SBFD / BFD detection method and routing equipment

Abstract

The invention provides an SBFD / BFD detection method and routing equipment, and the method comprises the steps: creating a first SBFD / BFD session according to SRv6TE Policy, judging whether a target forwarding table item matched with a first SID list used for creating the first SBFD / BFD session exists in the corresponding relation between the SID list and the forwarding table item recorded by the SBFD / BFD session, and if yes, executing the SBFD / BFD session according to the target forwarding table item matched with the first SID list used for creating the first SBFD / BFD session; and if yes, taking the target forwarding table item as the forwarding table item of the first SID list. Through the method, the number of BFD / SBFD sessions can be reduced, and consumption of equipment and network resources is reduced.

Description

Technical Field

[0001] This specification relates to the field of communication technologies, and particularly to a detection method for SBFD / BFD and a routing device. Background Art

[0002] BFD: Bidirectional Forwarding Detection, bidirectional forwarding detection;

[0003] SBFD: Seamless BFD, seamless bidirectional forwarding detection;

[0004] SRv6 TE Policy: Segment Routing for IPv6 Traffic Engineering Policy, traffic engineering policy based on SRv6;

[0005] SID: Segment Identifier, segment identifier;

[0006] SID List: Segment Identifier List, SID list, a list composed of multiple SIDs.

[0007] SRv6 TE Policy is a traffic forwarding tunnel widely used in various networks. In the RFC standard, it is defined that each SRv6 TE Policy is uniquely identified by a triple of the tunnel's head node Headend, the IP address of the tail node End-point, and Color representing the service intention, that is, such a tunnel of SRv6 TE Policy is not uniquely identified by the forwarding path, and the forwarding path is only a component of SRv6 TE Policy.

[0008] The architecture of SRv6 TE Policy includes the following two levels:

[0009] Candidate Path: There can be multiple Candidate Paths (candidate paths) with different priorities in SRv6 TE Policy.

[0010] SID list: Each candidate path can further include one or more forwarding paths identified by a SID List (SID list).

[0011] Such as Figure 1As shown in the figure, Device A is the tunnel head node of the SRv6 TE Policy, and Device D is the tunnel tail node. There is an SRv6 TE Policy named AtoD between A and D. Its triple is: Headend = DeviceA, Tail node destination address = DeviceD, Color = 10. There are two forwarding paths, SID list 1 and SID list 2, under the optimal candidate path of the SRv6 TE Policy AtoD. When the service traffic is carried and forwarded through the SRv6 TE Policy, it will be shared by the two forwarding paths in the figure. In the actual network, since each SRv6 TE Policy serves as a tunnel for carrying a certain service, it is often necessary to create a large number of SRv6 TE Policies to carry different types of service traffic respectively.

[0012] On the other hand, BFD / SBFD is a reliability guarantee mechanism for detecting the reachability of the forwarding path of the SRv6 TE Policy. BFD / SBFD detects the reachability of the entire forwarding path by periodically (millisecond level) constructing and sending detection messages at the tunnel head node. Only when the detection message is received and confirmed within a certain time is the forwarding path considered reachable. Currently, the detection mechanism of BFD / SBFD for SRv6 TE Policy creates a BFD / SBFD session separately for each forwarding path (SID list) of the optimal candidate path in all SRv6 TE Policies. If there are a large number of SRv6 TE Policies in the network, a large number of BFD / SBFD sessions will be created on the device, and the network will be flooded with BFD / SBFD detection messages, consuming device and network resources. Summary of the Invention

[0013] To overcome the problems existing in the related art, this specification provides a detection method for SBFD / BFD and a routing device.

[0014] According to the first aspect of the embodiments of this specification, a detection method for SBFD / BFD is provided. The method includes:

[0015] Create a first SBFD / BFD session according to the SRv6 TE Policy;

[0016] Judge whether there is a target forwarding entry in the corresponding relationship between the SID list recorded by itself and the forwarding entry table that matches the first SID list used to create the first SBFD / BFD session;

[0017] If it exists, use the target forwarding entry as the forwarding entry of the first SID list.

[0018] Among them, determining whether there is a target forwarding entry in the correspondence between the SID list recorded by itself and the forwarding entries that matches the first SID list for creating the first SBFD / BFD session includes:

[0019] Obtain the first forwarding information for creating the forwarding entry corresponding to the first SID list;

[0020] Traverse the recorded forwarding entries according to the first forwarding information to check whether there is a corresponding target forwarding entry;

[0021] If there is, use the target forwarding entry as the forwarding entry of the first SID list.

[0022] Among them, the method further includes:

[0023] When it is determined that there is no target forwarding entry in the correspondence between the SID list recorded by itself and the forwarding entries that matches the first SID list for creating the first SBFD / BFD session, create the first forwarding entry corresponding to the first SID list, and record the correspondence between the first forwarding entry and the first SID list.

[0024] Among them, using the target forwarding entry as the forwarding entry of the first SID list includes:

[0025] Establish the correspondence between the first SBFD / BFD session, the address SID list, and the target forwarding entry;

[0026] Encapsulate the first SBFD / BFD session according to the target forwarding entry.

[0027] Among them, before using the target forwarding entry as the forwarding entry of the first SID list, the method further includes:

[0028] Obtain the second SBFD / BFD session corresponding to the target forwarding entry;

[0029] Verify whether the session parameters of the first SBFD / BFD session and the second SBFD / BFD session match. If they match, use the target forwarding entry as the forwarding entry of the first SID list.

[0030] It can be seen from the above embodiments that when creating SBFD / BFD based on the SRv6 TE Policy, it will first determine whether there is a corresponding existing forwarding entry. If there is, the existing forwarding entry can be reused. If not, the corresponding forwarding entry will be created, thereby reducing the number of BFD / SBFD sessions, reducing the consumption of device and network resources, and reducing the forwarding entries generated by the same SID list.

[0031] According to a second aspect of the embodiments of the present specification, a routing device is provided, and the routing device includes:

[0032] A creation module, configured to create a first SBFD / BFD session according to the SRv6 TE Policy;

[0033] A judgment module, configured to judge whether there is a target forwarding entry in the corresponding relationship between the SID list recorded by itself and the forwarding entries that matches the first SID list for creating the first SBFD / BFD session;

[0034] If there is, the creation module is further configured to use the target forwarding entry as the forwarding entry of the first SID list.

[0035] Wherein, the judgment module is specifically configured to obtain first forwarding information for creating a forwarding entry corresponding to the first SID list;

[0036] Traverse the recorded forwarding entries according to the first forwarding information to determine whether there is a corresponding target forwarding entry.

[0037] Wherein, the judgment module is further configured to, when it is judged that there is no target forwarding entry in the corresponding relationship between the SID list recorded by itself and the forwarding entries that matches the first SID list for creating the first SBFD / BFD session, the creation module is further configured to create a first forwarding entry corresponding to the first SID list and record the corresponding relationship between the first forwarding entry and the first SID list.

[0038] Wherein, the creation module is specifically configured to establish a corresponding relationship among the first SBFD / BFD session, the address SID list, and the target forwarding entry;

[0039] Encapsulate the first SBFD / BFD session according to the target forwarding entry.

[0040] Wherein, the creation module is further configured to obtain a second SBFD / BFD session corresponding to the target forwarding entry;

[0041] Verify whether the session parameters of the first SBFD / BFD session and the second SBFD / BFD session match, and if they match, use the target forwarding entry as the forwarding entry of the first SID list.

[0042] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present specification. Description of the Drawings

[0043] The drawings here are incorporated into the specification and constitute a part of the specification, showing the embodiments consistent with the present specification, and are used together with the specification to explain the principles of the present specification.

[0044] Figure 1 This is a schematic diagram of an SRv6 TE Policy network architecture shown in this specification according to an exemplary embodiment.

[0045] Figure 2 This is a schematic diagram of the detection message forwarding of BFD for SRv6 TE Policy shown in this specification according to an exemplary embodiment.

[0046] Figure 3 This is a schematic flowchart of a detection method for SBFD / BFD shown in this specification according to an exemplary embodiment.

[0047] Figure 4 This is a schematic diagram of the session process of SRv6 and BFD shown in this specification according to an exemplary embodiment. Detailed implementation manners

[0048] Here, the exemplary embodiments will be described in detail, and the examples are shown in the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with this specification. On the contrary, they are merely examples of devices and methods consistent with some aspects of this specification as detailed in the appended claims.

[0049] The terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit this specification. The singular forms "a", "the", and "said" used in this specification and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0050] It should be understood that although the terms first, second, third, etc. may be used in this specification to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this specification, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "when" or "while" or "in response to determining".

[0051] Currently, for SRv6 TE Policy, even if the same SID list is referenced, multiple forwarding table entries will be created for the same SID list referenced by different SRv6 TE Policies. For BFD / SBFD, since the current detection mechanism of BFD / SBFD for SRv6 TE Policy creates sessions based on the forwarding table entries, each forwarding path (SID list) of the optimal candidate path in all SRv6 TE Policies will create a BFD / SBFD session separately.

[0052] As Figure 2 shown, although there is only one forwarding path (SID list), due to business requirements, two SRv6 TE Policies are still created in the network to carry different services. Both of these SRv6 TE Policies reference the same SID list. When using SBFD for SRv6 TE Policy to detect the reachability of the forwarding path (similarly for BFD for SRv6 TE Policy), the device will create SBFD sessions for the two SRv6 TE Policies respectively.

[0053] When there are a large number of SRv6 TE Policies in the network, a large number of forwarding table entries corresponding to the SID list will be generated. And BFD / SBFD for SRv6 TE Policy will create a large number of BFD / SBFD sessions, resulting in excessive resource consumption. Even if different SRv6 TE Policies reference the same forwarding path or the same SID list, multiple BFD / SBFD sessions will be created.

[0054] It can be seen from the above that in the original implementation solution, the forwarding table entries of the SID list are not generated when creating the SID list. Only when the SRv6 TE Policy references the SID list, the forwarding table entries of the SRv6 TE Policy and the SID list are generated. And even if the forwarding information of the SID lists referenced by different SRv6 TE Policies is the same, multiple forwarding table entries will be generated for each SID list referenced by the SRv6 TE Policy. That is, the forwarding table entries of the SID list exist attached to the forwarding table entries of the SRv6 TE Policy and cannot exist independently. Therefore, there may be multiple forwarding table entries generated for the same SID list, and multiple forwarding indexes will also be generated for SID lists with the same forwarding information but different names.

[0055] To solve the above technical problems, an embodiment of the present disclosure provides a detection method for SBFD / BFD, as Figure 3 shown, the method includes:

[0056] S301 Create the first SBFD / BFD session according to the SRv6 TE Policy;

[0057] S302 Determine whether there is a target forwarding entry in the correspondence between the SID list recorded locally and the forwarding entries that matches the first SID list used to create the first SBFD / BFD session;

[0058] S303 If there is a match, use the target forwarding entry as the forwarding entry for the first SID list.

[0059] In this embodiment, when the SRv6 TE Policy creates the first SBFD / BFD session, the first forwarding information for creating the first SBFD / BFD session is first obtained. The first forwarding information may include: Headend, the destination address of the tail node, and Color information.

[0060] Traverse the locally recorded forwarding entries using the first forwarding information to determine whether there is a target forwarding entry that matches the first forwarding information. In a specific implementation, the correspondence between each SID list that has been created locally and the forwarding entries may also be recorded, and then the first forwarding information is used to traverse and query for a matching target forwarding entry in this correspondence.

[0061] During the traversal process, if no matching target forwarding entry is found, it can be considered that the forwarding entry corresponding to the first forwarding information has not been created locally. At this time, the corresponding SID list and forwarding entry can be created according to the first forwarding information and recorded locally.

[0062] When executing step S303, obtain the second SBFD / BFD session corresponding to the target forwarding entry, and verify whether the session parameters of the first SBFD / BFD session and the second SBFD / BFD session match. For example: the negotiation parameters of the BFD / SBFD template, whether the BFD / SBFD session is specified to carry a specific source address and OAM information, and whether the BFD / SBFD session uses a special encapsulation method. When the verification result is a match, use the target forwarding entry as the forwarding entry for the first SID list.

[0063] As can be seen from the above embodiments, by adjusting the logic of generating forwarding entries based on the SRv6 TE Policy and the SID list, the SID list can generate forwarding entries independently, reducing the duplicate forwarding entries of the SID list, reducing the number of BFD / SBFD sessions in a large-scale SRv6 TE Policy network, and reducing the consumption of device and network resources.

[0064] Based on the above method embodiments, the present disclosure also provides an example, as Figure 4 shown

[0065] 1. For the SRv6 TE Policy, the SID list represents the specific forwarding path. In the forwarding table entry, the SID list is uniquely identified by the forwarding information such as the forwarding egress interface, next hop, and all SID values in the list. When the SRv6 function module creates a new SID list, it notifies the forwarding module to generate a forwarding table entry. At this time, the forwarding module verifies the forwarding information of the SID list. If there already exists a SID list with exactly the same forwarding information, a new forwarding table entry will not be generated, and the association relationship between the SID list name and the forwarding table entry will be established. When modifying an existing SID list by its name, the forwarding module needs to verify the forwarding information of the modified SID list again and update the forwarding table entry.

[0066] 2. When the SRv6 TE Policy references a SID list, the SRv6 function module notifies the forwarding module to create the forwarding table entries for the SRv6 TE Policy and its candidate paths, and associates the forwarding table entries of the SRv6 TE Policy and its candidate paths with the forwarding table entries of the referenced SID list according to the referenced SID list name. In this way, as long as the forwarding information is the same, the SID list forwarding table entries are the same, and there is only one forwarding table entry for controlling the final packet encapsulation, instead of having multiple forwarding indexes as shown in the current display segment-routing ipv6 forwarding command display forwarding table entries.

[0067] 3. After enabling the BFD / SBFD for SRv6 TE Policy function, the BFD module prepares to create a session for the SRv6 TE Policy. BFD / SBFD queries the SRv6 module about the relationship between the SRv6 TE Policy forwarding table entry ID and the SID list forwarding table entry ID, and the SRv6 module then obtains the relevant information from the forwarding module. If different SRv6 TEs obtained by the BFD module are associated with the same SID list forwarding ID, the BFD / SBFD packets encapsulated in the BFD / SBFD session may be the same, and the BFD module will continue with the next verification. If different SRv6 TEs obtained by the BFD module are associated with different SID list forwarding IDs, the BFD / SBFD session will be directly created.

[0068] 4. Since in addition to the forwarding information of the SID list affecting the BFD / SBFD encapsulation and session, the configuration of BFD / SBFD itself also affects whether the BFD / SBFD sessions are the same. Among them, it includes the negotiation parameters of the BFD / SBFD template, whether the BFD / SBFD session specifies carrying a specific source address and OAM information, and whether the BFD / SBFD session adopts a special encapsulation method. When the SID list forwarding entry IDs queried in the previous step are the same, the BFD module will verify the setting parameters of different BFD / SBFD sessions. Only when the above parameter configuration information is consistent, will a BFD / SBFD session be created for different SRv6 TE Policies.

[0069] As can be seen from this example again, by adjusting the logic of generating forwarding entries for SRv6 TE Policy and SID list, the SID list can independently generate forwarding entries, reducing the duplicate forwarding entries of the SID list.

[0070] Based on the above method embodiments, the embodiments of the present disclosure further provide a routing device, and the routing device includes:

[0071] A creation module, configured to create a first SBFD / BFD session according to the SRv6 TE Policy;

[0072] A judgment module, configured to judge whether there is a target forwarding entry in the corresponding relationship between the SID list and the forwarding entry recorded by itself that matches the first SID list used to create the first SBFD / BFD session;

[0073] If there is, the creation module is further configured to use the target forwarding entry as the forwarding entry of the first SID list.

[0074] Among them, the judgment module is specifically configured to obtain the first forwarding information for creating the forwarding entry corresponding to the first SID list;

[0075] Traverse the recorded forwarding entries according to the first forwarding information to check whether there is a corresponding target forwarding entry.

[0076] Among them, the judgment module is further configured to, when judging that there is no target forwarding entry in the corresponding relationship between the SID list and the forwarding entry recorded by itself that matches the first SID list used to create the first SBFD / BFD session, the creation module is further configured to create a first forwarding entry corresponding to the first SID list and record the corresponding relationship between the first forwarding entry and the first SID list.

[0077] Among them, the creation module is specifically configured to establish the corresponding relationship between the first SBFD / BFD session, the address SID list, and the target forwarding entry;

[0078] Encapsulate the first SBFD / BFD session according to the target forwarding table entry.

[0079] The creating module is further configured to obtain a second SBFD / BFD session corresponding to the target forwarding table entry;

[0080] Verify whether the session parameters of the first SBFD / BFD session and the second SBFD / BFD session match. If they match, use the target forwarding table entry as the forwarding table entry of the first SID list.

[0081] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can refer to the partial descriptions of the method embodiments. The device embodiments described above are only illustrative. The modules described as separate components may or may not be physically separated. The components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed to multiple network modules. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution in this specification. A person of ordinary skill in the art can understand and implement it without creative work.

[0082] The specific embodiments of this specification have been described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in a different order than in the embodiments and still achieve the desired result. Additionally, the processes depicted in the figures do not necessarily require the specific order or sequential order shown to achieve the desired result. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0083] Those skilled in the art will readily conceive of other embodiments of this specification after considering the specification and practicing the invention herein. This specification is intended to cover any variations, uses, or adaptations of this specification, which follow the general principles of this specification and include common general knowledge or conventional technical means in the technical field not claimed in this application. The specification and embodiments are only regarded as exemplary, and the true scope and spirit of this specification are pointed out by the following claims.

[0084] It should be understood that this specification is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of this specification is only limited by the appended claims.

[0085] The above are only the preferred embodiments of this specification and are not intended to limit this specification. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of this specification shall be included within the scope of protection of this specification.

Claims

1. A detection method for SBFD / BFD, characterized in that, The method includes: Create a first SBFD / BFD session according to the SRv6 TE Policy; Determine whether there is a target forwarding entry in the correspondence between the SID list recorded by itself and the forwarding entries that matches the first SID list used to create the first SBFD / BFD session; If it exists, use the target forwarding entry as the forwarding entry of the first SID list.

2. The method according to claim 1, wherein The determination of whether there is a target forwarding entry in the correspondence between the SID list recorded by itself and the forwarding entries that matches the first SID list used to create the first SBFD / BFD session includes: Obtain the first forwarding information for creating the forwarding entry corresponding to the first SID list; Traverse the recorded forwarding entries according to the first forwarding information to check whether there is a corresponding target forwarding entry; If it exists, use the target forwarding entry as the forwarding entry of the first SID list.

3. The method according to claim 1 or 2, characterized in that, The method further includes: When it is determined that there is no target forwarding entry in the correspondence between the SID list recorded by itself and the forwarding entries that matches the first SID list used to create the first SBFD / BFD session, create a first forwarding entry corresponding to the first SID list, and record the correspondence between the first forwarding entry and the first SID list.

4. The method according to claim 1, wherein Using the target forwarding entry as the forwarding entry of the first SID list includes: Establish the correspondence between the first SBFD / BFD session, the address SID list, and the target forwarding entry; Encapsulate the first SBFD / BFD session according to the target forwarding entry.

5. The method according to claim 1, wherein Before using the target forwarding entry as the forwarding entry of the first SID list, the method further includes: Obtain the second SBFD / BFD session corresponding to the target forwarding entry; Verify whether the session parameters of the first SBFD / BFD session and the second SBFD / BFD session match. If they match, use the target forwarding entry as the forwarding entry of the first SID list.

6. A routing device, characterized in that, The routing device includes: A creation module for creating a first SBFD / BFD session according to the SRv6 TE Policy; A determination module for determining whether there is a target forwarding entry in the correspondence between the SID list recorded by itself and the forwarding entries that matches the first SID list used to create the first SBFD / BFD session; If it exists, the creation module is further used to use the target forwarding entry as the forwarding entry of the first SID list.

7. The routing device according to claim 6, wherein The determination module is specifically configured to obtain the first forwarding information for creating the forwarding entry corresponding to the first SID list; Traverse the recorded forwarding entries according to the first forwarding information to check whether there is a corresponding target forwarding entry.

8. The routing device according to claim 6 or 7, wherein The determination module is further configured to, when there is no target forwarding entry in the correspondence between the SID list recorded by itself and the forwarding entries that matches the first SID list for creating the first SBFD / BFD session, the creation module is further configured to create a first forwarding entry corresponding to the first SID list and record the correspondence between the first forwarding entry and the first SID list.

9. The routing device according to claim 6, wherein the creation module is specifically configured to establish the correspondence between the first SBFD / BFD session, the address SID list, and the target forwarding entry; Encapsulate the first SBFD / BFD session according to the target forwarding entry.

10. The routing device according to claim 6, wherein the creation module is further configured to obtain a second SBFD / BFD session corresponding to the target forwarding entry; Verify whether the session parameters of the first SBFD / BFD session and the second SBFD / BFD session match, and if they match, use the target forwarding entry as the forwarding entry of the first SID list.

Images