CN112737937B

CN112737937B - Information cross-domain notification method, system and boundary router

Info

Publication number: CN112737937B
Application number: CN201910971856.6A
Authority: CN
Inventors: 王爱俊
Original assignee: China Telecom Corp Ltd
Current assignee: China Telecom Corp Ltd
Priority date: 2019-10-14
Filing date: 2019-10-14
Publication date: 2022-09-16
Anticipated expiration: 2039-10-14
Also published as: CN112737937A

Abstract

The invention discloses an information cross-domain notification method, an information cross-domain notification system and a boundary router, and relates to the field of IP network intellectualization. The method comprises the following steps: when the border router generates the summary LSA, if the fault link in the local domain is identified, the state of the fault link is identified, if the fault router is identified, and the summary LSA which identifies the state of the fault link or the fault router is broadcasted to the opposite-end domain, so that the router in the opposite-end domain updates the path resource according to the summary LSA. The method and the device can realize real-time perception of the routing state of the IGP cross-domain networking, and reduce flow interruption caused by cross-domain link failure.

Description

Information cross-domain notification method, system and boundary router

Technical Field

The present disclosure relates to the field of IP network intelligence, and in particular, to a method, a system, and a border router for information cross-domain advertisement.

Background

In a traditional IGP (Interior Gateway Protocol) cross-domain scenario, a border router performs route aggregation, and the main goal of the route aggregation is to reduce the number of route entries in one domain and improve the route processing capability of routers in each domain.

However, in a cross-domain traffic engineering scenario, when a router in a certain domain sends traffic to a router in another domain, if the reachability state of a destination cannot be sensed in time, a traffic black hole may occur.

In addition, when two routers across the domain establish BGP (Border Gateway Protocol) neighbors, if the reachability state change of the BGP at the opposite end cannot be sensed in time, the routing convergence of the BGP will be slow.

Disclosure of Invention

The technical problem to be solved by the present disclosure is to provide an information cross-domain advertisement method, system and border router, which can reduce traffic interruption caused by cross-domain link failure.

According to an aspect of the present disclosure, an information cross-domain advertisement method is provided, including: when the boundary router generates a summary Link State Advertisement (LSA), if a fault link in the local domain is identified, the fault link state is identified; and the boundary router broadcasts the summarized LSA which identifies the state of the fault link to the opposite terminal domain, so that the router in the opposite terminal domain updates the path resource according to the summarized LSA.

In some embodiments, the border router identifying the failed link state comprises: the border router sets the source information of the prefixes of the failed link to null.

In some embodiments, identifying the failed link within the local domain by the border router comprises: and if the boundary router does not receive the LSA information of a certain link positioned in the summary routing range in the domain, determining that the link is a fault link.

In some embodiments, updating the path resource by the router in the peer domain according to the summarized LSA includes: a router in the correspondent domain generates a static route, wherein the static route points to a prefix and a next hop of the static route is null.

According to another aspect of the present disclosure, there is also provided an information cross-domain advertising method, including: when the boundary router generates a summary Link State Advertisement (LSA), if a fault router in the local domain is identified, the fault router is identified; and the boundary router broadcasts the summary LSA which identifies the fault router to the opposite terminal domain, so that the router in the opposite terminal domain updates the path resource according to the summary LSA.

In some embodiments, the border router identifying the failed router comprises: the border router sets the source information of the prefix carried by the logical address of the failed router to null.

In some embodiments, identifying the failed router within the domain by the border router comprises: and the boundary router identifies the fault router according to the received IGP neighbor list in the local domain and in the summary routing range.

According to another aspect of the present disclosure, there is also provided a border router, including: the fault identification unit is configured to identify the state of a fault link if the fault link in the local domain is identified when the summary Link State Advertisement (LSA) is generated; and the information notification unit is configured to broadcast the summarized LSA which identifies the fault link state to the opposite-end domain, so that the router in the opposite-end domain updates the path resource according to the summarized LSA.

According to another aspect of the present disclosure, there is also provided a border router, including: the failure identification unit is configured to identify a failure router in the local domain if the failure router is identified when the summary Link State Advertisement (LSA) is generated; and the information notification unit is configured to broadcast the summarized LSA which identifies the failed router to the opposite-end domain, so that the router in the opposite-end domain updates the path resource according to the summarized LSA.

According to another aspect of the present disclosure, there is also provided a border router, including: a memory; and a processor coupled to the memory, the processor configured to perform the information cross-domain advertising method as described above based on instructions stored in the memory.

According to another aspect of the present disclosure, there is also provided an information cross-domain advertisement system, including: the above-mentioned border router; and the router in the opposite end domain is configured to update the path resource according to the summary LSA broadcasted by the boundary router.

According to another aspect of the present disclosure, a computer-readable storage medium is also proposed, on which computer program instructions are stored, which when executed by a processor implement the above-mentioned information cross-domain advertisement method.

Compared with the prior art, when the summary LSA is generated, if the fault link or the fault router in the domain is identified, the boundary router identifies the fault link state or the fault router, and broadcasts the summary LSA which identifies the fault link state or the fault router to the opposite-end domain, so that the router in the opposite-end domain updates the path resources, the IGP cross-domain networking routing state is sensed in real time, and the flow interruption caused by the cross-domain link fault is reduced.

Other features of the present disclosure and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description, serve to explain the principles of the disclosure.

The present disclosure may be more clearly understood from the following detailed description, taken with reference to the accompanying drawings, in which:

fig. 1 is a flow diagram illustrating some embodiments of a cross-domain advertising method of the disclosed information.

Fig. 2 is a flowchart illustrating further embodiments of the disclosed information cross-domain advertisement method.

Fig. 3 is a flowchart illustrating further embodiments of the disclosed information cross-domain advertisement method.

Fig. 4 is a flowchart illustrating further embodiments of the disclosed information cross-domain advertisement method.

Fig. 5 is a schematic diagram of an IGP cross-domain networking scenario.

Fig. 6 is a block diagram of some embodiments of a border router of the present disclosure.

Fig. 7 is a block diagram of alternate embodiments of a border router according to the present disclosure.

Fig. 8 is a block diagram of alternate embodiments of a border router according to the present disclosure.

Detailed Description

Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of parts and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present disclosure unless specifically stated otherwise.

Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

For the purpose of promoting a better understanding of the objects, aspects and advantages of the present disclosure, reference is made to the following detailed description taken in conjunction with the accompanying drawings.

Fig. 1 is a flow diagram illustrating some embodiments of a cross-domain advertisement method of the disclosed information.

In step 110, when the border router generates a summary LSA (Link-State Advertisement), if a failed Link in the local domain is identified, the State of the failed Link is identified.

Under an Open Shortest Path First (OSPF) protocol, a Border Router is an ABR (Area Border Router), and under an ISIS (Intermediate system to Intermediate system) protocol, a Border Router is a Level 1/2 Router.

In some embodiments, the OSPF/ISIS protocol has a mechanism to carry Prefix identifier (source information of Prefix), so the border router can set Null (Null) to the source information of the Prefix of the failed link.

At step 120, the border router broadcasts an aggregated LSA to the correspondent domain that has identified the failed link state. I.e. broadcasts a prefix with the source information empty to other domains.

At step 130, the router in the peer domain updates the path resource according to the summarized LSA.

In some embodiments, a router within the correspondent domain generates a static route, wherein the static route points to the prefix and a next hop of the static route is null. I.e., when traffic data is sent, the traffic data no longer traverses the failed link.

In the above embodiment, when the border router generates the summarized LSA, if the failed link in the local domain is identified, the state of the failed link is identified, and the summarized LSA that identifies the state of the failed link is broadcast to the opposite-end domain, so that the router in the opposite-end domain updates the path resources, thereby implementing real-time awareness of the routing state of the IGP cross-domain networking, and reducing traffic interruption caused by a cross-domain link failure.

In step 210, when the border router generates the summarized LSA, if the LSA information of a link located in the summarized routing range in the local area is not received, the link is determined to be a failed link.

The border router can receive all the LSA information broadcasted in the single domain, when a certain link fails, the router connected with the two ends of the link can send updated LSA information, wherein the updated LSA information does not contain the failed link.

At step 220, the border router sets the source information of the prefixes of the failed link to null.

At step 230, the border router broadcasts a summarized LSA containing the prefix to the correspondent domain.

In some embodiments, aggregated LSA information is flood broadcast within the IGP domain in a conventional manner.

At step 240, a static route is generated for the router in the correspondent domain, wherein the static route points to the prefix and the next hop of the static route is null.

When receiving the summarized LSA information, the router in the opposite end domain sets the empty route condition according to the source information of the prefix, judges that the prefix is unreachable, automatically generates a static route pointing to the prefix, and sets the next hop of the static route to be empty.

In some embodiments, routers within the peer domain terminate the BGP protocol based on the prefix in time and cease traffic transmission based on the prefix. I.e., timely termination of BGP protocol and traffic transmission based on the address used by the failed link.

In the above embodiment, when the border router generates the summarized LSA, if the LSA information of a link located in the summarized route range in the local area is not received, the link is determined to be a failed link, the source information of the prefix of the failed link is set to be null, the summarized LSA containing the prefix is broadcast to the opposite end area, the router receiving the summarized LSA senses the state change of the link located in other domains in time, a static route pointing to the prefix is automatically generated, the next hop of the static route is set to be null, traffic interruption caused by cross-domain link failure is reduced, and the protocol convergence speed of BGP and other protocols depending on the IGP protocol is improved.

In step 310, when the border router generates the summarized LSA, if a failed router in the local domain is identified, the failed router is identified.

In some embodiments, the border router may set null to the source information of the prefix carried by the logical address of the failed router, e.g., the loopback address.

At step 320, the border router broadcasts the aggregated LSA to the correspondent domain that has identified the failed router. I.e. broadcasts a prefix with the source information empty to other domains.

At step 330, the router in the peer domain updates the path resource according to the summarized LSA.

In some embodiments, a router within the correspondent domain generates a static route, wherein the static route points to the prefix and a next hop of the static route is null. I.e., the traffic data no longer passes through the failed router when the traffic data is sent.

In the above embodiment, when the border router generates the summarized LSA, if the failure router in the local domain is identified, the border router identifies the failure router, and broadcasts the summarized LSA, which identifies the failure router, to the opposite-end domain, so that the router in the opposite-end domain updates the path resources, thereby implementing real-time awareness of the routing state of the IGP cross-domain networking and reducing traffic interruption caused by a cross-domain link failure.

In step 410, when the border router generates the summarized LSA, if the failed router is identified according to the received IGP neighbor list located in the summarized routing range in the local area, the source information of the prefix carried by the loopback address of the failed router is set to null.

At step 420, the border router broadcasts a summarized LSA containing the prefix to the correspondent domain.

At step 430, a static route is generated for the router in the correspondent domain, wherein the static route points to the prefix and the next hop of the static route is null.

In some embodiments, routers within the peer domain terminate the BGP protocol based on the prefix in time and cease traffic transmission based on the prefix. Namely, the BGP protocol based on the address used by the failed router is terminated in time, and the sending of traffic data to the logical address identifying the failed router or to the address to which the link associated with the failed router belongs is stopped.

In the above embodiment, the method for notifying the cross-domain of the prefix unreachable information by setting the source information based on the prefix as empty can enable the router receiving the summarized LSA to sense the state change of the routers in other domains in time, thereby implementing the fast switching of the traffic and the routing protocol in the cross-domain IGP networking scenario.

As shown in fig. 5, routers R1, R2, and R3 are located in area 1, routers T2, T3, and T4 are located in area 2, R4, R5, T1, and T5 are border routers, and S0 is provided between R4 and T1. In the prior art, if the border routers R4 or R5 perform route aggregation, the routers T2, T3, and T4 in domain 2 can only receive aggregated routes in area 1. Routers located in both domains, e.g., R1 located in area 1 and T4 located in area 2, may send traffic normally and establish BGP neighbor relationships.

When a link between R1 and R2 fails, or R1 itself fails to send a failure, T4 located in area 2 cannot sense the state change in real time, the corresponding traffic will be sent according to the previous path, and the BGP protocol between the two will remain alive until the BGP keep-alive expires, and the failure will not be sensed, during which a traffic black hole will occur.

In the embodiment of the present disclosure, when the border router R4 or R5 recognizes that the link located in area 1 fails or the router fails, a summary LSA identifying the failed link or the failed router may occur. For example, in the summarized LSA, the source information of the prefix of the roadblock link is set to null, or the source information of the prefix of the logical address of the failed router is set to null. And R4 or R5 broadcasts the special summary LSA according to the traditional LSA broadcasting mechanism, thereby realizing cross-domain propagation. Under the ISIS protocol, border routers flood the aggregated LSA in addition to broadcasting the traditional default route. The router in the area 2 receiving the summarized LSA can sense the state change of the link and the router in the area 1 in real time, automatically generate a static route pointing to the prefix, and set the next hop of the static route to be null, thereby switching the flow and other application protocols in time. The protocol extension of the scheme is simple to implement, and the calculation speed of the traditional IGP SPF is not influenced.

Fig. 6 is a block diagram of some embodiments of a border router of the present disclosure. The apparatus includes a fault identification unit 610 and an information notification unit 620.

In some embodiments, the failure identification unit 610 is configured to identify a failed link state if a failed link within the local domain is identified when generating the aggregated LSA. The information advertisement unit 620 is configured to broadcast the summarized LSA, which identifies the failed link state, to the correspondent domain, so that routers within the correspondent domain update the path resources according to the summarized LSA. For example, if the LSA information of a certain link in the summary routing range in the local domain is not received, the link is determined to be a failed link, and the source information of the prefix of the failed link is set to be null.

In some embodiments, the failure identification unit 610 is configured to identify a failed router within the local domain if the failed router is identified when generating the aggregated LSA. The information advertisement unit 620 is configured to broadcast the summarized LSA, which identifies the failed router, to the opposite-end domain, so that routers in the opposite-end domain update the path resource according to the summarized LSA. For example, if the failed router is identified according to the received interior gateway protocol IGP neighbor list located in the summarized routing range in the local domain, the source information of the prefix carried by the logical address of the failed router is set to null.

Under the OSPF protocol, the border router is ABR, and under the ISIS protocol, the border router is Level 1/2 router.

In the above embodiment, the border router identifies the failed link and the failed router, so that the router that receives the summarized LSA can timely perceive the state changes of the links and routers in other domains, thereby implementing fast switching of traffic and routing protocols in a cross-domain IGP networking scenario.

Fig. 7 is a block diagram of alternate embodiments of a border router according to the present disclosure. The apparatus comprises a memory 710 and a processor 720, wherein: the memory 710 may be a magnetic disk, flash memory, or any other non-volatile storage medium. The memory is used to store instructions in the embodiments corresponding to fig. 1-4. Processor 720, coupled to memory 710, may be implemented as one or more integrated circuits, such as a microprocessor or microcontroller. The processor 720 is configured to execute instructions stored in the memory.

In some embodiments, as also shown in fig. 8, the border router 800 includes a memory 810 and a processor 820. The processor 820 is coupled to the memory 88 by a BUS 830. The border router 800 may also be coupled to an external storage device 850 via a storage interface 840 for facilitating retrieval of external data, and may also be coupled to a network or another computer system (not shown) via a network interface 860, which will not be described in detail herein.

In this embodiment, the memory stores data instructions, and the processor processes the instructions, so as to realize real-time sensing of the routing state of the IGP cross-domain networking and reduce traffic interruption caused by cross-domain link failure.

In still other embodiments of the present disclosure, an information cross-domain advertisement system is protected, the system including the border router described above, and further including a router in a correspondent domain, the router in the correspondent domain configured to update path resources according to a summarized LSA broadcast by the border router. For example, a static route is generated, where the static route points to a prefix and the next hop of the static route is null. And the router in the opposite-end domain terminates the BGP protocol based on the prefix in time and stops the flow transmission based on the prefix.

In other embodiments, a computer-readable storage medium has stored thereon computer program instructions which, when executed by a processor, implement the steps of the method in the embodiments corresponding to fig. 1-4. As will be appreciated by one skilled in the art, embodiments of the present disclosure may be provided as a method, apparatus, or computer program product. Accordingly, the present disclosure may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present disclosure may take the form of a computer program product embodied on one or more computer-usable non-transitory storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and so forth) having computer-usable program code embodied therein.

The present disclosure is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the disclosure. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Thus far, the present disclosure has been described in detail. Some details that are well known in the art have not been described in order to avoid obscuring the concepts of the present disclosure. Those skilled in the art can now fully appreciate how to implement the teachings disclosed herein, in view of the foregoing description.

Although some specific embodiments of the present disclosure have been described in detail by way of example, it should be understood by those skilled in the art that the foregoing examples are for purposes of illustration only and are not intended to limit the scope of the present disclosure. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. An information cross-domain advertising method, comprising:

when generating a summary Link State Advertisement (LSA), if a fault link in the local domain is identified, the boundary router identifies the fault link state, wherein the identifying the fault link state comprises: setting source information of a prefix of the fault link to be null;

and the boundary router broadcasts the summary LSA which identifies the fault link state to an opposite terminal domain, so that the router in the opposite terminal domain updates the path resource according to the summary LSA.

2. The method of information cross-domain advertisement of claim 1, wherein the border router identifying the failed link within the local domain comprises:

and if the boundary router does not receive the LSA information of a certain link positioned in the summary routing range in the local domain, determining that the link is a fault link.

3. The information cross-domain advertisement method of claim 1, wherein the router in the correspondent domain updating path resources according to the summarized LSA comprises:

the router in the opposite end domain generates a static route, wherein the static route points to the prefix, and the next hop of the static route is null.

4. An information cross-domain advertising method, comprising:

when generating a summary Link State Advertisement (LSA), if a failed router in the local domain is identified, the border router identifies the failed router, wherein identifying the failed router comprises: setting the source information of the prefix carried by the logic address of the fault router to be null;

and the boundary router broadcasts the summary LSA which identifies the fault router to an opposite terminal domain, so that the router in the opposite terminal domain updates the path resource according to the summary LSA.

5. The method of information cross-domain advertisement according to claim 4, wherein the identifying of the failed router within the local domain by the border router comprises:

and the boundary router identifies the fault router according to the received IGP neighbor list in the local domain and in the summary routing range.

6. The information cross-domain advertisement method of claim 5, wherein the updating of the path resources by the router within the correspondent domain according to the summarized LSA comprises:

7. A border router, comprising:

a fault identification unit configured to identify a fault link state if a fault link in the local domain is identified when generating a summary Link State Advertisement (LSA), wherein identifying the fault link state includes: setting source information of a prefix of the failed link to be null;

and the information notification unit is configured to broadcast the summarized LSA which identifies the fault link state to the opposite-end domain, so that the router in the opposite-end domain updates the path resource according to the summarized LSA.

8. A border router, comprising:

a failure identification unit configured to identify a failed router in a local domain if the failed router is identified when generating a summary Link State Advertisement (LSA), wherein identifying the failed router includes: setting the source information of the prefix carried by the logic address of the fault router to be null;

and the information notification unit is configured to broadcast the summarized LSA which identifies the fault router to the opposite-end domain, so that the router in the opposite-end domain updates the path resource according to the summarized LSA.

9. A border router, comprising:

a memory; and

a processor coupled to the memory, the processor configured to perform the information cross-domain advertising method of any of claims 1-6 based on instructions stored in the memory.

10. An information cross-domain advertisement system, comprising:

the border router of any one of claims 7-9; and

and the router in the opposite end domain is configured to update the path resource according to the summarized LSA broadcasted by the boundary router.

11. A computer readable storage medium having stored thereon computer program instructions which, when executed by a processor, implement the information cross-domain advertisement method of any of claims 1 to 6.