WO2022222884A1

WO2022222884A1 - Failure sensing method, apparatus and system for forwarding path

Info

Publication number: WO2022222884A1
Application number: PCT/CN2022/087422
Authority: WO
Inventors: 姚俊达; 胡志波
Original assignee: 华为技术有限公司
Priority date: 2021-04-19
Filing date: 2022-04-18
Publication date: 2022-10-27
Also published as: CN115225452A

Abstract

The present application relates to the technical field of communications, and provides a failure sensing method, apparatus and system for a forwarding path. In the solution provided by the present application, a first network device can carry, in a sent service message, a first identifier used for determining a first forwarding path; and after detecting a failure of the first forwarding path, a second network device can feed back a failure notification message carrying the first identifier to the first network device. Therefore, even if an end-to-end detection algorithm is not deployed in the first network device, the failure of the first forwarding path can also be determined on the basis of the first identifier in the failure notification message. By means of the solution provided by the present application, a network device can sense a failure of a forwarding path without deploying the end-to-end detection algorithm in the network device, so that the problems of high deployment complexity and low efficiency caused by the deployment of the end-to-end detection algorithm are effectively avoided.

Description

Fault sensing method, device and system for forwarding path

This application claims the priority of the Chinese patent application with the application number 202110418201.3 filed on April 19, 2021 and the title of the invention is "Fault Awareness Method, Device and System for Forwarding Path", the entire contents of which are incorporated into this application by reference .

technical field

The present application relates to the field of communication technologies, and in particular, to a method, device and system for fault sensing of a forwarding path.

Background technique

SRv6 is a segment routing (SR) forwarding technology based on Internet protocol version 6 (IPv6). A network device that supports the SRv6 technology can encapsulate a segment routing header (SRH) in the message, where the SRH includes a segment list (segment list) used to indicate the forwarding path of the message. The network device that receives the packet can forward the packet based on the segment list.

To implement fault detection on the forwarding path, an end-to-end detection algorithm, such as a bidirectional forwarding detection (BFD) algorithm, or a seamless BFD (SBFD) algorithm, needs to be deployed in the head-end network device of the forwarding path. . After detecting a packet forwarding path failure based on the end-to-end detection algorithm, the head-end network device can switch the packet forwarding path in time.

However, deploying end-to-end detection algorithms in network devices has high complexity and low efficiency.

SUMMARY OF THE INVENTION

The present application provides a fault sensing method, device and system for a forwarding path, which can solve the technical problems of high complexity and low efficiency of deploying an end-to-end detection algorithm in network equipment.

A first aspect provides a forwarding path fault sensing method, applied to a first network device; the method includes: sending a first service packet through the first forwarding path, and receiving a second network in the first forwarding path A failure notification message sent by the device; wherein the first service message includes a first identifier, and the first identifier is used to determine the first forwarding path, and the failure notification message also includes the first identifier, and the failure notification message The text is used to indicate that the first forwarding path is faulty.

Since the first network device can perceive the failure of the first forwarding path based on the failure notification message fed back by the second network device, there is no need to deploy an end-to-end detection algorithm in the first network device, thus effectively avoiding deployment of an end-to-end detection algorithm This leads to problems of high deployment complexity and low efficiency.

Optionally, the method may further include: sending a second service packet through a backup path of the first forwarding path, where the second service packet and the first service packet belong to the same service flow.

After determining that the first forwarding path is faulty, the first network device may also switch the path for forwarding packets to the backup path, thereby ensuring normal forwarding of the service flow and avoiding interruption of the service flow.

Optionally, the SR policy to which the first forwarding path belongs includes multiple candidate paths, and the first forwarding path belongs to the multiple candidate paths; the process of sending the second service packet through the backup path of the first forwarding path may include: : Based on the fault notification message, determine a second forwarding path from the multiple candidate paths as a backup path, and send a second service message encapsulated with a second identifier through the second forwarding path, and the second identifier is used for Determine the second forwarding path.

The first network device determines the second forwarding path from the SR policy to which the first forwarding path belongs, so as to ensure that the switched second forwarding path can still meet the performance requirements of the service flow and ensure the service experience of the service flow.

Optionally, the process of sending the second service message through the backup path of the first forwarding path may include: based on the fault notification message, adopting a virtual private network (virtual private network, VPN) fast reroute (fast reroute, FRR) ) technology determines the second forwarding path as a backup path, and sends a second service packet encapsulated with a second identifier through the second forwarding path, where the second identifier is used to determine the second forwarding path.

After determining that the SR policy to which the first forwarding path belongs does not include other candidate paths, the first network device may use the VPN FRR technology to determine the second forwarding path, thereby ensuring that the backup path can be reliably determined, thereby ensuring the reliability of the forwarding path. switch.

Optionally, the process of sending the second service packet through the backup path of the first forwarding path may include: sending fault information to the controller based on the fault notification packet, where the fault information is used to indicate that the first forwarding path is faulty; and use the second forwarding path delivered by the controller as a backup path, and send a second service message encapsulated with a second identifier through the second forwarding path, where the second identifier is used to determine the second forwarding path.

After determining that the SR policy to which the first forwarding path belongs does not include other candidate paths, the first network device may send fault information to the controller to request the controller to recalculate and deliver the second forwarding path. Alternatively, the first network device may send fault information to the controller after the VPN FRR technology is used and the switchable forwarding path has not been determined, so as to request the controller to recalculate and deliver the second forwarding path. By calculating and delivering the second forwarding path by the controller, reliable switching of the forwarding path can be ensured.

Optionally, the first identifier may be a binding segment identification (binding segment identification, BSID) of an SR policy to which the first forwarding path belongs; or, the first identifier may be a path identifier of a candidate path under the SR policy, That is, the path identifier of the first forwarding path. The path identifier may be the BSID of the forwarding path.

Optionally, the first service packet may include an SRH, and the SRH may carry the first identifier.

Optionally, the SRH also includes a segment list and a marker field, the segment list includes multiple segment identifiers; a segment identifier in the segment list carries the first identifier, and the marker field can be used to indicate that the segment list is in the segment list. Include the first logo. Therefore, it is convenient for the second network device to determine whether the segment list carries the first identifier based on the indication of the flag field.

Optionally, the last segment identifier in the segment list may carry the first identifier. Since the last segment identifier in the segment list is usually the segment identifier of the head-end network device (ie, the first network device) of the forwarding path, carrying the first identifier through the last segment identifier can not only ensure the normal operation of service packets forwarding without changing the structure of service packets.

Optionally, the fault notification packet includes an SRH, and the SRH carries the first identifier; or, the data field of the fault notification packet carries the first identifier, and the fault notification packet does not include the SRH.

Wherein, if the second network device directly encapsulates the SRH in the fault notification message and carries the first identifier through the SRH, the second network device does not need to parse the SRH in the service message to obtain the first identifier, so that it can The packet processing operation of the second network device is simplified. If the second network device does not encapsulate the SRH in the fault notification packet, and carries the first identifier through the data field in the fault notification packet, the structure of the fault notification packet can be effectively simplified.

Optionally, the fault notification message may be an Internet control message protocol (Internet control message protocol, ICMP) message. For example, ICMPv6 packets.

Since the ICMP message itself has the function of failure indication, the first identifier may be directly encapsulated in the ICMP message to indicate the failure of the first forwarding path. By multiplexing traditional ICMP packets, it is possible to avoid changing the network device's identification and processing behavior of packets on the premise of ensuring that network devices can accurately perceive forwarding path failures.

In another aspect, a method for sensing failure of a forwarding path is provided, which is applied to a second network device; the method includes: receiving a first service packet sent by the first network device through the first forwarding path, if it is determined that the first forwarding If the path fails, send a failure notification message to the first network device; wherein, the first service message includes a first identifier, and the first identifier is used to determine the first forwarding path, and the failure notification message also includes the The first identifier, the failure notification message is used to indicate the failure of the first forwarding path.

Optionally, the fault notification message includes an SRH, and the SRH carries the first identifier; or, a data field of the fault notification message carries the first identifier.

Optionally, the fault notification message is an ICMP message.

Optionally, the first identifier is the BSID of the SR policy to which the first forwarding path belongs; or, the first identifier is a path identifier of the first forwarding path.

Optionally, the first service message includes an SRH, and the SRH carries the first identifier.

Optionally, the SRH further includes a segment list and a marker field, the segment list includes multiple segment identifiers; a segment identifier in the segment list carries the first identifier, and the marker field is used to indicate that the segment list includes the first identification.

In yet another aspect, a first network device is provided, and the first network device includes at least one module, and the at least one module can be used to implement the fault sensing method applied to the forwarding path of the first network device provided by the above aspect.

In yet another aspect, a second network device is provided, and the second network device includes at least one module, and the at least one module can be used to implement the fault sensing method applied to the forwarding path of the second network device provided by the above aspects.

In yet another aspect, a network device is provided, and the network device may include: a memory, a processor, and a computer program stored on the memory and executable on the processor, and the processor implements the above-mentioned aspects when executing the computer program The provided fault sensing method applied to the forwarding path of the first network device, or implements the fault sensing method provided by the above aspect and applied to the forwarding path of the second network device.

In yet another aspect, a network device is provided, and the network device may include: a main control board and an interface board, and the interface board may be used to implement the fault sensing method provided in the above aspect and applied to the forwarding path of the first network device, Alternatively, the method may be used to implement the method for sensing faults provided in the above aspects and applied to the forwarding path of the second network device.

In another aspect, a network device is provided. The network device may be a first network device in a message forwarding system, and the network device includes: a main control board and an interface board. The main control board includes: a first processor and a first memory. The interface board includes: a second processor, a second memory and an interface card. The main control board and the interface board are coupled.

The second memory can be used to store program codes, and the second processor is used to call the program codes in the second memory, triggering the interface card to perform the following operations: sending the first service packet through the first forwarding path, and receiving the first forwarding path The failure notification message sent by the second network device in the device; wherein, the first service message includes a first identifier, the first identifier is used to determine the first forwarding path, and the failure notification message also includes the first identifier, The failure notification message is used to indicate a failure of the first forwarding path.

In another aspect, a network device is provided, and the network device may be a second network device in a message forwarding system, and the network device includes: a main control board and an interface board. The main control board includes: a first processor and a first memory. The interface board includes: a second processor, a second memory and an interface card. The main control board and the interface board are coupled.

The second memory can be used to store program codes, and the second processor is used to call the program codes in the second memory, and trigger the interface card to perform the following operations: receive the first service packet sent by the first network device through the first forwarding path, if If it is determined that the first forwarding path is faulty, a failure notification message is sent to the first network device; wherein the first service message includes a first identifier, and the first identifier is used to determine the first forwarding path, and the failure notification message The first identifier is also included, and the failure notification message is used to indicate a failure of the first forwarding path.

In yet another aspect, a computer-readable storage medium is provided, where instructions are stored in the computer-readable storage medium, and the instructions are executed by a processor to implement the fault sensing provided in the above aspect and applied to the forwarding path of the first network device The method, or, implement the fault sensing method provided in the above aspect and applied to the forwarding path of the second network device.

In yet another aspect, a computer program product containing instructions is provided, when the computer program product is run on a computer, the computer program product causes the computer to execute the fault sensing method applied to the forwarding path of the first network device provided in the above aspect, or, The fault sensing method provided in the above aspect and applied to the forwarding path of the second network device is performed.

In another aspect, a message forwarding system is provided, and the message forwarding system may include: the first network device provided in the above aspect, and the second network device provided in the above aspect.

In another aspect, a chip is provided, and the chip can be used to implement the fault sensing method provided in the above aspect and applied to the forwarding path of the first network device, or can be used to implement the method provided in the above aspect and applied to the second network The fault detection method of the forwarding path of the device.

To sum up, the present application provides a method, device and system for fault sensing of a forwarding path. The first network device can carry the first identifier used to determine the first forwarding path in the sent service packet, and the second network After detecting the failure of the first forwarding path, the device may feed back a failure notification message carrying the first identifier to the first network device. Therefore, even if the end-to-end detection algorithm is not deployed in the first network device, the first forwarding path failure can be determined based on the first identifier in the failure notification packet. Because the solution provided by the embodiments of the present application does not need to deploy an end-to-end detection algorithm in the network device, the network device can quickly and accurately perceive the failure of the forwarding path, thus effectively avoiding the complicated deployment caused by the deployment of the end-to-end detection algorithm. higher and lower efficiency issues.

Description of drawings

1 is a schematic structural diagram of a message forwarding system provided by an embodiment of the present application;

FIG. 2 is a flowchart of a method for sensing faults in a forwarding path provided by an embodiment of the present application;

3 is a flowchart of another method for sensing faults of forwarding paths provided by an embodiment of the present application;

FIG. 4 is a schematic structural diagram of an SRv6 message provided by an embodiment of the present application;

5 is a schematic structural diagram of another message forwarding system provided by an embodiment of the present application;

6 is a schematic structural diagram of an ICMPv6 message provided by an embodiment of the present application;

7 is a schematic structural diagram of another message forwarding system provided by an embodiment of the present application;

8 is a schematic structural diagram of still another message forwarding system provided by an embodiment of the present application;

FIG. 9 is a schematic structural diagram of a first network device provided by an embodiment of the present application;

FIG. 10 is a schematic structural diagram of a second network device provided by an embodiment of the present application;

FIG. 11 is a schematic structural diagram of a network device provided by an embodiment of the present application;

FIG. 12 is a schematic structural diagram of another network device provided by an embodiment of the present application.

Detailed ways

The method, device, and system for fault sensing of a forwarding path provided by the embodiments of the present application are described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic structural diagram of a message forwarding system provided by an embodiment of the present application. As shown in FIG. 1 , the message forwarding system may include multiple network devices 01, and communication connections are established between the multiple network devices 01 . Wherein, each network device 01 may be a device with a packet forwarding function, such as a router or a switch, and each network device 01 may also be referred to as a node.

Optionally, the network device 01 in the system may be a provider (provider, P) device or a provider edge (provider edge, PE) device. Wherein, if the network device 01 is a PE device, as shown in FIG. 1 , the system may further include one or more user edge (custom edge, CE) devices 02 connected to the PE device. The CE device 02 may be a router or a switch, and may be connected to a user terminal for providing access services for the user terminal. Alternatively, the CE device 02 may also be a user terminal. The user terminal may also be referred to as a host or user equipment.

Optionally, referring to FIG. 1 , the message forwarding system may further include a controller 03 , and the controller 03 is connected to at least one network device 01 for managing and controlling the network device 01 to which it is connected. The controller 03 can also be used to calculate the end-to-end forwarding path, and deliver the forwarding path to the head-end network device of the forwarding path, that is, the head node.

Wherein, the controller 03 can be a network controller, for example, can be a software defined network (software defined network, SDN) controller, a network control engine (network control engine, NCE) or a path computation element server (path computation element server, PCE) server), etc. Moreover, the controller 03 may be a server, or a server cluster composed of several servers, or a cloud computing service center.

In this embodiment of the present application, the packet forwarding system may be an SRv6 system, each network device 01 in the system supports the SRv6 technology, and an SRv6-based VPN connection can be established between the network devices 01 . In addition, the network device 01 may receive the SR policy sent by the controller 03, and forward the service packet based on the candidate paths in the SR policy.

Optionally, the controller 03 can collect the link state reported by each network device 01 in the system based on the BGP link-state (BGP link-state, BGP-LS) protocol, and can pass the path computation element communication protocol (path computation element communication). protocol, PCEP) to deliver the SR policy. Among them, BGP refers to the border gateway protocol (border gateway protocol). In an SRv6 system, the SR policy may also be referred to as an SRv6 traffic engineering (traffic engineering, TE) policy, that is, an SRv6-TE policy.

The embodiment of the present application provides a fault sensing method for a forwarding path, and the method can be applied to a packet forwarding system such as that shown in FIG. 1 . Referring to Figure 2, the method includes:

Step 101: The first network device sends a first service packet through a first forwarding path, where the first service packet includes a first identifier.

The first network device may be any network device in the message forwarding system, and the first network device is the head-end network device of the first forwarding path. The first service packet sent by the first network device through the first forwarding path may include a first identifier, where the first identifier is used to determine the first forwarding path.

Optionally, the first identifier may be the BSID of the SR policy to which the first forwarding path belongs. Alternatively, the first identifier may be the path identifier of the first forwarding path, for example, the path identifier may be the path identifier of the candidate path under the SR policy, and the path identifier may be the BSID of the candidate path.

Step 102: If the second network device determines that the first forwarding path is faulty, it sends a fault notification packet to the first network device, where the fault notification packet includes the first identifier.

The second network device is a network device in the first forwarding path. After receiving the first service message sent by the first network device through the first forwarding path, the second network device may send a failure notification message to the first network device if it detects that the first forwarding path is faulty. The failure notification message includes the first identifier, and the failure notification message is used to indicate a failure of the first forwarding path. Correspondingly, after receiving the failure notification message, the first network device may determine the failure of the first forwarding path based on the first identifier in the failure notification message.

It can be understood that the fault notification packet may further include a fault identifier, and the first network device may determine, based on the fault identifier, that the received packet is a fault notification packet for indicating a forwarding path fault.

To sum up, the embodiments of the present application provide a method for detecting faults in forwarding paths. The first network device can carry a first identifier used to determine the first forwarding path in the sent service After detecting the failure of the first forwarding path, a failure notification message carrying the first identifier may be fed back to the first network device. Therefore, even if the end-to-end detection algorithm is not deployed in the first network device, the first forwarding path failure can be determined based on the first identifier in the failure notification packet. Because the solution provided by the embodiments of the present application does not need to deploy an end-to-end detection algorithm in the network device, the network device can quickly and accurately perceive the failure of the forwarding path, thus effectively avoiding the complicated deployment caused by the deployment of the end-to-end detection algorithm. higher and lower efficiency issues.

In addition, when a network device detects whether a forwarding path is faulty based on an end-to-end detection algorithm, it needs to periodically send detection packets. The detection packets will occupy the bandwidth of service packets, resulting in low network bandwidth utilization. Since the solution provided by the embodiment of the present application does not need to send detection packets periodically, the utilization rate of network bandwidth can be effectively improved, and reliable sending of service packets can be ensured.

This embodiment of the present application provides another method for sensing failure of a forwarding path, and the method can be applied to a packet forwarding system such as that shown in FIG. 1 . Referring to Figure 3, the method includes:

Step 201: The first network device sends a first service packet through a first forwarding path, where the first service packet includes a first identifier.

The first network device may be any network device in the message forwarding system, and the first network device is the head-end network device of the first forwarding path. The first service packet sent by the first network device through the first forwarding path may include a first identifier, where the first identifier can be used to determine the first forwarding path.

As a possible example, the first identifier may be the BSID of the SR policy to which the first forwarding path belongs. As another possible example, the first identifier may be a path identifier of the first forwarding path, for example, the path identifier may be a BSID of the forwarding path.

Optionally, the first service packet may be an SRv6 packet, the SRv6 packet includes an SRH, and the SRH may carry the first identifier. FIG. 4 is a schematic structural diagram of an SRv6 packet provided by an embodiment of the present application. As shown in FIG. 4 , the SRv6 packet includes an IPv6 header, an SRH, and a payload. The IPv6 header at least includes a source address (source address, SA) and a destination address (destination address, DA) of the service packet.

SRH includes the following fields: next header (next header, NH), extension header length (header extension length, Hdr Ext Len), routing header type (routing type), number of remaining segments (segment left, SL), last The last entry, flags, tags, and segment list. The segment list includes multiple segment identifications (segment identifications, SIDs). For example, FIG. 4 shows a total of n+1 segment identifications from segment list [0] to segment list [n] (n may be an integer greater than or equal to 1). ). Wherein, each segment identifier is used to indicate a network device in the forwarding path of the service packet, for example, the segment identifier may be an IPv6 address of the network device. It can be seen from this that the forwarding path of the service packet can be determined based on the segment list. The SL field is used to indicate the number of intermediate network devices that still need to be accessed before reaching the destination network device (also referred to as the destination node).

Wherein, one of the segment identifiers included in the segment list may carry the first identifier, and the flag field is used to indicate that the segment list includes the first identifier. Therefore, it is convenient for the network device receiving the first service packet to determine whether the segment list carries the first identifier based on the indication of the flag field. For example, referring to FIG. 4 , 1 bit in the flag field can be used as flag bit B. When the value of flag bit B is 1, it can indicate that the first flag is included in the segment list, and the value of flag bit B can be used as flag bit B. When it is 0, it can indicate that the first identifier is not included in the segment list.

In this embodiment of the present application, the first identifier may be carried by the last segment identifier in the segment list (ie, the segment list [n]). Since the last segment identifier in the segment list is usually the segment identifier of the head-end network device (ie, the first network device) of the forwarding path, carrying the first identifier through the last segment identifier can not only ensure the normal operation of service packets forwarding without changing the structure of service packets.

Alternatively, a segment identifier (eg, segment list [-1] or segment list [n+1]) may also be added to the segment list to carry the first identifier.

It can be understood that the length of the first identifier may be equal to the length of a segment identifier. Alternatively, the length of the first identifier may be less than the length of a segment identifier, that is, a segment identifier in the segment list may carry other information than the first identifier in addition to the first identifier.

By way of example, referring to FIG. 5 , it is assumed that the first network device is PE1, which has received the SRv6 TE Policy issued by the controller 03:

Policy 1: Endpoint PE3, color red

Binding Sid: BSID1

Candidate path 1:

Preference 200

SID List:<PE1,P1,P3,PE3>

Candidate path 2:

Preference 100

SID List:<PE1,P2,P4,PE3>

Based on the above content, the endpoint of the SRv6 TE Policy is PE3, the color is red (red), and the BSID is BSID1. The endpoint can be used to indicate the end-end network device of the public network tunnel in the end-to-end forwarding path; the color is used to indicate the performance of the SRv6 TE Policy, that is, the performance of the tunnel indicated by the SRv6 TE Policy, such as a low-latency tunnel or a low-cost tunnel tunnel etc. Referring to the above content, it can also be seen that the SRv6 TE Policy includes two candidate paths. Among them, the first candidate path is: PE1→P1→P3→PE3, and its priority is 200; the second candidate path is: PE1→P2→P4→PE3, and its priority is 100.

Because the priority of the first candidate path is higher, PE1 may use the first candidate path as the first forwarding path (ie, the main path) to forward the first service packet. Referring to FIG. 5 , the first service message sent by PE1 is encapsulated with an SRH, and the segment list in the SRH includes 5 segment identifiers (ie, n=5). Among them, the first segment is identified as the SID used to identify the VPN information between the endpoint PE3 and the destination node CE2. According to the different VPN policies of PE3, the SID can be End.DT4, End.DT6, End.DX4 or End. .DX6, etc., are uniformly expressed as PE3-VPNSID here. The second to fourth segment identifiers are the segment identifiers of PE3, P3, and P1 in the first forwarding path, and the last segment identifier can carry the BSID of the SRv6 TE Policy: BSID1. In addition, the value of the flag bit B of the flag field in the SRH can be set to 1, and the value of SL can be set to n-1, that is, SL=3. The method of encapsulating the BSID by the last segment identifier in the segment list may also be called a reduced SRH (reduce SRH) encapsulation method.

Based on the above introduction about the SR policy and the segment list, the candidate paths in the SR policy can indicate the public network tunnel, and the segment list in the SRH not only includes the SID of each node in the public network tunnel, but also can be used to identify the public network tunnel. The SID of the VPN information between the endpoint and the destination node.

Step 202: If the second network device determines that the first forwarding path is faulty, it sends a fault notification packet to the first network device, where the fault notification packet includes the first identifier.

The second network device is a network device in the first forwarding path. After receiving the first service message sent by the first network device through the first forwarding path, the second network device may send a failure notification message to the first network device if it detects that the first forwarding path is faulty. The failure notification message includes the first identifier, and the failure notification message is used to indicate a failure of the first forwarding path. The second network device may determine that the first forwarding path is faulty when detecting that the outgoing interface used for forwarding the first service packet is faulty, or when the link corresponding to the outgoing interface is faulty. It can be understood that the failure notification message can be sent to the first network device based on a protocol such as IPv6.

As a possible example, the fault notification message may include an SRH, and the SRH carries the first identifier. That is, the second network device can directly encapsulate the SRH in the first service message into the fault notification message without parsing and acquiring the first identifier in the SRH, thereby effectively simplifying the second network device. message processing operations.

As another possible example, the data field of the fault notification packet carries the first identifier, that is, the fault notification packet does not include SRH. Therefore, the structure of the fault notification message is relatively simple. After receiving the failure notification message, the first network device can directly obtain the first identifier from the data field of the failure notification message without parsing the SRH, thereby effectively simplifying the message processing operation of the first network device.

It can be understood that, the fault notification message may also include a fault identifier. The network device (eg, the first network device) that receives the failure notification message may determine, based on the failure identifier, that the received message is a failure notification message for indicating a forwarding path failure.

Optionally, the fault notification message may be an ICMP message, for example, may be an IPv6-based ICMPv6 message. FIG. 6 is a schematic structural diagram of an ICMPv6 packet provided by an embodiment of the present application. FIG. 6 is described by taking the ICMPv6 packet including an SRH as an example. Referring to FIG. 6, the ICMPv6 message includes an IPv6 header, an SRH, an ICMP message and a payload. The NH field of the SRH may be used to indicate that the packet further includes an ICMP message, for example, the value of the NH field may be 58. The ICMP message may include the following fields: type (type), code (code), checksum (checksum) and message body (message body).

The message body field is the data field of the fault notification message. The type field is used to indicate the type of the ICMP message, and the value of the type field is 0 to 127 for an error message, and the value of the type field is 128 to 255 for an information message. The value of the code field is used to further subdivide the type of message. For example, a value of 1 in the type field may indicate that the destination is unreachable. When the value of the type field is 1, if the value of the code field is 0, it may indicate that the route does not reach the destination; if the value of the code field is 3, it may indicate that the address is unreachable. Based on the above definition, it can be known that the value of the type field (or the values of the type field and the code field) in the ICMP message can be used as a fault identifier. It can be understood that, the failure notification message may also not include the payload. For the relevant definitions of the fields in the ICMP message, reference may be made to the relevant descriptions in the request for comments (request for comments, RFC) document numbered 2463, and the relevant content in the document may be incorporated into the embodiments of the present application by reference.

For example, referring to FIG. 5 , it is assumed that P3 in the first forwarding path detects that its outgoing interface is faulty, then P3, as the second network device, can send a fault notification message encapsulated with BSID1 to PE1. The fault notification message is encapsulated with an SRH, and the SRH carries BSID1. As shown in Figure 5, the SA in the IPv6 header of the fault notification packet is P3, and the DA is PE1. The fault notification packet can be forwarded to PE1 based on IPv6.

It can be understood that, if the network device in the first forwarding path does not detect a path failure, the first service packet can be normally forwarded to the end-end network device through the first forwarding path. If the first identifier is encapsulated in the SRH of the first service packet, the first identifier may be ejected along with the SRH at the end network device or the penultimate hop network device of the first forwarding path.

Step 203: The first network device determines that the first forwarding path is faulty based on the first identifier in the fault notification packet.

In this embodiment of the present application, after receiving the failure notification message sent by the second network device, the first network device may determine the failure of the first forwarding path based on the first identifier in the failure notification message.

On the one hand, for the scenario where the first identifier is the BSID of the SR policy to which the first forwarding path belongs. If the SR policy includes only one candidate path (ie, the first forwarding path), after determining the SR policy based on the BSID, the first network device may determine that the first forwarding path in the SR policy is faulty. If the SR policy includes multiple candidate paths, since the path currently used for forwarding the first service packet (ie, the first forwarding path) among the multiple candidate paths is in an active state, the first network device based on the After the BSID determines the SR policy, it can be determined that the first forwarding path in the active state in the SR policy is faulty.

On the other hand, for a scenario where the first identifier is the path identifier of the first forwarding path (eg, the BSID of the forwarding path), the first network device may directly determine that the first forwarding path is faulty based on the first identifier.

It can be understood that, if the fault notification message includes the SRH and the SRH carries the first identifier, the first network device can parse the SRH to obtain the first identifier. If the fault notification packet does not include the SRH, and the data field in the fault notification packet carries the first identifier, the first network device may directly obtain the first identifier from the data field.

It can also be understood that the fault notification packet may further include a fault identifier, and the first network device may determine, based on the fault identifier, that the received packet is a fault notification packet for indicating a forwarding path fault. If the fault notification packet is an ICMP packet, the first network device may determine that the received packet is a fault notification packet based on the type field in the ICMP packet, and may determine based on the code field of the ICMP packet A failure type of the first forwarding path is determined.

Step 204: The first network device determines that the second forwarding path is a backup path.

After sensing the failure of the first forwarding path based on the failure notification message, the first network device may also determine a backup path of the first forwarding path, so as to switch the service flow to which the first service message belongs to the backup path to ensure that Normal forwarding of the service flow. The following description will be given by taking the first network device determining that the second forwarding path is a backup path of the first forwarding path as an example.

As a possible example, if the SR policy to which the first forwarding path belongs includes multiple candidate paths, the first network device may determine the second forwarding path as a backup path from the multiple candidate paths, so that forwarding can be implemented Hot-standby protection of paths. For example, the first network device may determine the candidate path with the highest priority among the multiple candidate paths except the first forwarding path as the second forwarding path.

By way of example, referring to the above step 201, assuming that the SRv6 TE Policy to which the first forwarding path belongs includes two candidate paths, after PE1 determines that the first candidate path is faulty, the second candidate path can be set as: PE1→P2→P4 →PE3 is determined as the second forwarding path.

In this example, since the switched second forwarding path and the first forwarding path belong to the same SR policy, it can be ensured that after the service packet is forwarded based on the second forwarding path, the service flow to which the service packet belongs can still be satisfied. Performance requirements to ensure the business experience of the business flow.

It can be understood that, if a hot backup protection mechanism is configured in the first network device, the first network device may determine the second forwarding path in the manner shown in this example.

As another possible example, the first network device may use the VPN FRR technology to determine the second forwarding path as a backup path. The VPN FRR technology is a fault protection mechanism applied to the CE dual-homing network model, which can solve the problem of fast end-to-end service convergence when the primary PE device fails. Wherein, CE dual-homing means that one CE device simultaneously accesses two PE devices, one of which is the active PE device and the other PE device is the backup PE device. For example, referring to FIG. 7 , the connection mode between CE1 and PE1 and PE2, and the connection mode between CE2 and PE3 and PE4 are both CE dual-homed network models.

It can be understood that, in this example, the controller may deliver two SR policies to the first network device, one of which includes the first forwarding path, and the endpoint of the SR policy is the primary user of CE dual-homing access. PE device; another SR policy includes the second forwarding path, and the endpoint of the SR policy is the standby PE device dual-homed by the CE. After determining that the first forwarding path is faulty and triggering the VPN FRR, the first network device may determine the second forwarding path from the other SR policy.

Taking the scenario shown in Figure 7 as an example, the SRv6 TE Policy delivered by the controller to PE1 may include:

Policy 1: Endpoint PE3, color red

Binding Sid: BSID1

Candidate path 1:

SID List:<PE1,P1,P3,PE3>

Policy 2: Endpoint PE4, color yellow

Binding Sid: BSID2

Candidate path 2:

SID List:<PE1,P2,P4,PE4>

Referring to the content of the above SRv6 TE Policy, it can be seen that the endpoint of an SR policy (that is, Policy 1) issued by the controller is the primary PE device dual-homed by CE2: PE3, the color is red, the BSID is BSID1, and the candidate path is It is: PE1→P1→P3→PE3. The endpoint of another SR policy (Policy 2) issued by the controller is the standby PE device dual-homed by CE2: PE4, the color is yellow (yellow), the BSID is BSID2, and the candidate path is: PE1→P2→P4→ PE4.

After receiving the failure notification message carrying the first identifier: BSID1, PE1 can determine that the candidate path in Policy 1 is faulty. Since there are no other candidate paths in Policy 1, PE1 can set the tunnel state of the tunnel indicated by Policy 1 to the down state, and trigger VPN FRR protection. Based on the VPN FRR protection technology, PE1 can switch the forwarding path of service packets to the candidate path in Policy 2, so as to access CE2 through PE4, that is, PE1 can determine the candidate path in Policy 2 as the second forwarding path path.

It can also be understood that, when the first network device determines the second forwarding path based on the VPN FRR technology, if it does not obtain a candidate path in another SR policy, it can also calculate a best effort forwarding (best effort, BE) path. as the second forwarding path.

It can also be understood that, if the VPN FRR mechanism is configured in the first network device, the first network device can use the VPN FRR technology to determine the second forwarding path.

As another possible example, the first network device may send fault information to the controller, where the fault information is used to indicate that the first forwarding path is faulty. After receiving the fault information, the controller can recalculate a new forwarding path (ie, the second forwarding path), and deliver the second forwarding path to the first network device. That is, the first network device may use the second forwarding path recalculated and delivered by the controller as a backup path.

For example, it is assumed that the SR policy delivered by the controller to PE1 is Policy 1, and the Policy 1 only includes the first forwarding path. Then, after receiving the failure notification message carrying the first identifier: BSID1, PE1 can determine that the first forwarding path in the Policy 1 is faulty. Since there are no other candidate paths in Policy 1, PE1 can set the tunnel status of the tunnel indicated by Policy 1 to Down, and report fault information to the controller, where the fault information includes the tunnel status of the tunnel indicated by Policy 1 . After the controller determines that the tunnel status of Policy 1 is down based on the fault information, it can recalculate a second forwarding path and deliver it to PE1.

It can be understood that, in this embodiment of the present application, if the first network device is configured with a hot backup protection mechanism and a VPN FRR mechanism, after sensing the failure of the first forwarding path based on the failure notification message, the first network device may First, check whether the SR policy to which the first forwarding path belongs includes other candidate paths. If the SR policy includes other candidate paths, the first network device may determine the second forwarding path from the other candidate paths as a backup path, that is, the first network device may switch forwarding paths in a hot backup protection manner. If the SR policy does not include other candidate paths, the first network device may use the VPN FRR technology to determine the second forwarding path as a backup path. If the first network device does not determine the second forwarding path by using the VPN FRR technology, it can report fault information to the controller to request the controller to recalculate and deliver the second forwarding path as a backup path. Based on the above manner, reliable switching of forwarding paths can be ensured, and normal forwarding of service flows can be avoided.

Step 205: The first network device sends the second service packet through the second forwarding path.

After the first network device determines the second forwarding path, the second service packet can be sent through the second forwarding path. The second service message and the first service message belong to the same service flow. That is, the first network device can switch the service flow to which the first service packet belongs to the second forwarding path, so as to ensure normal forwarding of the service flow and avoid interruption of the service flow. The second service packet may also be an SRv6 packet, and the SRH of the second service packet may also include a segment list, where the segment list is used to indicate the second forwarding path. For the structure of the second service message, reference may be made to the structure of the first service message, which will not be repeated here.

In this embodiment of the present application, the second service packet may be encapsulated with a second identifier, where the second identifier is used to determine the second forwarding path. It can be understood that the second identifier may be the BSID of the SR policy to which the second forwarding path belongs, or the second identifier may be the path identifier of the second forwarding path, for example, the BSID of the second forwarding path.

It can also be understood that if both the first identifier and the second identifier are the BSIDs of the SR policy, and the second forwarding path is a candidate path in the SR policy to which the first forwarding path belongs (that is, the second forwarding path and the first forwarding path) paths belong to the same SR policy), the second identifier and the first identifier may be the same. If the first identifier and the second identifier are both path identifiers, or if the second forwarding path and the first forwarding path belong to different SR policies, the second identifier and the first identifier are different.

For example, it is assumed that the second forwarding path is the second candidate path in the SR policy to which the first forwarding path belongs. 5, PE1 can encapsulate SRH in the second service message, and the first segment in the SRH segment list is identified as PE3-VPNSID, and the second to fourth segment identifiers are the second forwarding path in turn. The segment identifiers of PE3, P4 and P2 in the middle, and the last segment identifier can carry the BSID of the SR policy: BSID1.

Alternatively, it is assumed that the second forwarding path is a candidate path in another SR policy determined by PE1 based on VPN FRR, and the BSID of the SR policy to which the second forwarding path belongs is BSID2. 7, PE1 can encapsulate SRH in the second service message, and the first segment in the segment list of the SRH is identified as PE4-VPNSID, and the second to fourth segment identifiers are the second forwarding path. The segment identifiers of PE4, P4 and P2 in the middle, and the last segment identifier can carry the BSID of the other SR policy: BSID2.

Alternatively, it is assumed that the second forwarding path is a forwarding path recalculated and delivered by the controller 03, and the BSID of the SR policy to which the second forwarding path belongs is BSID2. 8, PE1 can encapsulate SRH in the second service message, and the first segment in the segment list of the SRH is identified as PE3-VPNSID, and the second to fourth segment identifiers are the second forwarding path. The segment identifiers of PE4, P4 and P2 in the middle, and the last segment identifier can carry BSID2.

It can be understood that the above embodiments are described by taking the first identifier carried in the SRH as an example. Of course, the first identifier can also be encapsulated in other locations in the message, for example, it can also be encapsulated in the IPv6 of the message. in the head. In addition, the above-mentioned embodiment is described by taking the fault notification message as an ICMP message as an example. Of course, the fault notification message can also be other types of messages. For example, the fault notification message can be constructed specifically for notification forwarding. Path failure packets.

It can also be understood that, the execution order of each step in the above-mentioned method for sensing a fault of a forwarding path can be adjusted according to the situation, and the steps can also be increased or decreased according to the situation. For example, the above steps 204 and 205 may be deleted according to the situation, that is, after the first network device determines that the first forwarding path is faulty, it may not be necessary to switch the path for forwarding the service packet. For example, the first network device may only report fault information to the controller.

In addition, because the solution provided by the embodiment of the present application does not require the first network device to periodically send detection packets to determine whether the first forwarding path is faulty, the utilization rate of network bandwidth can be effectively improved, and the reliable transmission of service packets can be ensured.

FIG. 9 is a schematic structural diagram of a first network device provided by an embodiment of the present application, and the first network device may be applied to a message forwarding system such as that shown in FIG. 1 , FIG. 5 , FIG. 7 , or FIG. 8 . For example, the first network device may be any network device 01 in the system shown in FIG. 1 , or may be PE1 in the system shown in FIG. 5 , FIG. 7 or FIG. 8 . The first network device may implement the steps performed by the first network device in the above-mentioned embodiment shown in FIG. 2 or FIG. 3 . Referring to Figure 9, the first network device includes:

The sending module 301 is configured to send a first service packet through a first forwarding path, where the first service packet includes a first identifier, and the first identifier is used to determine the first forwarding path. For the function implementation of the sending module 301, reference may be made to the relevant description of step 101 or step 201 in the foregoing method embodiments.

A receiving module 302, configured to receive a failure notification message sent by a second network device in the first forwarding path, where the failure notification message includes the first identifier, and the failure notification message is used to indicate that the first forwarding path is faulty . For the function implementation of the receiving module 302, reference may be made to the relevant description of step 102 or step 202 in the foregoing method embodiments.

Optionally, the sending module 301 may be further configured to send a second service packet through the backup forwarding path of the first forwarding path, where the second service packet and the first service packet belong to the same service flow. For the functional implementation of the sending module 301, reference may also be made to the relevant description of step 205 in the foregoing method embodiments.

As shown in FIG. 9 , the first network device may further include: a determining module 303, where the determining module 303 is configured to determine the second forwarding path as a backup path. For the functional implementation of the determining module 303, reference may be made to the relevant descriptions of step 203 and step 204 in the foregoing method embodiment.

The sending module 301 may be configured to send a second service packet encapsulated with a second identifier through the second forwarding path, where the second identifier is used to determine the second forwarding path.

As a possible example, the SR policy to which the first forwarding path belongs includes multiple candidate paths, and the first forwarding path belongs to the multiple candidate paths; the determining module 303 may be configured to: based on the fault notification message, from the Among the multiple candidate paths, the second forwarding path is determined as a backup path.

As another possible example, the determining module 303 may be configured to: determine the second forwarding path as a backup path by using the VPN FRR technology based on the fault notification message.

As another possible example, the sending module 301 may also be configured to send fault information to the controller based on the fault notification message, where the fault information is used to indicate that the first forwarding path is faulty; the determining module 303 may use The second forwarding path delivered by the controller is used as a backup path.

Optionally, the first identifier may be the BSID of the SR policy to which the first forwarding path belongs; or, the first identifier may be a path identifier of the first forwarding path.

Optionally, the last segment identifier in the segment list carries the first identifier.

Optionally, the fault notification message may be an ICMP message.

To sum up, the embodiments of the present application provide a first network device, the first network device can carry a first identifier used to determine the first forwarding path in a sent service packet, and the second network device is detecting After the first forwarding path fails, a failure notification message carrying the first identifier may be fed back to the first network device. Therefore, even if the end-to-end detection algorithm is not deployed in the first network device, the first forwarding path failure can be determined based on the first identifier in the failure notification packet. Because the solution provided by the embodiments of the present application does not need to deploy an end-to-end detection algorithm in the first network device, the first network device can quickly and accurately perceive the failure of the forwarding path, thus effectively avoiding the deployment of the end-to-end detection algorithm. The resulting deployment complexity is high and the efficiency is low.

FIG. 10 is a schematic structural diagram of a second network device provided by an embodiment of the present application, where the second network device may be applied to a packet forwarding system such as that shown in FIG. 1 , FIG. 5 , FIG. 7 , or FIG. 8 . For example, the second network device may be any network device 01 in the system shown in FIG. 1 , or may be P3 in the system shown in FIG. 5 , FIG. 7 or FIG. 8 . The second network device may implement the steps performed by the second network device in the above-mentioned embodiment shown in FIG. 2 or FIG. 3 . Referring to Figure 10, the second network device includes:

The receiving module 401 is configured to receive a first service packet sent by a first network device through a first forwarding path, where the first service packet includes a first identifier, and the first identifier is used to determine the first forwarding path. For the functional realization of the receiving module 401, reference may be made to the relevant description of step 101 or step 201 in the foregoing method embodiments.

The sending module 402 is configured to send a failure notification message to the first network device if it is determined that the first forwarding path is faulty, where the failure notification message includes the first identifier, and the failure notification message is used to indicate the first forwarding Path failure. For the function implementation of the sending module 402, reference may be made to the relevant description of step 102 or step 202 in the foregoing method embodiments.

Optionally, the fault notification message is an ICMP message.

Optionally, the first identifier is the BSID of the SR policy to which the first forwarding path belongs; or, the first identifier is the path identifier of the first forwarding path.

To sum up, the embodiment of the present application provides a second network device, the second network device can receive a service packet carrying a first identifier sent by the first network device through the first forwarding path, and can detect After the first forwarding path fails, a failure notification message carrying the first identifier is fed back to the first network device. Therefore, even if the end-to-end detection algorithm is not deployed in the first network device, the first forwarding path failure can be determined based on the first identifier in the failure notification packet. Because the solution provided by the embodiments of the present application does not need to deploy an end-to-end detection algorithm in the first network device, the first network device can quickly and accurately perceive the failure of the forwarding path, thus effectively avoiding the deployment of the end-to-end detection algorithm. The resulting deployment complexity is high and the efficiency is low.

Those skilled in the art can clearly understand that, for the convenience and brevity of description, for the specific working process of the first network device, the second network device and each module described above, reference may be made to the corresponding processes in the foregoing method embodiments, It is not repeated here.

It can be understood that, both the first network device and the second network device provided by the embodiments of the present application may be implemented by an application-specific integrated circuit (ASIC), or a programmable logic device (PLD) , the above-mentioned PLD can be a complex program logic device (complex programmable logical device, CPLD), field-programmable gate array (field-programmable gate array, FPGA), general array logic (generic array logic, GAL) or any combination thereof. Alternatively, the fault sensing method of the forwarding path provided by the above method embodiments may also be implemented by software. When the fault sensing method of the forwarding path provided by the above method embodiments is implemented by software, the first network device and the second network device. The individual modules may also be software modules.

FIG. 11 is a schematic structural diagram of a network device provided by an embodiment of the present application, and the network device may be applied to a packet forwarding system such as that shown in FIG. 1 , FIG. 5 , FIG. 7 , or FIG. 8 . For example, the network device may be any network device 01 in the system shown in FIG. 1 , or may be PE1 in the system shown in FIG. 5 , FIG. 7 or FIG. 8 , or may be the system shown in FIG. 5 , FIG. 7 or FIG. 8 Display P3 in the system. As shown in FIG. 11 , the network device may include: a processor 501 , a memory 502 , a transceiver 503 and a bus 504 . The bus 504 is used to connect the processor 501 , the memory 502 and the transceiver 503 . The communication connection with other devices can be realized through the transceiver 503 (which may be wired or wireless). A computer program for realizing various application functions is stored in the memory 502 . When each module in the network device shown in FIG. 10 is implemented in the form of software modules, programs corresponding to these software modules may be stored in the memory 502 of the network device.

It can be understood that, in this embodiment of the present application, the processor 501 may be a CPU, and the processor 501 may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gates Arrays (FPGAs), GPUs or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general purpose processor may be a microprocessor or any conventional processor or the like.

Memory 502 may be volatile memory or nonvolatile memory, or may include both volatile and nonvolatile memory. The non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically programmable Erase programmable read-only memory (electrically EPROM, EEPROM) or flash memory. Volatile memory may be random access memory (RAM), which acts as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), Double data rate synchronous dynamic random access memory (double data date SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, ESDRAM), synchronous link dynamic random access memory (synchlink DRAM, SLDRAM) and direct Memory bus random access memory (direct rambus RAM, DR RAM).

In addition to the data bus, the bus 504 may also include a power bus, a control bus, a status signal bus, and the like. For clarity, however, the various buses are labeled as bus 504 in the figure.

On the one hand, the processor 501 in the network device may be configured to send a first service packet through a first forwarding path, and receive a failure notification packet sent by a second network device in the first forwarding path; wherein the first forwarding path A service packet includes a first identifier, and the first identifier is used to determine the first forwarding path, and the failure notification packet includes the first identifier, and the failure notification packet is used to indicate that the first forwarding path is faulty. For the detailed processing process of the processor 501, reference may be made to the foregoing method embodiments. For example, reference may be made to the detailed description of step 101 in the embodiment shown in FIG. 2 , or reference may be made to the detailed description of step 201 and steps 203 to 205 in the embodiment shown in FIG. 3 , which will not be repeated here.

On the other hand, the processor 501 in the network device may be configured to receive the first service packet sent by the first network device through the first forwarding path, and if it is determined that the first forwarding path is faulty, send the packet to the first network device A failure notification message; wherein, the first service message includes a first identifier, and the first identifier is used to determine the first forwarding path, the failure notification message includes the first identifier, and the failure notification message is used to indicate the The first forwarding path is faulty. For the detailed processing process of the processor 501, reference may be made to the foregoing method embodiments. For example, reference may be made to the detailed description of step 102 in the embodiment shown in FIG. 2 , or reference may be made to the detailed description of step 202 in the embodiment shown in FIG. 3 , which will not be repeated here.

FIG. 12 is a schematic structural diagram of a network device provided by an embodiment of the present application, and the network device may be applied to a packet forwarding system such as that shown in FIG. 1 , FIG. 5 , FIG. 7 , or FIG. 8 . For example, the network device may be any network device 01 in the system shown in FIG. 1 , or may be PE1 in the system shown in FIG. 5 , FIG. 7 or FIG. 8 , or may be the system shown in FIG. 5 , FIG. 7 or FIG. 8 Display P3 in the system. As shown in FIG. 12 , the network device may include: a main control board 601 and at least one interface board (an interface board is also called a line card or a service board), for example, an interface board 602 and an interface board 603 are shown in FIG. 12 . In the case of multiple interface boards, a switch fabric board 604 may be included, and the switch fabric board 604 is used to complete data exchange between the interface boards.

The main control board 601 is used to complete functions such as system management, equipment maintenance, and protocol processing. The interface boards 602 and 603 are used to provide various service interfaces (eg, POS interface, GE interface, ATM interface, etc.), and realize packet forwarding. There are mainly three types of functional units on the main control board 601: a system management control unit, a system clock unit and a system maintenance unit. The main control board 601 , the interface board 602 and the interface board 603 are connected to the system backplane through the system bus to realize intercommunication. The interface board 602 includes one or more central processing units 6021 . The central processing unit 6021 is used to control and manage the interface board 602, communicate with the central processing unit 6011 on the main control board 601, and perform packet forwarding processing. The forwarding table entry memory 6024 on the interface board 602 is used to store the forwarding table entry, and the central processing unit 6021 can forward the message by searching for the forwarding table entry stored in the forwarding table entry memory 6024 .

The interface board 602 includes one or more physical interface cards 6023 for receiving the message sent by the previous hop node, and sending the processed message to the next hop node according to the instruction of the central processing unit 6021 . The specific implementation process will not be repeated here. The specific functions of the central processing unit 6021 are also not repeated here.

It can be understood that the sending module 301 and the receiving module 302 in the first network device may be located in the interface board 602 , and the determining module 303 may be located in the main control board 601 . The receiving module 401 and the sending module 402 in the second network device may be located in the interface board 602 .

It can also be understood that, as shown in FIG. 12 , this embodiment includes multiple interface boards and adopts a distributed forwarding mechanism. Under this mechanism, the structure of the interface board 603 is basically the same as that of the interface board 602 , and the interface board 603 The operations above are basically similar to those of the interface board 602, and are not repeated for brevity. In addition, it can be understood that the central processing unit 6021 and/or the network processor 6022 in the interface board 602 in FIG. 12 may be dedicated hardware or chips. For example, an application-specific integrated circuit may be used to implement the above functions. Special hardware or chip processing is adopted for the so-called forwarding plane. In another implementation manner, the central processing unit 6021 and/or the network processor 6022 may also use a general-purpose processor, such as a general-purpose CPU, to implement the functions described above.

In addition, it can be understood that there may be one or more main control boards 601, and when there are multiple pieces, it may include an active main control board and a backup main control board. There may be one or more interface boards. The stronger the data processing capability of the device, the more interface boards are provided. In the case of multiple interface boards, the multiple interface boards can communicate with each other through one or more switching network boards. When there are multiple interface boards, they can jointly implement load sharing and redundant backup. Under the centralized forwarding architecture, the device does not need a switching network board, and the interface board is responsible for the processing function of the service data of the entire system. Under the distributed forwarding architecture, the device includes multiple interface boards, which can realize data exchange among the multiple interface boards through the switching network board, and provide large-capacity data exchange and processing capabilities. Therefore, the data access and processing capabilities of network devices in a distributed architecture are greater than those in a centralized architecture. The specific architecture used depends on the specific networking deployment scenario, and there is no restriction here.

In specific embodiments, memory 6012 and memory 6024 may be read-only memory (ROM) or other types of static storage devices that can store static information and instructions, random access memory (RAM) Or other types of dynamic storage devices that can store information and instructions, and can also be electrically erasable programmable read-only memory (EEPROM), compact disc read-only Memory (CD- ROM) or other optical disc storage, optical disc storage (including compact disc, laser disc, optical disc, digital versatile disc, blu-ray disc, etc.), magnetic disc or other magnetic storage device, or capable of carrying or storing desired in the form of instructions or data structures program code and any other medium that can be accessed by a computer, but is not limited thereto. The memory 6024 in the interface board 602 may exist independently and be connected to the central processing unit 6021 through a communication bus; or, the memory 6024 may also be integrated with the central processing unit 6021 . The memory 6012 in the main control board 601 may exist independently and be connected to the central processing unit 6011 through a communication bus; or, the memory 6012 may also be integrated with the central processing unit 6011 .

The memory 6024 is used for storing program codes, and the execution is controlled by the central processing unit 6021, and the memory 6012 is used for storing the program codes, and the execution is controlled by the central processing unit 6011. The central processing unit 6021 and/or the central processing unit 6011 may execute the program code to implement the fault sensing method provided in the above embodiment and applied to the forwarding path of the first network device or the second network device. One or more software modules may be included in the program code stored in memory 6024 and/or memory 6012. The one or more software modules may be the functional modules provided in the above-mentioned embodiment shown in FIG. 9 or FIG. 10 .

In a specific embodiment, the physical interface card 6023 can be a device that uses any transceiver to communicate with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area network (wireless local area networks, WLAN), etc.

Embodiments of the present application further provide a computer-readable storage medium, where instructions are stored in the computer-readable storage medium, and the instructions are executed by a processor to implement the first network device or the second network device provided by the foregoing method embodiments. The failure-aware method of the forwarding path performed.

The embodiments of the present application further provide a computer program product containing instructions, when the computer program product runs on a computer, the computer program product enables the computer to execute the forwarding path provided by the above method embodiments and executed by the first network device or the second network device fault perception method.

An embodiment of the present application further provides a message forwarding system. As shown in FIG. 1 , the message forwarding system includes: a plurality of network devices 01 . The plurality of network devices 01 may include at least a first network device as shown in FIG. 9 , FIG. 11 or FIG. 12 , and may include a second network device as shown in FIG. 10 , FIG. 11 or FIG. 12 .

Optionally, the packet forwarding system may be an SRv6 system.

An embodiment of the present application further provides a chip, which can be used to implement the method for sensing faults of a forwarding path performed by the first network device or the second network device provided in the above method embodiments.

The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination. When implemented in software, the above-described embodiments may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer may be a general purpose computer, special purpose computer, computer network, or other programmable device. The computer instructions may be stored in or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions may be downloaded from a website site, computer, server or data center Transmission to another website site, computer, server, or data center is by wire (eg, coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (eg, infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, a data center, or the like that contains one or more sets of available media. The usable media may be magnetic media (eg, floppy disks, hard disks, magnetic tapes), optical media (eg, DVDs), or semiconductor media. The semiconductor medium may be a solid state drive (SSD).

The meaning of the term "at least one" in this application refers to one or more, and the meaning of the term "plurality" in this application refers to two or more, for example, a plurality of nodes refers to two or more node. The terms "system" and "network" are often used interchangeably herein. The "and/or" mentioned in this text means that there can be three kinds of relationships, for example, A and/or B, can mean that A exists alone, A and B exist at the same time, and B exists alone. The character "/" generally indicates that the associated objects are an "or" relationship.

The above are only optional embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of various equivalents within the technical scope disclosed in the present application. Modifications or substitutions of the present application shall be included within the scope of protection of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

A fault sensing method for a forwarding path, characterized in that it is applied to a first network device; the method includes:

Send a first service packet through a first forwarding path, where the first service packet includes a first identifier, and the first identifier is used to determine the first forwarding path;

A failure notification message sent by a second network device in the first forwarding path is received, where the failure notification message includes the first identifier, and the failure notification message is used to indicate a failure of the first forwarding path.
The method according to claim 1, wherein the method further comprises:

Based on the failure notification message, a second service message is sent through the backup path of the first forwarding path, where the second service message and the first service message belong to the same service flow.
The method according to claim 2, wherein the segment routing SR policy to which the first forwarding path belongs includes multiple candidate paths, and the first forwarding path belongs to the multiple candidate paths; The backup path of the first forwarding path sends the second service packet, including:

determining a second forwarding path from the multiple candidate paths as the backup path based on the failure notification message;

A second service packet encapsulated with a second identifier is sent through the second forwarding path, where the second identifier is used to determine the second forwarding path.
The method according to claim 2, wherein the sending the second service packet through the backup path of the first forwarding path comprises:

Based on the failure notification message, adopt the virtual private network VPN fast rerouting FRR technology to determine the second forwarding path as the backup path;

A second service packet encapsulated with a second identifier is sent through the second forwarding path, where the second identifier is used to determine the second forwarding path.
The method according to claim 2, wherein the sending the second service packet through the backup path of the first forwarding path comprises:

based on the fault notification message, sending fault information to the controller, where the fault information is used to indicate that the first forwarding path is faulty;

using the second forwarding path delivered by the controller as the backup path;

A second service packet encapsulated with a second identifier is sent through the second forwarding path, where the second identifier is used to determine the second forwarding path.
The method according to any one of claims 1 to 5, wherein the first identifier is a binding segment identifier of an SR policy to which the first forwarding path belongs;

Alternatively, the first identifier is a path identifier of the first forwarding path.
The method according to any one of claims 1 to 6, wherein the first service packet includes a routing extension header SRH, and the SRH carries the first identifier.
The method according to claim 7, wherein the SRH further comprises a segment list and a marker field, and the segment list includes a plurality of segment identifiers;

A segment identifier in the segment list carries the first identifier, and the flag field is used to indicate that the segment list includes the first identifier.
The method according to claim 8, wherein the last segment identifier in the segment list carries the first identifier.
The method according to any one of claims 1 to 9, wherein the fault notification message includes an SRH, and the SRH carries the first identifier;

Or, the data field of the fault notification message carries the first identifier.
The method according to any one of claims 1 to 10, wherein the failure notification message is an Internet Control Information Protocol (ICMP) message.
A fault sensing method for a forwarding path, characterized in that it is applied to a second network device; the method includes:

receiving a first service packet sent by a first network device through a first forwarding path, where the first service packet includes a first identifier, where the first identifier is used to determine the first forwarding path;

If it is determined that the first forwarding path is faulty, send a fault notification packet to the first network device, where the fault notification packet includes the first identifier, and the fault notification packet is used to indicate the first Forwarding path failure.
The method according to claim 12, wherein the fault notification message includes a routing extension header SRH, and the SRH carries the first identifier;

Or, the data field of the fault notification message carries the first identifier.
The method according to claim 12 or 13, wherein the failure notification message is an Internet Control Information Protocol (ICMP) message.
The method according to any one of claims 12 to 14, wherein the first identifier is a binding segment identifier of a segment routing SR policy to which the first forwarding path belongs;

Alternatively, the first identifier is a path identifier of the first forwarding path.
The method according to any one of claims 12 to 15, wherein the first service packet includes an SRH, and the SRH carries the first identifier.
The method of claim 16, wherein the SRH further comprises a segment list and a marker field, and the segment list includes a plurality of segment identifiers;

A segment identifier in the segment list carries the first identifier, and the flag field is used to indicate that the segment list includes the first identifier.
A first network device, characterized in that the first network device includes:

a sending module, configured to send a first service packet through a first forwarding path, where the first service packet includes a first identifier, and the first identifier is used to determine the first forwarding path;

a receiving module, configured to receive a failure notification message sent by a second network device in the first forwarding path, where the failure notification message includes the first identifier, and the failure notification message is used to indicate the first A forwarding path failure.
The first network device according to claim 18, wherein the sending module is further configured to:

Based on the failure notification message, a second service message is sent through the backup path of the first forwarding path, where the second service message and the first service message belong to the same service flow.
The first network device according to claim 19, wherein the segment routing SR policy to which the first forwarding path belongs includes multiple candidate paths, and the first forwarding path belongs to the multiple candidate paths; the The first network device also includes:

a determining module, configured to determine a second forwarding path from the multiple candidate paths as the backup path based on the failure notification message;

The sending module is configured to send a second service message encapsulated with a second identifier through the second forwarding path, where the second identifier is used to determine the second forwarding path.
The first network device according to claim 19, wherein the first network device further comprises:

a determining module, configured to determine a second forwarding path as the backup path based on the failure notification message by adopting the virtual private network VPN fast rerouting FRR technology;

The sending module is configured to send a second service message encapsulated with a second identifier through the second forwarding path, where the second identifier is used to determine the second forwarding path, and the second identifier is used to determine the second forwarding path.
The first network device according to claim 19, wherein,

The sending module is further configured to send fault information to the controller based on the fault notification message, where the fault information is used to indicate that the first forwarding path is faulty;

The first network device further includes: a determining module configured to use the second forwarding path delivered by the controller as the backup path;

The sending module is configured to send a second service message encapsulated with a second identifier through the second forwarding path, where the second identifier is used to determine the second forwarding path.
A second network device, characterized in that the second network device comprises:

a receiving module, configured to receive a first service packet sent by a first network device through a first forwarding path, where the first service packet includes a first identifier, and the first identifier is used to determine the first forwarding path;

A sending module, configured to send a failure notification message to the first network device if it is determined that the first forwarding path is faulty, where the failure notification message includes the first identifier, and the failure notification message is used for Indicates that the first forwarding path is faulty.
A computer-readable storage medium, characterized in that the computer-readable storage medium stores instructions, and the instructions are executed by a processor to implement the method according to any one of claims 1 to 17 .
A message forwarding system, characterized in that, the message forwarding system comprises: the first network device as claimed in any one of claims 18 to 22, and the second network device as claimed in claim 23.