WO2021043086A1 - Method, device and system for establishing sbfd session - Google Patents

Abstract

A method, device, and system for establishing an SBFD session. The method comprises: a first network device receives a first packet transmitted by a second network device, the first packet comprising SBFD information; the first network device determines, on the basis of the SBFD information, whether the first network device is to establish an SBFD session for a tunnel; moreover, when the first network device determines, on the basis of the SBFD information, that the first network device does not need to establish the SBFD session for the tunnel, the first network device refrains from establishing the SBFD session. Hence, the establishment of an unnecessary SBFD session is avoided, and the number of SBFD sessions in a network is reduced.

Description

Method, equipment and system for establishing SBFD session

This application claims the priority of a Chinese patent application filed with the State Intellectual Property Office, the application number is 201910839079.X, and the invention title is "A method, equipment and system for establishing an SBFD session" on September 5, 2019, and its entire contents Incorporated in this application by reference.

Technical field

This application relates to the field of communication technology, and in particular to a method, device and system for establishing a seamless BFD (SBFD) session.

Background technique

Segment routing (SR) is a protocol designed to forward data packets on the network based on the concept of source routing. SR multi-protocol label switch (MPLS) refers to Segment Routing based on the MPLS forwarding plane. Segment routing-best effort (SR-BE) is a new type of tunneling technology that uses SR as a control protocol. SR-BE is based on the interior gateway protocol (IGP) and the shortest path first (SPF) calculation to obtain the optimal SR label switched path (LSP). The SR-BE tunnel can control the transmission path of the message in the network according to the MPLS label of the first node. The SR-BE tunnel is used for connectionless, Mesh service bearer, provides service connections of any topology and simplifies tunnel planning and deployment.

The fault detection of the SR-BE tunnel requires the deployment of a bidirectional forwarding detection (bidirectional forwarding detection, BFD) mechanism. When a network device node failure occurs in the network, fast switching is realized according to the detection result of BFD. Seamless bidirectional forwarding detection (seamless BFD, SBFD) simplifies the BFD state machine, shortens the negotiation time, improves the flexibility of the entire network, and can support SR-BE tunnel detection.

In actual network scenarios, SR-BE tunnels are established based on end-to-end network devices in the network, and the network devices at both ends of each SR-BE tunnel enable the SBFD mechanism. Therefore, as long as the SR-BE service exists in the SR-BE tunnel, the network devices at both ends of the SR-BE tunnel will establish an SBFD session. However, only network devices with a node protection mechanism need to implement fast failover based on the detection result of the SBFD session. In this way, there may be a large number of useless SBFD sessions in the network, resulting in a waste of bandwidth resources in the network.

Summary of the invention

In view of this, the embodiments of the present application provide a method, device, and system for establishing an SBFD session. In the network, the first network device receives the SBFD information sent by the second network device, thereby determining, according to the SBFD information, to avoid creating an SBFD session for the tunnel, where the tunnel is from the first network device to the second network device. Tunneling of network devices, thereby reducing the number of SBFD sessions in the network.

The technical solutions provided by the embodiments of the present application are as follows.

In a first aspect, a method for establishing an SBFD session is provided. The method includes a first network device receiving a first packet sent by a second network device, the first packet including SBFD information. Wherein, the SBFD information is used to instruct the network device corresponding to the destination address of the first packet to determine whether to establish an SBFD session for the tunnel, and the tunnel is a tunnel from the first network device to the second network device The SBFD session is used to detect the state of the tunnel, and the destination address is the address of the first network device. Then, the first network device obtains the SBFD information in the first packet, and the SBFD information determines whether the first network device establishes the SBFD session for the tunnel. When the first network device determines according to the SBFD information that the first network device does not need to establish the SBFD session for the tunnel, the first network device avoids creating the SBFD session.

Based on the solution provided in the embodiment, in an actual network scenario, the first network device receives the SBFD information sent by the second network device, thereby determining whether it is necessary to create an SBFD session for the tunnel according to the SBFD information, where the tunnel is from all The tunnel from the first network device to the second network device is thus avoided to create unnecessary SBFD sessions, and the number of SBFD sessions in the network is reduced.

In a possible implementation manner of the first aspect, when the first network device determines that the first network device needs to establish the SBFD session for the tunnel according to the SBFD information, the first network device Create the SBFD session.

Optionally, the creation of the SBFD session by the first network device includes: sending an SBFD message to the second network device, where the SBFD message is used to request the establishment of the SBFD session; and receiving the second network device An SBFD response message sent by the device to the SBFD message, the SBFD response message indicating that the second network device is in a working state; and, according to the SBFD response message, the corresponding of the first network device The port of the tunnel is set to the UP state.

Optionally, after the first network device sets the port corresponding to the tunnel of the first network device to the UP state according to the SBFD response message, the method includes: The second network device sends an SBFD echo message, and the SBFD echo message is used to detect the state of the tunnel.

In a second aspect, a method for establishing an SBFD session is provided. The method includes that a second network device generates a first packet, and the first packet includes SBFD information. Wherein, the SBFD information is used to instruct the network device corresponding to the destination address of the first packet to determine whether to establish an SBFD session for the tunnel, and the tunnel is a tunnel from the first network device to the second network device, so The SBFD session is used to detect the state of the tunnel, and the destination address is the address of the first network device. Then, the second network device sends the first message to the first network device, where the SBFD information in the first message is used to prevent the first network device from establishing SBFD session of the tunnel.

Based on the solution provided in the embodiment, in an actual network scenario, the first network device receives the SBFD information sent by the second network device, thereby determining whether it is necessary to create an SBFD session for the tunnel according to the SBFD information, where the tunnel is from all The tunnel from the first network device to the second network device is thus avoided to create unnecessary SBFD sessions, and the number of SBFD sessions in the network is reduced.

In the foregoing first aspect or second aspect, optionally, the first message is a link state protocol data unit (link state protocol data unit) based on the intermediate system to intermediate system (intermediate system to intermediate system, IS-IS) protocol. protocol data unit, LSP) message, or the first message is a link state update (LSU) based on the Open Shortest Path First (Open Shortest Path First, OSPF) protocol, the first message The text also includes the segment identifier (SID) of the second network device, and the destination address of the tunnel is the address corresponding to the SID. Further optionally, the first message includes a flag field, and the flag field is used to carry the SBFD information.

Optionally, the tunnel is an SR-BE tunnel.

In a third aspect, a first network device is provided, and the first network device has a function of implementing the behavior of the first network device in the foregoing method. The functions can be implemented based on hardware, or implemented by corresponding software based on hardware. The hardware or software includes one or more modules corresponding to the above-mentioned functions.

In a possible design, the structure of the first network device includes a processor and an interface, and the processor is configured to support the first network device to perform corresponding functions in the foregoing method. The interface is used to support the communication between the first network device and the second network device, send the information or instructions involved in the above method to the second network device, or receive the information involved in the above method from the second network device Or instructions. The first network device may further include a memory, which is configured to be coupled with the processor and stores program instructions and data necessary for the first network device.

In another possible design, the first network device includes: a processor, a transmitter, a receiver, a random access memory, a read-only memory, and a bus. Among them, the processor is respectively coupled to the transmitter, the receiver, the random access memory, and the read-only memory through the bus. Wherein, when the first network device needs to be operated, the basic input/output system solidified in the read-only memory or the bootloader guide system in the embedded system is started to guide the first network device into a normal operating state. After the first network device enters the normal operating state, the application program and the operating system are run in the random access memory, so that the processor executes the first aspect or the method in any possible implementation manner of the first aspect.

In a fourth aspect, a first network device is provided. The first network device includes a main control board and an interface board, and may further include a switching network board. The first network device is configured to execute the first aspect or the method in any possible implementation manner of the first aspect. Specifically, the first network device includes a module for executing the first aspect or the method in any possible implementation manner of the first aspect.

In a fifth aspect, a first network device is provided. The first network device includes a controller and a first forwarding sub-device. The first forwarding sub-device includes: an interface board, and further, may also include a switching network board. The first forwarding sub-device is used to perform the function of the interface board in the fourth aspect, and further, may also perform the function of the switching network board in the fourth aspect. The controller includes a receiver, a processor, a transmitter, a random access memory, a read-only memory, and a bus. Among them, the processor is respectively coupled to the receiver, the transmitter, the random access memory, and the read-only memory through the bus. Among them, when the controller needs to be operated, the basic input/output system solidified in the read-only memory or the bootloader in the embedded system is used to guide the system to start, and the controller is guided to enter a normal operating state. After the controller enters the normal operating state, the application program and the operating system are run in the random access memory, so that the processor executes the function of the main control board in the fourth aspect.

In a sixth aspect, a computer storage medium is provided for storing programs, codes, or instructions used by the above-mentioned first network device. When a processor or hardware device executes these programs, codes, or instructions, the first in the above-mentioned aspect can be completed. The function or procedure of a network device.

In a seventh aspect, a second network device is provided, and the second network device has a function of realizing the behavior of the second network device in the foregoing method. The functions can be implemented based on hardware, or implemented by corresponding software based on hardware. The hardware or software includes one or more modules corresponding to the above-mentioned functions.

In a possible design, the structure of the second network device includes a processor and an interface, and the processor is configured to support the second network device to perform corresponding functions in the foregoing method. The interface is used to support the communication between the second network device and the first network device, send the information or instructions involved in the above method to the first network device, or receive the information or instructions involved in the above method from the first network device The information or instructions involved. The second network device may further include a memory, which is configured to be coupled with the processor and stores necessary program instructions and data for the second network device.

In another possible design, the second network device includes: a processor, a transmitter, a receiver, a random access memory, a read-only memory, and a bus. Among them, the processor is respectively coupled to the transmitter, the receiver, the random access memory, and the read-only memory through the bus. Wherein, when the second network device needs to be operated, the basic input/output system solidified in the read-only memory or the bootloader in the embedded system is used to boot the system to guide the second network device into a normal operating state. After the second network device enters the normal operating state, the application program and the operating system are run in the random access memory, so that the processor executes the second aspect or the method in any possible implementation manner of the second aspect.

In an eighth aspect, a second network device is provided. The second network device includes a main control board and an interface board, and may further include a switching network board. The second network device is used to execute the second aspect or the method in any possible implementation manner of the second aspect. Specifically, the second network device includes a module for executing the second aspect or the method in any possible implementation manner of the second aspect.

In a ninth aspect, a second network device is provided, and the second network device includes a controller and a second forwarding sub-device. The second forwarding sub-device includes: an interface board, and further, may also include a switching network board. The second forwarding sub-device is used to perform the function of the interface board in the eighth aspect, and further, may also perform the function of the switching network board in the eighth aspect. The controller includes a receiver, a processor, a transmitter, a random access memory, a read-only memory, and a bus. Among them, the processor is respectively coupled to the receiver, the transmitter, the random access memory, and the read-only memory through the bus. Among them, when the controller needs to be operated, the basic input/output system solidified in the read-only memory or the bootloader in the embedded system is used to guide the system to start, and the controller is guided to enter a normal operating state. After the controller enters the normal operating state, the application program and the operating system are run in the random access memory, so that the processor executes the function of the main control board in the eighth aspect.

In a tenth aspect, a computer storage medium is provided for storing programs, codes, or instructions used by the above-mentioned second network device. When a processor or hardware device executes these programs, codes or instructions, the second aspect of the above-mentioned aspect can be completed. The function or procedure of a network device.

An eleventh aspect provides a message processing system. The system includes a first network device and a second network device. The first network device is the third aspect or the fourth aspect or the fifth aspect described above. A network device, where the second network device is the second network device in the aforementioned seventh aspect or the eighth aspect or the ninth aspect.

Through the above solution, in an actual network scenario, the first network device receives the SBFD information sent by the second network device, thereby determining whether it is necessary to create an SBFD session for the tunnel according to the SBFD information, where the tunnel is from the first network device. A tunnel from the network device to the second network device, thereby avoiding the creation of unnecessary SBFD sessions, and reducing the number of SBFD sessions in the network.

Description of the drawings

FIG. 1 is a schematic diagram of a network structure according to an embodiment of the application;

FIG. 2 is a flowchart of a method for detecting an SR-BE tunnel according to an embodiment of the application;

FIG. 3 is a flowchart of another SR-BE tunnel detection method according to an embodiment of the application;

FIG. 4 is a schematic structural diagram of a first network device according to an embodiment of the application;

FIG. 5 is a schematic diagram of the hardware structure of a first network device according to an embodiment of the application;

6 is a schematic diagram of the hardware structure of another first network device according to an embodiment of the application;

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

FIG. 8 is a schematic diagram of the hardware structure of a second network device according to an embodiment of the application;

FIG. 9 is a schematic diagram of the hardware structure of another second network device according to an embodiment of the application.

detailed description

Detailed descriptions will be given below through specific embodiments.

Fig. 1 is a schematic diagram of a network structure according to an embodiment of the application. Exemplarily, FIG. 1 relates to a hierarchical virtual private network (HVPN). The HVPN includes a base station side gateway (cell site gateway, CSG), an aggregation side gateway (aggregation site gateway, ASG), and a base station controller side gateway (radio network controller site gateway, RSG). Figure 1 shows four CSG devices, namely CSG1, CSG2, CSG3 and CSG4. CSG1 communicates with CSG2 through a communication link, CSG2 communicates with CSG3 through a communication link, and CSG3 communicates with CSG4 through a communication link. CSG1, CSG2, CSG3 and CSG4 can be connected to one or more base stations respectively. Figure 1 shows two ASG devices, ASG1 and ASG2. ASG1 communicates with ASG2 through a communication link. In HVPN, ASG2 is the redundant device of ASG1. CSG1 communicates with ASG1 through a communication link, and CSG4 communicates with ASG2 through a communication link. Figure 1 shows two RSG devices, RSG1 and RSG2. RSG1 communicates with RSG2 through a communication link. In HVPN, RSG2 is the redundant device of RSG1. ASG1 communicates with RSG1 through a communication link, and ASG4 communicates with RSG2 through a communication link. Among them, RSG1 and RSG2 can be respectively connected to servers in a data center (DC).

In the embodiment, the data traffic is sent from the CSG device in FIG. 1 to the RSG device. Exemplarily, the description will be made by taking CSG1 sending data traffic to RSG1 as an example. According to the foregoing, ASG2 is the redundant device of ASG1. That is, ASG1 is the main ASG device in the HVPN, and ASG2 is the backup ASG device in the HVPN. Under normal circumstances, the data traffic sent by CSG1 reaches RSG1 via ASG1. When ASG1 fails, a master-backup switchover occurs between ASG1 and ASG2, ASG1 switches to a backup ASG device, and ASG2 switches to a master ASG device. Then, the data traffic sent by CSG1 reaches RSG1 via CSG2, CSG3, CSG4, ASG2 and RSG2. In the same way, RSG2 in FIG. 1 can also be used as a backup RSG device of RSG1, and the specific working mode is the same as that of the ASG device in FIG. 1, which will not be repeated here.

In the HVPN shown in Figure 1, a tunnel can be used to transmit data traffic. Optionally, the tunnel is an SR-BE tunnel. In the embodiments of this application, an SR-BE tunnel is taken as an example for description. It should be understood that the solution of this application can also be applied to other types of tunnels. Among them, the SR-BE tunnel is established based on end-to-end equipment, that is, as long as there is an SR-BE data traffic service, an SR-BE tunnel needs to be established. For example, CSG1 establishes SR-BE tunnels to CSG2, CSG3, CSG4, ASG1, ASG2, RSG1 and RSG2 in Figure 1 respectively. In the same way, CSG2 is established to CSG1, CSG3, CSG4, ASG1, ASG2, RSG1, and RSG2 in Figure 1, respectively. SR-BE tunnels; CSG3 is established to CSG1, CSG2, CSG4, ASG1, ASG2, RSG1 and RSG1 in Figure 1. The SR-BE tunnel of RSG2; CSG4 is established to the SR-BE tunnels of CSG1, CSG2, CSG3, ASG1, ASG2, RSG1 and RSG2 in Figure 1 respectively. The method for establishing SR-BE tunnels by ASG1, ASG2, RSG1, and RSG2 is similar to the way for CSG devices to establish SR-BE tunnels, and will not be repeated here.

The SBFD session is used to detect the failure of the SR-BE tunnel. Take the example of detecting the failure of the SR-BE tunnel from CSG1 to ASG1 based on the SBFD session mechanism. For the convenience of description, the SR-BE1 tunnel is used to represent the SR-BE tunnel from CSG1 to ASG1. CSG1 is the initiator of the SBFD session, and it can also become the detection end. The initial state of the SBFD state machine in CSG1 is the DOWN state, that is, the state of the port of the CSG1 corresponding to the SR-BE1 tunnel is the DOWN state. Specifically, the protocol state of the port corresponding to the SR-BE1 tunnel of CSG1 is DOWN with respect to the SBFD protocol. CSG1 sends a first SBFD packet to ASG1 via the SR-BE1 tunnel, where the first SBFD packet is used to request the second network device to establish the SBFD session. Wherein, the first SBFD packet carries DOWN state information. ASG1 is the reflecting end of the SBFD session. After the ASG1 receives the first SBFD message, it determines whether the peer identifier (your discriminator, YD) in the first SBFD message matches the identifier stored locally in the ASG1. The YD in the first SBFD message is used to indicate ASG1. After the ASG1 determines that the two match and the DOWN state information carried in the first SBFD packet, the ASG1 determines whether the ASG1 is in a working state. If ASG1 is in working state, ASG1 sends the first SBFD response message of the first SBFD message to CSG1 via the SR-BE tunnel; if ASG1 is in a non-working state, ASG1 does not send the first SBFD response message, and discards the first SBFD response message. An SBFD message. Wherein, when ASG1 sends the first SBFD response message of the first SBFD message to CSG1 via the SR-BE tunnel, the first SBFD response message carries UP state information, indicating that CSG1 can be switched to the UP state. After receiving the first SBFD response message, CSG1 switches the SBFD state machine in CSG1 from DOWN state to UP state according to the UP state information carried in the first SBFD response message, that is, CSG1 switches CSG1 The state of the port corresponding to the SR-BE1 tunnel is switched from the DOWN state to the UP state. Then, CSG1 periodically sends SBFD echo packets to ASG1 at predetermined intervals, where the predetermined duration is, for example, 100 milliseconds. If CSG1 can periodically receive SBFD echo messages sent by itself, CSG1 can determine that the SR-BE1 tunnel or ASG1 is working normally. If CSG1 does not receive the SBFD echo message sent by itself within a predetermined period, CSG1 can determine that the SR-BE1 tunnel or ASG1 is faulty. When CSG1 determines that the SR-BE1 tunnel or ASG1 is faulty, it triggers the active/standby switchover of the ASG device. Specifically, ASG1 is switched to the standby ASG device, and ASG2 is switched to the main ASG device. In addition, CSG1 does not send data traffic through the SR-BE1 tunnel, but sends data traffic through the SR-BE2 tunnel. Among them, the SR-BE2 tunnel is an SR-BE tunnel from CSG1 to ASG2.

It can be seen from the above implementation that when the SR-BE tunnel transmits data traffic, the tunnel endpoint device (for example, CSG1) of the SR-BE tunnel creates an SBFD session, and periodically detects the state of the SR-BE tunnel based on the SBFD session. As shown above, CSG1 establishes SR-BE tunnels to CSG2, CSG3, CSG4, ASG1, ASG2, RSG1, and RSG2 in Figure 1, respectively, and a total of 7 SR-BE tunnels. Correspondingly, CSG1 establishes 7 SBFD sessions corresponding to the 7 SR-BE tunnels mentioned above. Assume that in the HVPN scenario shown in Figure 1, only the ASG device needs to implement active/standby protection, that is, ASG1 is the active ASG device, and ASG2 is the standby ASG device. In this way, CSG1 needs to periodically detect the tunnel status of the SR-BE1 tunnel from CSG1 to ASG1 and periodically detect the tunnel status of the SR-BE2 tunnel from CSG1 to ASG2, so that when the SR-BE1 tunnel or ASG1 fails At this time, the data traffic sent by CSG1 can be quickly switched from the SR-BE1 tunnel to the SR-BE2 tunnel. Therefore, there is no need to establish corresponding SBFD sessions on the SR-BE tunnels from CSG1 to CSG2, CSG3, CSG4, RSG1 and RSG2 respectively. That is to say, in the foregoing implementation manner, CSG1 only needs to establish an SBFD session based on the SR-BE1 tunnel and the SR-BE2 tunnel, and does not need to establish another 5 SBFD sessions. Therefore, in the existing SR-BE scenario, a large number of useless SBFD sessions are established, and these SBFD sessions cause a waste of network bandwidth resources.

The embodiments of the present application provide a method, device, and system for establishing an SBFD session. For example, in the HVPN shown in FIG. 1, after the SR-BE1 tunnel from CSG1 to ASG1 is established, ASG1 generates a first packet. The first packet includes SBFD information, and the SBFD information is used to indicate the first packet. The network device corresponding to the destination address of a message determines whether to establish an SBFD session for the tunnel, where the destination address is the address of the first network device. In other words, the SBFD information indicates whether to start the detection mechanism for the SR-BE1 tunnel. Then, ASG1 sends the first message to CSG1. After receiving the first message, the CSG1 determines whether the CSG1 is an SR-BE1 tunnel to establish the SBFD session according to the SBFD information in the first message. If CSG1 determines according to the SBFD information that CSG1 does not need to establish an SBFD session for the SR-BE1 tunnel, CSG1 avoids establishing the SBFD session. That is, CSG1 does not send the first SBFD message to ASG1, and the first SBFD message is used to request ASG1 to establish the SBFD session. Specifically, CSG1 will not notify the SBFD state machine in CSG1 to send the first SBFD message. On the contrary, if CSG1 determines that an SBFD session needs to be established for the SR-BE1 tunnel according to the SBFD information, CSG1 creates the SBFD session. That is, CSG1 will send a second SBFD message to ASG1, and the second SBFD message is used to request ASG1 to establish the SBFD session. Specifically, CSG1 will notify the SBFD state machine in CSG1 to send the second SBFD message.

For example, in the network topology shown in FIG. 1, ASG1 may send the first message carrying SBFD-1 information to CSG1, CSG2, CSG3, and CSG4, respectively. Wherein, the SBFD-1 information indicates that the network device corresponding to the destination address of the first packet determines that an SBFD session needs to be established for the corresponding SR-BE tunnel. In this way, CSG1 is on the SR-BE tunnel from CSG1 to ASG1, CSG2 is on the SR-BE tunnel from CSG2 to ASG1, CSG3 is on the SR-BE tunnel from CSG3 to ASG1, and CSG4 is on the SR from CSG4 to ASG1. -Create an SBFD session on the BE tunnel. Correspondingly, ASG1 can send a second message carrying SBFD-2 information to ASG2, RSG1 and RSG2, respectively. Wherein, the SBFD-2 information indicates that the network device receiving the second message determines that it is not necessary to establish an SBFD session for the corresponding SR-BE tunnel. In this way, ASG2 does not create an SBFD session on the SR-BE tunnel from ASG2 to ASG1, RSG1 on the SR-BE tunnel from RSG1 to ASG1, and RSG2 on the SR-BE tunnel from RSG2 to ASG1. Similarly, other network nodes in FIG. 1 can notify the peer device whether it is necessary to establish an SBFD session for the corresponding SR-BE tunnel in the foregoing manner. Therefore, in the network shown in FIG. 1, a large number of useless SBFD sessions will not be established, thereby reducing the occupation of network bandwidth resources.

Fig. 2 is a flow chart of a method for detecting an SR-BE tunnel according to an embodiment of the application. The method shown in FIG. 2 can be applied to the network structure shown in FIG. 1. In the embodiments of this application, an SR-BE tunnel is taken as an example for description. It should be understood that the solution of this application can also be applied to other types of tunnels. The method includes S101-S105, specifically:

S101. The second network device generates a first packet, where the first packet includes SBFD information, and the SBFD information is used to indicate that the network device corresponding to the destination address of the first packet determines whether to establish an SR-BE tunnel. SBFD session, the SR-BE tunnel is a tunnel from the first network device to the second network device, the SBFD session is used to detect the status of the SR-BE tunnel, and the destination address is the first The address of the network device.

In this embodiment, the first network device corresponds to CSG1 in FIG. 1 and the second network device corresponds to CSG2 in FIG. 1 as an example for description. An SR-BE tunnel, that is, an SR-BE12 tunnel, is established between CSG1 and CSG2. The SR-BE12 tunnel is an SR-BE tunnel from CSG1 to CSG2. According to the description of the foregoing embodiment, in the scenario described in FIG. 1, ASG2 is the redundant device of ASG1, that is, ASG1 is the main ASG device, and ASG2 is the backup ASG device. The CSG2 in Figure 1 is not set with a backup CSG device, that is, CSG2 does not have a corresponding protection device. Therefore, no SBFD session needs to be established on the SR-BE tunnel to CSG2.

Correspondingly, CSG2 can generate a first message, and the first message includes SBFD information. The SBFD information is used to instruct the CSG1 that received the first message to determine whether to establish an SBFD session for the SR-BE12 tunnel, that is, the SBFD information indicates whether to start the SR-BE12 tunnel detection mechanism (SBFD). Conversation).

In a possible implementation manner, CSG2 generates the first message based on an intermediate system to intermediate system (intermediate system to intermediate system, IS-IS) protocol. Specifically, the first message is a link state protocol data unit (LSP) message. The first message includes a segment identifier (SID). Specifically, the SID is a prefix SID (Prefix-SID). In the application scenario of SR-BE, Prefix-SID is used for path calculation. Before transmitting data traffic, the Prefix-SID needs to be configured first. Therefore, the first message can be used to issue the Prefix-SID. Exemplarily, for the manner in which the first message carries the Prefix-SID, please refer to Internet Engineering Task Force (IETF) Draft 1: IS-IS Extensions for Segment Routing (draft-ietf-isis-segment) -routing-extensions-25), for example, see the description in Chapter 2.1 of Draft 1. Specifically, the first message includes a first type-length-value (type-length-value, TLV) field, and the first TLV field is used to carry the Prefix-SID. The first TLV field includes a flag (flags) field, and the length of the flag field is 8 bits. The flag field is used to carry the SBFD information. For example, the 6th or 7th bit of the flag field is used to carry the SBFD information. For example, when the value of the 6th bit in the flag field is "1", it means that the SBFD session is enabled to detect the SR-BE12 tunnel; when the value of the 6th bit in the flag field is "0" , Which means that the SBFD session is not enabled to detect the SR-BE12 tunnel.

In another possible implementation manner, CSG2 generates the first message based on the Open Shortest Path First (OSPF) protocol. Specifically, the first message is a link state update (LSU) message. The first message includes SID. Specifically, the LSU message includes link-state advertisement (link-state advertisement, LSA) information, the LSA information includes the SID, and the SID is the Prefix-SID. In the application scenario of SR-BE, Prefix-SID is used for path calculation. Before transmitting data traffic, the Prefix-SID needs to be configured first, so the first message can be used to issue the Prefix-SID. Exemplarily, for the manner in which the first message carries the Prefix-SID, please refer to Internet Engineering Task Force (IETF) Draft 2: OSPF Extensions for Segment Routing (draft-ietf-ospf-segment-routing) -extensions-27), for example, see the description in Chapter 5 of Draft 2. Specifically, the first message includes a second type length value (type-length-value, TLV) field, and the second TLV field is used to carry the Prefix-SID. The second TLV field includes a flags field, and the flag field has a length of 8 bits. The flag field is used to carry the SBFD information. For example, the 6th or 7th bit of the flag field is used to carry the SBFD information. For example, when the value of the 6th bit in the flag field is "1", it means that the SBFD session is enabled to detect the SR-BE12 tunnel; when the value of the 6th bit in the flag field is "0" , Which means that the SBFD session is not enabled to detect the SR-BE12 tunnel.

Optionally, in the above two possible implementation manners, the destination address of the SR-BE tunnel is the address corresponding to the SID. Specifically, multiple SR-BE tunnels may be included between the first network device and the second network device. In this way, the second network device may include multiple SIDs, and the multiple SIDs have a one-to-one correspondence with the destination addresses of the multiple SR-BE tunnels. In this way, the first network device can determine which SR-BE tunnel of the plurality of SR-BE tunnels needs to be operated according to the value of the SID, that is, for the connection between the first network device and the second network device The specific SR-BE tunnel determines whether an SBFD session needs to be created. For example, the first network device and the second network device include an SR-BE-1 tunnel, an SR-BE-2 tunnel, and an SR-BE-3 tunnel. The destination address of the SR-BE-1 tunnel corresponds to SID-1, the destination address of the SR-BE-2 tunnel corresponds to SID-2, and the destination address of the SR-BE-3 tunnel corresponds to SID-3. Assuming that the first packet sent by the second network device to the first network device includes SID-2, then the first network device can determine the destination address of the SR-BE-2 tunnel through SID-2, so that the first network The device can determine that it needs to operate on the SR-BE-2 tunnel, that is, whether it needs to create an SBFD session for the SR-BE-2 tunnel. Therefore, through the foregoing implementation manner, when there are multiple SR-BE tunnels between the first network device and the second network device, the SBFD session creation process can be implemented for some of the SR-BE tunnels. The SID may be a Prefix-SID, and the destination address of the SR-BE tunnel may be an Internet Protocol (IP) address.

S102. The second network device sends the first packet to the first network device.

After CSG2 generates the first message, it sends the first message to other network devices in the network structure shown in FIG. 1. The specific CSG2 is sent to CSG1, CSG3, CSG4, ASG1, ASG2, RSG1, and RSG2 respectively The first message. For example, in an IS-IS scenario, CSG2 sends LSP packets to CSG1, CSG3, CSG4, ASG1, ASG2, RSG1, and RSG2 respectively; in an OSPF scenario, CSG2 sends LSP packets to CSG1, CSG3, CSG4, ASG1, ASG2, and RSG1 respectively Send LSU message with RSG2.

In this embodiment, CSG2 is not configured with a backup CSG device, that is, CSG2 does not have a corresponding protection device. The SBFD information in the first message is used to prevent CSG1 from establishing an SBFD session for the SR-BE12 tunnel. Therefore, no SBFD session needs to be established on the SR-BE tunnel to CSG2. Therefore, the value of the SBFD information included in the first message sent by CSG2 may be "0", so as to prevent CSG1 from initiating an SBFD session for the SR-BE12 tunnel.

S103. The first network device receives the first packet sent by the second network device.

S104: The first network device determines whether the first network device establishes the SBFD session for the SR-BE tunnel according to the SBFD information.

For example, after receiving the first packet sent by CSG2, CSG1 parses the first packet to obtain the SBFD information carried in the first packet. Optionally, CSG1 may determine that the first message is a message sent by CSG2 according to the Prefix-SID carried in the first message, that is, CSG1 may determine that the first message is a message sent by CSG2 according to the Prefix-SID carried in the first message. -The SID determines that the SBFD information is detection information indicating the SR-BE12 tunnel.

The CSG1 determines whether an SBFD session needs to be established for the SR-BE12 tunnel according to the SBFD information, that is, the CSG1 determines whether to establish an SBFD session on the SR-BE12 tunnel according to the value of the SBFD information. For example, if the value of the SBFD information is "1", CSG1 determines to establish an SBFD session on the SR-BE12 tunnel; the value of the SBFD information is "0", and CSG1 determines not to establish an SBFD session on the SR-BE12 tunnel.

S105. When the first network device determines according to the SBFD information that the first network device does not need to establish the SBFD session for the SR-BE tunnel, the first network device avoids creating the SBFD session.

For example, according to the foregoing, CSG2 is not configured with a backup CSG device, that is, CSG2 does not have a corresponding protection device. Therefore, no SBFD session needs to be established on the SR-BE tunnel to CSG2. Therefore, the value of the SBFD information included in the first message sent by CSG2 may be "0", so as to prevent CSG1 from creating an SBFD session for the SR-BE12 tunnel. When CSG1 determines not to establish the SBFD session of the SR-BE12 tunnel according to the SBFD information, CSG1 does not send the first SBFD packet to CSG2. The first SBFD message is a first message for establishing an SBFD session, and is used to request CSG2 to establish the SBFD session. CSG1 does not send the first SBFD message to CSG2, which means that CSG1 does not establish an SBFD session for the SR-BE12 tunnel. In this way, CSG2 will not receive the first SBFD message, and therefore, CSG2 will not send the first SBFD response message of the first SBFD message to CSG1. Finally, the SBFD session for the SR-BE12 tunnel will not be established. Specifically, after determining that the value of the SBFD information is "0", the processor in CSG1 will not send a notification message to the SBFD state machine in CSG1. In this way, the SBFD state machine in CSG1 will not trigger the first Generation and transmission of SBFD messages.

In the same way, CSG2 can also send the first message to CSG3, CSG4, RSG1 and RSG2 respectively, so that CSG3, CSG4, RSG1 and RSG2 will not establish an SBFD session to the SR-BE tunnel of CSG2. Therefore, through the implementation of the present application, a large number of useless SBFD sessions will not be established, thereby reducing the occupation of network bandwidth resources.

FIG. 3 is a flowchart of another SR-BE tunnel detection method according to an embodiment of the application. The method shown in FIG. 3 can be applied to the network structure shown in FIG. 1. In the embodiments of this application, an SR-BE tunnel is taken as an example for description. It should be understood that the solution of this application can also be applied to other types of tunnels. In this embodiment, the first network device corresponds to CSG1 in FIG. 1 and the second network device corresponds to ASG1 in FIG. 1 as an example for description. An SR-BE tunnel, that is, an SR-BE11 tunnel, is established between CSG1 and ASG1. The SR-BE11 tunnel is an SR-BE tunnel from CSG1 to ASG1. The method shown in Figure 3 includes S101-S112. The expressions of S101, S102, S103, and S104 shown in FIG. 3 are the same as those of S101, S102, S103, and S104 shown in FIG. 2, and will not be repeated here. Furthermore, the implementation of S101-S104 in FIG. 3 exemplified based on CSG1 and ASG2 is similar to the exemplification of S101-S104 in FIG. 2 based on CSG1 and CSG2, and will not be repeated here.

S106: When the first network device determines according to the SBFD information that the first network device needs to establish an SBFD session for the SR-BE tunnel, the first network device creates the SBFD session.

S107. The first network device sends a second SBFD packet to the second network device, where the second SBFD packet is used to request the second network device to establish the SBFD session.

For example, according to the foregoing, ASG2 is the redundant device of ASG1, that is, ASG1 is the main ASG device, and ASG2 is the backup ASG device. Therefore, ASG2 is the corresponding protection device of ASG1, so an SBFD session needs to be established on the SR-BE tunnel to ASG1. Therefore, the value of the SBFD information included in the first message sent by ASG1 may be "1", so that CSG1 can create an SBFD session for the SR-BE11 tunnel. When CSG1 determines according to the SBFD information that CSG1 needs to establish an SBFD session for the SR-BE11 tunnel, CSG1 sends the second SBFD message to ASG1. The second SBFD message is the first message for establishing the SBFD session, and is used to request the ASG1 to establish the SBFD session. CSG1 sends the second SBFD message to ASG1, which means that CSG1 initiates a request for establishing an SBFD session for the SR-BE11 tunnel. Specifically, after determining that the value of the SBFD information is "1", the processor in CSG1 will send a notification message to the SBFD state machine in CSG1, so that the SBFD state machine in CSG1 will trigger the second SBFD message Generation and delivery. According to the description of the foregoing embodiment, the second SBFD packet carries DOWN state information.

S108. The second network device receives the second SBFD packet sent by the first network device.

S109. The second network device sends a second SBFD response message of the second SBFD message to the first network device, where the second SBFD response message indicates that the second network device is in a working state.

For example, ASG1 is the reflection end of the SBFD session. After the ASG1 receives the second SBFD message, it determines whether the opposite end YD in the second SBFD message matches the identifier stored locally in the ASG1. The YD in the second SBFD message is used to indicate ASG1. After the ASG1 determines that the two match and the DOWN state information carried in the second SBFD packet, the ASG1 determines whether the ASG1 is in a working state. If ASG1 is in the working state, ASG1 sends the second SBFD response message of the second SBFD message to CSG1 via the SR-BE11 tunnel. Wherein, the second SBFD response message carries UP state information, which indicates that CSG1 can be switched to the UP state.

S110. The first network device receives the second SBFD response message.

S111. The first network device sets the port of the first network device corresponding to the SR-BE tunnel to the UP state according to the second SBFD response message.

S112. The first network device sends an SBFD echo message to the second network device, where the SBFD echo message is used to detect the state of the SR-BE tunnel.

For example, after receiving the second SBFD response message, CSG1 switches the SBFD state machine in CSG1 from the DOWN state to the UP state according to the UP state information carried in the second SBFD response message, that is, CSG1 switches the status of the port corresponding to the SR-BE11 tunnel of CSG1 from the DOWN state to the UP state. Then, CSG1 periodically sends SBFD echo messages to ASG1 at intervals of a predetermined duration, where the predetermined duration is, for example, 100 milliseconds. If CSG1 can periodically receive the SBFD echo message sent by itself, CSG1 can determine that the SR-BE11 tunnel or ASG1 is working normally. If CSG1 does not receive the SBFD echo message sent by itself within a predetermined period, CSG1 can determine that the SR-BE11 tunnel or ASG1 is faulty. When CSG1 determines that the SR-BE11 tunnel or ASG1 is faulty, it triggers the active/standby switchover of the ASG device. Specifically, ASG1 is switched to the standby ASG device, and ASG2 is switched to the main ASG device. In addition, CSG1 does not send data traffic through the SR-BE11 tunnel, but sends data traffic through the SR-BE22 tunnel. Among them, the SR-BE22 tunnel is the SR-BE tunnel from CSG1 to ASG2.

Through the implementation of the present application, SBFD sessions can be established only on SR-BE tunnels that require SBFD detection. Therefore, a large number of useless SBFD sessions will not be established, thus reducing the occupation of network bandwidth resources.

FIG. 4 is a schematic structural diagram of a first network device 1000 according to an embodiment of the application. The first network device 1000 shown in FIG. 4 can execute the corresponding steps performed by the first network device in the method of the foregoing embodiment. As shown in FIG. 4, the first network device 1000 includes a receiving unit 1002 and a processing unit 1004.

The receiving unit 1002 is configured to receive a first packet sent by a second network device, where the first packet includes SBFD information, and the SBFD information is used to indicate the network device corresponding to the destination address of the first packet Determine whether to establish an SBFD session for a tunnel, where the tunnel is a tunnel from the first network device to the second network device, the SBFD session is used to detect the state of the tunnel, and the destination address is the first network device. The address of a network device;

The processing unit 1004 is configured to determine whether the first network device establishes the SBFD session for the tunnel according to the SBFD information;

When the processing unit 1004 determines according to the SBFD information that the first network device does not need to establish the SBFD session for the tunnel, the processing unit 1004 is further configured to avoid creating the SBFD session.

In a possible implementation manner, when the processing unit 1004 determines according to the SBFD information that the first network device needs to establish the SBFD session for the tunnel, the processing unit 1004 is further configured to create the SBFD session.

Optionally, when the processing unit 1004 is further configured to create the SBFD session, the processing unit 1004 is specifically configured to: send an SBFD message to the second network device, where the SBFD message is used to request establishment The SBFD session; receiving an SBFD response message for the SBFD message sent by the second network device, the SBFD response message indicating that the second network device is in a working state; and, responding according to the SBFD The message sets the port of the first network device corresponding to the tunnel to the UP state.

Optionally, after the processing unit 1004 sets the port of the first network device corresponding to the tunnel to the UP state according to the SBFD response message, the processing unit 1004 is further configured to report to the second network device Send an SBFD echo message, where the SBFD echo message is used to detect the state of the tunnel.

Optionally, the first message is an LSP message based on the IS-IS protocol, or the first message is an LSU message based on the OSPF protocol, and the first message further includes the second network The SID of the device, and the destination address of the tunnel is the address corresponding to the SID. Further optionally, the first message includes a flag field, and the flag field is used to carry the SBFD information.

Optionally, the tunnel is an SR-BE tunnel.

The first network device shown in FIG. 4 can execute the corresponding steps performed by the first network device in the method of the foregoing embodiment. In an actual network scenario, the first network device receives the SBFD information sent by the second network device, thereby determining whether it is necessary to create an SBFD session for the tunnel according to the SBFD information, where the tunnel is from the first network device to the The tunnel of the second network device is thus avoided to create unnecessary SBFD sessions, and the number of SBFD sessions in the network is reduced.

FIG. 5 is a schematic diagram of the hardware structure of the first network device 1100 according to an embodiment of the application. The first network device 1100 shown in FIG. 5 can execute the corresponding steps performed by the first network device in the method of the foregoing embodiment.

As shown in FIG. 5, the first network device 1100 includes a processor 1101, a memory 1102, an interface 1103, and a bus 1104. The interface 1103 may be implemented in a wireless or wired manner, and specifically may be a network card. The aforementioned processor 1101, memory 1102, and interface 1103 are connected through a bus 1104.

The interface 1103 may specifically include a transmitter and a receiver, which are used to send and receive information between the first network device and the second network device in the foregoing embodiment. For example, the interface 1103 is used to support receiving the first packet and the SBFD response packet of the SBFD packet sent by the second network device; it is used to support the sending of the SBFD packet and the SBFD echo packet to the second network device. As an example, the interface 1103 is used to support the processes S103, S107, S110, and S112 in FIG. 2 and FIG. 3. The processor 1101 is configured to execute the processing performed by the first network device in the foregoing embodiment. For example, the processor 1101 determines whether to establish an SBFD session for the tunnel; is used to avoid establishing an SBFD session according to the determination result or establish an SBFD session according to the determination result; and/or is used in other processes of the technology described herein. As an example, the processor 1101 is used to support the processes S104, S105, S106, and S111 in FIG. 2 and FIG. 3. The memory 1102 includes an operating system 11021 and an application program 11022 for storing programs, codes, or instructions. When a processor or hardware device executes these programs, codes, or instructions, the processing process involving the first network device in the method embodiment can be completed. Optionally, the memory 1102 may include a read-only memory (English: Read-only Memory, abbreviation: ROM) and a random access memory (English: Random Access Memory, abbreviation: RAM). Wherein, the ROM includes a basic input/output system (English: Basic Input/Output System, abbreviation: BIOS) or an embedded system; the RAM includes an application program and an operating system. When the first network device 1100 needs to be operated, the system is booted by the BIOS solidified in the ROM or the bootloader in the embedded system to guide the first network device 1100 into a normal operating state. After the first network device 1100 enters the normal operating state, the application program and the operating system run in the RAM, thereby completing the processing procedure involving the first network device in the method embodiment.

It is understandable that FIG. 5 only shows a simplified design of the first network device 1100. In practical applications, the first network device may include any number of interfaces, processors or memories.

FIG. 6 is a schematic diagram of the hardware structure of another first network device 1200 according to an embodiment of the application. The first network device 1200 shown in FIG. 6 can execute the corresponding steps performed by the first network device in the method of the foregoing embodiment.

As shown in FIG. 6, the first network device 1200 includes: a main control board 1210, an interface board 1230, a switching network board 1220, and an interface board 1240. The main control board 1210, the interface boards 1230 and 1240, and the switching network board 1220 are connected to the system backplane through the system bus to achieve intercommunication. Among them, the main control board 1210 is used to complete functions such as system management, equipment maintenance, and protocol processing. The switching network board 1220 is used to complete data exchange between various interface boards (interface boards are also called line cards or service boards). The interface boards 1230 and 1240 are used to provide various service interfaces (for example, POS interface, GE interface, ATM interface, etc.), and realize data packet forwarding

The interface board 1230 may include a central processing unit 1231, a forwarding entry memory 1234, a physical interface card 1233, and a network processor 1232. Among them, the central processing unit 1231 is used to control and manage the interface board and communicate with the central processing unit on the main control board. The forwarding entry storage 1234 is used to store forwarding entries. The physical interface card 1233 is used to complete the reception and transmission of traffic. The network storage 1232 is used to control the receiving and sending traffic of the physical interface card 1233 according to the forwarding entry.

Specifically, the physical interface card 1233 is configured to receive the first message and the SBFD response message of the SBFD message sent by the second network device, and is configured to send the SBFD message and the SBFD echo message to the second network device. Text.

The central processor 1211 is used to determine whether to establish an SBFD session for the tunnel; and used to avoid establishing an SBFD session according to the determination result or establish an SBFD session according to the determination result.

The central processor 1211 is also configured to process the received first message and the SBFD response message of the SBFD message; and generate the sent SBFD message and the SBFD echo message.

After receiving the first message and the SBFD response message of the SBFD message, the physical interface card 1233 sends the first message and the SBFD response message of the SBFD message to the central processing unit 1211 via the central processing unit 1231. 1211 processes the first message and the SBFD response message of the SBFD message.

The central processing unit 1231 is also used to control the network storage 1232 to obtain forwarding entries in the forwarding entry storage 1234, and the central processing unit 1231 is also used to control the network storage 1232 to receive and send traffic via the physical interface card 1233.

It should be understood that the operations on the interface board 1240 in the embodiment of the present invention are consistent with the operations on the interface board 1230, and will not be repeated for the sake of brevity. It should be understood that the first network device 1200 in this embodiment may correspond to the functions and/or various steps implemented in the foregoing method embodiments, and details are not described herein again.

In addition, it should be noted that there may be one or more main control boards, and when there are more than one, it may include a main main control board and a standby main control board. There may be one or more interface boards. The stronger the data processing capability of the first network device, the more interface boards provided. There may also be one or more physical interface cards on the interface board. The switching network board may not exist, or there may be one or more. When there are more than one, the load sharing and redundant backup can be realized together. Under the centralized forwarding architecture, the first network device may not need to switch the network board, and the interface board undertakes the processing function of the service data of the entire system. Under the distributed forwarding architecture, the first network device may have at least one switching network board, and data exchange between multiple interface boards is realized through the switching network board, providing large-capacity data exchange and processing capabilities. Therefore, the data access and processing capability of the first network device of the distributed architecture is greater than that of the device of the centralized architecture. The specific architecture used depends on the specific networking deployment scenario, and there is no restriction here.

FIG. 7 is a schematic structural diagram of a second network device 2000 according to an embodiment of the application. The second network device 2000 shown in FIG. 7 can execute the corresponding steps performed by the second network device in the method of the foregoing embodiment. As shown in FIG. 7, the second network device 2000 includes a processing unit 2004 and a sending unit 2006.

The processing unit 2004 is configured to generate a first message, the first message including seamless bidirectional forwarding detection SBFD information, and the SBFD information is used to indicate that the network device corresponding to the destination address of the first message is determined Whether to establish an SBFD session for the tunnel, the tunnel is a tunnel from the first network device to the second network device, the SBFD session is used to detect the state of the tunnel, and the destination address is the first network device the address of;

The sending unit 2006 is configured to send the first message to the first network device, where the SBFD information in the first message is used to prevent the first network device from establishing SBFD session of the tunnel.

Optionally, the first message is an LSP message based on the IS-IS protocol, or the first message is an LSU message based on the OSPF protocol, and the first message further includes the second network The SID of the device, and the destination address of the tunnel is the address corresponding to the SID. Further optionally, the first message includes a flag field, and the flag field is used to carry the SBFD information.

Optionally, the tunnel is an SR-BE tunnel.

The second network device shown in FIG. 7 can execute the corresponding steps performed by the second network device in the method of the foregoing embodiment. In an actual network scenario, the first network device receives the SBFD information sent by the second network device, thereby determining whether it is necessary to create an SBFD session for the tunnel according to the SBFD information, where the tunnel is from the first network device to the The tunnel of the second network device is thus avoided to create unnecessary SBFD sessions, and the number of SBFD sessions in the network is reduced.

FIG. 8 is a schematic diagram of the hardware structure of the second network device 2100 according to an embodiment of the application. The second network device 2100 shown in FIG. 8 can execute the corresponding steps performed by the second network device in the method of the foregoing embodiment.

As shown in FIG. 8, the second network device 2100 includes a processor 2101, a memory 2102, an interface 2103 and a bus 2104. The interface 2103 may be implemented in a wireless or wired manner, and specifically may be a network card. The aforementioned processor 2101, memory 2102, and interface 2103 are connected through a bus 2104.

The interface 2103 may specifically include a transmitter and a receiver, which are used to send and receive information between the second network device and the first network device in the foregoing embodiment. For example, the interface 2103 is used to support sending a first message and an SBFD message to the first network device; and is used to support receiving an SBFD response message and an SBFD echo message of an SBFD message sent by the first network device. As an example, the interface 2103 is used to support the processes S102, S108, and S109 in FIG. 2 and FIG. 3. The processor 2101 is configured to execute the processing performed by the second network device in the foregoing embodiment. For example, the processor 2101 is used to generate the first message; and/or used in other processes of the technology described herein. As an example, the processor 2101 is used to support the process S101 in FIG. 2 and FIG. 3. The memory 2102 includes an operating system 21021 and an application program 21022, which are used to store programs, codes, or instructions. When the processor or hardware device executes these programs, codes, or instructions, the processing process involving the second network device in the method embodiment can be completed. Optionally, the memory 2102 may include a read-only memory (English: Read-only Memory, abbreviation: ROM) and a random access memory (English: Random Access Memory, abbreviation: RAM). Wherein, the ROM includes a basic input/output system (English: Basic Input/Output System, abbreviation: BIOS) or an embedded system; the RAM includes an application program and an operating system. When the second network device 2100 needs to be operated, the system is booted by the BIOS solidified in the ROM or the bootloader in the embedded system to guide the second network device 2100 into a normal operating state. After the second network device 2100 enters the normal operating state, the application program and the operating system run in the RAM, thereby completing the processing procedure involving the second network device in the method embodiment.

It is understandable that FIG. 8 only shows a simplified design of the second network device 2100. In practical applications, the second network device may include any number of interfaces, processors or memories.

FIG. 9 is a schematic diagram of the hardware structure of another second network device 2200 according to an embodiment of the application. The second network device 2200 shown in FIG. 9 can execute the corresponding steps performed by the second network device in the method of the foregoing embodiment.

As shown in FIG. 9, the second network device 2200 includes: a main control board 2210, an interface board 2230, a switching network board 2220, and an interface board 2240. The main control board 2210, the interface boards 2230 and 2240, and the switching network board 2220 are connected to the system backplane through the system bus to achieve intercommunication. Among them, the main control board 2210 is used to complete functions such as system management, equipment maintenance, and protocol processing. The switching network board 2220 is used to complete data exchange between various interface boards (interface boards are also called line cards or service boards). The interface boards 2230 and 2240 are used to provide various service interfaces (for example, POS interface, GE interface, ATM interface, etc.), and realize the forwarding of data packets

The interface board 2230 may include a central processing unit 2231, a forwarding entry memory 2234, a physical interface card 2233, and a network processor 2232. Among them, the central processing unit 2231 is used to control and manage the interface board and communicate with the central processing unit on the main control board. The forwarding entry storage 2234 is used to store forwarding entries. The physical interface card 2233 is used to complete the reception and transmission of traffic. The network storage 2232 is used for controlling the receiving and sending traffic of the physical interface card 2233 according to the forwarding entry.

Specifically, the physical interface card 2233 is configured to send a first message and an SBFD message to the first network device; and is configured to receive an SBFD response message and an SBFD echo message of the SBFD message sent by the first network device.

The central processing unit 2211 is configured to generate the first message.

The central processing unit 2211 sends the first message to the physical interface card 2233 via the central processing unit 2231. The physical interface card 2233 sends the first packet to the NAT device.

The central processing unit 2231 is also used to control the network storage 2232 to obtain forwarding entries in the forwarding entry storage 2234, and the central processing unit 2231 is also used to control the network storage 2232 to complete the reception and transmission of traffic via the physical interface card 2233.

It should be understood that the operations on the interface board 2240 in the embodiment of the present invention are consistent with the operations on the interface board 2230, and will not be repeated for the sake of brevity. It should be understood that the second network device 2200 in this embodiment may correspond to the functions and/or various steps implemented in the foregoing method embodiments, and details are not described herein again.

In addition, it should be noted that there may be one or more main control boards, and when there are more than one, it may include a main main control board and a standby main control board. There may be one or more interface boards. The stronger the data processing capability of the second network device, the more interface boards provided. There may also be one or more physical interface cards on the interface board. The switching network board may not exist, or there may be one or more. When there are more than one, the load sharing and redundant backup can be realized together. Under the centralized forwarding architecture, the second network device may not need a switching network board, and the interface board is responsible for processing the service data of the entire system. Under the distributed forwarding architecture, the second network device may have at least one switching network board, and data exchange between multiple interface boards is realized through the switching network board, providing large-capacity data exchange and processing capabilities. Therefore, the data access and processing capability of the second network device of the distributed architecture is greater than that of the device of the centralized architecture. The specific architecture used depends on the specific networking deployment scenario, and there is no restriction here.

In addition, an embodiment of the present application provides a computer storage medium for storing computer software instructions used for the above-mentioned first network device, which includes a program for executing the above-mentioned method embodiment.

In addition, an embodiment of the present application provides a computer storage medium for storing computer software instructions used for the above-mentioned second network device, which includes a program for executing the above-mentioned method embodiment.

The embodiment of the present application also includes a system for processing a message. The system includes a first network device and a second network device. The first network device is the first network device in FIG. 4 or FIG. 5 or FIG. , The second network device is the second network device in FIG. 7 or FIG. 8 or FIG. 9 described above.

The steps of the method or algorithm described in combination with the disclosure of this application can be implemented in a hardware manner, or can be implemented in a manner in which a processor executes software instructions. Software instructions can be composed of corresponding software modules, which can be stored in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, mobile hard disk, CD-ROM or any other form of storage known in the art Medium. An exemplary storage medium is coupled to the processor, so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium may also be an integral part of the processor. The processor and the storage medium may be located in the ASIC. In addition, the ASIC may be located in the user equipment. Of course, the processor and the storage medium may also exist as discrete components in the user equipment.

Those skilled in the art should be aware that, in one or more of the above examples, the functions described in this application can be implemented by hardware or a combination of hardware and software. When implemented using a combination of hardware and software, the software can be stored in a computer-readable medium or transmitted as one or more instructions or codes on the computer-readable medium. The computer-readable medium includes a computer storage medium and a communication medium, where the communication medium includes any medium that facilitates the transfer of a computer program from one place to another. The storage medium may be any available medium that can be accessed by a general-purpose or special-purpose computer.

The specific implementations described above further describe the purpose, technical solutions, and beneficial effects of the present application in further detail. It should be understood that the above are only specific implementations of the application.

Claims (26)

1. A method, equipment and system for establishing a seamless two-way forwarding and detecting SBFD session. The method includes receiving, by a first network device, a first message sent by a second network device, the first message including SBFD information, and the SBFD information is used to indicate a network corresponding to a destination address of the first message The device determines whether to establish an SBFD session for the tunnel. The tunnel is a tunnel from the first network device to the second network device. The SBFD session is used to detect the status of the tunnel. The destination address is the The address of the first network device;

   Determining, by the first network device, whether the first network device establishes the SBFD session for the tunnel according to the SBFD information;

   When the first network device determines according to the SBFD information that the first network device does not need to establish the SBFD session for the tunnel, the first network device avoids creating the SBFD session.
2. The method of claim 1, wherein the method comprises:

   When the first network device determines according to the SBFD information that the first network device needs to establish the SBFD session for the tunnel, the first network device creates the SBFD session.
3. The method according to claim 2, wherein the creation of the SBFD session by the first network device comprises:

   Sending an SBFD packet to the second network device, where the SBFD packet is used to request the establishment of the SBFD session;

   Receiving an SBFD response message for the SBFD message sent by the second network device, where the SBFD response message indicates that the second network device is in a working state;

   Setting the port of the first network device corresponding to the tunnel to the UP state according to the SBFD response message.
4. The method of claim 3, wherein the method comprises:

   The first network device sends an SBFD echo message to the second network device, where the SBFD echo message is used to detect the state of the tunnel.
5. The method according to any one of claims 1-4, wherein the first message is a link state protocol LSP message based on the intermediate system to the intermediate system IS-IS protocol, and the first message The text also includes the segment identifier SID of the second network device, and the destination address of the tunnel is the address corresponding to the SID.
6. The method according to any one of claims 1-4, wherein the first message is a link state update LSU message based on the Open Shortest Path First OSPF protocol, and the first message also The segment identifier SID of the second network device is included, and the destination address of the tunnel is an address corresponding to the SID.
7. The method according to claim 5 or 6, wherein the first message includes a flag field, and the flag field is used to carry the SBFD information.
8. 7. The method according to any one of claims 1-7, wherein the tunnel is a segmented best-effort SR-BE tunnel.
9. A method for establishing a seamless two-way forwarding detection SBFD session, characterized in that the method includes:

   The second network device generates a first packet, the first packet includes SBFD information, and the SBFD information is used to indicate that the network device corresponding to the destination address of the first packet determines whether to establish an SBFD session for the tunnel, and A tunnel is a tunnel from a first network device to the second network device, the SBFD session is used to detect the state of the tunnel, and the destination address is the address of the first network device;

   The second network device sends the first message to the first network device, where the SBFD information in the first message is used to prevent the first network device from establishing a connection to the tunnel SBFD session.
10. The method according to claim 9, wherein the first message is a link state protocol LSP message based on the intermediate system-to-intermediate system IS-IS protocol, and the first message further includes the first message 2. The segment identifier SID of the network device, and the destination address of the tunnel is the address corresponding to the SID.
11. The method according to claim 9, wherein the first message is a link state update LSU message based on the Open Shortest Path First OSPF protocol, and the first message further includes the second network The segment identifier SID of the device, and the destination address of the tunnel is the address corresponding to the SID.
12. The method according to claim 10 or 11, wherein the first message includes a flag field, and the flag field is used to carry the SBFD information.
13. The method according to any one of claims 9-12, wherein the tunnel is a segmented best-effort SR-BE tunnel.
14. A first network device, characterized in that, the first network device includes:

    A receiver, configured to receive a first packet sent by a second network device, the first packet including seamless bidirectional forwarding detection SBFD information, and the SBFD information is used to indicate the destination address of the first packet corresponding to the The network device determines whether to establish an SBFD session for the tunnel. The tunnel is a tunnel from the first network device to the second network device. The SBFD session is used to detect the status of the tunnel. The address of the first network device;

    A processor, configured to determine whether the first network device establishes the SBFD session for the tunnel according to the SBFD information;

    When the processor determines according to the SBFD information that the first network device does not need to establish the SBFD session for the tunnel, the processor is further configured to avoid creating the SBFD session.
15. The first network device according to claim 14, wherein:

    When the processor determines according to the SBFD information that the first network device needs to establish the SBFD session for the tunnel, the processor is further configured to create the SBFD session.
16. The first network device according to claim 15, wherein when the processor is further configured to create the SBFD session, the processor is specifically configured to:

    Sending an SBFD packet to the second network device, where the SBFD packet is used to request the establishment of the SBFD session;

    Receiving an SBFD response message for the SBFD message sent by the second network device, where the SBFD response message indicates that the second network device is in a working state;

    Setting the port of the first network device corresponding to the tunnel to the UP state according to the SBFD response message.
17. The first network device of claim 16, wherein:

    The processor is further configured to send an SBFD echo message to the second network device, where the SBFD echo message is used to detect the state of the tunnel.
18. The first network device according to any one of claims 14-17, wherein the first message is a link state protocol LSP message based on the intermediate system to the intermediate system IS-IS protocol, and the The first message also includes the segment identifier SID of the second network device, and the destination address of the tunnel is an address corresponding to the SID.
19. The first network device according to any one of claims 14-17, wherein the first message is a link state update LSU message based on the Open Shortest Path First OSPF protocol, and the first The message also includes the segment identifier SID of the second network device, and the destination address of the tunnel is the address corresponding to the SID.
20. The first network device according to claim 18 or 19, wherein the first message includes a flag field, and the flag field is used to carry the SBFD information.
21. The first network device according to any one of claims 14-20, wherein the tunnel is a segmented best-effort SR-BE tunnel.
22. A second network device, characterized in that, the second network device includes:

    A processor, configured to generate a first packet, the first packet including seamless bidirectional forwarding detection SBFD information, and the SBFD information is used to indicate whether a network device corresponding to the destination address of the first packet determines whether it is a tunnel Establishing an SBFD session, where the tunnel is a tunnel from a first network device to the second network device, the SBFD session is used to detect the state of the tunnel, and the destination address is the address of the first network device;

    A transmitter, configured to send the first message to the first network device, where the SBFD information in the first message is used to prevent the first network device from establishing SBFD for the tunnel Conversation.
23. The second network device according to claim 22, wherein the first message is a link state protocol (LSP) message based on the intermediate system-to-intermediate system IS-IS protocol, and the first message further includes The segment identifier SID of the second network device, and the destination address of the tunnel is an address corresponding to the SID.
24. The second network device according to claim 22, wherein the first message is a link state update LSU message based on the Open Shortest Path First OSPF protocol, and the first message further includes the The segment identifier SID of the second network device, and the destination address of the tunnel is the address corresponding to the SID.
25. The second network device according to claim 23 or 24, wherein the first message includes a flag field, and the flag field is used to carry the SBFD information.
26. The second network device according to any one of claims 22-25, wherein the tunnel is a segmented best-effort SR-BE tunnel.

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