provider edge equipment, which are used for realizing the centralized control of DF election, thereby effectively realizing the unified management of DF election.

In order to solve the above technical problems, embodiments of the present invention provide the following technical solutions:

in a first aspect, an embodiment of the present invention provides a processing method for specifying a forwarder, including:

the method comprises the steps that a controller receives DF request information sent by a plurality of provider edge PE devices in the same core network;

the controller elects a PE device from the PE devices as a DF according to DF request information sent by each PE device in the PE devices to obtain DF election information;

the controller sends the DF election information to each of the PE devices, respectively.

With reference to the first aspect, in a first possible implementation manner of the first aspect, the DF request information includes at least one of the following information: the method comprises the following steps that an Ethernet network segment ES and an Ethernet Tag are adopted, and when a plurality of PE devices are connected with the same customer edge CE device through a virtual local area network VLAN network, the Ethernet Tag corresponds to a virtual local area network identification VLAN ID;

the controller elects a PE device from the PE devices as a DF according to the DF request information sent by each PE device, and obtains DF election information, which comprises the following steps:

when the service type of the VLAN network is VLAN basic service or VLAN binding service, the controller elects a PE device from the PE devices as DF according to the ES and the Ethernet Tag, and DF election information is obtained; or the like, or, alternatively,

when the service type of the VLAN network is VLAN binding sensing service, the controller selects one PE device from the PE devices as DF according to the ES and the Ethernet Tag binding group corresponding to the VLAN binding sensing service, and DF election information is obtained.

With reference to the first aspect, in a second possible implementation manner of the first aspect, the DF request information includes at least one of the following information: the Ethernet Tag corresponds to a Virtual Network Identifier (VNID) when the PE devices are connected with the same Customer Edge (CE) device through a three-layer-bearing-based network virtualization overlay NVO3 network;

when the service type of the NVO3 network is a VN basic service or a VN binding service, the controller elects a PE device from the PE devices as a DF according to the ES and the Ethernet Tag, to obtain DF election information.

With reference to the first aspect, in a third possible implementation manner of the first aspect, the method further includes:

the controller determining whether each of the plurality of PE devices fails;

when at least one PE device in the plurality of PE devices fails, the controller re-elects a PE device as a DF from all PE devices which do not fail according to an Ethernet virtual private network EVPN instance, the ES, the Ethernet Tag and the DF election information.

With reference to the third possible implementation manner of the first aspect, in a fourth possible implementation manner of the first aspect, the determining, by the controller, whether each PE device of the multiple PE devices fails includes:

the controller detects the device state of each of the plurality of PE devices through a Bidirectional Forwarding Detection (BFD) mechanism to determine whether each of the plurality of PE devices fails; or the like, or, alternatively,

and the controller receives equipment state information sent by the PE equipment in the PE equipment when the PE equipment detects that other PE equipment in the PE equipment has faults through a BFD mechanism, and determines the PE equipment with the faults in the PE equipment according to the received equipment state information.

With reference to the fourth possible implementation manner of the first aspect, in a fifth possible implementation manner of the first aspect, the reselecting, by the controller, one PE device as the DF from all PE devices that do not generate the failure according to the EVPN instance, the ES, the Ethernet Tag, and the DF election information includes:

if the DF election information indicates that the fault-free PE equipment is used as the DF, the controller determines that the elected DF is kept unchanged;

and if the DF election information indicates that the failed PE equipment is taken as the DF, the controller elects one non-failed PE equipment from all non-failed PE equipment according to the EVPN instance, the ES and the Ethernet Tag to be taken as the DF.

With reference to the first aspect or the first possible, the second possible, the third possible, the fourth possible, or the fifth possible implementation manner of the first aspect, in a sixth possible implementation manner of the first aspect, the DF request information sent by one PE device further includes at least one of the following information: the local port number of the PE equipment, the VPN identification corresponding to the EVPN instance and the service type corresponding to the EVPN instance;

the service type corresponding to the EVPN instance comprises at least one of the following service types: VLAN base services, or VLAN binding aware services, or VLAN port services, or VN base services, or VN binding services.

In a second aspect, an embodiment of the present invention provides a method for processing a designated forwarder DF, including:

provider edge PE equipment sends DF request information to a controller;

the PE device receives DF election information from the controller;

and the PE equipment determines whether the PE equipment is elected as the DF or not according to the DF election information.

With reference to the second aspect, in a first possible implementation manner of the second aspect, the DF request information sent by the PE device includes at least one of the following information: the local port number of the PE equipment, Ethernet Tag, virtual private network VPN identification corresponding to Ethernet virtual private network EVPN instance and service type corresponding to the EVPN instance;

With reference to the first possible implementation manner of the second aspect, in a second possible implementation manner of the second aspect, when the PE device is connected to a customer edge CE device through a network virtualization overlay NVO3 network based on a three-layer bearer, the Ethernet Tag corresponds to a virtual network identifier VNID;

when the PE device is connected with the CE device through a virtual local area network VLAN network, the Ethernet Tag corresponds to the virtual local area network identification VLAN ID.

With reference to the second aspect, in a third possible implementation manner of the second aspect, the method further includes:

the PE equipment detects the equipment state of other PE equipment in the same core network with the PE equipment through a Bidirectional Forwarding Detection (BFD) mechanism;

and when the PE equipment detects that other PE equipment in the same core network has faults, equipment state information of the faulty PE equipment is sent to the controller.

In a third aspect, an embodiment of the present invention provides a controller, including:

the receiving and sending module is used for receiving the DF request information of the designated forwarder sent by each of a plurality of provider edge PE devices in the same core network;

a DF election module, configured to elect a PE device from the multiple PE devices as a DF according to DF request information sent by each PE device of the multiple PE devices, so as to obtain DF election information;

the transceiver module is further configured to send the DF election information to each PE device of the multiple PE devices, respectively.

With reference to the third aspect, in a first possible implementation manner of the third aspect, the DF request information includes at least one of the following information: the method comprises the following steps that an Ethernet network segment ES and an Ethernet Tag are adopted, and when a plurality of PE devices are connected with the same customer edge CE device through a virtual local area network VLAN network, the Ethernet Tag corresponds to a virtual local area network identification VLAN ID;

the DF election module is specifically configured to, when the service type of the VLAN network is a VLAN basic service or a VLAN binding service, elect a PE device from the multiple PE devices as a DF according to the ES and the Ethernet Tag, and obtain DF election information; or, when the service type of the VLAN network is VLAN binding sensing service, selecting one PE device from the multiple PE devices as DF according to the ES and the Ethernet Tag binding group corresponding to the VLAN binding sensing service, to obtain DF election information.

With reference to the third aspect, in a second possible implementation manner of the third aspect, the DF request information includes at least one of the following information: the Ethernet Tag corresponds to a Virtual Network Identifier (VNID) when the PE devices are connected with the same Customer Edge (CE) device through a three-layer-bearing-based network virtualization overlay NVO3 network;

the DF election module is specifically configured to, when the service type of the NVO3 network is a VN basic service or a VN binding service, elect a PE device from the multiple PE devices as a DF according to the ES and the Ethernet Tag, and obtain DF election information.

With reference to the third aspect, in a third possible implementation manner of the third aspect, the controller further includes: a failure determination module to determine whether each of the plurality of PE devices fails;

the DF election module is further configured to, when at least one PE device of the PE devices fails, re-elect a PE device as a DF from all PE devices that do not fail according to an Ethernet virtual private network EVPN instance, an ES, an Ethernet Tag, and the DF election information.

With reference to the third possible implementation manner of the third aspect, in a fourth possible implementation manner of the third aspect, the failure determining module is specifically configured to detect, by using a Bidirectional Forwarding Detection (BFD) mechanism, a device state of each PE device in the multiple PE devices, so as to determine whether each PE device in the multiple PE devices generates a failure; or the like, or, alternatively,

the receiving and sending module is further configured to receive device status information sent by the PE device of the multiple PE devices when detecting, through a BFD mechanism, that another PE device of the multiple PE devices has a fault, and the fault determining module is specifically configured to determine, according to the received device status information, the PE device of the multiple PE devices that has a fault.

With reference to the fourth possible implementation manner of the third aspect, in a fifth possible implementation manner of the third aspect, the DF election module is specifically configured to, if the DF election information indicates that a failure-free PE device is used as a DF, determine that an elected DF remains unchanged by the controller; and if the DF election information indicates that the failed PE equipment is taken as the DF, selecting one non-failed PE equipment from all non-failed PE equipment according to the EVPN instance, the ES and the Ethernet Tag to be taken as the DF.

With reference to the third aspect or the first possible, the second possible, the third possible, the fourth possible, or the fifth possible implementation manner of the third aspect, in a sixth possible implementation manner of the third aspect, the DF request information sent by one PE device further includes at least one of the following information: the local port number of the PE equipment, the Ethernet network segment identifier ESI, the virtual private network VPN identifier corresponding to the EVPN instance and the service type corresponding to the EVPN instance;

In a fourth aspect, a provider edge PE device includes:

the receiving and sending module is used for sending DF request information of the appointed forwarder to the controller; the PE device receives DF election information from the controller;

and the DF determining module is used for determining whether the PE equipment elects as the DF or not according to the DF election information.

With reference to the fourth aspect, in a first possible implementation manner of the fourth aspect, the DF request information sent by the PE device includes at least one of the following information: the local port number of the PE equipment, Ethernet Tag, virtual private network VPN identification corresponding to Ethernet virtual private network EVPN instance and service type corresponding to the EVPN instance;

With reference to the first possible implementation manner of the fourth aspect, in a second possible implementation manner of the fourth aspect, when the PE device is connected to a customer edge CE device through a network virtualization overlay NVO3 network based on a three-layer bearer, the Ethernet Tag corresponds to a virtual network identifier VNID;

With reference to the fourth aspect, in a third possible implementation manner of the fourth aspect, the PE device further includes a failure detection module, configured to detect, through a Bidirectional Forwarding Detection (BFD) mechanism, a device state of another PE device in the same core network as the PE device;

the transceiver module is further configured to send device state information of the failed PE device to the controller when the PE device detects that the other PE devices in the same core network have a failure.

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

in the embodiment of the invention, a plurality of PE devices in the same core network independently send DF request information to a controller, the controller performs centralized control on DF election, after receiving the DF request information sent by each PE device, the controller elects one PE device from the PE devices as DF according to the DF request information to obtain DF election information, and the controller respectively sends DF election results to the PE devices according to the DF election information. In the embodiment of the invention, a single controller can be arranged in the core network to realize the centralized control of DF election, rather than each PE device independently performing DF election, so that the controller can be used for realizing the centralized control of DF election, thereby effectively realizing the unified management of DF election.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings.

Fig. 1 is a schematic diagram of an application system architecture of a processing method for designating a forwarder according to an embodiment of the present invention;

fig. 2 is a schematic flowchart of a processing method for designating a forwarder according to an embodiment of the present invention;

fig. 3 is a schematic flowchart of another method for processing a designated forwarder according to an embodiment of the present invention;

FIG. 4 is a flowchart illustrating a processing method for designating a forwarder according to an embodiment of the present invention;

FIG. 5-a is a schematic diagram of a controller according to an embodiment of the present invention;

FIG. 5-b is a schematic diagram of another controller according to an embodiment of the present invention;

fig. 6-a is a schematic structural diagram of a PE device according to an embodiment of the present invention;

fig. 6-b is a schematic structural diagram of another PE device according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of another controller according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of another PE device according to an embodiment of the present invention.

Detailed Description

In order to make the objects, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the embodiments described below are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments that can be derived by one skilled in the art from the embodiments given herein are intended to be within the scope of the invention.

The terms "comprises" and "comprising," and any variations thereof, in the description and claims of this invention and the above-described drawings are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

First, an application system architecture of the processing method for designating a forwarder provided by the embodiment of the present invention is explained. Please refer to fig. 1, a controller and a plurality of PE devices are arranged in a core network, each PE device is connected to the controller, for example, in fig. 1, n PE devices (PE 1, PE2, …, PEn, n may be a non-zero natural number) are connected to the controller, and the n PE devices are further connected to a same CE device in a two-layer network, so that the CE devices are connected to PE1, PE2, and PEn, and Bidirectional Forwarding Detection (BFD) may be configured between the PE devices for communication. The packet sent from the core network to the CE device is sent to the CE device through PE1, PE2, and PEn, but in order to prevent the CE from receiving multiple duplicate packets, only one PE device is allowed to send the packet to the locally accessed CE, where the packet may be a Unicast (english name: Broadcast) packet, an unknown Unicast (english name: Unicast) packet, or a Multicast (english name: Multicast) packet, and these packets may be collectively referred to as: BUM (English name: Broadcast, Unknown Unit cast, Multicast) messages. In the embodiment of the invention, a controller can be arranged in a core network, the controller can realize the centralized control of DF election, the DF elected by the controller sends a message to the CE equipment, and other non-DF can not send the message to the CE equipment, so that the CE equipment can only receive the message from the DF and can not receive a plurality of repeated messages. In a specific implementation scenario, the controller provided in the embodiment of the present invention may be a centralized control point arranged in a core network and electing a DF, for example, the controller may be a BGP route reflector, a network manager, a coordinator, and other devices, and in a specific implementation, a deployment mode and a device implementation structure of the controller may be flexibly selected.

The following describes in detail the DF processing method according to the embodiment of the present invention with a controller and a PE device according to the embodiment of the present invention. First, a method for processing a DF according to an embodiment of the present invention is described from a controller side, please refer to fig. 2, where the method for processing a DF according to an embodiment of the present invention may include the following steps:

201. the controller receives DF request information sent by a plurality of PE devices in the same core network.

In the embodiment of the present invention, multiple PE devices in the same core network are all connected to the same CE device, and a message from the core network may be sent to the CE device through the multiple PE devices, so that in order to avoid that the CE device receives the same message sent by all the multiple PE devices, only one PE device of the multiple PE devices can send a message to the CE device. In the embodiment of the present invention, only one PE device of the multiple PE devices may send a message to the CE device as a DF, and specifically, which PE device is determined by the controller as the DF, the multiple PE devices connected to the same CE device all send DF request information to the controller, and the controller may receive the multiple DF request information of the multiple PE devices, and information content included in the DF request information may be set according to a specific scenario. For example, the DF request information sent by a PE device may include at least one of the following information: the PE device comprises a local port number, a Virtual Private Network (VPN) identifier corresponding to an EVPN instance and a service type corresponding to the EVPN instance. The service type corresponding to the EVPN instance comprises at least one of the following service types: virtual Local Area Network (VLAN) basic service (english name: basic service), or VLAN binding service (english name: binding service), or VLAN binding aware service (english name: binding service), or VLAN port service (port service), or VN basic service, or VN binding service. In practical applications, the PE device may specifically determine which information or information is carried in the DF request information. In other implementation scenarios of the present invention, the DF requesting information may further include other information, for example, the DF requesting information includes at least one of the following information: ethernet network Segment (Ethernet Segment, ES) and Ethernet label (Ethernet Tag), wherein the ES is Ethernet Segment Identifier (ESI), ES is the physical port for accessing EVPN instance, and Ethernet Tag is access VLAN information on the physical port. It should be noted that the information content included in the DF request information is only an example, and in different application scenarios, other information may be further set, so that the controller can determine which PE device sends the DF request information according to the DF request information.

202. The controller selects one PE device from the PE devices as DF according to the DF request information sent by each PE device in the PE devices, and DF election information is obtained.

In the embodiment of the present invention, the controller is connected to a plurality of PE devices, and the controller receives a DF request message from each PE device, so that the controller can determine how many PE devices can participate in the election of the DF. The controller may select one PE device from the plurality of PE devices as a DF, and generate DF election information including: which PE device is elected to be the DF. In addition, the DF election information may also include which PE device or devices are non-DFs, and so on. In the embodiment of the invention, a single controller can be arranged in the core network to realize the centralized control of DF election, rather than each PE device independently carrying out DF election, so that the controller can be used for realizing the centralized control of DF election, thereby effectively realizing the unified management of DF election.

In the embodiment of the present invention, there may be various implementations in which the controller selects one PE device from the multiple PE devices as the DF, and the following description is provided. In some embodiments of the invention, the DF solicitation information includes at least one of the following information: the method comprises the following steps that when multiple PE devices are connected with the same CE device through a VLAN Network, the Ethernet Tag corresponds to a Virtual Local Area Network identifier (VLAN ID), and in step 202, a controller selects one PE device from the multiple PE devices as a DF according to DF request information sent by each PE device in the multiple PE devices to obtain DF election information, wherein the DF election information comprises the following steps:

a1, when the service type of VLAN network is VLAN basic service or VLAN binding service, the controller selects a PE device from multiple PE devices as DF according to ES and Ethernet Tag, and DF election information is obtained; or the like, or, alternatively,

a2, when the service type of VLAN network is VLAN binding sensing service, the controller selects a PE device from multiple PE devices as DF according to ES and Ethernet Tag binding group corresponding to VLAN binding sensing service, and DF election information is obtained.

When multiple PE devices are connected to a CE device through a VLAN network, the controller may determine the DF by using a specific DF election method for different service types of the VLAN network. For example, for normal two-tier network access, one EVPN instance may access one or more VLANs simultaneously. For VLAN Based service or VLAN Bundling service, only one broadcast domain is in one EVPN instance, all access VLANs share the broadcast domain, for VLAN Bundling service, a plurality of broadcast domains are in the EVPN instance, and each access VLAN adopts one broadcast domain. Therefore, for VLAN Based service or VLAN mapping service, the controller may determine the granularity of DF election as < ES, Ethernet Tag >, and for VLAN mapping service, the controller may determine the granularity of DF election as < ES, Ethernet Tag. For example, if the particle size is < ES, Ethernet Tag > and DF is chosen, assuming ESI is ESI1, EVPN is the example of EVPN associated with this ESI, and Tag11 and Tag12 are the Ethernet Tag of this EVPN, the controller can choose one PE device for each of ESI1+ Tag11 and ESI1+ Tag12 as DF, and choose two DFs in total. DF election is performed by < ES, Ethernet Tag bundle > for granularity, assuming ESI is ESI1, EVPN is an example of EVPN associated with this ESI, Tag of Ethernet for this EVPN is Tag11, Tag12 and Tag13, if Tag11 and Tag12 belong to the same Ethernet Tag binding group and Tag13 belongs to a single Ethernet Tag binding group, the controller may elect a PE device as DF for ESI1+ Tag11, ESI1+ Tag12, and elect two DFs together.

In some embodiments of the invention, the DF solicitation information includes at least one of the following information: and when a plurality of PE devices are connected with the same customer edge CE device through a network virtualization overlay NVO3 network based on three-layer bearing, the Ethernet Tag corresponds to the virtual network identification VNID. In step 202, the controller selects a PE device from the PE devices as a DF according to the DF request information sent by each of the PE devices, so as to obtain DF election information, which may include the following steps:

and B1, when the service type of the NVO3 network is VN basic service or VN binding service, the controller elects a PE device from the PE devices as DF according to ES and Ethernet Tag, and DF election information is obtained.

When multiple PE devices are connected to a CE device through an NVO3 network, the controller may determine the DF by using a specific DF election method for different service types of the NVO3 network. For example, for normal two-tier network access, one EVPN instance may access one or more NVOs 3 simultaneously. For the VN base service or the VN binding service, there is only one broadcast domain in one EVPN instance, all the access NVOs 3 share the broadcast domain, and the NVO3 network adopts a 24-bit VN ID as the virtual local area network identifier, and the VN ID is equivalent to Ethernet Tag. Thus, for VN base service or VN binding service, the controller may determine the granularity of DF election as < ES, Ethernet Tag >, for example, perform DF election with < ES, Ethernet Tag >, assuming that there is ESI1, the EVPN instance associated with this ESI is EVPN, and the Ethernet Tag of this EVPN is Tag11 and Tag12, then the controller may elect a PE device as DF for each of ESI1+ Tag11, ESI1+ Tag12, and elect two DFs in total.

In practical applications, it is an implementation manner that the controller elects one PE device from the PE devices as the DF, and if the number of PE devices is N, the controller elects the DF by: the controller sorts the IP addresses of the N PE devices from small to large, and calculates i ═ in the following manner (VLAN ID mod N), so that the ith PE device of the N PE devices is elected as DF, and the remaining PE devices of the N PE devices are regarded as non-DF, and N, i is a natural number.

For example, the controller may default to a number from 0 according to the order of the IP addresses of the PE devices from small to large, and the ith PE device is elected as DF by < ES, VLAN V >, and V is a VLAN ID if i is (V mod N).

203. The controller sends the DF election information to each of the plurality of PE devices, respectively.

In this embodiment of the present invention, after the controller elects one PE device from the multiple PE devices as the DF through the foregoing step 202, the controller may send the obtained DF election information to the multiple PE devices, so that each PE device may determine whether it is elected as the DF according to the DF election information sent by the controller. For example, as follows, 3 PE devices are participating in DF elections, the controller determines that PE1 is elected as DF, the controller determines that PE2 and PE3 are non-DF, the controller may send DF election information to PE1, PE2, and PE3, respectively, PE1 determines that it is elected as DF by the DF election information, and PE2 and PE3 determine that it is non-DF by the DF election information.

In some embodiments of the present invention, in addition to executing the foregoing methods in step 201 to step 203, the method for processing a DF according to embodiments of the present invention may further include the following steps:

c1, the controller determines whether each PE device in the plurality of PE devices generates a fault;

and C2, when at least one PE device in the PE devices generates faults, the controller re-elects a PE device as DF from all PE devices which do not generate faults according to the EVPN instance, the ES, the Ethernet Tag and the DF election information.

The controller may obtain device statuses of the plurality of PE devices, and then determine whether each of the plurality of PE devices has failed. In the embodiment of the invention, the failure of the PE equipment means that the PE equipment cannot work normally and does not have the capability of sending a message to the CE equipment as a DF. After the controller determines whether each PE device in the PE devices fails, when at least one PE device in the PE devices fails, the controller re-elects a PE device as a DF from all PE devices which do not fail according to EVPN instance, ES, Ethernet Tag and DF election information, wherein the DF re-election performed by the controller is similar to the DF election process, and the difference is that the controller needs to re-elect a DF from all PE devices which do not fail, and the PE device which fails does not re-elect a DF as a DF, so that the DF cannot send a message to a CE device.

In some embodiments of the present invention, the step C1 where the controller determines whether each PE device of the multiple PE devices fails, may specifically include the following steps:

c11, the controller detects the device status of each PE device in the multiple PE devices through a Bidirectional Forwarding Detection (BFD) mechanism to determine whether each PE device in the multiple PE devices fails; or the like, or, alternatively,

and C12, the controller receives device status information sent by the PE device of the multiple PE devices when detecting that the other PE devices of the multiple PE devices have a failure through the BFD mechanism, and determines the PE device of the multiple PE devices that has a failure according to the received device status information.

In the embodiment of the present invention, the controller, the PE devices, and each PE device may configure a BFD protocol, so that the controller may automatically detect whether each PE device has a failure through a BFD mechanism, or may perform failure detection on other PE devices by a non-failed PE device, and send device status information of the failed PE device to the controller by the non-failed PE device, so that the controller may also determine a PE device having a failure among the multiple PE devices, and a specific implementation manner is not limited.

In some embodiments of the present invention, the step C2 includes that the controller re-elects a PE device as the DF from all PE devices that do not generate the failure according to the EVPN instance, the ES, the Ethernet Tag, and the DF election information, and specifically includes the following steps:

c21, if the DF election information indicates that the PE equipment without the fault is taken as the DF, the controller determines that the elected DF is kept unchanged;

and C22, if the DF election information indicates that the failed PE device is taken as the DF, the controller elects a non-failed PE device from all non-failed PE devices according to the EVPN instance, the ES and the Ethernet Tag to be taken as the DF.

When the controller re-elects the DF, if it is determined that the elected DF is the non-faulty PE device according to the DF election information generated by the controller in step 202, it may be determined that the elected DF remains unchanged. If the DF election information generated by the controller indicates a failed PE device as the DF according to step 202, the controller elects one non-failed PE device from all non-failed PE devices as the DF according to the EVPN instance, the ES, and the Ethernet Tag. For example, if the controller is connected to 3 PE devices (PE 1, PE2, and PE3, respectively), as described in step 202, the controller elects PE3 as DF, and if the controller determines that PE3 has a failure according to the device state of PE3, PE3 cannot act as DF any more, so PE3 may be removed as DF, the controller may re-elect a PE device from PE1 and PE2 as DF, and the controller may send DF election information to PE1 and PE 2.

As can be seen from the foregoing description of the present invention, in the embodiment of the present invention, multiple PE devices in the same core network independently send DF request information to a controller, the controller performs centralized control on DF elections, after receiving the DF request information sent by each PE device, the controller elects a PE device from the multiple PE devices as a DF according to the DF request information to obtain DF election information, and the controller sends DF election results to the multiple PE devices according to the DF election information. In the embodiment of the invention, a single controller can be arranged in the core network to realize the centralized control of DF election, rather than each PE device independently performing DF election, so that the controller can be used for realizing the centralized control of DF election, thereby effectively realizing the unified management of DF election.

The foregoing embodiment describes a method for processing a DF according to an embodiment of the present invention from a controller perspective, and then a PE device perspective is described a method for processing a DF according to an embodiment of the present invention, please refer to fig. 3, where the method for processing a DF according to an embodiment of the present invention may include the following steps:

301. the PE device sends DF request information to the controller.

In the embodiment of the present invention, multiple PE devices in the same core network are all connected to the same CE device, and a message from the core network may be sent to the CE device through the multiple PE devices, so that in order to avoid that the CE device receives the same message sent by all the multiple PE devices, only one PE device of the multiple PE devices can send a message to the CE device. In the embodiment of the present invention, only one PE device of the multiple PE devices may send a message to the CE device as a DF, and specifically, which PE device is determined by the controller as the DF, and the PE device sends DF request information to the controller, where information content included in the DF request information may be set according to a specific scenario. For example, the DF request information sent by the PE device may include at least one of the following information: the local port number of the PE device, the VPN identification corresponding to the EVPN instance and the service type corresponding to the EVPN instance. The service type corresponding to the EVPN instance comprises at least one of the following service types: VLAN base services, or VLAN binding aware services, or VLAN port services (port services), or VN base services, or VN binding services. In practical applications, the PE device may specifically determine which information or information is carried in the DF request information. In other implementation scenarios of the present invention, the DF requesting information may further include other information, for example, the DF requesting information includes at least one of the following information: ES, which is a physical port accessing the EVPN instance, and Ethernet Tag, which is access VLAN information on the physical port. It should be noted that the information content included in the DF request information is only an example, and in different application scenarios, other information may be further set, so that the controller can determine which PE device sends the DF request information according to the DF request information.

In some embodiments of the present invention, when the PE device is connected to the CE device through the NVO3 network, the Ethernet Tag corresponds to the VNID; when the PE device is connected with the CE device through the VLAN network, the Ethernet Tag corresponds to the VLAN ID.

302. The PE device receives DF election information from the controller.

In the embodiment of the present invention, as can be seen from the foregoing description of the controller side, after the controller generates the DF election information, the controller sends the DF election information to the PE device, and then the PE device may receive the DF election information from the controller, and then execute step 303.

303. And the PE equipment determines whether the PE equipment is elected as the DF or not according to the DF election information.

In the embodiment of the present invention, the PE device determines whether it is elected as DF according to DF election information received from the controller, and if the PE device is elected as DF, the PE device may forward, as the DF, a message that needs to be sent to the CE device in the core network to the CE device. In the embodiment of the invention, the PE equipment cannot independently determine DF election, but the controller in the core network performs unified centralized control on the DF election.

In some embodiments of the present invention, the DF processing method according to an embodiment of the present invention may further include:

d1, detecting the device state of other PE devices in the same core network with the PE device by the PE device through a BFD mechanism;

and D2, when the PE device detects that other PE devices in the same core network have faults, sending the device state information of the faulty PE device to the controller.

In the embodiment of the present invention, a BFD protocol may be configured between PE devices, a non-failed PE device performs failure detection on other PE devices, and the non-failed PE device sends device status information of a failed PE device to a controller, so that the controller may determine a PE device that has a failure among a plurality of PE devices.

In order to better understand and implement the above-mentioned schemes of the embodiments of the present invention, the following description specifically illustrates corresponding application scenarios.

Fig. 4 is a schematic flow chart of a DF processing method according to an embodiment of the present invention. In the prior art, under the condition that there is no centralized control point, the load sharing based on the Ethernet Tag cannot be effectively realized, for example, as specified in the existing EVPN basic protocol, all PEs use the same algorithm to calculate DF, if there are only two PEs, PE1 is responsible for even VLAN access, and PE2 is responsible for odd VLAN access. If there are three PEs, one of PE3 fails, the DF needs to be readjusted, but the existing algorithm will cause the DF on some PE1 to be adjusted to PE2, which will cause flow disruption. In the embodiment of the invention, the access state is controlled by a centralized control method, the uniform load sharing of DF can be realized, and the unnecessary adjustment of DF state under the condition of PE state change can be avoided.

In fig. 4, it is described by taking an example that a CE2 transmits a message to a CE1, where the message of the CE2 is first transmitted to a PE4, the PE4, the PE1, the PE2, and the PE3 are in a core network, the PE1, the PE2, and the PE3 are respectively connected to the CE1, the PE1, the PE2, and the PE3 may all forward the message to the CE1, and in order to avoid that the CE1 receives 3 repeated messages, only one PE device among the PE1, the PE2, and the PE3 can transmit the message to the CE 1. In the embodiment of the present invention, the PE device elected as the DF sends a message to the CE 1. Each PE reports the local port number, ESI, Ethernet Tag and VPN identification to a controller (controller) through BGP, and the PE can send an Auto-Discovery (AD) route carrying extended community attribute for requesting DF from the controller. The controller may determine one PE device from the three PE devices as the DF. For example, the controller determines PE1 as the DF, then both PE2 and PE3 as non-DFs. The controller may issue a release status to PE1 indicating PE1 was elected DF and a block status to PE2 and PE3 indicating that PE2 and PE3 are both non-DFs. The PE device sets the corresponding state of the local access port according to the instruction of the controller, for example, the PE device may obtain the DF state that it should set through the extended community attribute of the AD route.

After the controller elects the DF and generates DF election information, the controller may further perform the following two methods: 1. and rapidly detecting the equipment state of each PE equipment through protocols such as BFD (bidirectional forwarding detection) and the like, and recalculating the DF state by the controller under the condition of PE equipment failure. 2. PE1 detects PE2 state and PE3 state through protocols such as BFD, the same PE2 detects PE1 state and PE3 state through protocols such as BFD, PE3 detects PE1 state and PE2 state through protocols such as BFD, PE1, PE2 and PE3 report other PE equipment states to the controller respectively, and the controller is triggered to recalculate DF state. The controller carries out DF re-election according to EVPN instance, ES, Ethernet Tag and DF election information, and can effectively avoid invalid adjustment of DF. For example, the DF of VLAN 1, VLAN2, VLAN3, VLAN4 generated by the controller are PE1, PE2, PE3, PE1, respectively. If the PE3 failure is detected, the controller may reselect DF for VLAN 1, VLAN2, VLAN3, and VLAN4, and the DF for each VLAN becomes: PE1, PE2, PE2, PE 1. The table description is as follows:

before PE3 fails, the DF corresponding to each VLAN ID is shown in table 1 below:

after PE3 fails, according to the solution provided by the embodiment of the present invention, the DF PE corresponding to each VLAN ID is as shown in table 2 below:

as shown in the above table, the load on PE1 and PE2 is in equilibrium when implemented in accordance with an embodiment of the present invention.

In addition, after the failure of PE3, if it is according to the prior art: for original VLAN3, PE3 is selected as DF, and after PE3 fails, VLAN3 selects PE1 as DF, as shown in table 3 below:

as shown in table 3 above, according to the prior art, each PE elects DF separately, PE1 will be the DF for VLANs 1, 3, 4, and PE2 will be the DF for VLAN2 only. Thus, there would be an imbalance in the loads on PE1 and PE2 in the prior art.

The embodiment of the invention realizes DF election by a centralized control mode, can realize load sharing with more uniform granularity, and can avoid unnecessary DF adjustment under the scenes of PE node failure and the like.

It should be noted that, for simplicity of description, the above-mentioned method embodiments are described as a series of acts or combination of acts, but those skilled in the art will recognize that the present invention is not limited by the order of acts, as some steps may occur in other orders or concurrently in accordance with the invention. Further, those skilled in the art should also appreciate that the embodiments described in the specification are preferred embodiments and that the acts and modules referred to are not necessarily required by the invention.

To facilitate a better implementation of the above-described aspects of embodiments of the present invention, the following also provides relevant means for implementing the above-described aspects.

Referring to fig. 5-a, a controller according to an embodiment of the present invention includes: a transceiver module 501 and a DF election module 502, wherein,

a transceiver module 501, configured to receive request information of a designated forwarder DF sent by multiple provider edge PE devices in the same core network;

a DF election module 502, configured to elect a PE device from the multiple PE devices as a DF according to DF request information sent by each PE device of the multiple PE devices, so as to obtain DF election information;

the transceiver module 501 is further configured to send the DF election information to each PE device of the multiple PE devices.

In some embodiments of the invention, the DF solicitation information includes at least one of the following information: the method comprises the following steps that an Ethernet network segment ES and an Ethernet Tag are adopted, and when a plurality of PE devices are connected with the same customer edge CE device through a virtual local area network VLAN network, the Ethernet Tag corresponds to a virtual local area network identification VLAN ID;

the DF election module 502 is specifically configured to, when the service type of the VLAN network is a VLAN basic service or a VLAN binding service, elect a PE device from the multiple PE devices as a DF according to the ES and the Ethernet Tag, and obtain DF election information; or, when the service type of the VLAN network is VLAN binding sensing service, selecting one PE device from the multiple PE devices as DF according to the ES and the Ethernet Tag binding group corresponding to the VLAN binding sensing service, to obtain DF election information.

In some embodiments of the invention, the DF solicitation information includes at least one of the following information: the Ethernet Tag corresponds to a Virtual Network Identifier (VNID) when the PE devices are connected with the same Customer Edge (CE) device through a three-layer-bearing-based network virtualization overlay NVO3 network;

the DF election module 502 is specifically configured to, when the service type of the NVO3 network is a VN basic service or a VN binding service, elect a PE device from the multiple PE devices as a DF according to the ES and the Ethernet Tag, and obtain DF election information.

In some embodiments of the present invention, as shown in fig. 5-b, the controller 500 further comprises: a failure determining module 503, configured to determine whether each PE device in the plurality of PE devices generates a failure;

the DF election module 502 is further configured to, when at least one PE device of the PE devices fails, re-elect a PE device as a DF from all PE devices that do not fail according to an Ethernet virtual private network EVPN instance, an ES, an Ethernet Tag, and the DF election information.

In some embodiments of the present invention, the failure determining module 503 is specifically configured to detect, through a Bidirectional Forwarding Detection (BFD) mechanism, a device status of each PE device in the multiple PE devices, so as to determine whether each PE device in the multiple PE devices generates a failure; or the like, or, alternatively,

the transceiver module 501 is further configured to receive device status information sent by a PE device of the multiple PE devices when detecting that another PE device of the multiple PE devices fails through a BFD mechanism, and the failure determining module 503 is specifically configured to determine, according to the received device status information, a PE device of the multiple PE devices that fails.

In some embodiments of the present invention, the DF election module 502 is specifically configured to, if the DF election information indicates that a non-faulty PE device is used as a DF, the controller determines that an elected DF remains unchanged; and if the DF election information indicates that the failed PE equipment is taken as the DF, selecting one non-failed PE equipment from all non-failed PE equipment according to the EVPN instance, the ES and the Ethernet Tag to be taken as the DF.

In some embodiments of the present invention, the DF request information sent by a PE device further includes at least one of the following information: the local port number of the PE equipment, the Ethernet network segment identifier ESI, the virtual private network VPN identifier corresponding to the EVPN instance and the service type corresponding to the EVPN instance;

Referring to fig. 6-a, in a PE device according to an embodiment of the present invention, the PE device 600 includes: a transceiver module 601 and a DF determination module 602, wherein,

a transceiver module 601, configured to send a DF request message designating a forwarder to a controller; the PE device receives DF election information from the controller;

a DF determining module 602, configured to determine, by the PE device, whether the PE device is elected as a DF according to the DF election information.

In some embodiments of the present invention, the DF request information sent by the PE device includes at least one of the following information: the local port number of the PE equipment, Ethernet Tag, virtual private network VPN identification corresponding to Ethernet virtual private network EVPN instance and service type corresponding to the EVPN instance;

In some embodiments of the present invention, when the PE device is connected to a customer edge CE device through a network virtualization overlay NVO3 network based on three-layer bearer, the Ethernet Tag corresponds to a virtual network identifier VNID;

In some embodiments of the present invention, as shown in fig. 6-b, the PE device 600 further includes a failure detection module 603, configured to detect, through a Bidirectional Forwarding Detection (BFD) mechanism, a device state of another PE device in the same core network as the PE device;

the transceiver module 601 is further configured to send device status information of a failed PE device to the controller when the PE device detects that the other PE devices in the same core network have a failure.

It should be noted that, because the contents of information interaction, execution process, and the like between the modules/units of the apparatus are based on the same concept as the method embodiment of the present invention, the technical effect brought by the contents is the same as the method embodiment of the present invention, and specific contents may refer to the description in the foregoing method embodiment of the present invention, and are not described herein again.

An embodiment of the present invention further provides a computer storage medium, where the computer storage medium stores a program, and the program executes some or all of the steps described in the above method embodiments.

Referring to fig. 7, a controller 700 according to another embodiment of the present invention includes:

a receiver 701, a transmitter 702, a processor 703 and a memory 704 (wherein the number of processors 703 in the controller 700 may be one or more, one processor being exemplified in fig. 7). In some embodiments of the present invention, the receiver 701, the transmitter 702, the processor 703 and the memory 704 may be connected by a bus or other means, wherein fig. 7 illustrates the connection by a bus.

The memory 704 may include read-only memory and random access memory, and provides instructions and data to the processor 703. A portion of Memory 704 may also include Non-Volatile Random Access Memory (NVRAM). The memory 704 stores an operating system and operating instructions, executable modules or data structures, or a subset or an expanded set thereof, wherein the operating instructions may include various operating instructions for performing various operations. The operating system may include various system programs for implementing various basic services and for handling hardware-based tasks.

The processor 703 controls the operation of the controller, and the processor 703 may also be referred to as a Central Processing Unit (CPU). In a particular application, the various components of the controller are coupled together by a bus system that may include a power bus, a control bus, a status signal bus, etc., in addition to a data bus. For clarity of illustration, the various buses are referred to in the figures as a bus system.

The method disclosed in the above embodiments of the present invention may be applied to the processor 703 or implemented by the processor 703. The processor 703 may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the method may be implemented by hardware integrated logic circuits in the processor 703 or by instructions in the form of software. The processor 703 may be a general-purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Programmable Gate Array (FPGA), or other Programmable logic device, discrete Gate or transistor logic device, or discrete hardware component. The various methods, steps and logic blocks disclosed in the embodiments of the present invention may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in a memory 704, and a processor 703 reads information in the memory 704 and performs the steps of the above method in combination with hardware thereof.

In this embodiment of the present invention, the processor 703 is configured to execute the method executed by the controller in the foregoing embodiment.

Referring to fig. 8, another PE device according to an embodiment of the present invention is described, in which a PE device 800 includes:

a receiver 801, a transmitter 802, a processor 803, and a memory 804 (wherein the number of processors 803 in the PE device 800 may be one or more, one processor being exemplified in fig. 8). In some embodiments of the present invention, the receiver 801, the transmitter 802, the processor 803 and the memory 804 may be connected by a bus or other means, wherein fig. 8 illustrates a connection by a bus.

The memory 804 may include a read-only memory and a random access memory, and provides instructions and data to the processor 803. A portion of the memory 804 may also include NVRAM. The memory 804 stores an operating system and operating instructions, executable modules or data structures, or a subset or an expanded set thereof, wherein the operating instructions may include various operating instructions for performing various operations. The operating system may include various system programs for implementing various basic services and for handling hardware-based tasks.

The processor 803 controls the operation of the PE device, and the processor 803 may also be referred to as a CPU. In a specific application, the various components of the PE device are coupled together by a bus system, wherein the bus system may include a power bus, a control bus, a status signal bus, and the like, in addition to a data bus. For clarity of illustration, the various buses are referred to in the figures as a bus system.

The method disclosed in the above embodiments of the present invention can be applied to the processor 803 or implemented by the processor 803. The processor 803 may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method may be performed by integrated logic circuits of hardware or instructions in the form of software in the processor 803. The processor 803 described above may be a general purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware components. The various methods, steps and logic blocks disclosed in the embodiments of the present invention may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in the memory 804, and the processor 803 reads the information in the memory 804 to complete the steps of the method in combination with the hardware thereof.

In this embodiment of the present invention, the processor 803 is configured to execute the method executed by the PE device in the foregoing embodiment.

It should be noted that the above-described embodiments of the apparatus are merely schematic, where the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. In addition, in the drawings of the embodiment of the apparatus provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, and may be specifically implemented as one or more communication buses or signal lines. One of ordinary skill in the art can understand and implement it without inventive effort.

Through the above description of the embodiments, those skilled in the art will clearly understand that the present invention may be implemented by software plus necessary general hardware, and may also be implemented by special hardware including special integrated circuits, special CPUs, special memories, special components and the like. Generally, functions performed by computer programs can be easily implemented by corresponding hardware, and specific hardware structures for implementing the same functions may be various, such as analog circuits, digital circuits, or dedicated circuits. However, the implementation of a software program is a more preferable embodiment for the present invention. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which is stored in a readable storage medium, such as a floppy disk, a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk of a computer, and includes instructions for enabling a computer device (which may be a personal computer, a server, or a network device) to execute the methods according to the embodiments of the present invention.

In summary, the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the above embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the above embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A method of handling a designated forwarder DF, comprising:

a controller receives a plurality of DF request messages sent by a plurality of provider edge PE devices in the same core network, wherein the PE devices correspond to the DF request messages one by one;

the controller elects a PE device from the PE devices as a DF according to the DF request information to obtain DF election information;

the controller sends the DF election information to the PE devices.

2. The method of claim 1, further comprising:

when at least one PE device in the PE devices fails, the controller reselects one PE device from the at least one PE device without the failure as a DF according to the Ethernet Tag, the Ethernet segment identifier ESI and the Ethernet virtual private network EVPN instance, so as to realize load sharing of the PE devices.

3. The method of claim 1, wherein the DF solicitation information includes at least one of: ethernet network segment identification ESI and Ethernet label Ethernet Tag, when said multiple PE apparatuses are connected to the same customer edge CE apparatus through VLAN network, said Ethernet Tag and VLAN ID correspond;

the controller selects one PE device from the PE devices as a DF according to the DF request information sent by each PE device of the PE devices, and obtains DF election information, including:

when the service type of the VLAN network is VLAN basic service or VLAN binding service, the controller elects a PE device from the PE devices as DF according to the ESI and the Ethernet Tag, and DF election information is obtained; or the like, or, alternatively,

when the service type of the VLAN network is VLAN binding sensing service, the controller selects one PE device from the PE devices as DF according to the ESI and the Ethernet Tag binding group corresponding to the VLAN binding sensing service, and DF election information is obtained.

4. The method of claim 1, wherein the DF solicitation information includes at least one of: ESI and Ethernet Tag, when said multiple PE apparatuses are connected to the same customer edge CE apparatus through network virtualization overlay NVO3 network based on three-layer bearer, said Ethernet Tag and virtual network identification VNID are corresponding;

when the service type of the NVO3 network is a VN basic service or a VN binding service, the controller elects a PE device from the PE devices as a DF according to the ESI and the Ethernet Tag, and obtains DF election information.

5. The method of claim 2, wherein the controller determining whether each of the plurality of PE devices is malfunctioning comprises:

6. The method of claim 1, further comprising:

when at least one PE device in the PE devices fails, the controller acquires the DF election information;

and if the DF election information indicates that the PE equipment with the fault is taken as the DF, the controller re-elects a PE equipment without the fault as the DF according to the Ethernet Tag, the Ethernet network segment identifier ESI and the Ethernet virtual private network EVPN instance.

7. The method according to any one of claims 1 to 6, wherein the DF request information sent by a PE device further comprises at least one of the following information: the local port number of the PE equipment, the VPN identification corresponding to the EVPN instance and the service type corresponding to the EVPN instance;

8. A method of handling a designated forwarder DF, comprising:

provider edge PE equipment sends DF request information to a controller;

the PE device receives DF election information from the controller and determines that the PE device is elected as a DF;

and the PE equipment forwards the received message to Customer Edge (CE) equipment connected with the PE equipment according to the selection of the PE equipment as DF.

9. The method of claim 8, wherein the DF solicitation information sent by the PE device includes at least one of: the local port number of the PE equipment, Ethernet Tag, virtual private network VPN identification corresponding to Ethernet virtual private network EVPN instance and service type corresponding to the EVPN instance;

10. The method according to claim 9, wherein when the PE device is connected to a customer edge CE device through a network virtualization overlay NVO3 network based on triple-layer bearer, the Ethernet Tag corresponds to a virtual network identity VNID;

11. The method of claim 8, further comprising:

12. A controller, comprising:

a transceiver module, configured to receive multiple pieces of DF request information of designated forwarders sent by multiple provider edge PE devices in a same core network, where the PE devices correspond to the DF request information one to one;

a DF election module, configured to elect a PE device from the multiple PE devices as a DF according to the multiple DF request information, to obtain DF election information;

the transceiver module is further configured to send the DF election information to the PE devices.

13. The controller of claim 12, further comprising:

the DF election module is further configured to reselect a PE device from the at least one PE device without the fault as a DF according to the Ethernet Tag, the Ethernet segment identifier ESI, and the Ethernet virtual private network EVPN instance when the at least one PE device in the multiple PE devices fails, so as to implement load sharing of the PE devices.

14. The controller according to claim 12, wherein said DF solicitation information includes at least one of: ethernet network segment identification ESI and Ethernet label Ethernet Tag, when said multiple PE apparatuses are connected to the same customer edge CE apparatus through VLAN network, said Ethernet Tag and VLAN ID correspond;

the DF election module is specifically configured to, when the service type of the VLAN network is a VLAN basic service or a VLAN binding service, elect a PE device from the multiple PE devices as a DF according to the ESI and the Ethernet Tag, and obtain DF election information; or, when the service type of the VLAN network is VLAN binding sensing service, selecting one PE device from the multiple PE devices as DF according to the ESI and an Ethernet Tag binding group corresponding to the VLAN binding sensing service, and obtaining DF election information.

15. The controller according to claim 12, wherein said DF solicitation information includes at least one of: ESI and Ethernet Tag, when said multiple PE apparatuses are connected to the same customer edge CE apparatus through network virtualization overlay NVO3 network based on three-layer bearer, said Ethernet Tag and virtual network identification VNID are corresponding;

the DF election module is specifically configured to, when the service type of the NVO3 network is a VN basic service or a VN binding service, elect a PE device from the multiple PE devices as a DF according to the ESI and the Ethernet Tag, and obtain DF election information.

16. The controller according to claim 13, wherein the failure determining module is specifically configured to detect a device status of each PE device in the plurality of PE devices through a Bidirectional Forwarding Detection (BFD) mechanism, so as to determine whether each PE device in the plurality of PE devices fails; or the like, or, alternatively,

17. The controller according to claim 12, further comprising an obtaining module configured to obtain the DF election information when at least one of the plurality of PE devices fails;

the DF election module is further configured to, if the DF election information indicates that a faultless PE device is used as a DF, determine that an elected DF remains unchanged by the controller; and if the DF election information indicates that the PE equipment with the fault is taken as the DF, selecting a PE equipment without the fault as the DF according to the Ethernet Tag, the Ethernet network segment identifier ESI and the Ethernet virtual private network EVPN example.

18. The controller according to any one of claims 12 to 17, wherein DF solicitation information sent by a PE device further comprises at least one of: the local port number of the PE equipment, the Ethernet network segment identifier ESI, the virtual private network VPN identifier corresponding to the EVPN instance and the service type corresponding to the EVPN instance;

19. A provider edge PE device, comprising:

the receiving and sending module is used for sending DF request information of the appointed forwarder to the controller;

the transceiver module is further configured to receive DF election information from the controller and determine that the PE device is elected as a DF;

and a DF determining module, configured to forward the received packet to a customer edge CE device connected to the PE device according to the PE device being elected as DF.

20. The PE device of claim 19, wherein the DF solicitation information sent by the PE device includes at least one of: the local port number of the PE equipment, Ethernet Tag, virtual private network VPN identification corresponding to Ethernet virtual private network EVPN instance and service type corresponding to the EVPN instance;

21. The PE device of claim 19, wherein the Ethernet Tag corresponds to a virtual network identity, VNID, when the PE device is connected to a customer edge, CE, device via a three-tier bearer-based network virtualization overlay, NVO3 network;

22. The device according to claim 19, wherein the PE device further comprises a failure detection module for detecting the device status of other PE devices in the same core network as the PE device through a Bidirectional Forwarding Detection (BFD) mechanism;

23. A communication system comprising a controller according to any of claims 12 to 18 and a provider edge PE device according to any of claims 19 to 22.