Network intercommunication method and device

Abstract

The present application provides a network intercommunication method and apparatus, the method being applied to a first network device, the first network device having deployed a first network service, the first network device having established a first tunnel with a second network device, the second network device having deployed a second network service, the method comprising: receiving, through the first tunnel, a first service message sent by the second network device, the first service message comprising a first exit identifier of the first tunnel; if the first exit identifier belongs to a first identifier of a locally established EVPN HUB service model and the first exit identifier is associated with the first network service, sending the first service message to the first network service, so that the first network service forwards the first service message according to a forwarding policy of its own service.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a network intercommunication method and device. Background Art

[0002] L2VPN is a Layer 2 VPN (Virtual Private Network) technology based on MPLS. L2VPN encapsulates Layer 2 data (such as Ethernet data frames) into packets that can be transmitted in IP or MPLS networks, and forwards them through IP paths or MPLS tunnels. The receiving end decapsulates the packets and restores the original Layer 2 data, thereby achieving transparent transmission of Layer 2 data across IP or MPLS networks between different sites.

[0003] Currently, L2VPN can provide both point-to-point connection technology and multi-point connection technology. For example, point-to-point connection technology is called Virtual Private Wire Service (VPWS), and point-to-multipoint connection technology is called Virtual Private LAN Service (VPLS) and Virtual Extensible Local Area Network (VXLAN).

[0004] In recent years, due to the rise of software defined network (SDN) technology and the development of 5G technology, operators generally need to expand or upgrade the original core network to support new network structures. In the process of upgrading the core network, there may be scenarios where multiple types of business networks are interconnected.

[0005] like Figure 1 As shown, Figure 1 This is a schematic diagram of the network interconnection of various existing business types. Figure 1 In the example, the network device on the A-Leaf side is deployed with an Ethernet Virtual Private Network (EVPN) VPWS network, while the network device on the B-Leaf side needs to access multiple servers and other devices to meet the SDN network requirements. The EVPN VPLS network is deployed, and the point-to-multipoint characteristics of the EVPN VPLS network are used to complete multi-server access.

[0006] When the networks of these two types of services need to be interconnected, Layer 2 switching technology is preferred. A Layer 2 switch is deployed between the VPWS network and the VPLS network, and the traffic on the VPWS network side and the traffic on the VPLS network side are introduced into the Layer 2 switch. The traffic on the two network sides is exchanged using Layer 2 switching.

[0007] Even if the above solution can realize the intercommunication of networks of various service types, it also causes the following defects: the intercommunication of existing networks of various service types will inevitably introduce fixed equipment, thereby increasing network costs. Summary of the invention

[0008] In view of this, the present application provides a network intercommunication method and apparatus to solve the problem of introducing fixed equipment and increasing network costs in existing network intercommunication solutions for multiple business types.

[0009] In a first aspect, the present application provides a network intercommunication method, the method is applied to a first network device, the first network device has deployed a first network service, the first network device has established a first tunnel with a second network device, and the second network device has deployed a second network service, the method comprising:

[0010] Receiving, through the first tunnel, a first service message sent by the second network device, where the first service message includes a first exit identifier of the first tunnel;

[0011] If the first egress identifier belongs to the first identifier of the locally established EVPN HUB service model and the first egress identifier is associated with the first network service, sending the first service message to the first network service so that the first network service forwards the first service message according to the forwarding policy of its own service;

[0012] The first network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, the second network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, and the first network service is different from the second network service.

[0013] In a second aspect, the present application provides a network intercommunication device, the device is applied to a first network device, the first network device has deployed a first network service, the first network device has established a first tunnel with a second network device, and the second network device has deployed a second network service, the device comprising:

[0014] A receiving unit, configured to receive, through the first tunnel, a first service message sent by the second network device, wherein the first service message includes a first exit identifier of the first tunnel;

[0015] a sending unit, configured to send the first service message to the first network service if the first egress identifier belongs to the first identifier of the locally established EVPN HUB service model and the first egress identifier is associated with the first network service, so that the first network service forwards the first service message according to the forwarding policy of its own service;

[0016] The first network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, the second network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, and the first network service is different from the second network service.

[0017] In a third aspect, the present application provides a network device, including a processor and a machine-readable storage medium, the machine-readable storage medium storing machine-executable instructions that can be executed by the processor, and the processor is prompted by the machine-executable instructions to execute the method provided in the first aspect of the present application.

[0018] Therefore, by applying the network intercommunication method and device provided by the present application, the first network device receives the first service message sent by the second network device through the first tunnel, and the first service message includes the first exit identifier of the first tunnel; if the first exit identifier belongs to the first identifier of the locally established EVPN HUB service model and the first exit identifier is associated with the first network service, the first network device sends the first service message to the first network service, so that the first network service forwards and processes the first service message according to the forwarding policy of its own service.

[0019] The first network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, the second network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, and the first network service is different from the second network service.

[0020] In this way, the EVPN HUB service model built locally is used to establish tunnels between network devices that support different network services. By encapsulating the tunnel exit identifier in the outer layer of the service message, the receiving end can identify the exit identifier and process messages that are different from local network services. This solves the problem of introducing fixed equipment and increasing network costs in the existing network interconnection solutions for multiple types of services. It achieves the purpose of achieving network interconnection for multiple types of services without adding additional equipment to the network. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1This is a schematic diagram of the network interconnection of various existing business types;

[0022] Figure 2 A flowchart of a network intercommunication method provided in an embodiment of the present application;

[0023] Figure 3 A schematic diagram of network interconnection of various service types provided in an embodiment of the present application;

[0024] Figure 4 A structural diagram of a network intercommunication device provided in an embodiment of the present application;

[0025] Figure 5 The network device hardware structure provided in the embodiment of the present application. DETAILED DESCRIPTION

[0026] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0027] The terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in this article refers to and includes any or all possible combinations of one or more corresponding listed items.

[0028] It should be understood that although the terms first, second, third, etc. may be used in the present application to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0029] The following is a detailed description of a network intercommunication method provided in an embodiment of the present application. Figure 2 , Figure 2 A flowchart of a network intercommunication method provided in an embodiment of the present application. The method is applied to a first network device. The network intercommunication method provided in an embodiment of the present application may include the following steps.

[0030] Step 210: Receive a first service message sent by the second network device through the first tunnel, where the first service message includes a first exit identifier of the first tunnel;

[0031] Specifically, the first network device, the second network device, and the third network device have achieved IP intercommunication and established BGPEVPN neighbors.

[0032] Different network services are deployed in the first network device, the second network device, and the third network device, respectively. For example, the first network service is EVPN VPWS, the second network service is EVPN VPLS, and the third network service is EVPN VXLAN.

[0033] The first network device establishes a first tunnel with the second network device; similarly, the first network device also establishes a second tunnel with the second network device. Through the established tunnels, network devices can achieve intercommunication of multiple service type networks.

[0034] Through the first tunnel, the first network device receives a first service message sent by the second network device, where the first service message includes a first exit identifier of the first tunnel.

[0035] Optionally, before this step, the process also includes constructing an EVPN centralized switching (HUB) service model in the first network device, synchronizing EVPN route announcement messages, establishing a tunnel with the other end, and sending service messages to the other end using the tunnel.

[0036] It is understandable that both the second network device and the third network device need to perform the above optional process, which is described below using the first network device as an example.

[0037] The EVPN HUB function is started in the first network device, that is, an EVPN HUB business model is constructed in the first network device. The EVPN HUB business model includes business members, and the business members can represent a certain network service supported by the network device (for example, business member 1 supports EVPN VPWS service, or business member 1 supports EVPN VPLS service, or business member 1 supports EVPN VXLAN service). Each business member in different network devices and belonging to the same EVPN HUB business model can realize network intercommunication of multiple business types according to the rules defined in the EVPN HUB business model.

[0038] In the embodiment of the present application, the EVPN HUB service model has an identifier, namely, an EVPN HUB ID, which is used to identify the EVPN HUB service model to which the network service supported by the network device belongs. At the same time, according to the network service supported by the first network device, an EVPN HUB flag (FLAG) is configured for the network service, and the EVPN HUB flag of each network service is associated with a service member in the EVPN HUB service model.

[0039] For example, if the first network device supports EVPN VPWS service, the EVPN HUB flag is 1, and the service members in the EVPN HUB service model are associated with EVPN HUB flag 1; if the first network device supports EVPN VPLS service, the EVPN HUB flag is 2, and the service members in the EVPN HUB service model are associated with EVPN HUB flag 2; if the first network device supports EVPN VXLAN service, the EVPN HUB flag is 3, and the service members in the EVPN HUB service model are associated with EVPN HUB flag 3.

[0040] The EVPN HUB flag can also be used to distinguish the network services supported by the peer network device. When the network devices at both ends support the same type of network services, the EVPN HUB flags are the same. In this way, there is no need for intercommunication between the network devices at both ends, and the EVPN HUB service model establishment process will not be entered.

[0041] It is understandable that, since the first network device can support multiple network services at the same time, multiple service members can be configured in the EVPN HUB service module, and each service member is associated with an EVPN HUB flag, that is, each service member is associated with a supported network service. Of course, multiple EVPN HUB service models can also be established in the first network device, and one service member is configured in each EVPN HUB service model. Multiple EVPN HUB service models are suitable for scenarios in which the first network device includes multiple VMs and each VM supports different network services.

[0042] After the first network device completes the above-mentioned EVPN HUB function startup, configures the EVPN HUB ID, and the EVPN HUB flag of its own network service, it generates and publishes an EVPN route announcement message to the BGP EVPN neighbor. The EVPN route announcement message includes the EVPN HUB ID and the EVPN HUB flag, so that the peer end determines the network service supported by the first network device and the EVPN HUB service model to which the network service belongs, and establishes a corresponding tunnel with the first network device under the same EVPN HUB service model.

[0043] The above tunnel may be specifically a new type of tunnel defined in the embodiment of the present application, namely, Ethernet virtual private network centralized switching tunnel (EVPN HUB Tunnel, EHT for short). EHT is used to shield the differences in message encapsulation of different service types and realize concise message exchange.

[0044] It is understandable that each network device generates and publishes different types of EVPN route advertisement messages to BGP EVPN neighbors according to the network services it supports.

[0045] For example, if the first network device supports EVPN VPWS service, the first network device generates and publishes EVPN1 type routing announcement messages; if the second network device supports EVPN VPLS service, the second network device generates and publishes EVPN 1 / 2 / 3 type routing announcement messages; if the third network device supports EVPN VXLAN service, the third network device generates and publishes EVPN 1 / 2 / 3 type routing announcement messages.

[0046] In an embodiment of the present application, the first network device generates a first EVPN route advertisement message, which includes an EVPN HUB ID (also referred to as a first identifier) ​​of a locally established EVPN HUB service model and an EVPN HUB flag (also referred to as a first EVPN HUB flag) corresponding to the first network service.

[0047] The first network device adds a new portable field in the Ext-Community attribute (extended community attribute) included in the EVPN route advertisement message: the EVPN HUB attribute field. This field occupies 4 bytes and has the format:<EVPN HUB:id xxx,flagxxx> .

[0048] Among them, ID and FLAG refer to the above definition, ID occupies 3 bytes (value range 0 to 16777215), FLAG occupies 1 byte (value range 0 to 256).

[0049] The first network device sends a first EVPN route advertisement message to the second network device and the third network device respectively. After receiving the first EVPN route advertisement message, the second network device and the third network device obtain the first identifier and the first EVPN HUB mark therefrom.

[0050] The second network device is taken as an example for description.

[0051] The second network device identifies whether the first identifier matches the locally established EVPN HUB ID (also referred to as the second identifier). If so, it identifies whether the first EVPN HUB identifier matches the EVPN HUB identifier (also referred to as the second EVPN HUB identifier) ​​corresponding to the second network service supported by the device.

[0052] If there is no match, the second network device determines that the network service supported by the first network device is different from the network service supported by itself, and then the second network device establishes a first tunnel with itself as the starting point and the first network device as the end point.

[0053] The first EVPN routing announcement message also includes a first exit identifier, which is used to enable the peer end to distinguish the service type to which the service message belongs, that is, the network service supported by the network device sending the service message. After the second network device establishes the first tunnel, it also associates the first exit identifier and the first EVPN HUB flag with the first tunnel.

[0054] Similarly, the third network device establishes a second tunnel and associates the first exit identifier and the first EVPN HUB flag with the second tunnel.

[0055] In an embodiment of the present application, the egress identifier is associated with the EVPN HUB ID and the EHT. Its significance lies in that the service message sent locally through the EHT will have the egress identifier encapsulated outside the service message. After receiving the service message, the peer end obtains the egress identifier and determines whether the corresponding EVPN HUB ID exists locally. If it exists locally, the service message can be delivered to the service member corresponding to the egress identifier in the EVPN HUB service model indicated by the EVPN HUB ID (the network service associated with the service member is the same as the network service corresponding to the egress identifier) ​​for further processing, thereby realizing network interoperability of multiple service types.

[0056] The egress identifier may be specifically an identifier that already exists in the existing EVPN route, and the identifier may be specifically an attribute identifier that represents the attribute of the network device. It is understandable that when the existing EVPN route is published, the attribute identifier of the network device has been sent to the peer end, and in the embodiment of the present application, the peer end may use the attribute identifier as the egress identifier.

[0057] In different networks, the egress identifier can be implemented by different attribute identifiers. For example, in an IPv4 network, the egress identifier can be specifically the label MPLS LABEL of the network device, in an IPv6 network, the egress identifier can be specifically the address SRv6 SID of the network device, and in a VXLAN network, the egress identifier can be specifically the VXLAN ID of the VXLAN to which the network device belongs.

[0058] It should be noted that due to the different services supported by network devices, they can send multiple types of EVPN routing announcements at the same time. After the other end obtains multiple types of EVPN routing announcements, it can preferentially obtain the attribute identifier included in a certain type of EVPN routing announcement as the export identifier.

[0059] For example, the local end supports the EVPN VPWS service, and the peer end supports the EVPN VPLS / VXLAN service. If the local end establishes an EHT tunnel to the peer end, the egress identifier is obtained from the EVPN 1 / 2 / 3 route advertised by the peer end. The local end preferentially obtains the attribute representation included in the EVPN 1 route as the egress identifier.

[0060] The local end supports the EVPN VPLS service, and the remote end supports the EVPN VPWS service. If the local end establishes an EHT tunnel to the remote end, the egress identifier is obtained from the EVPN Class 1 route advertised by the remote end.

[0061] It is understandable that the multiple types of EVPN route advertisements sent by the network device all include the EVPN HUB ID, the EVPN HUB flag, and the egress identifier.

[0062] The local end supports EVPN VPLS services, and the remote end supports EVPN VXLAN services. If the local end establishes an EHT tunnel to the remote end, the egress identifier is obtained from the EVPN 1 / 2 / 3 routes advertised by the remote end. The local end preferentially obtains the attribute representation included in the EVPN 1 route as the egress identifier.

[0063] The local end supports EVPN VXLAN services, and the remote end supports EVPN VPWS services. If the local end establishes an EHT tunnel to the remote end, the egress identifier is obtained from the EVPN Class 1 route advertised by the remote end.

[0064] The local end supports EVPN VXLAN services, and the remote end supports VPLS services. If the local end establishes an EHT tunnel to the remote end, the egress identifier is obtained from the EVPN 1 / 2 / 3 routes advertised by the remote end. The local end preferentially obtains the attribute representation included in the EVPN 1 route as the egress identifier.

[0065] Similarly, the first network device also receives EVPN route advertisement messages issued by the second network device and the third network device, and establishes an EHT tunnel.

[0066] The process of the second network device and the third network device generating the EVPN route advertisement message is the same as the process of the first network device generating the EVPN route advertisement message, which will not be repeated here.

[0067] Optionally, the first network device receives a second EVPN route advertisement message sent by the second network device, where the second EVPN route advertisement message includes a second identifier of an EVPN HUB service model locally established by the second network device and a second EVPN HUB flag corresponding to the second network service.

[0068] The first network device identifies whether the second identifier matches the first identifier. If so, the first network device continues to identify whether the second EVPN HUB identifier matches the first EVPN HUB identifier. If not, the first network device determines that the network service supported by the second network device is different from that supported by itself. The first network device establishes a first tunnel with itself as the starting point and the second network device as the end point.

[0069] Similarly, the first network device receives a third EVPN route advertisement message sent by the third network device, where the third EVPN route advertisement message includes a third identifier of an EVPN HUB service model locally established by the third network device and a third EVPN HUB flag corresponding to a third network service.

[0070] The first network device identifies whether the third identifier matches the first identifier. If so, the first network device continues to identify whether the third EVPN HUB identifier matches the first EVPN HUB identifier. If not, the first network device determines that the network service supported by the third network device is different from that of the first network device. The first network device establishes a second tunnel with itself as the starting point and the third network device as the end point.

[0071] Optionally, the second EVPN routing announcement message also includes a third exit identifier (in order to correspond the second exit identifier to the second tunnel, the one sent by the second network device is referred to as the third exit identifier), and the third EVPN routing announcement message also includes the second exit identifier.

[0072] After establishing the first tunnel and the second tunnel, the first network device also associates the third exit identifier and the second EVPN HUB flag with the first tunnel, and associates the second exit identifier and the third EVPN HUB flag with the second tunnel.

[0073] Subsequently, the first network device may use the first tunnel and the second tunnel to send service messages to the second network device and the third network device.

[0074] The following description is given by taking an example where the first network device sends a service message to the third network device.

[0075] Optionally, the first network device receives a private network message sent by the virtual machine, determines an outbound interface for forwarding the private network message according to the characteristics of the first network service deployed by the first network device, and obtains a second egress identifier of the second tunnel when the outbound interface for forwarding the private network message is determined to be the second tunnel.

[0076] The first network device encapsulates the second egress identifier in the outer layer of the private network message, and encapsulates the public network tunnel information in the outer layer of the second egress identifier to obtain the second service message. The first network device sends the second service message to the third network device through the second tunnel.

[0077] It should be noted that the process of encapsulating the second egress identifier in the outer layer of the private network message is to encapsulate the second egress identifier as a header in the outer layer of the private network message. For example, in an IPv4 network, the egress identifier can be encapsulated as an MPLS header in the outer layer of the private network message, in an IPv6 network, the egress identifier can be encapsulated as an IPv6 header in the outer layer of the private network message, and in a VXLAN network, the egress identifier can be encapsulated as a VXLAN header in the outer layer of the private network message.

[0078] In the embodiment of the present application, after the EVPN HUB flag is associated with the EHT, the EHT also has the attribute of the network service. The attribute of the network service is the same as the above-mentioned EVPN HUB flag, that is, it is used to distinguish the type of the peer network service.

[0079] For example, if the local end supports the EVPN VPWS service and the peer end supports the EVPN VPLS service, the tunnel service attribute of the EHT established by the local end is 2, indicating that the EHT peer end supports the EVPN VPLS service. At the same time, the local end also associates the EHT with the EVPN HUB ID of the EVPN HUB service model.

[0080] If the local end supports the EVPN VPWS service and the peer end supports the EVPN VXLAN service, the tunnel service attribute of the EHT established by the local end is 3, indicating that the EHT peer end supports the EVPN VXLAN service. At the same time, the local end also associates the EHT with the EVPN HUB ID of the EVPN HUB service model.

[0081] In the embodiment of the present application, EHT also has a learning attribute, that is, learning MAC addresses. For example, the EVPN VPWS service is a point-to-point service. In the process of forwarding messages, it does not forward by looking up the MAC table, but forwards through the binding relationship between AC and PW. In other words, the MAC table is not established in the network device that supports the EVPN VPWS service.

[0082] Therefore, in the EVPN HUB service model, after the EVPN VPLS service / VXLAN service receives the service message sent by the peer from the EHT, it determines that the peer is the EVPN VPWS service through the service attributes of the EHT, then learns the source MAC address of the service message to the EHT, and publishes the EVPN2 type routing advertisement message corresponding to the MAC address. If the peer is determined to be the EVPN VPLS service / EVPN VXLAN service through the service attributes of the EHT, the source MAC address is not learned.

[0083] Step 220: If the first egress identifier belongs to the first identifier of the locally established EVPN HUB service model and the first egress identifier is associated with the first network service, the first service message is sent to the first network service so that the first network service forwards the first service message according to the forwarding policy of its own service.

[0084] Specifically, according to the description of step 210, after obtaining the first egress identifier of the first tunnel, the first network device identifies whether the first egress identifier belongs to the first identifier of the locally established EVPN HUB service model.

[0085] If yes, the first network device continues to identify whether the first egress identifier is associated with the first network service. If yes, the first network device determines that the network service supported by itself can process the first service message. The first network device sends the first service message to the first network service, so that the first network service forwards and processes the first service message according to the forwarding strategy of its own service.

[0086] In the embodiment of the present application, the above steps 210 and 220 may be executed by an EVPN HUB virtual tunnel endpoint (English: EVPN HUB VIRTUAL ENDPOINT, referred to as: EHVE endpoint) configured in the first network device.

[0087] The EHVE endpoint is a virtual endpoint within the EVPN network. It is a protocol layer or a logical layer, and is not physically present. It is used to correspond to network services supported by the other end but not supported by the local end, and to establish EHT to achieve communication across network services.

[0088] Therefore, by applying the network intercommunication method provided by the present application, the first network device receives the first service message sent by the second network device through the first tunnel, and the first service message includes the first exit identifier of the first tunnel; if the first exit identifier belongs to the first identifier of the locally established EVPN HUB service model and the first exit identifier is associated with the first network service, the first network device sends the first service message to the first network service, so that the first network service forwards and processes the first service message according to the forwarding policy of its own service.

[0089] The first network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, the second network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, and the first network service is different from the second network service; the EVPN HUB service model includes multiple service members, and each service member corresponds to an export identifier associated with a network service.

[0090] In this way, the EVPN HUB service model built locally is used to establish tunnels between network devices that support different network services. By encapsulating the tunnel exit identifier in the outer layer of the service message, the receiving end can identify the exit identifier and process messages that are different from local network services. This solves the problem of introducing fixed equipment and increasing network costs in the existing network interconnection solutions for multiple types of services. It achieves the purpose of achieving network interconnection for multiple types of services without adding additional equipment to the network.

[0091] The network intercommunication method provided in the embodiment of the present application is described in detail below. Figure 3 , Figure 3 A schematic diagram of network interconnection of various service types provided in the embodiment of the present application. Figure 3 In the example, there are three network devices, namely A, B, and C, and each network device is connected to one VM.

[0092] Assume that the EVPN VXLAN service is deployed in network device A, the EVPN VPWS service is deployed in network device B, and the EVPN VPLS service is deployed in network device C. The EVPN services of network devices A, B, and C are interconnected through the EVPN HUB service model.

[0093] EVPN route advertisement message publishing process:

[0094] Network devices A, B, and C have achieved IP interconnection and have established BGP EVPN neighbors with each other.

[0095] Network device A configures the EVPN VXLAN service, specifies RD(100:1) / RT(100:1), VXLAN ID(200), creates an EVPN HUB service model, and specifies the EVPN HUB ID as 123. At this time, the EVPN HUB FLAG is 3, indicating the VXLAN service tag. The network device attribute identifier of network device A is 200 (the network device attribute identifier can be used as the tunnel egress identifier by the peer end). Network device A publishes an EVPN Class 3 route advertisement message.

[0096] Network device B configures the EVPN VPWS service, specifies RD(100:1) / RT(100:1), VPWS service ID(100), creates an EVPN HUB service model, and specifies the EVPN HUB ID as 123. At this time, the EVPN HUB FLAG is 1, indicating the VPWS service tag. The network device attribute identifier of network device B is 100 (the network device attribute identifier can be used as the tunnel exit identifier by the peer end). Network device B publishes the EVPN1 type route advertisement message.

[0097] Network device C configures the EVPN VPLS service, specifies RD(100:1) / RT(100:1), PW label (300), creates an EVPN HUB service model, and specifies the EVPN HUB ID as 123. At this time, the EVPN HUB FLAG is 2, indicating the VPLS service tag. The network device attribute identifier of network device C is 300 (the network device attribute identifier can be used as the tunnel egress identifier by the peer end). Network device C publishes an EVPN Class 3 route advertisement message.

[0098] The network device receives, identifies, processes, and establishes the EHT process for EVPN route advertisement messages:

[0099] Network device A receives an EVPN type 1 route advertisement message issued by network device B. Network device A identifies that the RT included in the EVPN type 1 route advertisement message matches the local Import target attribute, but the EVPN type 1 route advertisement message does not include a VXLAN ID. Therefore, network device A cannot establish a VXLAN tunnel with network device B.

[0100] Network device A identifies the EVPN HUB ID and EVPN HUB FLAG included in the EVPN Class 1 routing advertisement message. The EVPN HUB ID matches the locally configured EVPN HUB ID. The EVPN HUB FLAG is 1, indicating that network device B supports the EVPNVPWS service, which is different from the service supported locally. Network device A establishes EHT1 with itself as the EHVE starting point and network device B as the EHVE end point. The exit identifier of EHT1 can be determined from the network device attribute identifier (100) included in the EVPN Class 1 routing advertisement message. Network device A associates EHT1 with the local EVPN HUB service model. The ID of the EVPN HUB service model is 123, and the service members are the locally supported EVPN VXLAN services.

[0101] Network device A receives the EVPN type 3 route advertisement message issued by network device C. Network device A recognizes that the RT included in the EVPN type 3 route advertisement message matches the local Import target attribute, but the EVPN type 3 route advertisement message does not include the VXLAN ID, so network device A cannot establish a VXLAN tunnel with network device C.

[0102] Network device A identifies the EVPN HUB ID and EVPN HUB FLAG included in the EVPN Class 3 routing announcement message. The EVPN HUB ID matches the locally configured EVPN HUB ID. The EVPN HUB FLAG is 2, indicating that network device C supports EVPNVPLS services, which are different from the services supported locally. Network device A establishes EHT2 with itself as the EHVE starting point and network device C as the EHVE end point. The exit identifier of EHT2 can be determined from the network device attribute identifier (300) included in the EVPN Class 3 routing announcement message. Network device A associates EHT2 with the local EVPN HUB service model. The ID of the EVPN HUB service model is 123, and the service members are the locally supported EVPN VXLAN services.

[0103] Similarly, network device B receives the EVPN type 3 route advertisement message issued by network device A. Network device B recognizes that the RT included in the EVPN type 3 route advertisement message matches the local Import target attribute, but the EVPN type 3 route advertisement message does not include the VPWS service ID, so network device B cannot establish an EVPN PW tunnel with network device A.

[0104] Network device B identifies the EVPN HUB ID and EVPN HUB FLAG included in the EVPN Class 3 routing announcement message. The EVPN HUB ID matches the locally configured EVPN HUB ID. The EVPN HUB FLAG is 3, indicating that network device A supports EVPNVXLAN services, which are different from the services supported locally. Network device B establishes EHT3 with itself as the starting point of EHVE and network device A as the end point of EHVE. The exit identifier of EHT3 can be determined from the network device attribute identifier (200) included in the EVPN Class 3 routing announcement message. Network device B associates EHT3 with the local EVPN HUB service model. The ID of the EVPN HUB service model is 123, and the service members are the locally supported EVPN VPWS services.

[0105] Network device B receives the EVPN type 3 route advertisement message issued by network device C. Network device B recognizes that the RT included in the EVPN type 3 route advertisement message matches the local Import target attribute, but the EVPN type 3 route advertisement message does not include the VPWS service ID, so network device B cannot establish an EVPN PW tunnel with network device C.

[0106] Network device B identifies the EVPN HUB ID and EVPN HUB FLAG included in the EVPN Class 3 routing announcement message. The EVPN HUB ID matches the locally configured EVPN HUB ID. The EVPN HUB FLAG is 2, indicating that network device C supports EVPNVPLS services, which are different from the services supported locally. Network device B establishes EHT4 with itself as the EHVE starting point and network device C as the EHVE end point. The exit identifier of EHT4 can be determined from the network device attribute identifier (300) included in the EVPN Class 3 routing announcement message. Network device B associates EHT4 with the local EVPN HUB service model. The ID of the EVPN HUB service model is 123, and the service member is the locally supported EVPN VPWS service.

[0107] Similarly, network device C receives the EVPN type 1 route passing message issued by network device B. Network device C identifies that the RT included in the EVPN type 1 route advertisement message matches the local Import target attribute, but the EVPN type 1 route advertisement message does not include a PW label. Therefore, network device C cannot establish an EVPN PW tunnel with network device B.

[0108] Network device C identifies the EVPN class 1 route through the EVPN HUB ID and EVPN HUB FLAG included in the message. The EVPN HUB ID matches the locally configured EVPN HUB ID. The EVPN HUB FLAG is 1, indicating that network device B supports the EVPNVPWS service, which is different from the service supported locally. Network device C establishes EHT5 with itself as the EHVE starting point and network device B as the EHVE end point. The exit identifier of EHT5 can be determined from the network device attribute identifier (100) included in the EVPN class 1 route announcement message. Network device C associates EHT5 with the local EVPN HUB service model. The ID of the EVPN HUB service model is 123, and the service members are the locally supported EVPN VPLS services.

[0109] Network device C receives the EVPN type 3 route passing message issued by network device A. Network device C identifies that the RT included in the EVPN type 3 route advertisement message matches the local Import target attribute. The EVPN type 3 route advertisement message does not include a PW label, so network device C cannot establish an EVPN PW tunnel with network device A.

[0110] Network device C identifies the EVPN class 3 route through the EVPN HUB ID and EVPN HUB FLAG included in the message. The EVPN HUB ID matches the locally configured EVPN HUB ID. The EVPN HUB FLAG is 3, indicating that network device A supports EVPNVXLAN services, which are different from the services supported locally. Network device C establishes EHT6 with itself as the EHVE starting point and network device A as the EHVE end point. The exit identifier of EHT6 can be determined from the network device attribute identifier (200) included in the EVPN class 3 route announcement message. Network device C associates EHT6 with the local EVPN HUB service model. The ID of the EVPN HUB service model is 123, and the service members are the locally supported EVPN VPLS services.

[0111] At this point, the EVPN HUB service models between network devices A, B, and C have been created. The three EVPN services between network devices A, B, and C can be interconnected through the EVPN HUB service model:

[0112] Network device A establishes two EHTs, among which EHT1 leads to network device B and EHT 2 leads to network device C. Network device B establishes two EHTs, among which EHT3 leads to network device A and EHT 4 leads to network device C. Network device C establishes two EHTs, among which EHT5 leads to network device B and EHT6 leads to network device A.

[0113] Service message forwarding process:

[0114] The forwarding behaviors between network devices A, B, and C are similar. The following takes the forwarding between network device A and network device B as an example for explanation.

[0115] Network device A sends a service message to network device B:

[0116] Network device A receives private network message X sent by VM1. Since network device A deploys EVPN VXLAN service, network device A learns the source MAC address included in private network message X and establishes a MAC table. Network device A publishes EVPN type 2 route advertisement message to BGP EVPN neighbor, and then, according to the forwarding rule of EVPN VXLAN service, first queries the local MAC table. If the table entry corresponding to the destination MAC address included in private network message X is found in the local MAC table, it is forwarded according to the outbound interface indicated by the found MAC table entry, otherwise it is broadcast forwarded within EVPN VXLAN. In this example, network device A finds the MAC table entry corresponding to the destination MAC address and the outbound interface indicated by the MAC table entry is EHT1. Network device A encapsulates the egress identifier of EHT1 in the outer layer of private network message X, and encapsulates the public network tunnel information in the outer layer of the egress identifier to obtain the service message. The service message is forwarded to network device B through EHT1.

[0117] After network device B receives the service message through EHT1, it first strips the public network tunnel encapsulation. Then, network device B identifies the exit identifier included in the service message. The exit identifier belongs to ID 123 of the EVPN HUB service model created locally by network device B, and the service member of the EVPN HUB service model supports the EVPN VPWS service. Network device B forwards private network message X to the locally supported EVPN VPWS service for forwarding processing. After the EVPN VPWS service receives private network message X, it determines the AC1 port associated with EHT1 and forwards private network message X to VM2 through the AC1 port.

[0118] Network device B sends a service message to network device A:

[0119] Network device B receives private network message Y sent by VM2 through the AC1 port. Since network device B deploys the EVPN VPWS service, network device B determines the EHT used to forward private network message Y through the association between the AC1 port receiving private network message Y and the EHT. In this example, the AC1 port is associated with EHT1, which means forwarding to network device A. Network device B encapsulates the egress identifier of EHT1 in the outer layer of private network message Y, and encapsulates the public network tunnel information in the outer layer of the egress identifier to obtain the service message. The service message is forwarded to network device A through EHT1.

[0120] After network device A receives the service message through EHT1, it first strips the public network tunnel encapsulation. Then, network device A identifies the egress identifier included in the service message. The egress identifier belongs to ID 123 of the EVPN HUB service model created locally by network device A, and the service members of the EVPN HUB service model support the EVPN VXLAN service. Network device A forwards the private network message Y to the locally supported EVPN VXLAN service for forwarding processing. After the EVPN VXLAN service receives the private network message Y, it determines the peer of EHT1, that is, network device B supports the VPWS service, based on the EVPN HUB flag associated with EHT1. The EVPNVXLAN service learns the source MAC address of the private network message Y, establishes a MAC table, and publishes an EVPN2 class routing advertisement message to the BGP EVPN neighbor. The EVPN VXLAN service first queries the local MAC table according to the forwarding rules of the VXLAN service. If the entry corresponding to the destination MAC address included in the private network message Y is found in the local MAC table, it is forwarded according to the outbound interface indicated by the found MAC entry, otherwise it is broadcast forwarded within the EVPN VXLAN. In this example, network device A finds the MAC entry corresponding to the destination MAC address and the outbound interface indicated by the MAC entry is the interface connected to VM1, so network device A forwards the private network message Y to VM1 through the interface.

[0121] It should be noted that the EVPN 2 type route advertisement message issued by the EVPN VXLAN service includes the contents of the existing EVPN 2 type route advertisement message, as well as the EVPN HUB ID and EVPN HUB FLAG. Among them, the EVPN HUBFLAG is 1, which is used to indicate that the MAC address learned from EHT1 is obtained from the service message sent by the network device supporting the EVPN VPWS service.

[0122] Based on the same inventive concept, the embodiment of the present application also provides a network intercommunication device corresponding to the network intercommunication method. Figure 4 , Figure 4A network intercommunication device provided in an embodiment of the present application is applied to a first network device, the first network device has deployed a first network service, the first network device has established a first tunnel with a second network device, and the second network device has deployed a second network service, the device includes:

[0123] A receiving unit 410 is configured to receive, through the first tunnel, a first service message sent by the second network device, where the first service message includes a first exit identifier of the first tunnel;

[0124] A sending unit 420 is configured to send the first service message to the first network service if the first egress identifier belongs to the first identifier of the locally established EVPN HUB service model and the first egress identifier is associated with the first network service, so that the first network service forwards the first service message according to the forwarding policy of its own service;

[0125] The first network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, the second network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, and the first network service is different from the second network service.

[0126] Optionally, the first network device has established a second tunnel with a third network device, and the third network device has deployed a third network service;

[0127] The receiving unit 410 is also used to receive a private network message sent by the virtual machine;

[0128] The device further includes: an acquisition unit (not shown in the figure), configured to acquire a second exit identifier of the second tunnel when it is determined that the outgoing interface for forwarding the private network message is the second tunnel;

[0129] a processing unit (not shown in the figure), configured to encapsulate the second egress identifier in an outer layer of the private network message, and encapsulate the public network tunnel information in an outer layer of the second egress identifier to obtain a second service message;

[0130] The sending unit 420 is further configured to send the second service message to the third network device through the second tunnel;

[0131] The first network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, the third network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, and the first network service is different from the third network service.

[0132] Optionally, the sending unit 420 is further used to send a first EVPN routing announcement message to the second network device and the third network device, where the first EVPN routing announcement message includes the first identifier, the first EVPN HUB flag corresponding to the first network service, and the first exit identifier, so that the second network device or the third network device, after determining that an EVPN HUB service model matching the first identifier has been established locally and the local network service does not match the first EVPN HUB flag, takes itself as the starting point and the first network device as the end point, respectively establishes the first tunnel and the second tunnel, and associates the first exit identifier and the first EVPN HUB flag with the corresponding tunnels.

[0133] Optionally, the receiving unit 410 is further used to receive a second EVPN route advertisement message sent by the second network device, where the second EVPN route advertisement message includes a second identifier of an EVPN HUB service model locally established by the second network device and a second EVPN HUB flag corresponding to the second network service;

[0134] The apparatus further includes: an establishing unit (not shown in the figure), configured to establish the first tunnel with the first network device as a starting point and the second network device as an end point if the second identifier matches the first identifier and the second EVPN HUB flag does not match the first EVPN HUB flag;

[0135] or,

[0136] The receiving unit 410 is further configured to receive a third EVPN route advertisement message sent by the third network device, wherein the third EVPN route advertisement message includes a third identifier of the EVPN HUB service model locally established by the third network device and a third EVPN HUB flag corresponding to the third network service;

[0137] The device also includes: an establishing unit (not shown in the figure), which is used to establish the second tunnel with the first network device as the starting point and the third network device as the end point if the third identifier matches the first identifier and the third EVPN HUB flag does not match the first EVPN HUB flag.

[0138] Optionally, the second EVPN route advertisement message further includes a third egress identifier;

[0139] The device further includes: an associating unit (not shown in the figure), configured to associate the third egress identifier, the second EVPN HUB flag and the first tunnel;

[0140] The third EVPN route advertisement message also includes the second egress identifier;

[0141] The associating unit (not shown in the figure) is further configured to associate the second egress identifier, the third EVPN HUB flag and the second tunnel.

[0142] Therefore, by applying the network intercommunication device provided by the present application, the first network device receives the first service message sent by the second network device through the first tunnel, and the first service message includes the first exit identifier of the first tunnel; if the first exit identifier belongs to the first identifier of the locally established EVPN HUB service model and the first exit identifier is associated with the first network service, the first network device sends the first service message to the first network service, so that the first network service forwards and processes the first service message according to the forwarding policy of its own service.

[0143] The first network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, the second network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, and the first network service is different from the second network service.

[0144] In this way, the EVPN HUB service model built locally is used to establish tunnels between network devices that support different network services. By encapsulating the tunnel exit identifier in the outer layer of the service message, the receiving end can identify the exit identifier and process messages that are different from local network services. This solves the problem of introducing fixed equipment and increasing network costs in the existing network interconnection solutions for multiple types of services. It achieves the purpose of achieving network interconnection for multiple types of services without adding additional equipment to the network.

[0145] Based on the same inventive concept, the embodiment of the present application also provides a network device, such as Figure 5 As shown, it includes a processor 510, a transceiver 520 and a machine-readable storage medium 530, the machine-readable storage medium 530 stores machine-executable instructions that can be executed by the processor 510, and the processor 510 is prompted by the machine-executable instructions to execute the network intercommunication method provided in the embodiment of the present application. Figure 4 The network intercommunication device shown in FIG. Figure 5 The network device hardware structure shown is implemented.

[0146] The computer-readable storage medium 530 may include a random access memory (RAM) or a non-volatile memory (NVM), such as at least one disk storage. Optionally, the computer-readable storage medium 530 may also be at least one storage device located away from the processor 510.

[0147] The processor 510 may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0148] In the embodiment of the present application, the processor 510 reads the machine executable instructions stored in the machine readable storage medium 530, and the machine executable instructions enable the processor 510 itself and the transceiver 520 to execute the network intercommunication method described in the aforementioned embodiment of the present application.

[0149] In addition, an embodiment of the present application provides a machine-readable storage medium 530, which stores machine-executable instructions. When called and executed by the processor 510, the machine-executable instructions prompt the processor 510 itself and the calling transceiver 520 to execute the network intercommunication method described in the aforementioned embodiment of the present application.

[0150] The implementation process of the functions and effects of each unit in the above-mentioned device is specifically described in the implementation process of the corresponding steps in the above-mentioned method, and will not be repeated here.

[0151] For the device embodiment, since it basically corresponds to the method embodiment, the relevant parts can refer to the partial description of the method embodiment. The device embodiment described above is only schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they 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 present application scheme. A person of ordinary skill in the art can understand and implement it without paying any creative work.

[0152] As for the network intercommunication device and the machine-readable storage medium embodiments, since the method contents involved are basically similar to the aforementioned method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiments.

[0153] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A network intercommunication method, characterized in that: The method is applied to a first network device, the first network device has deployed a first network service, the first network device has established a first tunnel with a second network device, the first tunnel is an Ethernet virtual private network centralized switching tunnel EHT, and the second network device has deployed a second network service. The method includes: Receiving, through the first tunnel, a first service message sent by the second network device, where the first service message includes a first exit identifier of the first tunnel; If the first egress identifier is associated with a first identifier of a locally established EVPN HUB service model and the first egress identifier is associated with the first network service, sending the first service message to the first network service so that the first network service forwards the first service message according to a forwarding policy of its own service; The first network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, the second network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, and the first network service is different from the second network service; Before receiving, through the first tunnel, the first service message sent by the second network device, the method further includes: A first EVPN route advertisement message is sent to the second network device, where the first EVPN route advertisement message includes the first identifier, a first EVPN HUB flag corresponding to the first network service, and the first exit identifier, so that after the second network device determines that an EVPN HUB service model matching the first identifier has been established locally and the local network service does not match the first EVPN HUB flag, the second network device takes itself as a starting point and the first network device as an end point, establishes the first tunnel, and associates the first exit identifier and the first EVPN HUB flag with the first tunnel.

2. The method according to claim 1, characterized in that The first network device has established a second tunnel with a third network device, the second tunnel is an Ethernet virtual private network centralized switching tunnel EHT, the third network device has deployed a third network service, and the method further includes: Receive private network messages sent by the virtual machine; When it is determined that the outbound interface for forwarding the private network message is the second tunnel, obtaining a second egress identifier of the second tunnel; Encapsulating the second egress identifier in an outer layer of the private network message, and encapsulating the public network tunnel information in an outer layer of the second egress identifier, to obtain a second service message; Sending the second service message to the third network device through the second tunnel; The first network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, the third network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, and the first network service is different from the third network service.

3. The method according to claim 2, characterized in that Before receiving the private network message sent by the virtual machine, the method further includes: A first EVPN route advertisement message is sent to the third network device, where the first EVPN route advertisement message includes the first identifier, a first EVPN HUB flag corresponding to the first network service, and the first exit identifier, so that after the third network device determines that an EVPN HUB service model matching the first identifier has been established locally and the local network service does not match the first EVPN HUB flag, the third network device takes itself as a starting point and the first network device as an end point, establishes the second tunnel, and associates the first exit identifier and the first EVPN HUB flag with the second tunnel.

4. The method according to claim 1, characterized in that: Before receiving, through the first tunnel, the first service message sent by the second network device, the method further includes: receiving a second EVPN route advertisement message sent by the second network device, where the second EVPN route advertisement message includes a second identifier of an EVPN HUB service model locally established by the second network device and a second EVPN HUB flag corresponding to the second network service; If the second identifier matches the first identifier, and the second EVPN HUB flag does not match the first EVPN HUB flag, the first tunnel is established with the first network device as a starting point and the second network device as an end point.

5. The method according to claim 3, characterized in that: Before receiving the private network message sent by the virtual machine, the method further includes: receiving a third EVPN route advertisement message sent by the third network device, wherein the third EVPN route advertisement message includes a third identifier of an EVPN HUB service model locally established by the third network device and a third EVPN HUB flag corresponding to the third network service; If the third identifier matches the first identifier, and the third EVPN HUB flag does not match the first EVPN HUB flag, the second tunnel is established with the first network device as a starting point and the third network device as an end point.

6. The method according to claim 4, characterized in that The second EVPN route advertisement message also includes a third egress identifier; After establishing the first tunnel, the method further includes: The third egress identifier, the second EVPN HUB flag and the first tunnel are associated.

7. The method according to claim 5, characterized in that The third EVPN route advertisement message also includes the second egress identifier; After establishing the second tunnel, the method further includes: Associating the second egress identifier, the third EVPN HUB flag and the second tunnel.

8. A network intercommunication device, characterized in that: The apparatus is applied to a first network device, the first network device has deployed a first network service, the first network device has established a first tunnel with a second network device, the first tunnel is an Ethernet virtual private network centralized switching tunnel EHT, and the second network device has deployed a second network service, the apparatus includes: A receiving unit, configured to receive, through the first tunnel, a first service message sent by the second network device, wherein the first service message includes a first exit identifier of the first tunnel; a sending unit, configured to send the first service message to the first network service if the first egress identifier is associated with the first identifier of the locally established EVPN HUB service model and the first egress identifier is associated with the first network service, so that the first network service forwards the first service message according to a forwarding policy of its own service; The first network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, the second network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, and the first network service is different from the second network service; Before the receiving unit receives the first service message sent by the second network device through the first tunnel, the sending unit is further used to send a first EVPN route advertisement message to the second network device, where the first EVPN route advertisement message includes the first identifier, a first EVPN HUB flag corresponding to the first network service, and the first exit identifier, so that after the second network device determines that an EVPN HUB service model matching the first identifier has been established locally and the local network service does not match the first EVPN HUB flag, the second network device takes itself as the starting point and the first network device as the terminal, establishes the first tunnel, and associates the first exit identifier and the first EVPN HUB flag with the first tunnel.

9. The device according to claim 8, characterized in that The first network device has established a second tunnel with the third network device, the second tunnel is an Ethernet virtual private network centralized switching tunnel EHT, and the third network device has deployed a third network service; The receiving unit is also used to receive a private network message sent by the virtual machine; The device further includes: an acquisition unit, configured to acquire a second exit identifier of the second tunnel when it is determined that the outgoing interface for forwarding the private network message is the second tunnel; A processing unit, configured to encapsulate the second egress identifier in an outer layer of the private network message, and encapsulate the public network tunnel information in an outer layer of the second egress identifier to obtain a second service message; The sending unit is further used to send the second service message to the third network device through the second tunnel; The first network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, the third network service is any one of EVPN VPWS, EVPN VPLS, and EVPN VXLAN, and the first network service is different from the third network service.

10. The device according to claim 9, characterized in that The sending unit is further configured to send a first EVPN route advertisement message to the third network device, where the first EVPN route advertisement message includes the first identifier, a first EVPN HUB flag corresponding to the first network service, and the first exit identifier, so that after the third network device determines that an EVPN HUB service model matching the first identifier has been established locally and the local network service does not match the first EVPN HUB flag, the third network device takes itself as a starting point and the first network device as an end point, establishes the second tunnel, and associates the first exit identifier and the first EVPN HUB flag with the second tunnel.

11. The device according to claim 8, characterized in that The receiving unit is further configured to receive a second EVPN route advertisement message sent by the second network device, where the second EVPN route advertisement message includes a second identifier of an EVPN HUB service model locally established by the second network device and a second EVPN HUB flag corresponding to the second network service; The apparatus also includes: an establishing unit, configured to establish the first tunnel with the first network device as a starting point and the second network device as an end point if the second identifier matches the first identifier and the second EVPN HUB flag does not match the first EVPN HUB flag.

12. The device according to claim 10, characterized in that The receiving unit is further configured to receive a third EVPN route advertisement message sent by the third network device, wherein the third EVPN route advertisement message includes a third identifier of an EVPN HUB service model locally established by the third network device and a third EVPN HUB flag corresponding to the third network service; The apparatus also includes: an establishing unit, configured to establish the second tunnel with the first network device as a starting point and the third network device as an end point if the third identifier matches the first identifier and the third EVPN HUB flag does not match the first EVPN HUB flag.

13. The device according to claim 11, characterized in that The second EVPN route advertisement message also includes a third egress identifier; The device also includes: an associating unit, configured to associate the third exit identifier, the second EVPN HUB flag, and the first tunnel.

14. The device according to claim 12, characterized in that The third EVPN route advertisement message also includes the second egress identifier; The device also includes: an associating unit, configured to associate the second exit identifier, the third EVPN HUB flag and the second tunnel.

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