CN111131030B

CN111131030B - Route processing method, equipment and medium under EVPN

Info

Publication number: CN111131030B
Application number: CN201911348797.3A
Authority: CN
Inventors: 张钟凯; 赖雪峰
Original assignee: Inspur Cisco Networking Technology Co Ltd
Current assignee: Inspur Cisco Networking Technology Co Ltd
Priority date: 2019-12-24
Filing date: 2019-12-24
Publication date: 2020-10-30
Anticipated expiration: 2039-12-24
Also published as: CN111131030A

Abstract

The application discloses a route processing method, equipment and medium under an EVPN. The method is applied to a first VTEP, and comprises the following steps: deleting the related routing information of the second-layer VNI in response to a switching instruction for switching from the second-layer VNI to the third-layer VNI, wherein the switching instruction is issued by binding the second-layer VNI with the corresponding VRF; and after the switched three-layer VNI takes effect, performing full-volume routing update by interacting with a second VTEP, wherein the second VTEP is a BGP neighbor of the first VTEP. According to the method and the device, the switching between the two-layer VNI and the three-layer VNI can be realized, and the configuration is simple and the cost is low.

Description

Route processing method, equipment and medium under EVPN

Technical Field

The present application relates to the field of communications technologies, and in particular, to a method, a device, and a medium for processing a route under an EVPN.

Background

An Ethernet Virtual Private Network (EVPN) is a two-layer VPN technology, in which a control plane uses a Border Gateway Protocol (BGP) to announce EVPN routing information, and a data plane uses an eXtensible Virtual local area Network (VXLAN) encapsulation mode to forward a packet. The EVPN can provide two-layer interconnection for the same subnet of the same tenant based on the existing service provider or enterprise IP network, and provide three-layer interconnection for different subnets of the same tenant through the EVPN gateway and provide three-layer interconnection with an external network.

EVPN usually adopts a core (denoted by Spine) -branch (denoted by Leaf) layered structure, wherein a device of the Leaf layer is used as a VXLAN Tunnel EndPoint (VXLAN Tunnel EndPoint, VTEP) to perform EVPN related processing on a message, and a device of the Spine layer is used as a core device to forward the message according to a destination IP address of the message. When all devices in the EVPN belong to the same Autonomous System (AS), in order to avoid establishing an Internal BGP (IBGP) peer between all VTEPs, a core device may be configured AS a Route Reflector (RR).

The BGP routing table is protocol-stored routing information for processing BGP protocol message learning. The BGP routing table stores all the routing Information received by the BGP process, and stores the Routing Information Base (RIB) table after processing, selecting the optimal Route, and the like.

The RIB table is a location where all IP routing information is stored. The RIB is not specific to any routing protocol, but rather all routing protocols place a repository of all their routes. Each time a routing protocol running on a router learns of a new route, the route is inserted into the RIB table. When a destination becomes unreachable, the route is first marked as unavailable and then removed from the RIB table according to the specifications of the routing protocol known from it. It should be noted that the RIB is not used to forward IP datagrams nor to advertise to the rest of the network to which the router is connected.

In the existing EVPN, the switching between the two-tier VNI (L2 VNI) and the three-tier VNI (L3 VNI) is not supported, and modifying the L3/L2 value of the VNI requires completely deleting the VNI and reconfiguring, which results in a long effective interval of new configuration, large network fluctuation and increased network outage time.

Disclosure of Invention

The embodiment of the application provides a routing processing method, a device and a medium under an EVPN, which are used for solving the following technical problems in the prior art: in the existing EVPN, switching between the L2VNI and the L3VNI is not supported, modifying the L3/L2 value of the VNI requires completely deleting the VNI and reconfiguring, which results in a long effective interval of new configuration, large network fluctuation and increased network outage time.

The embodiment of the application adopts the following technical scheme:

a routing processing method under EVPN is applied to a first VTEP, and the method comprises the following steps:

deleting relevant Routing information of an L2VNI in response to a handover instruction for a handover of the L2VNI to the L3VNI, the handover instruction issued by binding the L2VNI with a corresponding Virtual Routing Forwarding (VRF);

and after the L3VNI of the switching is validated, performing full-volume routing update by interacting with a second VTEP, wherein the second VTEP is a BGP neighbor of the first VTEP.

Optionally, before performing the full-volume route update, the method further includes:

and sending a routing message of a specified type to the second VTEP in response to the switching instruction, where the routing message carries an egress Route Target (egress RT) of the L2VNI, so that the second VTEP updates its own related routing information accordingly.

Optionally, the method further comprises:

after the L3VNI of the handover is validated, the related routing information of the L2VNI in the VRF associated with the L3VNI is updated according to the Export RT of the L3 VNI.

Optionally, after updating the relevant routing information of the L2VNI in the VRF associated with the L3VNI, the method further includes:

and sending the updated related routing information to the second VTEP through a routing message of a specified type so that the second VTEP correspondingly updates the related routing information of the second VTEP.

Optionally, the method further comprises:

if the Export RT of the L2VNI is changed, updating the related routing information of the L2VNI according to the changed Export RT;

and informing the second VTEP to correspondingly update the relevant routing information of the second VTEP according to the updated relevant routing information.

Optionally, the method further comprises:

if the Import RT of the L2VNI is changed, the relevant routing information of the L2VNI is updated according to the changed Import routing target (Import route target, Import RT), and the second VTEP is not notified to be updated accordingly.

Optionally, the method further comprises:

after the switched L3VNI takes effect, if the L3VNI configuration is modified, the relevant routing information of the L2VNI associated with the L3VNI is updated, and the second VTEP is notified to update its own relevant routing information accordingly according to the updated relevant routing information.

Optionally, the method further comprises:

in response to a switching instruction for switching from the L3VNI to the L2VNI, deleting the Export RT of the L3VNI, performing corresponding updating according to the Export RT of the L2VNI, and informing the second VTEP of corresponding updating;

after the L2VNI switched is validated, the route introduced according to the Import RT of the L3VNI is deleted.

A route processing device under EVPN, applied to a first VTEP, the device comprising:

at least one processor; and the number of the first and second groups,

a memory communicatively coupled to the at least one processor; wherein the content of the first and second substances,

the memory stores instructions executable by the at least one processor to enable the at least one processor to:

revoking relevant routing information of the L2VNI in response to a switching instruction for switching from the L2VNI to the L3VNI, the switching instruction being issued by a binding operation of the L2VNI with a VRF;

after the L3VNI of the handover is validated, a full volume routing update is performed by interacting with a second VTEP, which is a BGP neighbor of the first VTEP.

A routing processing medium under EVPN storing computer executable instructions for application to a first VTEP, the computer executable instructions configured to:

The embodiment of the application adopts at least one technical scheme which can achieve the following beneficial effects: the switching between the L2VNI and the L3VNI can be realized, and the configuration is simple and the cost is low; moreover, in a demand scene of three-layer VNI configuration modification, the route updating cost is low, the total route updating messages can be effectively reduced, the method is suitable for large-scale networks, the operation dependence on the total route updating is low, the bandwidth can be effectively saved, and the equipment power consumption is reduced.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

fig. 1 is a schematic flow chart of a routing processing method under EVPN according to some embodiments of the present application;

fig. 2 is a scene schematic diagram of a distributed gateway applying the method in fig. 1 in an application scenario provided in some embodiments of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be described in detail and completely with reference to the following specific embodiments of the present application and the accompanying drawings. It should be apparent that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The problems of the prior art have been addressed in the background, and will be described in more detail in the following aspects for the sake of understanding.

The configuration aspect is as follows: VNI is created by specifying VNI type, L3VNI is created under VRF view, L2VNI is created under EVPN view. Once designated, the L3VNI and the L2VNI are not allowed to be freely switched, and if the L3VNI needs to be switched to the L2VNI, all configurations related to the L3VNI need to be deleted, and then the VNI is reconfigured to be the L2 VNI.

And (3) message processing: if the L3VNI is not configured, the L3VNI is not in effect, and at this time, when the device receives the message, the device does not process the packet without the L3VNI, or does not process the BGP packet with the L3 VNI; if the L3VNI configuration is complete, then the BGP message without the L3VNI is not processed.

And routing transmission updating aspect: if the configuration of the L3VNI is not completed, the Route update message only carries the Route Target (RT) of the L2VNI and the L2 VNI; if the L3VNI configuration is completed, the route update message carries the L2VNI, the L3VNI, and the corresponding RT.

Route reception update aspect: if the L3VNI configuration is not completed, any message received is not processed; and if the L3VNI configuration is completed, only the carried BGP messages with L3VNI configuration matched with the local L3VNI configuration are processed.

It can be seen that at least the following problems are particularly present in the above solution:

free switching between the L2VNI and the L3VNI is not supported, and modifying the L3/L2 value of the VNI requires completely deleting the VNI and reconfiguring it. The new configuration has longer effective interval, larger network fluctuation and increased network disconnection time.

The configuration is relatively fixed, the configuration commands of the L2VNI and the L3VNI are not common, the configuration is more when the network plan is changed, and more configuration time is needed for the new configuration to take effect.

When the L3VNI needs to be modified, the route update overhead is high.

The solution of the present application is capable of solving at least part of the above problems, as explained below.

Fig. 1 is a schematic flowchart of a routing processing method under EVPN according to some embodiments of the present application, and an execution subject of the flowchart may be any VTEP (referred to as a first VTEP for convenience of description).

The method of fig. 1 comprises the steps of:

s100: deleting relevant routing information of the layer two VNI in response to a switching instruction for switching from the layer two VNI to the layer three VNI, wherein the switching instruction is issued by binding the layer two VNI with a corresponding VRF.

In some embodiments of the present application, the L2VNI and the L3VNI are configured in an EVPN view, and when configured, the relevant VLAN interfaces are bound to the corresponding VRFs. After configuration is completed, entering a VRF view, and selecting one VNI to perform binding operation, wherein the VNI is switched from an L2VNI to an L3 VNI; in this case, the binding between the VNI and the VRF is deleted, or the VRF to which the VLAN interface belongs is different from the VRF to which the VNI is bound, or the VNI is not configured with a Route Distingguisser (RD), RT, and these events may all cause the L3VNI to switch to the L2 VNI.

Further, in configuration, direct replacement operation of the L3VNI is supported, and when configuration modification of the L3VNI is required, the L3VNI bound by the VRF may be directly replaced after the VNI is created and relevant information such as RD and RT is configured.

In some embodiments of the present application, the relevant routing information in step S100 may include an entry in a local (i.e., first VTEP) BGP routing table. If there is a MAC/IP host route in the second-layer VNI, it is further required to notify the corresponding VTEP (including the BGP neighbor of the first VTEP, the second VTEP) to update the route information accordingly according to the MAC/IP host route, and after the notification is completed, the MAC/IP host route may also be deleted.

For example, in response to the switching instruction, the first VTEP sends a routing packet of a specified type to the second VTEP, where the routing packet carries an Export RT of the layer two VNI, so that the second VTEP updates its own relevant routing information accordingly. The notified VTEP can search whether the Import RT of L2/VNI is the same as the RT in the EVPN routing message, if the Import RT of the local VNI is matched with the RT in the EVPN route, the routing information of the VNI matched with the RT on the VTEP is updated, and the EVPN route is deleted from the routing table of the VTEP. The specified type of routing packet includes, for example, a Withdraw routing packet.

S102: and after the switched three-layer VNI takes effect, performing full-volume routing update by interacting with a second VTEP, wherein the second VTEP is a BGP neighbor of the first VTEP.

In some embodiments of the present application, after the three-tier VNI for switching becomes effective, the first VTEP may send a message to the second VTEP, request the routing table of the opposite end, and perform the full-volume routing update through the routing table of the opposite end, so that it is possible to avoid the routing asynchronization caused by the change of the route introduction policy.

By the method of fig. 2, the switching between the two-layer VNI and the three-layer VNI can be realized, and the configuration is simple and the cost is low.

Based on the method of fig. 2, the present application also provides some specific embodiments and extensions of the method, which are described further below.

In some embodiments of the present application, after the three-tier VNI of the handover is validated, the first VTEP may update the relevant routing information of the two-tier VNI within the VRF associated with the three-tier VNI according to the Export RT of the three-tier VNI. The related routing information includes, for example, a local routing table entry, and an Export RT of a three-layer VNI may be added to the corresponding routing table entry as an extended attribute, so as to support a three-layer routing egress capability.

Further, after the first VTEP updates the relevant routing information of the second-layer VNI in the VRF associated with the third-layer VNI, the updated relevant routing information may also be sent to the second VTEP through a routing packet of a specified type, so that the second VTEP updates its own relevant routing information accordingly. The specified type of routing packet herein includes, for example, an update routing packet.

In some embodiments of the present application, if the Export RT of the two-layer VNI is changed, the first VTEP may update the relevant routing information of the two-layer VNI according to the changed Export RT; and informing the second VTEP to correspondingly update the relevant routing information of the second VTEP according to the updated relevant routing information.

Similarly, if the inport RT of the second-layer VNI changes, the first VTEP may update the relevant routing information of the second-layer VNI according to the changed inport RT, except that the second VTEP may not be notified to update accordingly.

In some embodiments of the present application, after the three-tier VNI being switched takes effect, if the configuration of the three-tier VNI is modified, the relevant routing information of the two-tier VNI associated with the three-tier VNI is updated, and the second VTEP is notified to update its own relevant routing information accordingly according to the updated relevant routing information. The updated relevant routing information includes, for example, RD, RT, etc. Thereby enabling support for configuration modifications of the three-tier VNI.

While the foregoing describes some of the processing involved in switching the VTEP from the second-tier VNI to the third-tier VNI, the VTEP may also switch from the third-tier VNI to the second-tier VNI based on the solution of the present application. For example, the first VTEP may delete the Export RT of the three-layer VNI in response to a switch instruction for switching from the three-layer VNI to the two-layer VNI, perform corresponding update according to the Export RT of the two-layer VNI, and notify the second VTEP of the corresponding update; and after the switched two-layer VNI takes effect, deleting the route introduced according to the ImportRT of the three-layer VNI.

According to the foregoing description, for convenience of understanding, some embodiments of the present application further provide a specific implementation of the foregoing scheme in an application layer scenario, which is described with reference to fig. 2, and fig. 2 is a scenario diagram of a distributed gateway applying the method in fig. 1 in the application scenario. In fig. 2, VTEP1 is the first VTEP, and VTEP2 is the second VTEP.

The following is a route processing flow when the L2VNI is switched to the L3 VNI:

after configuring the VNI binding VRF, the VNI is handed over from the L2VNI to the L3VNI, and the handover procedure first revokes the routing information related to the VNI, including: deleting an entry in a local BGP routing table; a Withdraw message is sent to the relevant BGP neighbor. The specific operation comprises the following steps: and if the MAC/IP host route exists in the VNI, sending a Withdraw message to the VTEP2, wherein RTs carried by the EVPN route in the message are all Export RTs of the VNI, and clearing the MAC/IP host route in the VNI after the completion of the route withdrawal.

After receiving the Withdraw message, VTEP2 searches whether the Import RT of L2VNI locally is the same as the RT in the EVPN route message, and if the Import RT of local VNI locally matches the RT in the EVPN route, processes the Withdraw message, updates VNI route information matching the RT on VTEP2, and deletes the EVPN route from the local VNI route table.

After the L3VNI of VTEP1 is validated, VTEP1 sends a route-refresh message to VTEP2 requesting the correspondent routing table. By requesting the update of the full amount of routes and processing the full amount of routes after receiving the routing table entries, the asynchronous routes caused by the change of the route introduction strategy can be avoided.

After L3VNI of VTEP1 takes effect, traverse and update local MAC/IP host routing information of all L2 VNIs in VRF associated with L3VNI, and add new extended attribute on the basis of original routing information: the Export RT of the L3VNI forms a new routing table entry, replaces the original table entry in the VNI routing table, and sends the newly formed routing table entry to the VTEP2 using update message. The specific operation is as follows: and updating the routing identifier RT attribute in the original table entry into all Export RTs of the L2VNI and all Export RTs of the L3VNI, and storing the routing identifier RT attribute in the host routing table of the original L2VNI again. And converting the updated routing information to obtain an EVPN route, and sending an update message to the VTEP 2.

After receiving the update message, the VTEP2 first searches whether a local L3VNI exists, and if the corresponding L3VNI does not exist, discards the message; and if the L3VNI is configured, searching whether the Import RT of all local VNIs is the same as the RT in the EVPN routing message, and if the RT is matched with the RT of the local VNI, processing the update message. And updating the routing information of the VNI matched with the RT on the VTEP2, and adding the EVPN route to a local VNI routing table.

If the Export RT of the L2VNI is changed, the MAC/IP host route of the L2VNI is traversed immediately, the new RT is used for replacing the original RT value, the original RT value is stored in the route table entry of the L2VNI, and the route update is sent to the VTEP2 by the EVPN route obtained by conversion of the new RT.

If the Import RT of the L2VNI changes, the route needs to be updated again. The specific route updating method comprises the following steps: and reading a routing entry from the routing identification RD routing table, and updating the route by using the routing entry without sending a route-refresh message to the VTEP 2.

The following is the route processing flow of VTEP1 when the L3VNI configuration is modified:

after the command is used for directly replacing L3 VNIs bound by the VRF, local MAC/IP host routing information of all L2 VNIs in the VRF associated with the L3 VNIs is updated in a traversing mode, and corresponding RD and RT of the L2 VNIs and RD and RT information of new L3 VNIs are used for forming a new routing table. And sends the newly formed routing table entry to VTEP2 using the update message. I.e. the route update procedure of the L3VNI modification is completed directly.

The following is a route processing flow of VTEP1 when the L3VNI switches to the L2 VNI:

before the L3VNI fails, traversing and updating local MAC/IP host routing information of all L2 VNIs in a VRF associated with the L3VNI, deleting an Export RT of the L3VNI of the original routing information, forming a new routing table item, replacing the original table item in the VNI routing table, and sending the newly formed routing table item to a VTEP2 by using an update message. The specific operation is as follows: and updating the routing identifier RT attribute in the original table entry into all Export RTs of the L2VNI, and then storing the routing identifier RT attribute in the host routing table of the original L2VNI again. And converting the updated routing information to obtain an EVPN route, and sending an update message to the VTEP 2.

And after the L3VNI is successfully switched to the L2VNI, deleting all routes introduced according to the Import RT of the L3VNI when the original L3VNI takes effect.

The above scheme has the following advantages:

the configuration is flexible and variable, the L3VNI and the L2VNI are universally switchable, and the switching between the L2VNI and the L3VNI can be completed with fewer configuration commands when the network is changed.

The routing update overhead is low in the scene of the requirement of the L3VNI configuration modification, and 50% of total routing update messages can be reduced. The method is suitable for large-scale networks, and has less dependence on the operation of updating the route in full quantity. The bandwidth can be effectively saved, and the power consumption of the equipment is reduced. In a large-scale network, the network bandwidth occupied by route updating can be effectively saved, the economic investment of the network bandwidth is reduced, and the cost is saved.

The problem of long-time network outage caused by the switching of the L3VNI is effectively solved.

Based on the same idea, some embodiments of the present application further provide devices and media corresponding to the above system.

Some embodiments of the present application provide a routing processing device under EVPN, applied to a first VTEP, the device including:

at least one processor; and the number of the first and second groups,

Some embodiments of the present application provide a routing processing medium under EVPN, applied to a first VTEP, the medium including a non-volatile computer storage medium storing computer-executable instructions configured to:

The embodiments in the present application are described in a progressive manner, and the same and similar parts among the embodiments can be referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the device and media embodiments, the description is relatively simple as it is substantially similar to the method embodiments, and reference may be made to some descriptions of the method embodiments for relevant points.

The device, the medium and the method provided by the embodiment of the application are corresponding, so that the device and the medium also have similar beneficial technical effects as the corresponding method.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a system, apparatus, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams 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.

In a typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include forms of volatile memory in a computer readable medium, Random Access Memory (RAM) and/or non-volatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM). Memory is an example of a computer-readable medium.

Computer-readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), Digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed by a computing device. As defined herein, a computer readable medium does not include a transitory computer readable medium such as a modulated data signal and a carrier wave.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The above description is only an example of the present application and is not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A routing processing method under EVPN is applied to a first VTEP, and the method comprises the following steps:

deleting relevant routing information of a two-layer VNI in response to a handover instruction for handover from the two-layer VNI to a three-layer VNI, the handover instruction being issued by binding the two-layer VNI with a corresponding VRF;

after the switched three-layer VNI takes effect, performing full-scale routing update by interacting with a second VTEP, wherein the second VTEP is a BGP neighbor of the first VTEP;

after deleting the routing information related to the layer two VNI, the method further includes:

responding to the switching instruction, sending a routing message of a specified type to the second VTEP, wherein the routing message carries an Export RT of the two-layer VNI, so that the second VTEP correspondingly updates the relevant routing information of the second VTEP;

the method further comprises the following steps:

after the switched three-layer VNI takes effect, updating relevant routing information of a two-layer VNI in a VRF associated with the three-layer VNI according to an Export RT of the three-layer VNI;

after updating the relevant routing information of the second-layer VNI in the VRF associated with the third-layer VNI, the method further includes:

2. The method of claim 1, wherein the method further comprises:

if the Export RT of the second-layer VNI is changed, updating the related routing information of the second-layer VNI according to the changed Export RT;

3. The method of claim 1, wherein the method further comprises:

and if the Import RT of the second-layer VNI is changed, updating the related routing information of the second-layer VNI according to the changed Import RT, and not informing that the second VTEP is updated correspondingly.

4. The method of claim 1, wherein the method further comprises:

after the three-layer VNI switched takes effect, if the configuration of the three-layer VNI is modified, the related routing information of the two-layer VNI associated with the three-layer VNI is updated, and the second VTEP is informed to correspondingly update the related routing information of the second VTEP according to the updated related routing information.

5. The method of claim 1, wherein the method further comprises:

in response to a switching instruction for switching from the three-layer VNI to the two-layer VNI, deleting an Export RT of the three-layer VNI, performing corresponding updating according to the Export RT of the two-layer VNI, and notifying the second VTEP of corresponding updating;

and after the switched second-layer VNI takes effect, deleting the route introduced according to the Import RT of the third-layer VNI.

6. A route processing device under EVPN, applied to a first VTEP, the device comprising:

at least one processor; and the number of the first and second groups,

revoking related routing information of a two-layer VNI in response to a switching instruction for switching from the two-layer VNI to a three-layer VNI, wherein the switching instruction is issued by a binding operation of the two-layer VNI and a VRF;

after the switched three-layer VNI takes effect, performing total routing update by interacting with a second VTEP, wherein the second VTEP is a BGP neighbor of the first VTEP;

7. A computer-readable storage medium storing computer-executable instructions for a first VTEP in routing processing under EVPN, the computer-executable instructions configured to: