CN109818860B

CN109818860B - Method for establishing virtual link, router and storage medium

Info

Publication number: CN109818860B
Application number: CN201711158179.3A
Authority: CN
Inventors: 何建军
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2017-11-20
Filing date: 2017-11-20
Publication date: 2022-04-01
Anticipated expiration: 2037-11-20
Also published as: CN109818860A

Abstract

The invention discloses a method for establishing a virtual link, which is applied to a router in a network comprising a backbone area and at least one non-backbone area, and comprises the following steps: acquiring Area Border Router (ABR) information of an accessible area through a preset strategy; and when the preset virtual link establishment condition is determined to be met based on the regional reachable ABR information, sending a first virtual link establishment request to the corresponding regional reachable ABR so as to establish a first virtual link with the ABR. The invention also discloses a router and a storage medium.

Description

Method for establishing virtual link, router and storage medium

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a method for establishing a virtual link, a router, and a storage medium.

Background

In an Open Shortest Path First (OSPF) protocol, a non-backbone Area is required to form a star-type networking with a backbone Area as a center around the backbone Area, that is, each Area must be directly connected with the backbone Area (Area 0), but in an actual networking, the network situation is very complex, and sometimes when areas are divided, each Area cannot be guaranteed to meet the requirement. To solve this problem, the user manually performs the configuration of the virtual link. A virtual link refers to a logical connection path established between two Area Border Routers (ABRs) across a non-backbone Area such that a separate backbone Area, or a non-backbone Area isolated from the backbone Area, can be connected to the backbone Area via the virtual link.

However, manual configuration of the virtual links wastes a lot of labor cost, is inefficient, and often causes problems such as networking errors and routing obstruction due to human factors.

Disclosure of Invention

In view of this, embodiments of the present invention provide a method, a router, and a storage medium for establishing a virtual link, which at least solve the problems in the prior art and can automatically implement establishment of a virtual link.

The technical scheme of the embodiment of the invention is realized as follows:

the embodiment of the invention provides a method for establishing a virtual link, which is applied to a router in a network comprising a backbone area and at least one non-backbone area, and comprises the following steps:

obtaining reachable ABR information of the area through a preset strategy;

and when the preset virtual link establishment condition is determined to be met based on the regional reachable ABR information, sending a first virtual link establishment request to the corresponding regional reachable ABR so as to establish a first virtual link with the ABR.

In the foregoing solution, when determining that the preset virtual link establishment condition is satisfied based on the area-reachable ABR information, sending a first virtual link establishment request to a corresponding area-reachable ABR includes:

in response to the router being an ABR in a non-tip region, determining that there is a backbone region unreachable ABR among the region reachable ABRs based on the region reachable ABR information;

and sending a first virtual link establishment request to the unreachable ABR of the backbone area.

In the foregoing solution, the sending the first virtual link establishment request to the unreachable ABR in the backbone area includes:

sending the first virtual link establishment request to the unreachable ABR of the backbone area in a preset communication mode;

the first virtual link establishment request carries at least one of the following information: and establishing the area of the virtual link, the virtual link neighbor interface address, the virtual link neighbor router identification, the local terminal equipment virtual link outlet interface address and the local terminal router identification.

in response to the router being a non-ABR in a non-tip area, the non-ABR connecting at least two non-backbone areas, and there being at least one non-backbone area in the at least two non-backbone areas without an area-reachable ABR, determining that there is at least one area-reachable ABR based on the area-reachable ABR information;

and selecting one ABR from the at least one regional reachable ABR to send the first virtual link establishment request.

In the foregoing solution, the selecting one ABR from the at least one area reachable ABR and sending the first virtual link establishment request includes:

selecting the ABR with the highest priority from the reachable ABRs of the at least one region;

and sending a first virtual link establishment request to the ABR with the highest priority.

In the above scheme, the method further comprises:

sending information to other routers whether the router has the capability of automatically configuring virtual links, either through opaque LSAs or router LSAs.

In the above scheme, the method further comprises:

receiving a second virtual link establishment request;

based on the second virtual link establishment request, judging the validity of the second virtual link establishment request to obtain a judgment result;

when the judgment result represents that the second virtual link establishment request is effective, sending a response of the second virtual link establishment request;

and when the judgment result represents that the second virtual link establishment request is invalid, sending a notice for rejecting the second virtual link establishment request.

In the above scheme, the method further comprises:

storing the related information of the first virtual link to a virtual link list according to the sequence of the link priority from high to low;

the related information of the first virtual link at least comprises area information and virtual link neighbor information corresponding to the first virtual link.

In the above scheme, the method further comprises:

traversing all virtual link information stored in the virtual link list;

and when the first virtual link stored in the virtual link list is determined to be a redundant link, sending a notification for removing the first virtual link.

In the above scheme, the method further comprises:

acquiring that the corresponding regional reachable ABR does not have the capacity of automatically configuring the virtual link any more through the notification sent by the corresponding regional reachable ABR;

updating the stored capability information of the corresponding regional reachable ABR, and deleting the relevant information of the first virtual link stored in the virtual link list.

An embodiment of the present invention further provides a router, where the router includes:

the acquisition module is used for acquiring accessible ABR information of the region through a preset strategy;

and the processing module is used for sending a first virtual link establishment request to the corresponding regional reachable ABR to establish a first virtual link with the ABR when the preset virtual link establishment condition is determined to be met based on the regional reachable ABR information.

In the foregoing solution, the processing module is further configured to determine, in response to that the router is an ABR in a non-peripheral area, that an ABR in which a backbone area is unreachable exists in an ABR in which an area is reachable based on the ABR information in which the area is reachable;

In the foregoing aspect, the processing module is further configured to determine that at least one area-reachable ABR exists based on the area-reachable ABR information in response to the router being a non-ABR in a non-tip area, the non-ABR connecting at least two non-backbone areas, and there being at least one non-backbone area without an area-reachable ABR in the at least two non-backbone areas;

a memory configured to store an executable program;

and the processor is configured to implement the method for establishing the virtual link when executing the executable program stored in the memory.

The embodiment of the invention also provides a storage medium which stores an executable program, and the executable program is executed by a processor to realize the method for establishing the virtual link.

According to the method for establishing the virtual link, the router and the storage medium provided by the embodiment of the invention, the reachable ABR information of the area is obtained through a preset strategy; and when the preset virtual link establishment condition is determined to be met based on the regional reachable ABR information, sending a first virtual link establishment request to the corresponding regional reachable ABR so as to establish a first virtual link with the ABR. Therefore, the router automatically identifies the condition of needing to establish the virtual link, realizes the establishment of the virtual link, saves the labor cost, improves the virtual link establishment efficiency, and avoids the problems of networking errors, further routing obstruction and the like caused by artificial virtual link establishment.

Drawings

Fig. 1 is a schematic diagram of an alternative networking system with backbone area isolation according to an embodiment of the present invention;

fig. 2 is a schematic diagram of an alternative networking scheme in which there is isolation between non-backbone areas and backbone areas according to an embodiment of the present invention;

fig. 3 is a schematic flowchart of a method for establishing a virtual link according to an embodiment of the present invention;

fig. 4 is a flowchart illustrating an embodiment of declaring an automatic configuration virtual link capability;

fig. 5 is a schematic flowchart of updating a virtual link list based on received information for updating an automatic configuration virtual link capability according to an embodiment of the present invention;

fig. 6 is a schematic diagram of a process flow for receiving a notification of a request for rejecting establishment of a virtual link according to an embodiment of the present invention;

fig. 7 is a schematic processing flow diagram of a received virtual link establishment request according to an embodiment of the present invention;

fig. 8 is a schematic diagram of a virtual chain check processing flow for configuring a current node according to an embodiment of the present invention;

fig. 9 is a schematic diagram of a virtual link teardown check processing flow according to an embodiment of the present invention;

fig. 10 is a schematic diagram of a process of deleting redundant virtual chains according to an embodiment of the present invention;

fig. 11 is a schematic diagram of a determination process for determining whether a specific virtual link can be deleted according to an embodiment of the present invention;

fig. 12 is a schematic processing flow diagram of receiving a returned virtual chain removal notification acknowledgement according to an embodiment of the present invention;

fig. 13 is a schematic processing flow diagram of receiving a returned notification of rejecting virtual chain removal according to an embodiment of the present invention;

fig. 14 is a schematic processing flow diagram of receiving a virtual link removal notification according to an embodiment of the present invention;

fig. 15 is a flowchart illustrating a method for establishing a virtual link according to an embodiment of the present invention;

fig. 16 is an alternative schematic diagram of regional networking provided by an embodiment of the present invention;

fig. 17 is a schematic structural diagram of a router according to an embodiment of the present invention;

fig. 18 is an alternative schematic diagram of a router as a hardware entity according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail below with reference to the accompanying drawings and examples. It should be understood that the examples provided herein are merely illustrative of the present invention and are not intended to limit the present invention. In addition, the following embodiments are provided as partial embodiments for implementing the present invention, not all embodiments for implementing the present invention, and the technical solutions described in the embodiments of the present invention may be implemented in any combination without conflict.

It should be noted that the terms "first \ second \ third" related to the embodiments of the present invention only distinguish similar objects, and do not represent a specific ordering for the objects, and it should be understood that "first \ second \ third" may exchange a specific order or sequence when allowed. It should be understood that the terms first, second, and third, as used herein, are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in other sequences than those illustrated or otherwise described herein.

In the embodiments of the present invention, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a method or apparatus that comprises a list of elements does not include only the elements explicitly recited, but also includes other elements not explicitly listed or inherent to the method or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other elements of interest in a method or apparatus comprising the element (e.g., steps in a method or modules in an apparatus, such as a part of a circuit, a part of a processor, a part of a program or software, etc.).

For example, the method for establishing a virtual link according to the embodiment of the present invention includes a series of steps, but the method for establishing a virtual link according to the embodiment of the present invention is not limited to the described steps, and similarly, the apparatus for establishing a virtual link according to the embodiment of the present invention includes a series of modules, but the apparatus for establishing a virtual link according to the embodiment of the present invention is not limited to include the explicitly described modules, and may further include a unit that is required to be configured to acquire relevant information or perform processing based on the information.

Before further describing the embodiments of the present invention in detail, the case of isolation of the backbone region and isolation of the non-backbone region from the backbone region in the embodiments of the present invention will be described first.

For the backbone area isolation, under the normal networking condition, each ABR is connected with the backbone area, namely any two ABRs can reach the backbone area, and when the two ABRs cannot reach the backbone area, the backbone area isolation occurs in the networking. Fig. 1 is a schematic diagram of an alternative networking system with backbone area isolation according to an embodiment of the present invention, and referring to fig. 1, in fig. 1, because of the backbone area isolation, route 1 cannot access route 4, and route 4 cannot access route 1.

For the isolation between the non-backbone areas and the backbone areas, because each non-backbone area is connected to a backbone area by an ABR in a normal networking situation, when a certain non-backbone area is connected to another non-backbone area and is not connected to a backbone area, it can be known that the isolation between the non-backbone areas and the backbone areas occurs in the networking. Fig. 2 is a schematic diagram of an alternative networking system in which a non-backbone area is isolated from a backbone area according to an embodiment of the present invention, referring to fig. 2, in fig. 2, because a case in which a non-backbone area is isolated from a backbone area exists, route 3 and route 4 cannot access route 1, and route 1 cannot access route 3 and route 4.

Based on the above description of the isolation of the backbone region and the isolation of the non-backbone region from the backbone region, the following describes embodiments of the present invention in detail.

Example one

Fig. 3 is a schematic flowchart of a method for establishing a virtual link according to an embodiment of the present invention, where the method is applied to a router in a networking system including a backbone area and at least one non-backbone area, and the router is connected to the non-backbone area; as shown in fig. 3, a method for establishing a virtual link according to an embodiment of the present invention includes:

step 101: obtaining reachable ABR information of the area through a preset strategy;

step 102: and when the preset virtual link establishment condition is determined to be met based on the regional reachable ABR information, sending a first virtual link establishment request to the corresponding regional reachable ABR so as to establish a first virtual link with the ABR.

Here, in actual implementation, before sending the virtual link establishment request, the router advertises to the outside whether it has the capability of automatically configuring the virtual link, and specifically, the router may send information about whether it has the capability of automatically configuring the virtual link to other routers through an opaque LSA or a router LSA (the capability information is placed in an unused field in the router LSA). Specifically, referring to fig. 4, fig. 4 is a schematic diagram illustrating a flow of a router announcing an automatic configuration virtual link capability, where in fig. 4, the router determines whether the router has the automatic configuration virtual link capability, and if not, determines whether a virtual link list for storing relevant information of the virtual link is empty (i.e., whether an automatic configuration virtual link request has been initiated previously), and if the virtual link list is not empty, since the device does not support the automatic configuration virtual link capability at this time, the virtual link list needs to be emptied, and the router advertises that the router does not support the automatic configuration virtual link capability any more; if the virtual chain list is empty, ending the processing flow; if the router has the capability of automatically configuring the virtual link, the router is declared to have the capability of automatically configuring the virtual link outwards.

Correspondingly, when receiving the information whether the other router has the capability of automatically configuring the virtual link, storing the capability information of the automatically configured virtual link of the other router (supporting the automatically configured virtual link or not supporting the automatically configured virtual link), and when receiving the information of updating the capability of the automatically configured virtual link sent by the other router, updating the stored capability information of the automatically configured virtual link of the other router (for example, updating the supported automatic configuration into the unsupported mode or updating the unsupported mode into the supported mode).

In practical application, after the router performs Shortest Path First (SPF) calculation, the reachable ABR information of the area is obtained, at this time, the router judges whether it has the capability of automatically configuring virtual links, if not, the processing flow is ended; if the capability of automatically configuring the virtual link is available, whether the non-backbone area connected with the router is a peripheral area is further judged, such as: a STUB/NSSA (not So STUB area) area, if the area is a peripheral STUB/NSSA area, no processing is required because the two devices cannot establish a virtual link via the peripheral STUB/NSSA area.

In one embodiment, in response to the router being an ABR in a non-tip region, determining that there is an ABR unreachable for a backbone region among the ABRs reachable for the region based on the acquired ABR information reachable for the region;

Here, when the router finds that an unreachable ABR exists in the backbone area as an ABR, it is known that backbone area separation has occurred in the current networking and it is necessary to establish a virtual link, and therefore a first virtual link establishment request is transmitted to the backbone area unreachable ABR.

In another embodiment, in response to the router being a non-ABR in a non-tip area, the non-ABR connecting at least two non-backbone areas, and there being at least one non-backbone area in the at least two non-backbone areas having no area-reachable ABR, determining that there is at least one area-reachable ABR based on the area-reachable ABR information;

Here, in actual implementation, when the router is used as a non-ABR, it is found that the router itself connects at least two non-backbone areas, and at least one non-backbone area in the non-backbone area has no area that can reach the ABR, and it is known that a virtual link needs to be established when the non-backbone area and the backbone area are isolated in the current networking, and therefore, a first virtual link establishment request is sent to the ABR. When the number of the acquired areas can reach two or more than two, the selection of the ABRs is needed, and the virtual link can be randomly selected to be established, or the ABR with the highest priority (such as the largest/smallest area number) is selected to be established.

In actual implementation, the router may send the first virtual link establishment request to the unreachable ABR in the backbone area through a preset communication mode (e.g., opaque LSA); an opaque LSA may carry at least one of the following information via Type-Length-content (TLV): and establishing the area of the first virtual link, the virtual link neighbor interface address, the virtual link neighbor ROUTER identification (route ID), the virtual link outgoing interface address of the local terminal equipment and the local terminal ROUTER identification.

In some embodiments, while sending the first virtual link establishment request, a HELLO packet may also be sent on an interface of the first virtual link (the destination address is an unreachable ABR device interface address of the backbone area, and the source address is a virtual link port address of the router). In the Link State routing algorithm, neighbors are discovered by sending and receiving HELLO messages, Link State Databases (LSDB) are synchronized among the neighbors, after the LSDB is synchronized, a local router constructs an SPF tree by using the LSDB, and finally, an optimal path reaching each destination address is calculated.

After sending the first virtual link establishment request, the router may further store the relevant information of the first virtual link to a virtual link list; the information of the first link is stored according to the sequence of the area numbers of the area where the information of the first link is located from large to small, and under the condition that the area numbers are the same, the information of the neighbor of the virtual link is stored according to the sequence of the priority of the neighbor of the virtual link from high to low.

Correspondingly, since the router stores the virtual link list for storing the relevant information of the virtual link, in an embodiment, referring to fig. 5, fig. 5 shows a schematic flow diagram of updating the virtual link list based on the received information for updating the capability of the automatically configured virtual link according to the embodiment of the present invention, when the router receives the information for updating the capability of the automatically configured virtual link sent by another router, if the other router does not support the automatically configured virtual link and is changed from the automatically configured virtual link to the automatically configured virtual link, the router is identified to support the automatically configured virtual link; if the other router does not support the automatic configuration virtual link from the support of the automatic configuration virtual link, searching whether the virtual link established with the router is stored in the virtual link list, and if so, deleting the related virtual link information.

In some embodiments, after the router sends the first virtual link establishment request, there may be two cases:

the first condition is as follows: receiving a response to the first virtual link setup request;

case two: receiving a notice of refusing to establish the first virtual link;

for the second case, after receiving the notification of refusing to establish the virtual link, the virtual link neighbor initiating the virtual link request needs to be matched. Referring to fig. 6, fig. 6 is a schematic diagram of a processing flow for receiving a notification of a request for rejecting establishment of a virtual link according to an embodiment of the present invention, where a ROUTER searches a virtual link list according to two elements, namely, a route ID of a message device for rejecting establishment of a virtual link and an area associated with an interface for receiving a notification of a message for rejecting establishment of a virtual link;

if the virtual chain neighbor is found to exist, deleting the virtual chain neighbor information from the virtual chain list, re-triggering and checking the area configuration virtual chain request, and selecting new equipment to establish a virtual chain neighbor connection relation to make up for the influence of the previously rejected virtual chain request;

if the virtual chain neighbor is not found, the abnormal virtual chain establishment rejection request notification message is possibly received, and the processing is finished without any response.

In some embodiments, the router may also monitor in real time whether it has received a virtual link establishment request (as a passive end) while determining whether the virtual link establishment condition is satisfied (as an active end), and if there is a virtual link establishment request sent by another device, it indicates that the other device determines that a virtual link connection relationship needs to be established with the device.

In practical implementation, if a second virtual link establishment request sent by an area-reachable ABR is received;

judging the validity of the second virtual link establishment request based on the second virtual link establishment request to obtain a judgment result;

when the judgment result indicates that the second virtual link establishment request is valid, sending a response of the second virtual link establishment request, and also sending a HELLO message on a corresponding virtual link output interface to establish a virtual link neighbor connection relation with the request terminal equipment;

and when the judgment result indicates that the second virtual link establishment request is invalid, sending a notice for rejecting the second virtual link establishment request.

In practical application, the validity of the second virtual link establishment request can be judged in the following manner:

judging whether the area associated with the interface receiving the second virtual link establishment request is a backbone area, an STUB area or an NSSA area;

if the association area is a backbone area, a STUB area or an NSSA area, it indicates that the request end has sent an erroneous virtual link establishment request, that is, the second virtual link establishment request is invalid;

and if the associated area is not the backbone area, the STUB area or the NSSA area, determining that the second virtual link establishment request is valid. Exemplarily, referring to fig. 7, fig. 7 is a schematic view of a processing flow of a received virtual link establishment request according to an embodiment of the present invention, when a virtual link establishment request sent by another device is received, it is determined whether an area associated with an interface receiving the request is not a backbone area, not a STUB area, and not an NSSA area, and if so, the virtual link establishment request is received, and a virtual link neighbor relationship is established; if not, the virtual link establishment request is rejected.

In practical implementation, the notification for rejecting the second virtual link establishment request may be sent in a form of a reject request message, specifically, the reject request message may be encapsulated in an opaque LSA, and the TLV information content in the LSA includes information such as an area for establishing the second virtual link, a virtual link neighbor interface address, a virtual link neighbor ROUTER identifier (ROUTER ID), a local device virtual link-out interface address, a local device ROUTER identifier (ROUTER ID), and a reject reason.

In actual implementation, a situation that both ends of the virtual link are simultaneously used as active ends also exists, that is, both ends simultaneously initiate virtual link establishment requests with respect to the same virtual link, at this time, the router may use the virtual link establishment request sent by the opposite end as a confirmation (response) of the virtual link establishment request sent by the router, and the default opposite end accepts the virtual link establishment request.

In practical applications, based on the above embodiments of the present invention, the router monitors the change of the attributes of itself and other routers at any time, where the attributes mentioned herein at least include topology reachability and ABR role (i.e. ABR or not). When the attribute of the router or other routers is monitored to be changed, triggering SPF calculation, after the SPF calculation is completed, and when the area connected with the current processing node is not a STUB area but is not an NSSA area, comparing the result of the SPF calculation with the last time and processing the result as follows:

if the topology of the current processing node is reachable previously and the current topology is also reachable, judging whether the ABR role of the node is changed or not, if the ABR role is not changed, indicating that the related attribute of the topology node is not changed, and continuing traversing the next topology node without any processing; if the ABR role of the node is changed and the area is a backbone area, the virtual chain is not influenced, and the next topological node is continuously traversed without any treatment; if the ABR role of the node has changed and the area is not a backbone area, further judgment processing is needed: if the node is ABR and is not ABR, the node indicates that the topological node is not needed to establish the virtual chain connection relationship any more, and initiates the virtual chain checking process of the detachment and the current node (namely, judging whether the virtual chain between the node and the current node needs to be detached or not); if the current node is not ABR and is ABR, the virtual chain connection relation possibly needs to be established with the topology node at present, and the virtual chain checking processing for configuring the current topology node is initiated (namely, whether the virtual chain between the current node and the current node needs to be established or not is judged) (in the checking processing, according to whether the area is a backbone area or not, the parameters of the incoming processing comprise an area number or not, namely, only router identification parameters are needed under the condition of the backbone area, fuzzy search is carried out in all non-backbone areas meeting the condition, the non-backbone areas need to be accurately searched in a specific area by the two parameters of the incoming router identification and the area);

if the current processing node topology was previously reachable, the current topology is not reachable: further judging whether the current node is ABR or not, if not, not affecting the virtual chain, and traversing the next topological node; if the node is an ABR and the area is not a backbone area, the virtual chain connection relation of the topological node is not needed to be established any more, and the virtual chain checking processing of the node and the current node is initiated to be removed; if the current topology node is an ABR and the area is a backbone area, the virtual chain connection relation possibly needs to be established with the topology node, and virtual chain checking processing for configuring the current topology node is initiated;

if the current processing node topology was previously unreachable, the current topology is reachable: further judging whether the current node is ABR or not, if not, traversing the next topological node without influencing the virtual chain; if the current topology node is an ABR and the area is not a backbone area, the virtual chain connection relation possibly needs to be established with the topology node, and virtual chain checking processing for configuring the current topology node is initiated; if the current topology node is an ABR and the area is a backbone area, the virtual chain connection relation with the topology node is not needed to be established, and the virtual chain checking processing of the current topology node is initiated to be removed;

if the current processing node topology was previously unreachable, the current topology is also unreachable: the topological nodes do not influence the chain, and the next topological node is continuously traversed without any processing.

After the SPF calculation is completed, if the virtual chain check processing for configuring the current node is triggered (i.e., it is determined whether a virtual link with the current node needs to be established), referring to fig. 8, fig. 8 is a schematic diagram of a virtual chain check processing flow for configuring the current node provided in the embodiment of the present invention, in actual implementation, if the virtual chain check processing is triggered in the SPF calculation of the backbone area, the introduced parameter does not have an area number (area ID), and only one area is selected from non-backbone areas that meet the requirements to establish a virtual chain connection relationship with the corresponding topology node; fuzzy searching all the virtual link related information matched with the route ID in the virtual link list, and if the corresponding virtual link exists, the fact that the virtual link does not need to be reconfigured is shown; if the corresponding virtual chain cannot be searched, judging whether an area where the route ID node topology can reach exists and the area is not a STUB/NSSA area, and if the area meeting the conditions does not exist, establishing a virtual chain connection relation; if the area meeting the condition exists, selecting the area with the largest area number from the rest areas, initiating a request for establishing a virtual link to the route ID equipment, and comparing and inserting the relevant information of the virtual link into a virtual link list according to the priority order of the area number and the route ID of the neighbor of the virtual link;

if the configuration virtual chain checking processing is triggered in the SPF calculation of the non-backbone area, the transmitted parameters carry an area number (area ID) and whether a virtual chain connection relation needs to be established between the area and the corresponding topological node is checked; accurately searching the virtual chain matching the 'area number and route ID' in the virtual chain list, and if the corresponding virtual chain exists, indicating that the configuration is not required to be reconfigured; if the corresponding virtual chain cannot be found, judging whether the topology of the route ID equipment is reachable in the backbone area, if so, establishing a virtual chain connection relation is not needed; if the topology is not reachable, the virtual link connection relation needs to be established, a request for establishing the virtual link is initiated to the route ID equipment, and the related information of the virtual link is compared and inserted into the virtual link list according to the area number and the priority order of the route ID of the neighbor of the virtual link.

If the virtual link setup with a specific node initiated previously is triggered to be torn down after SPF calculation is completed, referring to fig. 9, fig. 9 is a schematic diagram of a virtual link teardown check processing flow provided in the embodiment of the present invention, in practical implementation, if the virtual link removal processing of a specific topology node is triggered in the SPF calculation of the backbone area, the transmitted parameters do not have an area number, all the virtual link connection relations previously established with the corresponding topology node in all non-backbone areas need to be removed, the virtual link removal mark is marked for waiting deletion, a notification of virtual link removal is sent to all virtual link neighbors, wherein, the removal notification message can be packaged in an opaque LSA, and TLV information content in the LSA comprises an area for establishing a virtual link, a virtual link neighbor interface address, a virtual link neighbor ROUTER identification (ROUTER ID), a local terminal equipment virtual link-out interface address and a local terminal equipment ROUTER identification (ROUTER ID);

if the virtual link is triggered and configured to be established in the SPF calculation of the non-backbone area, the transmitted parameters carry an area number, whether a virtual link connection relation with the corresponding topology node exists in the area is checked, if the corresponding virtual link exists, the virtual link is removed, a waiting deletion mark is added, and a notification of removing the virtual link is sent to a virtual link neighbor.

In practical applications, since the main purpose of establishing virtual links is to connect isolated backbone areas, or non-backbone areas, with backbone areas, there is a possibility that a plurality of functionally identical virtual links are established, in this case, there is obviously a redundant virtual link, and accordingly, in an embodiment, the process of the router removing the redundant virtual link is also included, therefore, the router (active end) needs to perform a checking and processing process of removing redundant virtual chains, the redundant virtual chains are removed and installed, only the minimum number of virtual chains with the highest priority meeting the requirements are reserved, here, we use the priority of the region with the larger number, and the priority of the route ID with the larger number if the region numbers are the same, or use the opposite rule, as long as the processing rules of the devices are consistent, specifically, see fig. 10, where fig. 10 is a schematic diagram of the processing procedure for deleting the redundant virtual chain according to the embodiment of the present invention:

the router traverses all virtual links in the virtual link list according to the sequence of the priority from low to high, judges whether the virtual link can be deleted, if so, marks a mark waiting for deletion on the corresponding virtual link, and sends a notice of removing the virtual link to a virtual link neighbor; and if the virtual chain cannot be deleted, traversing the next virtual chain in the virtual chain list until the virtual chain list is completely traversed.

Here, the process of determining whether a specific virtual link can be deleted, referring to fig. 11, includes: running a limited SPF algorithm in a backbone area, wherein the virtual chain neighbor relation is also reflected in a database of a computational topology, so that the virtual chain topology corresponding to a virtual chain interface and the virtual chain topology with a mark waiting for deletion need to be excluded in SPF operation, and if the virtual chain neighbor topology is reachable in a final operation result, the corresponding virtual chain connection relation can be deleted, and the virtual chain connection relation can be deleted if the virtual chain neighbor topology is returned; if the virtual chain neighbor topology is not reachable, the corresponding virtual chain connection relation cannot be deleted yet, and the virtual chain connection relation is returned to be not deleted.

In actual implementation, after the router sends the notification of tearing down the virtual link, there are two cases as follows:

the first condition is as follows: receiving a returned virtual chain removal notification confirmation;

case two: receiving a notice of refusing to dismantle the virtual chain;

for the case one, referring to fig. 12, fig. 12 is a schematic diagram of a processing flow for receiving a returned virtual chain removal notification acknowledgement according to an embodiment of the present invention, where a router receives a virtual chain removal notification acknowledgement sent by another device, and needs to determine whether a corresponding virtual chain exists in a virtual chain list, and if the corresponding virtual chain does not exist, no processing is performed; if the corresponding virtual chain exists, whether the virtual chain is waiting for the removal confirmation or not needs to be further judged, namely whether a waiting deletion mark is marked or not is judged, if the waiting deletion mark is marked, the deletion confirmation sent by the virtual chain neighbor equipment is indicated to be waited, the corresponding virtual chain connection relation is deleted from the virtual chain list, and the virtual chain removal process is successful; if deletion is not being waited for, no processing is done.

For the case two, referring to fig. 13, fig. 13 is a schematic view of a processing flow of receiving a returned notification of rejecting a virtual chain removal, where the processing flow is provided in the embodiment of the present invention, in actual implementation, a home device waits for a virtual chain neighbor device to send a removal confirmation notification, but for some reason, an opposite device cannot delete a virtual chain connection relationship and sends a virtual chain removal rejection notification; the router receives the notice of rejecting the virtual chain removal, judges whether the virtual chain with the corresponding mark to be deleted exists in the virtual chain list, if so, the opposite party rejects the virtual chain removal, the mark to be deleted of the virtual chain needs to be removed, and the virtual chain removal process fails; if no corresponding virtual chain exists, no processing is performed.

Correspondingly, in practical application, a router may also receive a virtual link removal notification sent by another router, see fig. 14, where fig. 14 is a schematic diagram of a processing flow for receiving a virtual link removal notification provided in the embodiment of the present invention, and a router receives a virtual link removal notification sent by another router, and first needs to check whether the virtual link neighbor exists, and if the virtual link neighbor does not exist, sends a virtual link removal confirmation notification; if the virtual link neighbor exists, whether a corresponding virtual link exists in a virtual link list or not needs to be checked so as to judge whether the virtual link relation is established passively or actively;

if the virtual chain list does not have the corresponding virtual chain, the virtual chain connection relation is passively established, the local terminal immediately deletes the virtual chain neighbor connection relation, and sends a virtual chain removal confirmation notice;

if the corresponding virtual chain exists in the virtual chain list, it indicates that both ends of the virtual chain are active initiators, and further judgment processing is needed to determine whether the current virtual chain can be deleted. Judging whether the virtual chain is marked with a waiting deletion mark or not, if so, indicating that the local terminal equipment is also preparing to delete the virtual chain, deleting the corresponding virtual chain from the virtual chain list, and sending a virtual chain removal confirmation notice to the virtual chain neighbor equipment; if the virtual chain is not marked with a waiting deletion mark, whether the virtual chain can be deleted or not needs to be judged, if the virtual chain can be deleted, the corresponding virtual chain is deleted from the virtual chain list, and a virtual chain removal confirmation is sent to the virtual chain neighbor equipment; and if the virtual chain cannot be deleted, sending a virtual chain removal rejection notification to the virtual chain neighbor device, wherein the removal rejection message can be encapsulated in an opaque LSA, and TLV information content in the LSA comprises an area for establishing the virtual chain, a virtual chain neighbor interface address, a virtual chain neighbor ROUTER identifier (Router ID), a local terminal device virtual chain outgoing interface address, a local terminal device ROUTER identifier and a rejection reason.

Example two

Fig. 15 is a schematic flowchart of a method for establishing a virtual link according to an embodiment of the present invention, and fig. 16 is an optional schematic diagram of area networking according to an embodiment of the present invention; the method for establishing a virtual link according to the embodiment of the present invention is described in detail with reference to fig. 15 and 16.

Referring to the area networking diagram shown in fig. 16, after the device enables the OSPF protocol, it wants to advertise whether it supports the auto-configuration virtual link capability, and all of route 1, route 2, route 3, and route 4 notify other devices that it has the auto-configuration virtual link capability. Next, the ROUTER route 2 will be explained.

In actual implementation, when SPF calculation of a non-backbone area of the ROUTER route 2 is completed, triggering judgment on whether to automatically establish a virtual link, the ROUTER 2 judging whether itself is in a STUB area or an NSSA area, and if so, ending the processing flow; if the area is neither in the STUB area nor in the NSSA area, step 201 and subsequent processes are performed.

Step 201: and obtaining the ABR information which is reachable by the area and supports the automatic configuration of the virtual link.

Here, in practical applications, the router may obtain the reachable ABR information of the area through SPF calculation, and may know whether the corresponding router supports the auto-configuration virtual link through the notification sent by other routers.

Step 202: judging whether the ABR is the ABR or not, if so, executing step 203; if it is not ABR, step 206 is performed.

It can be seen by the networking shown in fig. 16 that route 2 is not ABR.

Step 203: judging whether the ABRs with inaccessible backbone areas exist in the accessible ABRs, and if yes, executing step 204; if not, step 212 is performed.

Step 204: and sending a first virtual link establishment request to the inaccessible ABR of the backbone area so as to establish a first virtual link between the inaccessible ABR of the backbone area and the inaccessible ABR of the backbone area.

Step 205: and storing the related information of the first virtual link into a virtual link list.

Here, in practical applications, the information about the first virtual link includes: the area information corresponding to the first virtual link, the virtual link neighbor information (virtual link neighbor router identification, virtual link neighbor interface address), and the like.

Step 206: judging whether the self is connected with at least two non-backbone areas, and if so, executing step 207; otherwise, step 212 is performed.

It can be seen from the networking shown in fig. 16 that route 2, as a non-ABR, connects three non-diaphyseal areas, namely area1, area2, and area3, where area1 has no area accessible ABR, resulting in isolation of non-diaphyseal area1 from diaphyseal area 0.

Step 207: judging whether the obtained reachable area and the ABR information supporting the automatic configuration of the virtual link are empty, if not, executing the step 208; if empty, step 212 is performed.

Step 208: and selecting an accessible ABR from the obtained ABR information to send a second virtual link establishment request.

Here, in actual implementation, as can be seen from the networking shown in fig. 16, route 2 can reach ROUTER3 at area2 and area3, and therefore, a second virtual link establishment request is sent to device ROUTER3 at area2 and area3, respectively.

Correspondingly, in practical application, Router3 also monitors whether a request for establishing a virtual link is sent by another device, receives a second virtual link establishment request sent by Router 2 from area2 and area3, checks validity of the second virtual link establishment request, and establishes a virtual link neighbor relationship between area2 and area3 in cooperation with Router 2.

Step 209: and storing the related information of the second link into the virtual link list.

Here, the information about the second virtual link includes: and the area information corresponding to the second virtual link, the virtual link neighbor information (virtual link neighbor router identification, virtual link neighbor interface address), and the like.

Step 210: and when determining that the redundant link exists in the virtual link list, sending a notice for removing the redundant virtual link.

Here, as can be known from the networking shown in fig. 16 and the description of the foregoing embodiment, the virtual links established between Router 2 and Router3 in area2 and area3 have the same function, and there is redundancy, Router 2 traverses all the virtual link information stored in the virtual link list, knows that the virtual links established in area2 and area3 have redundancy, and needs to tear down one of the virtual links, and in an embodiment, when selecting a virtual link that needs to be torn down, may be based on the area number corresponding to the virtual link, such as: in this embodiment, the virtual link in area2 is selected to be removed, a notification of removing the virtual link is sent from area2 to Router3, Router3 receives the notification of removing the virtual link sent from Router 2, the virtual link in area2 is approved to be removed and a virtual link removal confirmation notification is sent to Router 2, and Router 2 deletes the virtual link after receiving the removal confirmation notification.

Step 211: and receiving a virtual link removal confirmation notice, and deleting the corresponding virtual link.

In practical applications, the following may occur: at a certain moment, when a connection interface of Router 2 and Router3 in area3 fails, Router 2 triggers SPF calculation to find that area3 cannot reach Router3, that is, the virtual link that is established has a problem and needs to be reestablished, and Router 2 performs the following operations: the virtual link previously established in area3 is torn down and virtual links are reestablished in area2 and Router 3.

Step 212: and ending the processing flow.

By applying the embodiment of the invention, the router automatically identifies the condition of needing to establish the virtual link, realizes the establishment of the virtual link, saves the labor cost, improves the virtual link establishment efficiency, and avoids the problems of networking errors, further routing obstruction and the like caused by artificial virtual link establishment.

EXAMPLE III

Fig. 17 is a schematic diagram illustrating a structure of a router according to an embodiment of the present invention, where as shown in fig. 17, the router according to the embodiment of the present invention includes:

an obtaining module 41, configured to obtain reachable ABR information of an area through a preset policy;

and the processing module 42 is configured to send a first virtual link establishment request to the corresponding area-reachable ABR to establish a first virtual link with the ABR when it is determined that a preset virtual link establishment condition is met based on the area-reachable ABR information.

In an embodiment, the processing module 42 is further configured to determine, in response to the router being an ABR in a non-tip area, that there is an ABR unreachable for a backbone area among ABRs reachable by the area based on the ABR information reachable by the area;

In an embodiment, the processing module 42 is further configured to send the first virtual link establishment request to an unreachable ABR in the backbone area through a preset communication manner;

In an embodiment, the processing module 42 is further configured to determine that there is at least one area-reachable ABR based on the area-reachable ABR information in response to the router being a non-ABR in a non-tip area and the non-ABR connecting at least two non-backbone areas and there being at least one non-backbone area without an area-reachable ABR in the at least two non-backbone areas;

In an embodiment, the processing module 42 is further configured to select an ABR with the highest priority from the reachable ABRs of the at least one area;

In one embodiment, the processing module 42 is further configured to send information about whether the router has the capability of automatically configuring the virtual link to other routers through opaque LSAs or router LSAs.

In an embodiment, the processing module 42 is further configured to receive a second virtual link establishment request;

In an embodiment, the processing module 42 is further configured to store the relevant information of the first virtual link in a virtual link list according to a link priority from high to low;

In an embodiment, the processing module 42 is further configured to traverse all the virtual link information stored in the virtual link list;

In an embodiment, the processing module 42 is further configured to obtain that the corresponding area-reachable ABR no longer has the capability of automatically configuring the virtual link through a notification sent by the corresponding area-reachable ABR;

Example four

Fig. 18 is a schematic diagram of an optional hardware structure of a router according to an embodiment of the present invention, and as shown in fig. 18, the router according to the embodiment of the present invention includes: a processor 51, a memory 52 and at least one external communication interface 53; the processor 51, the memory 52 and the external communication interface 53 are all connected through a bus 54; wherein the content of the first and second substances,

a memory 52 configured to store an executable program;

a processor 51 configured to implement, when executing the executable program stored in the memory:

obtaining reachable ABR information of the area through a preset strategy;

when the preset virtual link establishment condition is determined to be met based on the regional reachable ABR information, a first virtual link establishment request is sent to the corresponding regional reachable ABR so as to establish a first virtual link between the regional reachable ABR and the corresponding regional reachable ABR

In an embodiment, the processor 51 is further configured to, when executing the executable program stored in the memory, implement:

in response to the router being a non-ABR in a non-tip area, and the non-ABR connecting at least two non-backbone areas, and there being at least one non-backbone area in the at least two non-backbone areas having no area-reachable ABR, determining that there is at least one area-reachable ABR based on the area-reachable ABR information;

receiving a second virtual link establishment request;

traversing all virtual link information stored in the virtual link list;

The embodiment of the invention also provides a computer storage medium, which stores an executable program, and when the executable program is executed by a processor, the executable program realizes that:

obtaining reachable ABR information of the area through a preset strategy;

In one embodiment, the executable program, when executed by the processor, further implements:

transmitting the first virtual link establishment request to the unreachable ABR of the backbone area through an opaque link state broadcast (LSA);

the opaque LSA carries at least one of the following information: and establishing the area of the virtual link, the virtual link neighbor interface address, the virtual link neighbor router identification, the local terminal equipment virtual link outlet interface address and the local terminal router identification.

in response to the router being a non-ABR in a non-tip area and the non-ABR connecting at least two non-backbone areas, determining that there is at least one area-reachable ABR based on the area-reachable ABR information;

receiving a second virtual link establishment request sent by an accessible ABR in an area;

traversing all virtual link information stored in the virtual link list;

Here, it should be noted that: the above description related to the router is similar to the above description of the method, and the description of the beneficial effects of the same method is omitted for brevity. For technical details not disclosed in the embodiments of the router of the present invention, refer to the description of the embodiments of the method of the present invention.

Those of ordinary skill in the art will understand that: all or part of the steps for implementing the method embodiments may be implemented by hardware related to program instructions, and the program may be stored in a computer readable storage medium, and when executed, the program performs the steps including the method embodiments; and the aforementioned storage medium includes: a mobile storage device, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

Alternatively, the integrated unit of the present invention may be stored in a computer-readable storage medium if it is implemented in the form of a software functional module and sold or used as a separate product. Based on such understanding, the technical solutions of the embodiments of the present invention may be essentially implemented or a part contributing to the prior art may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the methods described in the embodiments of the present invention. And the aforementioned storage medium includes: a removable storage device, a ROM, a RAM, a magnetic or optical disk, or various other media that can store program code.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. A method for establishing a virtual link, for a router in a network including a backbone area and at least one non-backbone area, the method comprising:

acquiring ABR information of an area border router with an accessible area through a preset strategy;

when the preset virtual link establishment condition is determined to be met based on the regional reachable ABR information, a first virtual link establishment request is sent to the corresponding regional reachable ABR so as to establish a first virtual link with the ABR;

wherein, when it is determined that a preset virtual link establishment condition is satisfied based on the area-reachable ABR information, sending a first virtual link establishment request to a corresponding area-reachable ABR includes:

sending a first virtual link establishment request to an unreachable ABR of the backbone area;

after receiving the notice of refusing to establish the virtual link, if the virtual link neighbor initiating the virtual link request is found, deleting the virtual link neighbor information from the virtual link list, and re-triggering the virtual link request configured in the inspection area so as to select new equipment to establish the virtual link neighbor relation;

and when determining whether a preset virtual link establishment condition is met or not based on the reachable ABR information of the area, monitoring whether the virtual link establishment request sent by other equipment is received or not in real time.

2. The method of claim 1, wherein the sending the first virtual link setup request to the unreachable ABR of the backbone area comprises:

3. The method of claim 1, wherein when it is determined that a preset virtual link establishment condition is satisfied based on the area-reachable ABR information, sending a first virtual link establishment request to a corresponding area-reachable ABR comprises:

4. The method of claim 3, wherein selecting one of the at least one regional reachable ABR for sending the first virtual link setup request comprises:

5. The method of claim 1, further comprising:

6. The method of claim 1, further comprising:

receiving a second virtual link establishment request;

7. The method of claim 1, further comprising:

8. The method of claim 7, further comprising:

traversing all virtual link information stored in the virtual link list;

9. The method of claim 7, further comprising:

10. A router, the router comprising:

the acquisition module is used for acquiring the ABR information of the area border router with the reachable area through a preset strategy;

the processing module is used for sending a first virtual link establishment request to the corresponding regional reachable ABR to establish a first virtual link with the ABR when the preset virtual link establishment condition is determined to be met based on the regional reachable ABR information;

wherein the processing module is further configured to determine, in response to the router being an ABR in a non-tip region, that there is an ABR unreachable for a backbone region among ABRs reachable for a region based on the ABR information reachable for the region;

11. The router according to claim 10,

the processing module, further configured to determine that there is at least one area-reachable ABR based on the area-reachable ABR information in response to the router being a non-ABR in a non-tip area, the non-ABR connecting at least two non-backbone areas, and there being at least one non-backbone area in the at least two non-backbone areas having no area-reachable ABR;

12. A router, the router comprising:

a memory configured to store an executable program;

a processor configured to execute an executable program stored in the memory to implement the method of establishing a virtual link according to any one of claims 1 to 9.

13. A storage medium storing an executable program which, when executed by a processor, implements a method of establishing a virtual link as claimed in any one of claims 1 to 9.