Method and network device for generating path information

Abstract

The present disclosure provides a method and a network device for generating path information. The method for generating path information comprises: after receiving a first BGP packet including a VPN SID sent by a tail-end device in a second AS, extracting a set of autonomous system identifiers and a first color parameter through which the first BGP packet is transmitted in the process from the autonomous system path attribute information of the first BGP packet; after receiving a second BGP packet including a BSID TLV, extracting a second color parameter from the BSID TLV, wherein a first ASBR device in the first AS and a second ASBR device in the second AS send the second packet including the BSID TLV after completing VPN service configuration and SR policy configuration; if the first color parameter and the second color parameter are the same, extracting an AS identifier of a device sending the second BGP packet from the autonomous system path attribute information of the second BGP packet; and generating path information according to the correspondence between the AS identifier and the set of autonomous system identifiers, the BSID TLV, an AS sub-TLV of a head-end connection and an AS sub-TLV of a tail-end connection.

Description

Technical Field

[0001] This disclosure relates to the field of network technology, and in particular to a method and network device for generating path information. Background Technology

[0002] BSID (Binding Segment Identifier) ​​is an important component of SR (Segment Routing) policies. BSID serves three main functions: first, it acts as an identifier for SR policies, explicitly directing traffic to a specific SR policy; second, it replaces complete path information (SID (Segment Identifier) ​​- List), reducing the SID stack depth before entering the SR policy; and third, it serves as an external identifier for SR policies, mitigating security risks associated with SID-list leakage for security reasons. Summary of the Invention

[0003] The inventors noted that in related technologies, no message has been defined that can transmit cross-domain application-related attributes of SR policies, such as the AS (Autonomous System) to which the policy's starting point is connected. Therefore, current router devices find it difficult to automatically generate cross-domain dynamic TE (Traffic Engineering) paths based on information obtained from BGP (Border Gateway Protocol) messages, and cannot use TE policies within adjacent domains across domains.

[0004] Therefore, this disclosure provides a scheme for generating path information, thereby solving the problem of cross-domain BSID transmission.

[0005] According to a first aspect of the present disclosure, a method for generating path information is provided, executed by a headend device in a first AS, comprising: upon receiving a first BGP message including a VPN SID sent by a tailend device in a second AS, extracting an autonomous system identifier set and a first color parameter from the autonomous system path attribute information of the first BGP message during transmission; upon receiving a second BGP message including a BSID TLV, extracting a second color parameter from the BSID TLV, wherein a first ASBR device in the first AS and a second ASBR device in the second AS send the second message including the BSID TLV after completing VPN service configuration and SR policy configuration; if the first color parameter and the second color parameter are the same, extracting an AS identifier that sent the second BGP message from the autonomous system path attribute information of the second BGP message; determining the order of BSIDs in the BSID TLV according to the correspondence between the AS identifier and the autonomous system identifier set, the BSID TLV included in the second BGP message, the AS sub-TLV of the headend connection, and the AS sub-TLV of the tailend connection, to generate path information; wherein the BSIDs A TLV includes a BSID, a header SID, and a tail SID. The AS sub-TLV connected to the header includes the AS information connected to the header, and the AS sub-TLV connected to the tail includes the AS information connected to the tail.

[0006] In some embodiments, determining the order of BSIDs in a BSID TLV includes: if the AS identifier is a first AS identifier included in the Autonomous System Identifier set, then obtaining the headend SID from the BSID TLV; if the locator of the headend SID is consistent with the locator of the headend device's own SID, then extracting the headend-connected AS information from the headend-connected AS sub-TLV; if the headend-connected AS information includes a second AS identifier, then extracting the BSID from the BSID TLV as the first BSID.

[0007] In some embodiments, if the AS identifier is a second AS identifier included in the set of autonomous system identifiers, then the trailing SID is obtained from the BSID TLV; if the locator of the trailing SID is consistent with the locator of the VPN SID, then the AS information of the trailing connection is extracted from the AS sub-TLV of the trailing connection; if the AS information of the trailing connection includes a first AS identifier, then the BSID is extracted from the BSID TLV as the second BSID.

[0008] In some embodiments, the path information includes, in sequence: VPN SID, second BSID, and first BSID.

[0009] According to a second aspect of the present disclosure, a network device for generating path information is provided, comprising: a first processing module configured to, upon receiving a first BGP message including a VPN SID sent by a tail device in a second AS, extract from the autonomous system identifier set and a first color parameter the first BGP message traversed during transmission by the autonomous system path attribute information of the first BGP message; a second processing module configured to, upon receiving a second BGP message including a BSID TLV, extract from the BSID TLV the second BGP message, wherein a first ASBR device in the first AS and a second ASBR device in the second AS send the second message including the BSID TLV after completing VPN service configuration and SR policy configuration; and a third processing module configured to, if the first color parameter and the second color parameter are the same, extract the AS identifier of the sending second BGP message from the autonomous system path attribute information of the second BGP message, and determine the BSID based on the correspondence between the AS identifier and the autonomous system identifier set, the BSID TLV included in the second BGP message, the AS sub-TLV connected at the headend, and the AS sub-TLV connected at the tailend. The order of BSIDs in the TLV is used to generate path information; wherein, the BSID TLV includes BSID, head end SID and tail end SID, the AS sub-TLV connected to the head end includes the AS information connected to the head end, and the AS sub-TLV connected to the tail end includes the AS information connected to the tail end.

[0010] In some embodiments, the third processing module is configured to obtain the headend SID from the BSID TLV if the AS identifier is a first AS identifier included in the autonomous system identifier set; extract the headend connected AS information from the AS sub-TLV of the headend connected if the locator of the headend SID is consistent with the locator of the headend device's own SID; and extract the BSID from the BSID TLV as the first BSID if the AS information of the headend connected includes a second AS identifier.

[0011] In some embodiments, the third processing module is configured to obtain the trailing SID from the BSID TLV if the AS identifier is a second AS identifier included in the Autonomous System Identifier set; extract the AS information of the trailing connection from the AS sub-TLV of the trailing connection if the locator of the trailing SID is consistent with the locator of the VPN SID; and extract the BSID from the BSID TLV as the second BSID if the AS information of the trailing connection includes a first AS identifier.

[0012] In some embodiments, the path information includes, in sequence: VPN SID, second BSID, and first BSID.

[0013] According to a third aspect of the present disclosure, a network device for generating path information is provided, comprising: a memory configured to store instructions; and a processor coupled to the memory, the processor being configured to execute instructions stored in the memory to implement the method as described in any of the above embodiments.

[0014] According to a fourth aspect of the present disclosure, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions that, when executed by a processor, implement the method as described in any of the above embodiments.

[0015] Other features and advantages of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of a network structure for generating path information according to an embodiment of the present disclosure;

[0018] Figure 2 This is a schematic diagram of a process for generating path information according to an embodiment of the present disclosure;

[0019] Figure 3 This is a schematic diagram of the structure of a network device for generating path information according to an embodiment of the present disclosure;

[0020] Figure 4 This is a schematic diagram of the structure of a network device for generating path information according to another embodiment of the present disclosure;

[0021] Figure 5 This is a schematic diagram of a network structure for generating path information according to another embodiment of this disclosure. Detailed Implementation

[0022] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0023] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of this disclosure.

[0024] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0025] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0026] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0027] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0028] Figure 1 This is a schematic diagram of a network structure for generating path information according to an embodiment of this disclosure. Figure 1 As shown, controllers 1 and 2 exchange the BSID and VPN (Virtual Private Network)-SID corresponding to the policy via an API interface, and negotiate that one controller (e.g., controller 1) will be responsible for calculating the splicing path and configuring the splicing path in R1. Since controller 1 needs to participate in the splicing path calculation, this increases the workload of controller 1. Furthermore, the interaction between controllers from different vendors via API interfaces also presents some complexity.

[0029] Figure 2 This is a flowchart illustrating a method for generating path information according to an embodiment of the present disclosure. In some embodiments, the following method for generating path information is performed by a headend device in a first AS.

[0030] In step 201, after receiving the first BGP message including the VPN SID sent by the tail device in the second AS, the set of autonomous system identifiers and the first color parameter that the first BGP message passed through during transmission are extracted from the autonomous system path (AS_PATH) attribute information of the first BGP message.

[0031] In step 202, after receiving the second BGP message including the BSID TLV, the second color parameter is extracted from the BSID TLV.

[0032] It should be noted that after completing the VPN service configuration and SR policy configuration, the first ASBR device in the first AS and the second ASBR device in the second AS send a second message including the BSID TLV.

[0033] In step 203, if the first color parameter and the second color parameter are the same, the AS identifier for sending the second BGP message is extracted from the Autonomous System Path Attribute Information of the second BGP message.

[0034] In step 204, the order of BSIDs in the BSID TLV is determined based on the correspondence between the AS identifier and the set of autonomous system identifiers, the BSID TLV included in the second BGP message, the AS sub-TLV connected at the header, and the AS sub-TLV connected at the tail, so as to generate path information.

[0035] It should be noted that the BSID TLV (Type-Length-Value) is shown in Table 1.

[0036]

[0037] Table 1

[0038] It should be noted that the parameter Color is used to represent the business type.

[0039] The head-connected AS sub-TLVs are shown in Table 2.

[0040]

[0041] Table 2 shows the tail-connected AS sub-TLVs, as shown in Table 3.

[0042]

[0043] Table 3

[0044] In some embodiments, if the AS identifier sending the second BGP message is a first AS identifier included in the Autonomous System Identifier set, then the headend SID is obtained from the BSID TLV. If the locator of the headend SID matches the locator of the headend device's own SID, then the AS information of the headend connection is extracted from the AS sub-TLV of the headend connection. If the AS information of the headend connection includes a second AS identifier, then the BSID is extracted from the BSID TLV as the first BSID.

[0045] In some embodiments, if the AS identifier is a second AS identifier included in the Autonomous System Identifier set, the trailing SID is obtained from the BSIDTLV. If the locator of the trailing SID matches the locator of the VPN SID, the AS information of the trailing connection is extracted from the AS sub-TLV of the trailing connection. If the AS information of the trailing connection includes a first AS identifier, the BSID is extracted from the BSID TLV as the second BSID.

[0046] In some embodiments, the path information includes, in sequence: VPN SID, second BSID, and first BSID.

[0047] Figure 3 This is a schematic diagram of the structure of a network device for generating path information according to an embodiment of this disclosure. Figure 3 As shown, the network device used to generate path information includes a first processing module 31, a second processing module 32, and a third processing module 33.

[0048] The first processing module 31 is configured to, upon receiving a first BGP message including a VPNSID sent by a tail device in the second AS, extract from the autonomous system identifier set and the first color parameter that the first BGP message passed through during transmission from the autonomous system path attribute information of the first BGP message.

[0049] The second processing module 32 is configured to extract the second color parameter from the BSIDTLV after receiving a second BGP message that includes the BSIDTLV.

[0050] It should be noted that the first ASBR device in the first AS and the second ASBR device in the second AS send a second message including the BSID TLV after completing the VPN service configuration and SR policy configuration.

[0051] The third processing module 33 is configured to extract the AS identifier of the sending second BGP message from the autonomous system path attribute information of the second BGP message if the first color parameter and the second color parameter are the same, and determine the order of BSIDs in the BSID TLV according to the correspondence between the AS identifier and the set of autonomous system identifiers, the BSID TLV included in the second BGP message, the AS sub-TLV connected at the headend and the AS sub-TLV connected at the tailend, so as to generate path information.

[0052] Among them, the BSID TLV is shown in Table 1 above, the AS sub-TLV connected to the head end is shown in Table 2 above, and the AS sub-TLV connected to the tail end is shown in Table 3 above.

[0053] In some embodiments, the third processing module 33 is configured to obtain the headend SID from the BSID TLV if the AS identifier is a first AS identifier included in the autonomous system identifier set; extract the headend connected AS information from the AS sub-TLV of the headend connected if the locator of the headend SID is consistent with the locator of the headend device's own SID; and extract the headend connected AS information from the AS sub-TLV of the headend connected if the headend connected AS information includes a second AS identifier, extract the BSID from the BSID TLV as the first BSID.

[0054] In some embodiments, the third processing module 33 is configured to obtain the trailing SID from the BSID TLV if the AS identifier is a second AS identifier included in the autonomous system identifier set; extract the trailing connection AS information from the trailing connection AS sub-TLV if the locator of the trailing SID is consistent with the locator of the VPN SID; and extract the BSID from the BSID TLV as the second BSID if the trailing connection AS information includes a first AS identifier.

[0055] In some embodiments, the path information includes, in sequence: VPN SID, second BSID, and first BSID.

[0056] Figure 4 This is a schematic diagram of the structure of a network device for generating path information according to another embodiment of this disclosure. Figure 4 As shown, the network device includes a memory 41 and a processor 42.

[0057] Memory 41 is used to store instructions, and processor 42 is coupled to memory 41. Processor 42 is configured to execute instructions based on the memory storage, as shown in the example. Figure 2 The method involved in any of the embodiments.

[0058] like Figure 4As shown, the network device also includes a communication interface 43 for exchanging information with other devices. Additionally, the network device includes a bus 44, through which the processor 42, communication interface 43, and memory 41 communicate with each other.

[0059] The memory 41 may include high-speed RAM, and may also include non-volatile memory, such as at least one disk storage device. The memory 41 may also be a memory array. The memory 41 may also be divided into blocks, and the blocks may be combined into virtual volumes according to certain rules.

[0060] Furthermore, processor 42 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present disclosure.

[0061] This disclosure also relates to a computer-readable storage medium storing computer instructions that, when executed by a processor, implement... Figure 2 The method involved in any of the embodiments.

[0062] The following is a specific example to illustrate this disclosure, such as... Figure 5 As shown.

[0063] 1. When the service is activated, R2 will send a BGP message carrying the VPN SID to R1. After receiving the message, R1 will perform the following operations:

[0064] 1.1 Obtain the AS identifier that the packet passed through during transmission from the AS_PATH attribute of the BGP packet. In this embodiment, AS_PATH includes AS1 and AS2.

[0065] 1.2 Obtain the Color associated with the VPN SID (used to identify the service type of the VPN SID) from the AS_PATH attribute of the BGP message.

[0066] 1.3 Obtain the SID of the service tail node from the AS_PATH attribute of the BGP message.

[0067] Version 1.4R1 uses the VPN SID as the last SID in the BSID concatenation.

[0068] 2. After R1 receives the BGP message carrying the BSID TLV, it performs the following operations:

[0069] 2.1 Obtain the Color from the BSID TLV and compare it with the Color of the VPN SID. If the Color values ​​are the same, proceed to step 2.2;

[0070] 2.2 Extract the AS identifier that provides the message from the AS_PATH attribute of the BGP message;

[0071] 2.3 Compare the obtained AS identifier with the AS identifiers traversed by the VPN SID. If AS = AS1, retrieve the Head End SID from the BSID TLV and compare its locator with the locator of its own SID to check if they match. Simultaneously, retrieve the Head Connected AS from the Head Connected AS Sub-TLV and check if it contains AS2. If both conditions are met, retrieve the BSID from the BSID TLV; otherwise, perform no operation.

[0072] If AS = AS2, then retrieve the Tail End SID from the BSID TLV and compare its locator with the VPN SID's locator to see if they are the same. Simultaneously, retrieve the Tail Connected AS from the Tail Connected AS Sub-TLV and check if it contains AS1. If both conditions are met, retrieve the BSID from the BSID TLV; otherwise, do nothing.

[0073] It should be noted that after ASBR1 in AS1 and ASBR2 in AS2 complete the VPN service configuration and SR policy configuration, they send a second message including the BSID TLV.

[0074] 3. R1 generates path information based on the AS_PATH attribute in the BGP packet carrying the VPN SID. The path information includes, in order: VPN SID → Second BSID → First BSID.

[0075] exist Figure 5 In this diagram, R1 is the headend device, R2 is the tailend device, ASBR1 is the Autonomous System Boundary Router of AS1, and ASBR2 is the Autonomous System Boundary Router of AS2.

[0076] In some embodiments, the functional unit modules described above may be implemented as general-purpose processors, programmable logic controllers (PLCs), digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or any suitable combination thereof for performing the functions described herein.

[0077] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0078] The description in this disclosure is provided for illustrative and descriptive purposes only and is not intended to be exhaustive or to limit the disclosure to its forms. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of this disclosure and to enable those skilled in the art to understand this disclosure and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A method for generating path information, performed by a headend device in a first AS, comprising: After receiving the first BGP message including the VPN SID sent by the tail device in the second AS, the set of autonomous system identifiers and the first color parameter that the first BGP message passed through during transmission are extracted from the autonomous system path attribute information of the first BGP message. After receiving the second BGP message including the BSID TLV, the second color parameter is extracted from the BSID TLV. The first ASBR device in the first AS and the second ASBR device in the second AS send the second BGP message including the BSID TLV after completing the VPN service configuration and SR policy configuration. If the first color parameter and the second color parameter are the same, then the AS identifier for sending the second BGP message is extracted from the Autonomous System Path Attribute information of the second BGP message. Based on the correspondence between the AS identifier and the set of autonomous system identifiers, the BSID TLV included in the second BGP message, the AS sub-TLV connected at the header end and the AS sub-TLV connected at the tail end, the order of BSIDs in the BSID TLV is determined to generate path information. The BSID TLV includes a BSID, a headend SID, and a tailend SID. The AS sub-TLV connected to the headend includes AS information connected to the headend, and the AS sub-TLV connected to the tailend includes AS information connected to the tailend.

2. The method according to claim 1, wherein, Determining the order of BSIDs in the BSID TLV includes: If the AS identifier is a first AS identifier included in the Autonomous System Identifier set, then the headend SID is obtained from the BSID TLV; if the locator of the headend SID is consistent with the locator of the headend device's own SID, then the headend connected AS information is extracted from the AS sub-TLV of the headend connected; if the headend connected AS information includes a second AS identifier, then the BSID corresponding to the second AS identifier is extracted from the BSID TLV as the first BSID.

3. The method according to claim 2, further comprising: If the AS identifier is the second AS identifier included in the set of autonomous system identifiers, then the tail SID is obtained from the BSID TLV; If the locator of the trailing SID matches the locator of the VPN SID, then the AS information of the trailing connection is extracted from the AS sub-TLV of the trailing connection; if the AS information of the trailing connection includes a first AS identifier, then the BSID corresponding to the first AS identifier is extracted from the BSID TLV as the second BSID.

4. The method according to claim 3, wherein, The path information includes, in sequence: VPN SID, second BSID, and first BSID.

5. A network device for generating path information, comprising: The first processing module is configured to, upon receiving a first BGP message including a VPN SID sent by a tail device in the second AS, extract from the autonomous system path attribute information of the first BGP message the set of autonomous system identifiers and the first color parameter that the first BGP message passed through during transmission. The second processing module is configured to extract the second color parameter from the BSID TLV after receiving the second BGP message including the BSID TLV, wherein the first ASBR device in the first AS and the second ASBR device in the second AS send the second BGP message including the BSID TLV after completing the VPN service configuration and SR policy configuration. The third processing module is configured to extract the AS identifier of the sending BGP message from the autonomous system path attribute information of the second BGP message if the first color parameter and the second color parameter are the same, and determine the order of BSIDs in the BSID TLV according to the correspondence between the AS identifier and the set of autonomous system identifiers, the BSID TLV included in the second BGP message, the AS sub-TLV connected at the head end and the AS sub-TLV connected at the tail end, so as to generate path information. The BSID TLV includes a BSID, a headend SID, and a tailend SID. The AS sub-TLV connected to the headend includes AS information connected to the headend, and the AS sub-TLV connected to the tailend includes AS information connected to the tailend.

6. The network device according to claim 5, wherein, The third processing module is configured to obtain the headend SID from the BSID TLV if the AS identifier is a first AS identifier included in the autonomous system identifier set; if the locator of the headend SID is consistent with the locator of the headend device's own SID; extract the headend connected AS information from the AS sub-TLV of the headend connected; and if the headend connected AS information includes a second AS identifier, extract the BSID corresponding to the second AS identifier from the BSID TLV as the first BSID.

7. The network device according to claim 6, wherein, The third processing module is configured to obtain the trailing SID from the BSID TLV if the AS identifier is a second AS identifier included in the Autonomous System Identifier set; if the locator of the trailing SID is consistent with the locator of the VPN SID, extract the AS information of the trailing connection from the AS sub-TLV of the trailing connection; and if the AS information of the trailing connection includes a first AS identifier, extract the BSID corresponding to the first AS identifier from the BSID TLV as the second BSID.

8. The network device according to claim 7, wherein, The path information includes, in sequence: VPN SID, second BSID, and first BSID.

9. A network device for generating path information, comprising: The memory is configured to store instructions; A processor, coupled to memory, configured to implement the method as described in any one of claims 1-4 based on memory-stored instruction execution.

10. A computer-readable storage medium, wherein, A computer-readable storage medium stores computer instructions that, when executed by a processor, implement the method as described in any one of claims 1-4.

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