Fault handling method and device

Abstract

The present application discloses a fault handling method and apparatus, which relate to the field of communications and are useful for reducing unknown unicast flooding. When applied to scenarios such as Ethernet Virtual Private Networks (EVPNs), the method helps reduce unknown unicast flooding in EVPNs, thereby reducing the waste of communication resources. A first network device and a second network device are in communication connection, and the method includes: first, the second network device determines that a route to a media access control (MAC) address is unreachable, where the MAC address is a MAC address of a user-side network device or user host connected to the first network device. Second, in response to the determination, the second network device sets indication information corresponding to the route to the MAC address, where the indication information is used to instruct the second network device not to forward a message sent to the MAC address upon receipt.

Description

Technical Field

[0001] The present application relates to the field of communications, and in particular to a fault handling method and apparatus. Background Art

[0002] Ethernet virtual private network (EVPN) is a private virtual network (VPN) technology used for Layer 2 network interconnection. Figure 1 The following is a schematic diagram of the EVPN architecture. EVPN includes multiple provider edge (PE) devices. The PE devices in EVPN are connected to each other. The customer edge (CE) device is connected to the PE device through a switch. Figure 1 In the example, EVPN includes PE devices 1-3, with CE devices 1A and 1B connected to PE device 1 via switch 1, CE device 2 connected to PE device 2 via switch 2, and CE device 3 connected to PE device 3 via switch 3. Each CE device can connect to one or more user hosts.

[0003] In the future fifth-generation (5G) bearer network, EVPN can be used as an important service implementation solution. The Ethernet local area network (E_LAN) under the EVPN network architecture is also widely used in 5G bearer networks. In an E_LAN, when a switch fails, the PE device connected to the switch deletes the media access control (MAC) routes of the CE device connected to the switch in the local routing table, such as the MAC routes to the CE device and / or the MAC routes to the user-side host connected to the CE device, referred to herein as the MAC routes of the CE device. Afterwards, the PE device sends a Border Gateway Protocol (BGP) update message to other PE devices, so that the other PE devices delete the MAC routes of the CE device in the local routing table. However, the switch connected to the other PE device cannot detect that the switch has failed in time, so the switch connected to the other PE device may send a message to the other PE device that is sent to the MAC address. After receiving the message, the other PE device cannot find the MAC route in the local routing table, and triggers unknown unicast flooding in the EVPN, thereby wasting communication resources.

[0004] For example, based on Figure 1Assuming that Switch 1 fails, PE device 1 deletes the MAC routes for CE device 1A and 1B. It also sends BGP update messages to PE devices 2 and 3, causing them to delete the MAC routes for CE device 1A and 1B. However, with this deletion method, Switches 2 and 3 may not promptly detect that Switch 1 has failed, and therefore may continue to send packets destined for CE device 1A. If PE device 2 receives a packet from Switch 2 destined for CE device 1A, it cannot find the MAC route for CE device 1A in its local routing table, triggering unknown unicast flooding within the EVPN. Summary of the Invention

[0005] The embodiments of the present application provide a fault handling method and apparatus that help reduce unknown unicast flooding, and can be applied to various possible network scenarios such as EVPN, helping to reduce the flooding of unknown unicast traffic in the network, thereby reducing the waste of communication resources.

[0006] In order to achieve the above objectives, this application provides the following technical solutions:

[0007] In a first aspect, the present application provides a fault handling method, in which a first network device and a second network device are in communication connection. The method includes: the second network device determines that a route to a MAC address is unreachable, and the MAC address is a MAC address of a user-side network device or a user host connected to the first network device. In response to the determination, the second network device sets indication information corresponding to the route to the MAC address. The indication information is used to instruct the second network device not to forward a message sent to the MAC address upon receiving the message. Since the second network device does not forward the message sent to the MAC address, it helps to reduce the flooding of unknown unicast traffic in the network, thereby reducing the waste of communication resources.

[0008] In one possible design, after the second network device sets the indication information corresponding to the route of the MAC address, the method further includes: the second network device deleting the route of the MAC address. This helps to free up storage space of the second network device, thereby improving storage space utilization.

[0009] In one possible design, the second network device deletes the route to the MAC address, including: when the second network device determines that the route to the MAC address is unreachable for a preset time, or determines that the setting of the indication information meets the preset time, deleting the route to the MAC address. In other words, the second network device delays deleting the route to the MAC address. This helps to further reduce the risk of triggering unknown unicast flooding, thereby further reducing the waste of communication resources.

[0010] In one possible design, the second network device determines that the route to the MAC address is unreachable, including: when a third network device fails, or when a link between the first network device and the third network device fails, the second network device receives a first message from the first network device, and determines, based on the first message, that the route to the MAC address is unreachable. The third network device is a user-side network device connected to the first network device. This possible design provides a specific implementation method for determining that the MAC route is unreachable when a user-side network device fails or a link fails.

[0011] In one possible design, in addition to the first network device, one or more other network devices are also connected to the user-side network device or user host with the MAC address. In this case, the second network device receives a first message from the first network device and determines, based on the first message, that the MAC address is unreachable. This may include: the second network device receives the first message from the first network device and receives one or more second messages from one or more other network devices. The second network device then determines, based on the first message and the one or more second messages, that the MAC address is unreachable. This possible design can be applied to multi-homing scenarios for user-side devices.

[0012] In one possible design, the second network device determines that a route to a MAC address is unreachable, including: the second network device determines that a route to the MAC address is unreachable based on determining that the status of the first network device is faulty. This possible design provides a specific implementation method for determining that a MAC route is unreachable when a network device, particularly a network-side device, fails.

[0013] In one possible design, in addition to the first network device, one or more other network devices are also connected to the user-side network device or user host with the MAC address. In this case, the second network device determines that the route to the MAC address is unreachable based on determining that the first network device is in a faulty state, including: the second network device determines that the route to the MAC address is unreachable based on determining that the first network device and the one or more other network devices are all in a faulty state. This possible design can be applied to multi-homing scenarios for user-side devices.

[0014] In one possible design, the method further includes: the second network device determines that the status of the first network device is faulty based on a detection message sent to the first network device.

[0015] In one possible design, the third network device includes a switch.

[0016] In one possible design, the first message is a BGP Update message.

[0017] In one possible design, the indication information includes that the next hop of the route of the MAC address is NULL0.

[0018] In one possible design, the first network device and the second network device are EVPN neighbors.

[0019] In one possible design, the first network device and the second network device are PE devices.

[0020] In a second aspect, the present application provides a fault handling device, which may be a chip or a network device.

[0021] In one possible design, the fault handling device is used to execute any one of the methods provided in the first aspect above. The present application can divide the fault handling device into functional modules according to the method provided in the first aspect above. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. Exemplarily, the present application can divide the fault handling device into a determination unit, a setting unit, and a deletion unit, etc. according to the function. The description of the possible technical solutions and beneficial effects executed by each of the divided functional modules can refer to the corresponding technical solutions in the first aspect above, and will not be repeated here.

[0022] In another possible design, the fault handling device includes: a processor for implementing any one of the methods described in the first aspect above. The device may also include a memory, the memory is coupled to the processor, and when the processor executes the instructions stored in the memory, it can implement any one of the methods described in the first aspect above. The device may also include a communication interface, which is used for the device to communicate with other devices. Exemplarily, the communication port can be a transceiver, circuit, bus, module or other type of communication interface. In this application, the instructions in the memory can be pre-stored or downloaded from the Internet and stored when the device is used. This application does not make a unique limitation on the source of the instructions in the memory. The coupling in the embodiment of the present application is an indirect coupling or connection between units or modules, which can be electrical, mechanical or other forms, and is used for information exchange between units or modules.

[0023] In a third aspect, the present application provides a computer-readable storage medium, such as a non-transitory computer-readable storage medium, storing a computer program (or instruction) thereon, which, when executed on a fault handling device, causes the fault handling device to perform any of the methods provided in the first aspect.

[0024] In a fourth aspect, the present application provides a computer program product, which, when executed on a computer, enables any one of the methods provided in the first aspect to be executed.

[0025] In a fifth aspect, the present application provides a chip system, comprising: a processor, the processor being used to call and run a computer program stored in a memory from the memory, and execute any one of the methods provided in the first aspect.

[0026] In a sixth aspect, the present application provides a fault handling system, comprising: a first network device and a second network device. The first network device and the second network device are communicatively connected. The second network device is configured to perform any of the methods provided in the first aspect. The system may further include a third network device, which is a user-side network device connected to the first network device, such as a switch or a CE device.

[0027] It can be understood that any of the fault handling devices, computer storage media, computer program products or conference systems provided above can be applied to the corresponding methods provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding methods and will not be repeated here.

[0028] In this application, the names of the aforementioned fault handling devices do not limit the devices or functional modules themselves. In actual implementation, these devices or functional modules may appear with other names. As long as the functions of the respective devices or functional modules are similar to those of this application, they are within the scope of the claims of this application and their equivalents.

[0029] These and other aspects of the present application will become more readily apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of an EVPN architecture applicable to embodiments of the present application;

[0031] Figure 2 A schematic diagram of the structure of a fault handling system provided in an embodiment of the present application;

[0032] Figure 3 A schematic diagram of the structure of another fault handling system provided in an embodiment of the present application;

[0033] Figure 4 A schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0034] Figure 5 A flowchart of a fault handling method provided in an embodiment of the present application;

[0035] Figure 6 A schematic diagram of the structure of a second network device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0036] The terms "first", "second" and "third" in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects rather than to limit a specific order.

[0037] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner to facilitate understanding.

[0038] In the description of this application, unless otherwise specified, " / " indicates that the objects associated before and after are in an "or" relationship, for example, A / B can represent A or B; "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. In addition, in the description of this application, unless otherwise specified, "multiple" refers to two or more than two. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0039] In the embodiments of the present application, at least one can also be described as one or more, and multiple can be two, three, four or more, which is not limited in this application.

[0040] As previously mentioned, in an EVPN, if a switch fails, the PE device connected to the switch deletes the MAC route to the CE device connected to the switch from its local routing table, causing other PE devices to delete the MAC route to the CE device connected to the switch. This causes other PE devices to receive packets with the CE device's destination MAC address to fail to find the CE device's MAC route in their local routing table. This triggers unknown unicast flooding within the EVPN, wasting communication resources.

[0041] In view of this, an embodiment of the present application provides a fault handling method. Specifically, when the second network device determines that the route to the MAC address is unreachable, it sets indication information corresponding to the MAC address. The indication information is used to instruct the second network device not to forward the message when it receives a message sent to the MAC address. The MAC address is the MAC address of the user-side network device or user host connected to the first network device. In this way, even if the second network device cannot find the route to the MAC address in the local routing table when receiving a message sent to the MAC address, it will not trigger unknown unicast flooding in certain application scenarios, such as EVPN scenarios. Compared with traditional technologies, this helps to reduce the waste of communication resources.

[0042] As an example of a possible scenario, the technical solution provided in the embodiments of the present application can be applied to E-LAN, or in some scenarios, it can also be called: EVPN virtual private LAN service (VPLS). It is understandable that the embodiments of the present application can also be applied to other network scenarios that may cause similar technical problems.

[0043] The solution provided in the embodiment of the present application can be applied to Figure 2 In the fault handling system 20 shown. Figure 2 As shown, the message transmission system 20 may include multiple network-side network devices (such as network-side network devices 201-204), multiple user-side network devices (such as user-side network devices 205-207), and multiple user hosts (such as user hosts 208-211).

[0044] Network-side network devices can communicate with each other via the Border Gateway Protocol (BGP). Network-side network devices can communicate with each other via tunnels or other means. A network-side network device can be connected to one or more user-side network devices, for example, network-side network device 201 is connected to user-side network device 205, and network-side network device 204 is connected to user-side network devices 206-207. The network-side network device can be a PE device. For example, when the network-side network device is a PE device, each PE device in the fault handling system 20 can be configured with the same EVPN instance. Each network-side network device includes one or more outgoing interfaces, and each outgoing interface can be connected to a network-side network device or a user-side network device. For example, network-side network device 204 includes outgoing interfaces 1-5, which are used to connect to user-side network devices 206-207 and network-side network devices 201-203, respectively.

[0045] A user-side network device communicates with another user-side network device through one or more network-side network devices. For example, user-side network device 205 communicates with user-side network device 206 through network-side network device 201 and network-side network device 204. A user-side network device can be connected to one or more network-side network devices. For example, user-side network device 206 is connected to network-side network device 204 in a single-homing scenario; user-side network device 205 is connected to network-side network devices 201-203 respectively in a multi-homing scenario. A user-side network device can be connected to one or more user hosts. For example, user-side network device 205 is connected to user host 208, and user-side network device 206 is connected to user hosts 209-210. User-side network devices can be CE devices or switches. For example, the switch can act as an access server.

[0046] A user host communicates with another user host through one or more user-side network devices and one or more network-side network devices. For example, user host 208 communicates with user host 209 through user-side network device 205, network-side network devices 201 and 204, and user-side network device 206.

[0047] Each network-side network device can maintain (or manage) a local routing table, also known as a local routing table. This local routing table can contain one or more routes, also known as MAC routes. Each route includes a destination MAC address and the identifier of the next-hop node corresponding to that destination MAC address. The identifier of the next-hop node indicates the next-hop node for packets destined for that destination MAC address.

[0048] The destination MAC address contained in the route in the local routing table maintained by the network device on the network side includes at least the following:

[0049] Case 1: The destination MAC address is the MAC address of the user-side network device to which the network-side network device is connected.

[0050] Case 2: The destination MAC address is the MAC address of the user host connected to the network device on the network side. For example, the destination MAC address is the MAC address of the user host connected to the network device on the network side.

[0051] Case 3: The destination MAC address is the MAC address of a user-side network device connected to another network-side network device.

[0052] Case 4: The destination MAC address is the MAC address of a user host connected to another network device.

[0053] For example, based on Figure 2The routing table maintained by the network side network device 204 may exemplarily include the following routing table entry information:

[0054] Table 1

[0055] routing Destination MAC address The identifier of the next hop corresponding to the destination MAC address Route 1 MAC address of the user-side network device 206 The identifier of the outgoing interface 1 of the network device 204 on the network side Route 2 MAC address of the user-side network device 207 The identifier of the outgoing interface 2 of the network device 204 on the network side Route 3 MAC address of user host 209 The identifier of the outgoing interface 1 of the network device 204 on the network side Route 4 MAC address of user host 210 The identifier of the outgoing interface 1 of the network device 204 on the network side Route 5 MAC address of user host 211 The identifier of the outgoing interface 2 of the network device 204 on the network side Route 6 MAC address of the user-side network device 205 The identifier of the outgoing interface 3-5 of the network device 204 on the network side Route 7 MAC address of user host 208 The identifier of the outgoing interface 3-5 of the network device 204 on the network side

[0056] It should be noted that, in one example, each network-side network device can learn local MAC addresses, i.e., the MAC address of the user-side network device connected to the network-side network device and the MAC address of the user host connected to the network-side network device, and establish a routing table entry (referred to as a local routing table entry) based on the learned MAC address. Then, the network-side network device can send local routing table entries to other network-side network devices and receive local routing table entries established by other network-side network devices sent by other network-side network devices. Each network-side network device generates a routing table based on the local routing table entries established by itself and the local routing table entries established by the other network-side network devices. Its specific implementation method can refer to the existing technology and will not be repeated here.

[0057] For example, when the network-side network device is a PE device, the PE devices can exchange local routing table entries using ad-route, inclusive multicast route, or mac-route. Subsequently, when a network-side network device receives a packet, it queries the routing table based on the packet's destination address to determine the next hop node for the packet and forwards the packet to that next hop node.

[0058] Optionally, the fault handling system 20 may include multiple levels of user-side network devices. For example, Figure 3 FIG. 2 shows an example of a fault handling system 20 including multiple user-side network devices. Specifically, Figure 3 The user host 211 in the network accesses the network side network device 204 through the user side network device 212 and the user side network device 207 (ie, two-level user side network devices). Among them, one user side network device can be connected to one or more user side network devices. Figure 3 is based on Figure 2 To draw, therefore, Figure 3 For explanations of other devices, please refer to Figure 2 The description is not repeated here.

[0059] Further optionally, the user-side network device directly connected to the user host may be a CE device, and the user-side network device indirectly connected to the user host may be a switch. Figure 3The user-side network device 212 in the example may be a CE device, and the user-side network device 207 may be a switch.

[0060] The fault handling system 20 can be used for EVPN. When applied to EVPN, the network-side network device can be a PE device, and the user-side network device can be a CE device or a switch. In EVPN, any two PE devices can be connected through a provider backbone (P) device. The P device acts as a forwarding device between the two PE devices, forwarding data packets between the PE devices. The EVPN here can be a single-homing scenario or a multi-homing scenario (such as a dual-homing scenario). The single-homing scenario refers to a user-side network device (such as a CE device or switch) accessing the EVPN through a PE device. The multi-homing scenario refers to a user-side network device accessing the EVPN through multiple PE devices. The dual-homing scenario refers to a user-side network device accessing the EVPN through two PE devices.

[0061] Example, combined Figure 1 , Figure 1 The PE device can be Figure 2 The specific implementation of the network side network equipment in Figure 1 The CE devices and switches in the Figure 2 The specific implementation of the user-side network equipment in Figure 1 The user host in can be Figure 2 The specific implementation of the user host in .

[0062] In terms of hardware implementation, the above network side network devices and user side network devices can be implemented as follows: Figure 4 The communication device shown is implemented. Figure 4 FIG. 4 is a schematic diagram of the hardware structure of a communication device 40 provided in an embodiment of the present application. The communication device 40 can be used to implement the functions of the above-mentioned network-side network device or user-side network device.

[0063] Figure 4 The communication device 40 shown may include: a processor 401 , a memory 402 , a communication interface 403 , and a bus 404 . The processor 401 , the memory 402 , and the communication interface 403 may be connected via the bus 404 .

[0064] The processor 401 is the control center for generating the communication device 40 and can be a general-purpose central processing unit (CPU) or other general-purpose processors, etc. The general-purpose processor can be a microprocessor or any conventional processor.

[0065] As an example, the processor 401 may include one or more CPUs, such as Figure 4 CPU 0 and CPU1 are shown in Figure 1.

[0066] The memory 402 may be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM) or other type of dynamic storage device that can store information and instructions, an electrically erasable programmable read-only memory (EEPROM), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto.

[0067] In one possible implementation, memory 402 may exist independently of processor 401. Memory 402 may be connected to processor 401 via bus 404 and used to store data, instructions, or program code. When processor 401 calls and executes the instructions or program code stored in memory 402, the fault handling method provided in the embodiments of the present application can be implemented.

[0068] In another possible implementation, the memory 402 may also be integrated with the processor 401 .

[0069] Communication interface 403 is used to connect communication device 40 to other devices via a communication network, such as Ethernet, a radio access network (RAN), a wireless local area network (WLAN), etc. Communication interface 403 may include a receiving unit for receiving data and a sending unit for sending data.

[0070] Bus 404 can be an industry standard architecture (ISA) bus, a peripheral component interconnect (PCI) bus, or an extended industry standard architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 4 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0071] It should be pointed out that Figure 4 The structure shown in the figure does not constitute a limitation on the communication device 40, except Figure 4 In addition to the components shown, the communication device 40 may include more or fewer components than shown, or combine certain components, or arrange the components differently.

[0072] like Figure 5 , which is a flow chart of a fault handling method provided in an embodiment of the present application. Figure 5 The method shown can be applied to Figure 2 or Figure 3 The fault handling system shown. Figure 5 The method shown is applied to a second network device. The second network device is connected to the first network device for communication. Optionally, the second network device communicates with the first network device via BGP. The second network device may be Figure 2 or Figure 3 Any network side network device in the network. The first network device can be Figure 2 or Figure 3 Any network-side network device other than the second network device.

[0073] Optionally, the second network device and the first network device are EVPN neighbors. EVPN neighbors generally refer to neighbor relationships between PE devices. EVPN neighbors can also communicate through established tunnels, the type of which can be, for example, a Label Distribution Protocol (LDP) tunnel, a Virtual Extensible Local Area Network (VXLAN) protocol tunnel, etc. Optionally, the second network device and the first network device are PE devices.

[0074] Figure 5 The method shown may include the following steps:

[0075] S501: The second network device determines that a route to a MAC address is unreachable, where the MAC address is a MAC address of a user-side network device or a user host connected to the first network device.

[0076] For example, combined with Figure 1 The second network device may be PE device 2, the first network device may be PE device 1, the network side network device may be switch 1, CE device 1A or CE device 2A, and the user host may be a user host connected to CE device 1A or a user host connected to CE device 1B.

[0077] For example, combined with Figure 2 or Figure 3, the second network device may be the network side network device 204, the first network device may be any one of the network side network devices 201-203, the user side network device may be the network side network device 205, and the user host may be the user host 208. Or, in combination Figure 2 or Figure 3 The second network device may be the network side network device 201, the first network device may be the network side network device 204, the user side network device may be the network side network device 206 or the network side user device 207, and the user host may be any user host among the user hosts 209-211.

[0078] The MAC address is the MAC address of any user-side network device or any user host connected to the first network device. A route to a MAC address, or a MAC address route, refers to a route whose destination MAC address is the MAC address. For example, the route to the MAC address can be any route in the local routing table maintained by the second network device.

[0079] It should be noted that for the sake of convenience, the following description will refer to a route with a destination MAC address as a route to the MAC address or a route to the MAC address. This description will be omitted here.

[0080] Optionally, S501 can be implemented in the following ways:

[0081] Method 1: When a third network device fails, or when the link between the first and third network devices fails, the second network device receives a first message from the first network device and determines, based on the first message, that the route to the MAC address is unreachable. The third network device is a user-side network device connected to the first network device.

[0082] The third network device may be any user-side network device directly or indirectly connected to the first network device, such as a switch or a CE device. Figure 1 , if the first network device is PE device 1, then the third network device can be CE device 1A or CE device 1B or switch 1. For another example, Figure 2 or Figure 3 If the first network device is any one of the network-side network devices 201 - 203 , the third network device may be the user-side network device 205 .

[0083] The first message is a message received by the second network device from the first network device when "the third network device is faulty, or the link between the first network device and the third network device is faulty" and is used to determine that the route to the MAC address is unreachable. This embodiment of the application does not impose a single limitation on the form in which the first message indicates unreachability; as long as the second network device can determine that the MAC address is unreachable based on the first message, it is sufficient.

[0084] In one example, a second network device receives a first message sent by a first network device, where the first message is used to indicate an unreachable route, and determines the unreachable route based on the first message. The unreachable route includes the route in S501. The first network device may send the first message to the second network device when it determines that the third network device is faulty, or the link between the first network device and the third network device is faulty. The embodiment of the present application does not uniquely limit what information the first message carries to indicate the unreachable route. In one possible scenario, the first message may be a MAC revocation route, such as a revocation type ad-route route.

[0085] In another example, a second network device receives a first message sent by a first network device, where the first message indicates a route currently reachable through the first network device. The second network device compares the currently reachable route indicated by the first message with the stored reachable routes, thereby determining a route in the local routing table whose status has actually changed to unreachable. The unreachable route determined includes the route in S501. In this example, the first network device may send the first message to the second network device when the third network device fails or the link between the first network device and the third network device fails.

[0086] In yet another example, the second network device receives a first message sent by the first network device, where the first message is used to indicate a failure of the third network device or a failure of a link between the first network device and the third network device.

[0087] Among them, the embodiment of the present application does not uniquely limit what information the first message carries to indicate the failure of the third network device, or the failure of the link between the first network device and the third network device. For example, the first message can carry information for notifying the failure of the third network device, or information for notifying the failure of the link between the first network device and the third network device. For another example, in addition to carrying information for notifying the above-mentioned "information for indicating the failure of the third network device, or information for indicating the failure of the link between the first network device and the third network device", the first message can also carry routes currently reachable through the first network device, or routes currently unreachable through the first network device, etc.

[0088] The embodiment of the present application does not impose a unique limitation on the type of the first message. For example, the first message may be a BGPUpdate message.

[0089] Optionally, in addition to the first network device, one or more other network devices are also connected to the user-side network device having the MAC address. In this case, Method 1 may include: when the third network device fails, or when the link between the first network device and the third network device fails, the second network device receives a first message from the first network device and receives one or more corresponding second messages from the one or more other network devices. Based on the first message and the one or more second messages, the second network device determines that the route to the MAC address is unreachable.

[0090] This optional implementation provides a method for determining that a MAC address is unreachable when the troubleshooting method provided in the embodiments of the present application is applied to a multi-homing scenario. Specifically, a third network device is connected to multiple network-side network devices, and the third network device is multi-homed to the access network-side network devices. The multiple network-side network devices include the first network device.

[0091] The difference between the second message and the first message is that they are messages sent by different network devices. Therefore, for the specific implementation of the second message, please refer to the above description of the first message and will not be repeated here.

[0092] In an example, if the third network device is multi-homed to multiple network-side network devices, the second network device may determine that the route in S501 is unreachable upon receiving the first message / second message sent by each of the multiple network-side network devices.

[0093] For example, based on Figure 2Assuming that the first network device is network-side network device 201 and the second network device is network-side network device 204, the unreachable route in S501 may be the route of user-side network device 205 or the route of user host 208. Because the user-side network device (i.e., user-side network device 205) or user host (i.e., user host 208) with this MAC address is still connected to network-side network devices 202 and 203, if the link between user-side network device 205 and network-side network device 201 fails, packets destined for user-side network device 205 or user host 208 may still be forwarded via network-side network device 202 or 203. For example, in an EVPN multi-homing multi-active scenario, assuming that a CE device, acting as a user-side network device, is multi-homed to multiple network-side network devices, the CE device can receive packets through all of these multiple network-side network devices. Therefore, assuming that the third network device is the user-side network device 205, the network-side network device 204 may consider that the route to the MAC address of the user-side network device 205 is unreachable or the route to the MAC address of the user host 208 is unreachable only when it receives the first message or the second message sent by the network-side network devices 201-203 respectively.

[0094] Method 2: The second network device determines that the route to the MAC address is unreachable based on determining that the status of the first network device is faulty. Method 2 can be understood as: the second network device determines that the route to the MAC address is unreachable when it actively determines that the status of the first network device is faulty.

[0095] Optionally, the second network device determines that the status of the first network device is a fault based on the detection message sent to the first network device. Specifically, the second network device can send a detection message to the first network device, and when no response message to the detection message is received within a preset time period (such as a preset time period from the start of sending the detection message), the second network device determines that the status of the first network device is a fault. For example, the second network device can send a detection message to the first network device based on a bidirectional forwarding detection (BFD) protocol or a connectivity fault management (CFM) protocol.

[0096] Optionally, in addition to the first network device, one or more other network devices are also connected to the user-side network device or user host with the MAC address. For example, in an EVPN multi-homing multi-active scenario, a CE device is multi-homed to multiple PE devices. In this case, method 2 may include: the second network device determining that the route to the MAC address is unreachable based on determining that the first network device and the one or more other network devices are all in a faulty state.

[0097] The method for the second network device to determine that the status of one or more other network devices is faulty may refer to the above-mentioned method for determining that the status of the first network device is faulty, which will not be repeated here.

[0098] In one example, when multiple network devices are connected to a user-side network device or a user host having the MAC address, the second network device may determine that the MAC address is unreachable when determining that the statuses of the multiple network devices are all faulty.

[0099] For example, based on Figure 2 Assuming that the second network device is network-side network device 204 and the first network device is network-side network device 201, the unreachable route in S501 may be the route of user-side network device 205 or the route of user host 208. Since the user-side network device (i.e., user-side network device 205) or user host (i.e., user host 208) with the MAC address is also connected to network-side network devices 202 and 203, network-side network device 204 may determine that the MAC address is unreachable when determining that the status of network-side network devices 201-203 are all faulty.

[0100] S502: In response to the determination in S501, the second network device sets indication information corresponding to the route of the MAC address, wherein the indication information is used to instruct the second network device not to forward a message sent to the MAC address upon receiving the message. For example, as a possible manner of not forwarding the message, the second network device may discard the message.

[0101] The embodiment of the present application does not impose a single limitation on the specific implementation method of setting the indication information, as long as it can achieve the purpose of instructing the second network device not to forward the message sent to the MAC address. The following methods ac are used as possible examples.

[0102] Mode a: Setting the indication information may include: changing the route of the MAC address so that the second network device does not forward the message when receiving the message sent to the MAC address.

[0103] For example, the instruction information may be to modify the next hop of the route for the MAC address to NULL0. In other words, the identifier of the next hop node included in the route for the MAC address is set to NULL0. For example, based on Table 1 above, assuming that the unreachable route is route 7, the "next hop identifier corresponding to the destination MAC address" in route 7 is set to NULL0. With this setting, the route can be called a black hole route.

[0104] Method b: Setting the indication information may include setting an indicator for the route to the MAC address. That is, each route in the local routing table corresponds to an indicator. When the value of the indicator is set to a preset value, the second network device does not forward the message when it receives a message sent to the MAC address. Alternatively, a corresponding indicator is set for at least the MAC address, not necessarily the entire route. When the value of the indicator is set to a preset value, the second network device does not forward the message when it receives a message sent to the MAC address.

[0105] Method c: Setting the indication information may include storing the route for the MAC address, or at least the MAC address, in an unreachable MAC routing table or a MAC address record table, so that the second network device determines not to forward packets sent to the MAC address based on the MAC address belonging to the unreachable MAC routing table or the MAC address record table. The indication information may be considered to be the unreachable MAC routing table or the MAC address record table itself.

[0106] Optionally, after executing S502, the method may further include the following S503.

[0107] S503: The second network device deletes the route of the MAC address.

[0108] After executing S502, when the second network device receives a message sent to the MAC address, it no longer forwards the message based on the route. Therefore, the route maintained by the second network device becomes a redundant route. On this basis, executing S503 helps to free up the storage space of the second network device, thereby improving the utilization of the storage space.

[0109] Optionally, the second network device deletes the route to the MAC address when it determines that the route to the MAC address is unreachable for a preset time, or when it determines that the preset time is met according to setting the indication information.

[0110] For example, the second network device deletes the route of the MAC address after a preset time from determining that the route of the MAC address is unreachable.

[0111] For another example, the second network device deletes the route of the MAC address after a preset time from determining the indication information.

[0112] It should be noted that, in a specific implementation, the second network device can implement this optional solution by setting a timer. For example, when it is determined that the route to the MAC address is unreachable or when it is determined to set the indication information, the timer starts, and when the timed time meets a preset time, the route to the MAC address is deleted. The timer can be implemented by software, hardware, or a combination of software and hardware.

[0113] In one example, this optional implementation can be understood as: the second network device delaying deletion of the route to the MAC address. The term "delayed deletion" is primarily a relative term, distinguishing it from immediate deletion in the background art. It is understood that in actual applications, both immediate and delayed deletion require a certain amount of time.

[0114] Several implementations of the preset time are described below, which can be applied at least to implementations where the setting of the indication information is directly related to the route of the MAC address, such as the case where the indication information is set for the MAC route in the above-mentioned method a or method b:

[0115] Implementation method 1: The preset time is greater than or equal to the MAC aging time of the user-side network device to which the second network device is connected.

[0116] Among them, if the second network device is connected to multiple user-side network devices, and the MAC aging times set on the multiple user-side network devices are different or not exactly the same, the preset time can be greater than or equal to the longest aging time among the multiple MAC aging times corresponding to the multiple user-side network devices.

[0117] When a MAC route's aging time expires, the user-side network device can delete the MAC route from its MAC routing table. Consequently, before the MAC route's aging time expires, the user-side network device may send packets to its connected network-side network device based on the MAC route. However, after the MAC route's aging time expires, the user-side network device will no longer send packets to its connected network-side network device based on the MAC route because the MAC route has been deleted. In the example described in the background technology, before the aging time of CE device 1A's MAC address expires, switch 2 may send packets to PE device 2. This may trigger unknown unicast flooding in the EVPN because it cannot find a route for CE device 1A's MAC address in the local routing table. After the aging time of the MAC address expires, PE device 2 will no longer receive packets sent by switch 2 based on the route for the MAC address, thus preventing unknown unicast flooding in the EVPN.

[0118] Based on this, when setting the indication information, if the indication information is of a type related to a routing table entry for a MAC address, then after the indication information is set and before the maximum MAC aging time set on the user-side network device to which the second network device is connected has expired, the MAC route will be deleted. While this ensures that unknown unicast traffic will not be flooded in the EVPN before the route is deleted, it cannot guarantee that unknown unicast traffic will not be flooded in the EVPN after the route is deleted. Therefore, it is advisable to consider setting the preset time to be greater than or equal to the MAC aging time of the user-side network device to which the second network device is connected.

[0119] Implementation method 2: The preset time is greater than or equal to the fault detection period of the user-side network device to which the second network device is connected. The fault detection period is a period for detecting whether other user-side network devices in the fault handling system have faults.

[0120] Among them, if the second network device is connected to multiple user-side network devices, and the fault detection cycles of different user-side network devices are different or not exactly the same, the preset time can be greater than or equal to the longest fault detection cycle among the multiple fault detection cycles of the multiple user devices.

[0121] The user-side network device can periodically detect whether other user-side network devices in the fault handling system are faulty. In the example in the background technology, switch 2 can periodically detect whether switch 1 is faulty.

[0122] If, at the start of a fault detection cycle, a user-side network device determines that another user-side network device has not experienced a fault, then during that fault detection cycle, that user-side network device may still send packets to that other user-side network device. Therefore, before the end of a fault detection cycle, if the network-side network device connected to that other user-side network device deletes the local route to that other user-side network device, then when that network-side network device receives packets destined for that other user-side network device, it will be unable to find the corresponding route, causing unknown unicast flooding within the EVPN. At the next fault detection cycle, the user-side network device will be able to detect that the other user-side network device has failed and will no longer send packets to it. Consequently, the network-side network device connected to that other user-side network device will not receive the packets, and thus will not cause unknown unicast flooding within the EVPN.

[0123] In the example used in the background technology, at the beginning of a fault detection cycle, switch 2 determines that switch 1 has not experienced a fault. However, before the end of the fault detection cycle, even if switch 1 has experienced a fault, switch 2 will not be aware of it and may still send packets to switch 1. If PE device 2 deletes the local route of switch 1 during the fault detection cycle, after the packet reaches PE device 2, PE device 2 will not be able to find the local route of switch 1 in its stored routing table, causing unknown unicast flooding in the EVPN.

[0124] Based on this, after setting the indication information associated with the MAC route, timing can be performed. The second network device will only delete the MAC route after reaching or exceeding the fault detection cycle of the user-side network device connected to the second network device, so as to ensure that unknown unicast traffic flooding caused by premature deletion of the MAC route will not occur.

[0125] Implementation method 3: The preset time is greater than or equal to the minimum value of the MAC aging time of the user-side network device connected to the second network device and the fault detection period of the user-side network device connected to the second network device, and the fault detection period is used to detect whether other user-side network devices in the fault handling system are faulty.

[0126] Implementation method 3 refers to the MAC aging time of the user-side network device connected to the second network device and the fault detection period of the user-side network device connected to the second network device. The reasons can be referred to the description in the above implementation methods 1 and 2, which will not be repeated here.

[0127] In the troubleshooting method provided by an embodiment of the present application, a second network device determines that a route to a MAC address is unreachable. The MAC address can be the MAC address of a user-side network device or user host connected to the first network device. In response to this determination, the second network device sets indication information corresponding to the route to the MAC address. This indication information is used to instruct the second network device not to forward packets sent to the MAC address upon receipt. Compared to the technical solutions in the prior art, since the second network device does not forward packets sent to the MAC address, it does not trigger unknown unicast flooding in the EVPN, thereby reducing the waste of communication resources.

[0128] The above mainly introduces the solution provided by the embodiment of the present application from the perspective of method. In order to realize the above functions, it includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should easily appreciate that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in a hardware or computer software driven hardware manner depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0129] In the embodiment of the present application, the fault handling device (such as the second network device) can be divided into functional modules according to the above method example. For example, each functional module can be divided corresponding to each function, or two or more functions can be integrated into one processing module. The above-mentioned integrated module can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical functional division. There may be other division methods in actual implementation.

[0130] like Figure 6 As shown, Figure 6 The second network device 60 is used to execute the above-mentioned fault handling method, for example, Figure 5 As shown in the fault handling method, for example, the second network device 60 may include a determining unit 601 and a setting unit 602 .

[0131] The determining unit 601 is used to determine that the route to the MAC address is unreachable, and the MAC address is the MAC address of the user-side network device or the user host connected to the first network device. The setting unit 602 is used to set the indication information corresponding to the route of the MAC address in response to the determination. The indication information is used to instruct the second network device not to forward the message when receiving the message sent to the MAC address. For example, in combination with Figure 5 , the determining unit 601 can be used to execute S501, and the setting unit 602 can be used to execute S502.

[0132] Optionally, the second network device 60 further includes: a deleting unit 603, configured to delete the route of the MAC address after the setting unit 602 sets the indication information corresponding to the route of the MAC address. Figure 5 , the deleting unit 603 can be used to execute S503.

[0133] Optionally, the deleting unit 603 is specifically configured to: delete the route to the MAC address when it is determined that the route to the MAC address is unreachable for a preset time, or when the preset time is met according to setting the indication information.

[0134] Optionally, the second network device 60 further includes a receiving unit 604 configured to receive a first message from the first network device when the third network device fails or when the link between the first network device and the third network device fails. In this case, the determining unit 601 is specifically configured to determine, based on the first message, that the route to the MAC address is unreachable. The third network device is a user-side network device connected to the first network device.

[0135] Optionally, in addition to the first network device, one or more other network devices are also connected to the user-side network device or user host having the MAC address. In this case, the receiving unit 604 is specifically configured to receive a first message from the first network device and one or more second messages from the one or more other network devices. The determining unit 601 is specifically configured to determine, based on the first message and the one or more second messages, that the MAC address is unreachable.

[0136] Optionally, the determining unit 601 is specifically configured to: determine that the route to the MAC address is unreachable based on determining that the status of the first network device is faulty.

[0137] Optionally, in addition to the first network device, one or more other network devices are also connected to the user-side network device or user host having the MAC address. In this case, the determining unit 601 is specifically configured to: determine that the route to the MAC address is unreachable based on determining that the status of the first network device and the one or more other network devices are all faulty.

[0138] Optionally, the determining unit 601 is further configured to: determine, according to a detection message sent to the first network device, that the status of the first network device is faulty.

[0139] Optionally, the third network device includes a switch.

[0140] Optionally, the first message is a BGP Update message.

[0141] Optionally, the indication information includes that the next hop of the route of the MAC address is NULL0.

[0142] Optionally, the first network device and the second network device are EVPN neighbors.

[0143] Optionally, the first network device and the second network device are PE devices.

[0144] For the detailed description of the above optional manners, please refer to the above method embodiments, which will not be repeated here. In addition, the explanation and beneficial effects of any of the above second network devices 60 can be referred to the above corresponding method embodiments, which will not be repeated here.

[0145] As an example, combined with Figure 4 , the functions partially or entirely implemented by the determining unit 601, setting unit 602 and deleting unit 603 in the second network device 60 can be realized by Figure 4 Processor 401 in the execution Figure 4 The receiving unit 604 can be implemented by the program code in the memory 402. Figure 4 The receiving unit in the communication interface 403 is implemented.

[0146] The embodiment of the present application also provides a fault handling system, which includes a first network device and a second network device. The second network device can be any of the second network devices 60 provided above, and the first network device can be Figure 1 Any PE device shown that is not a second network device, or Figure 2 or Figure 3 The system may further include a third network device, which may be, for example, Figure 1 Any switch or CE device shown, or Figure 2 or Figure 3 Any user-side network device shown in .

[0147] An embodiment of the present application further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is run on a computer, the computer is caused to execute any of the methods executed by the second network device provided above.

[0148] For explanations of the relevant contents and descriptions of the beneficial effects of any of the above-mentioned fault handling systems and computer-readable storage media, reference may be made to the above-mentioned corresponding embodiments, which will not be repeated here.

[0149] The embodiment of the present application also provides a chip. The chip integrates a control circuit and one or more ports for implementing the functions of the above-mentioned second network device 60. Optionally, the functions supported by the chip can be referred to above and will not be repeated here. Those skilled in the art will understand that all or part of the steps of implementing the above-mentioned embodiment can be completed by instructing the relevant hardware through a program. The program can be stored in a computer-readable storage medium. The storage medium mentioned above can be a read-only memory, a random access memory, etc. The above-mentioned processing unit or processor can be a central processing unit, a general-purpose processor, an application specific integrated circuit (ASIC), a microprocessor (digital signal processor, DSP), a field programmable gate array (FPGA) or other programmable logic device, transistor logic device, hardware component or any combination thereof.

[0150] The present application also provides a computer program product comprising instructions, which, when executed on a computer, causes the computer to perform any of the methods described in the above embodiments. The computer program product comprises one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated therein. The available media may be magnetic media (e.g., floppy disk, hard disk, tape), optical media (e.g., DVD), or semiconductor media (e.g., SSD).

[0151] It should be noted that the above-mentioned devices for storing computer instructions or computer programs provided in the embodiments of the present application, such as but not limited to the above-mentioned memories, computer-readable storage media and communication chips, etc., are all non-transitory.

[0152] In the process of implementing the claimed application, those skilled in the art can understand and implement other changes to the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit can implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results. Although the present application has been described in conjunction with specific features and embodiments thereof, various modifications and combinations may be made thereto without departing from the spirit and scope of the present application. Accordingly, this specification and the drawings are merely exemplary illustrations of the present application as defined by the appended claims, and are deemed to have covered any and all modifications, changes, combinations or equivalents within the scope of the present application.

Claims

1. A fault handling method, characterized in that: The first network device is communicatively connected to the second network device, and the method includes: The second network device determines that a route to a media access control MAC address is unreachable, where the MAC address is a MAC address of a user-side network device or a user host connected to the first network device; In response to the determination, the second network device sets indication information corresponding to the route of the MAC address, the indication information being used to instruct the second network device not to forward a message sent to the MAC address when the message is received; The second network device deletes the route to the MAC address when it determines that the route to the MAC address is unreachable for a preset time, or when it determines that the setting of the indication information meets a preset time, and the preset time is greater than or equal to the MAC aging time of the user-side network device connected to the second network device.

2. The method according to claim 1, characterized in that The second network device determining that a route to the MAC address is unreachable includes: When a third network device fails or a link between the first network device and the third network device fails, the second network device receives a first message from the first network device and determines, based on the first message, that the route to the MAC address is unreachable, wherein the third network device is a user-side network device connected to the first network device; or The second network device determines that the route to the MAC address is unreachable based on determining that the status of the first network device is faulty.

3. The method according to claim 2, characterized in that In addition to the first network device, one or more other network devices are also connected to the user-side network device or user host having the MAC address; The second network device receives a first message from the first network device, and determines, according to the first message, that the route to the MAC address is unreachable, including: The second network device receives a first message from the first network device and receives one or more second messages from the other one or more network devices; The second network device determines, based on the first message and the one or more second messages, that the route to the MAC address is unreachable; or The second network device determining, based on determining that the state of the first network device is faulty, that the route to the MAC address is unreachable includes: The second network device determines that the route to the MAC address is unreachable based on determining that the status of the first network device and the other one or more network devices are all faulty.

4. The method according to claim 2 or 3, characterized in that The method further comprises: The second network device determines, based on the detection message sent to the first network device, that the status of the first network device is faulty.

5. The method according to any one of claims 2 to 4, characterized in that The third network device includes a switch.

6. The method according to any one of claims 2 to 5, characterized in that The first message is a Border Gateway Protocol update BGP Update message.

7. The method according to any one of claims 1 to 6, characterized in that The indication information includes that the next hop of the route of the MAC address is NULL0.

8. The method according to any one of claims 1 to 7, characterized in that The first network device and the second network device are Ethernet Private Virtual Network (EVPN) neighbors.

9. The method according to any one of claims 1 to 8, characterized in that The first network device and the second network device are provider edge (PE) devices.

10. A second network device, characterized in that: The first network device is communicatively connected to the second network device, where the second network device includes: a determining unit, configured to determine that a route to a media access control MAC address is unreachable, wherein the MAC address is a MAC address of a user-side network device or a user host connected to the first network device; a setting unit, configured to, in response to the determination, set indication information corresponding to the route of the MAC address, the indication information being used to instruct the second network device not to forward a message sent to the MAC address upon receiving the message; A deletion unit is used to delete the route to the MAC address when it is determined that the route to the MAC address is unreachable for a preset time, or when it is determined that the setting of the indication information meets a preset time, and the preset time is greater than or equal to the MAC aging time of the user-side network device connected to the second network device.

11. The second network device according to claim 10, characterized in that: The second network device further includes: a receiving unit configured to receive a first message from the first network device when a third network device fails or a link between the first network device and the third network device fails; the determining unit is specifically configured to determine, based on the first message, that the route to the MAC address is unreachable, wherein the third network device is a user-side network device connected to the first network device; or The determining unit is specifically configured to: determine that the route to the MAC address is unreachable based on determining that the state of the first network device is faulty.

12. The second network device according to claim 11, characterized in that: In addition to the first network device, one or more other network devices are also connected to the user-side network device or user host having the MAC address; The receiving unit is specifically configured to: receive a first message from the first network device and receive one or more second messages from the other one or more network devices; the determining unit is specifically configured to: determine, based on the first message and the one or more second messages, that the MAC address is unreachable; or, The determining unit is specifically configured to determine that the route to the MAC address is unreachable based on determining that the statuses of the first network device and the other one or more network devices are all faulty.

13. The second network device according to claim 11 or 12, characterized in that: The determining unit is further configured to determine, based on a detection message sent to the first network device, that the status of the first network device is faulty.

14. The second network device according to any one of claims 11 to 13, characterized in that: The third network device includes a switch.

15. The second network device according to any one of claims 11 to 14, characterized in that: The first message is a Border Gateway Protocol update BGP Update message.

16. The second network device according to any one of claims 10 to 15, characterized in that: The indication information includes that the next hop of the route of the MAC address is NULL0.

17. The second network device according to any one of claims 10 to 16, characterized in that: The first network device and the second network device are Ethernet Private Virtual Network (EVPN) neighbors.

18. The second network device according to any one of claims 10 to 17, characterized in that: The first network device and the second network device are provider edge (PE) devices.

19. A fault handling device, characterized in that: include: A memory and a processor, the memory being used to store a computer program, and the processor being used to call the computer program to execute the method according to any one of claims 1 to 9.

20. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is run on a computer, the computer is enabled to execute the method according to any one of claims 1 to 9.

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