CN112104547A

CN112104547A - Method and device for avoiding loop in EVPN multi-homing networking

Info

Publication number: CN112104547A
Application number: CN202010776964.0A
Authority: CN
Inventors: 陈建
Original assignee: Hangzhou H3C Technologies Co Ltd
Current assignee: New H3C Information Technologies Co Ltd
Priority date: 2020-08-05
Filing date: 2020-08-05
Publication date: 2020-12-18
Anticipated expiration: 2040-08-05
Also published as: CN112104547B

Abstract

The application provides a method and a device for avoiding a loop in an EVPN multi-homing networking, wherein the method comprises the following steps: receiving a first network message sent by a far-end PE, wherein the first network message comprises a first VPN label of the first PE; according to the first VPN label, acquiring a local VPN example corresponding to the first VPN label, and acquiring a first output interface of the VPN example; and when determining that the first link corresponding to the first output interface fails, sending a second network message to the second PE through the bypass link, wherein the second network message comprises a bypass label of the second PE and a second VPN label of the second PE, so that the second PE determines that the second network message is sent through the bypass link for the first PE belonging to the same multi-attribution group according to the bypass label of the second PE, and discards the second network message when determining that the corresponding second link fails according to the second VPN label.

Description

Method and device for avoiding loop in EVPN multi-homing networking

Technical Field

The present application relates to the field of communications technologies, and in particular, to a method and an apparatus for avoiding a loop in an EVPN multi-homing networking.

Background

In an Ethernet Virtual Private Network (EVPN) multi-homing networking, when a link fails, a bypass (bypass) link technology is usually adopted in order to achieve the purpose of uninterrupted traffic. As shown in fig. 1, fig. 1 is a schematic diagram of an EVPN multihoming networking system. After a data message sent by a user Edge (CE) 2 reaches PE3, PE3 encapsulates the data message, and then forwards the encapsulated network message to an operator Edge (PE) 1 or PE2 through an equivalent path between PE1 and PE2, and any PE of PE1 and PE2 decapsulates the network message and sends the data message to CE 1. When the link between PE1 and CE1 is down, the network packet sent by PE3 to PE1 will pass through the protection link between PE1 and PE2, pass through PE2, and then reach CE 1.

As described above, when the link between CE1 and PE1 and PE2 is down at the same time, or when the failure of CE1 causes the link between CE1 and PE1 and PE2 to be down at the same time, it is CE1 going off-line. Because the positions of PE1 and PE2 are symmetrical and a bypass link exists between PE1 and PE2, a network packet sent by PE3 will be forwarded between PE1 and PE2 without stop, and a situation of a short loop occurs until one of PE1 and PE2 cancels an EVPN route issued by itself.

In order to solve the aforementioned problem that a transient loop occurs between PE1 and PE2, two tags are usually allocated to each EVPN instance configured in a PE in the prior art, where one tag identifies a network packet sent by a remote network side (e.g., PE3), and the other tag identifies a network packet sent by a bypass link side. Therefore, after the multi-homing member PE in the multi-homing group receives the network message, the source of the network message can be distinguished through different labels, and for the network message sent from the bypass link side, when the link between the PE and the CE is down, the network message does not return through the bypass link any more, so that a loop is avoided.

However, this approach, while avoiding the loop formation, has the following drawbacks: 1) the bypass tag used for identifying the bypass link side needs to be configured independently, and if an independent bypass tag is not configured, the problem of the transient loop can occur; 2) if an independent bypass tag is configured, each EVPN instance in the PE needs to be configured with multiple tags, and thus, the problem of excessive application tags may also occur.

Disclosure of Invention

In view of this, the present application provides a method and an apparatus for avoiding a loop in an EVPN multi-homing networking, so as to solve the problem in the prior art that a PE cannot identify a network packet source without configuring an independent bypass tag, which results in a transient loop in networking, and the problem that the PE configures an independent bypass tag, which results in an excessive number of tags.

In a first aspect, the present application provides a method for avoiding a loop in an EVPN multihoming networking, where the method is applied to a first PE, the first PE is in a multihoming networking, the multihoming networking further includes a CE and a second PE, the CE is connected with the first PE and the second PE through a first link and a second link, respectively, the first PE is connected with the second PE through a bypass link, and the method includes:

receiving a first network message sent by a far-end PE, wherein the first network message comprises a first VPN label of the first PE;

acquiring a local VPN instance corresponding to the first VPN label according to the first VPN label, and acquiring a first output interface of the VPN instance;

when determining that the first link corresponding to the first output interface fails, sending a second network message to the second PE through the bypass link, wherein the second network message comprises a bypass label of the second PE and a second VPN label of the second PE, so that the second PE determines that the second network message belongs to the same multi-attribution group according to the bypass label of the second PE, the first PE sends the second network message through the bypass link, and the second PE discards the second network message when determining that the corresponding second link fails according to the second VPN label.

In a second aspect, the present application provides a device for avoiding a loop in EVPN multi-homing networking, the device is applied to a first PE, the first PE is in the multi-homing networking, the multi-homing networking further includes a CE and a second PE, the CE is respectively connected with the first PE and the second PE through a first link and a second link, the first PE with be connected through a bypass link between the second PE, the device includes:

a receiving unit, configured to receive a first network packet sent by a far-end PE, where the first network packet includes a first VPN label of the first PE;

an obtaining unit, configured to obtain, according to the first VPN label, a local VPN instance corresponding to the first VPN label, and obtain a first output interface of the VPN instance;

and the sending unit is used for sending a second network message to the second PE through the bypass link when determining that the first link corresponding to the first output interface fails, wherein the second network message comprises a bypass label of the second PE and a second VPN label of the second PE, so that the second PE determines that the second network message belongs to the same multi-attribution group according to the bypass label of the second PE, the first PE sends the second network message through the bypass link, and the second network message is discarded when determining that the corresponding second link fails according to the second VPN label.

In a third aspect, the present application provides a network device comprising a processor and a machine-readable storage medium storing machine-executable instructions executable by the processor, the processor being caused by the machine-executable instructions to perform the method provided by the first aspect of the present application.

Therefore, by applying the method and the device for avoiding the loop in the EVPN multi-homing networking, the first PE obtains the corresponding local VPN instance and the first outgoing interface of the VPN instance according to the first VPN label after receiving the first network packet carrying the first VPN label of the first PE. When the first PE determines that the link corresponding to the first output interface fails, a second network message carrying a bypass label of the second PE and a second VPN label of the second PE is sent to the second PE through the bypass link, so that the second PE determines that the second network message is sent through the bypass link for the first PE belonging to the same multi-attribution group according to the bypass label of the second PE, and discards the second network message when determining that the corresponding second link fails according to the second VPN label. In the process of forwarding the network message, the PE can determine the sender of the network message through the bypass label, so that the problems that in the prior art, the PE is not provided with an independent bypass label and cannot identify the source of the network message, so that a short loop in networking is caused, and the PE is provided with an independent bypass label and the number of labels is too large can be solved.

Drawings

Fig. 1 is a schematic diagram of an EVPN multi-homing networking;

fig. 2 is a flowchart of a method for avoiding a loop in EVPN multihoming networking according to an embodiment of the present application;

fig. 3 is a format diagram of a field where a bypass tag is carried in a route advertisement packet according to an embodiment of the present application;

fig. 4 is a diagram of an apparatus structure for avoiding a loop in an EVPN multihoming networking according to an embodiment of the present application;

fig. 5 is a hardware structure diagram of a network device according to an embodiment of the present application.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the corresponding listed items.

It is to be understood that although the terms first, second, third, etc. may be used herein to describe various information, such information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present application. The word "if" as used herein may be interpreted as "at … …" or "when … …" or "in response to a determination", depending on the context.

The method for avoiding loops in EVPN multihoming networking provided in the embodiments of the present application is described in detail below. Referring to fig. 2, fig. 2 is a flowchart of a method for avoiding loops in EVPN multihoming networking according to an embodiment of the present application. The method is applied to a first PE. The first PE is in a multi-homing network, the multi-homing network further comprises a CE and a second PE, the CE is a multi-homing device, namely the CE is respectively connected with the first PE and the second PE through a first link and a second link, and the first PE and the second PE belong to the same multi-homing group. The first PE and the second PE are connected through a bypass link. The method for avoiding the loop in the EVPN multi-homing networking provided by the embodiment of the application can comprise the following steps.

Step 210, receiving a first network packet sent by a far-end PE, where the first network packet includes a first VPN label of the first PE.

Specifically, as shown in fig. 1. The networking includes CE1, CE2, PE1, PE2, and PE 3. CE1 is a multihomed device and is connected to PE1 and PE2 via a first link and a second link, respectively. PE1 and PE2 are connected through a bypass link, and PE1 and PE2 belong to multi-homing members of the same multi-homing group. PE3 is connected to PE1 and PE2 via tunnels (e.g., Virtual eXtensible Local Area Network (VXLAN) tunnels).

In the embodiment of the present application, PE1 is used as the first PE for explanation. It will be appreciated that other multi-homed members in the same multi-homed group as PE1 also perform the same process.

In this step, after receiving the data packet sent by the CE2, the remote PE (i.e., PE3) encapsulates the data packet, so as to obtain a first network packet. PE3 forwards to PE1 via a tunnel (of course, it may also forward to PE2, and PE2 performs the same steps as PE 1). After receiving the first Network packet sent by PE3, PE1 obtains a first Virtual Private Network (VPN) label of the first PE from the first Network packet.

Further, before this step, a process is included in which the first PE starts a bypass protection function and assigns its own bypass tag.

Specifically, PE1 receives a configuration instruction input by a user, where the configuration instruction is used to instruct a first PE to open a bypass protection function. According to the configuration instruction, PE1 allocates a bypass tag to its own device, where the bypass tag is used to identify that the sender of the network packet carrying the bypass tag is a multi-homing member in the multi-homing group.

Further, before this step, a process of mutually advertising EVPN routes by PEs within the group is also included.

Specifically, after a PE in the networking joins the EVPN multi-homing group and establishes peers with other PEs in the networking, EVPN routes are generated and advertised to each other. For example, PE2 generates a first route advertisement message that includes the bypass tag of PE2 and the ethernet segment ES information. After receiving the first route advertisement packet sent by PE2, PE1 obtains the bypass tag and Ethernet Segment (ES) information of PE2 from the first route advertisement packet. PE1 determines the value of ES information. If the value of ES information is a first value (e.g., the first value is 0), PE1 saves the bypass tag of PE 2.

In the embodiment of the present application, the bypass tag of PE2 is assigned by PE2, and the specific assignment process may refer to the foregoing process of PE1 assigning its own bypass tag. The ES information is specifically a value of Ethernet Segment Identifier (ESI), and when the ESI is 0, it indicates that the ES information is not related to any ES link but only to a device.

It is understood that PE1 also generates a second route advertisement message that includes the bypass tag of PE1 and ES information. After receiving the second route advertisement packet sent by PE1, PE2 obtains the bypass tag and ES information of PE1 from the second route advertisement packet. PE2 determines the value of ES information. If the value of ES information is a first value (e.g., the first value is 0), PE2 saves the bypass tag of PE 1.

In this embodiment of the present application, the first Route advertisement packet and the second Route advertisement packet may specifically be EVPN 1-type routes (i.e., Ethernet Auto-discovery routes), where the Route advertisement packet adds an Extended Community attribute (i.e., BYPASS Extended Community) field, and the Extended Community attribute field is used for carrying a BYPASS label of the PE. As shown in fig. 3, fig. 3 is a format diagram of a field where a bypass tag is carried in a route advertisement packet according to the embodiment of the present application.

Wherein the extended community attribute includes a Type (Type) field that can be set to 0x06, a Sub-Type (Sub-Type) field that can be set to 0x05, a Reserved (Reserved) field, and a Bypass Label (Bypass Label) field.

Further, EVPN 1-like routes specifically include EVPN AD per ES routes and EVPN AD per EVI routes. The EVPN1 type route carrying the bypass label is specifically an EVPN AD per ES route, or referred to as a special EVPN AD per ES route.

It is to be appreciated that each PE (e.g., PE1) issues two EVPN 1-like routes to the outside (i.e., PE2, PE3) after establishing peers with other PEs within the networking. Namely EVPN AD per ES routing and EVPN AD per EVI routing. Where EVPN AD per ES routing is used to advertise its ES link state. The EVPN AD per EVI route is used for advertising own Virtual Private Wire Service (VPWS) VPN information. Both routes include a Route Identifier (RD), an Ethernet Segment Identifier (ESI), an Ethernet Tag id (Ethernet Tag id), and an MPLS label.

In the EVPN AD per ES route, the RD field is a BGP route site flag, which is set to a local configuration value, the ESI field is set to a PE ES link value, the ethernet flag ID is set to 0 xfffffffff, and the MPLS label field is set to 0. In the EVPN AD per EVI route, an RD field is a BGP routing site mark and is set as a local configuration value, an ESI field is set as an ES link value of a PE, an Ethernet mark ID is set as site information of the PE, and an MPLS label field is set as a VPN label of the PE.

After the PE1 advertises an EVPN AD per ES route to the outside, and after receiving the route, the PE2 and the PE3 acquire and store a bypass label of the PE1 from the route; after the PE1 advertises the EVPN AD per EVI route to the outside, the PE2 and the PE3 acquire and store the first VPN label of the PE1 from the route after receiving the route.

Thus, in this step, after receiving the data packet sent by the CE2, the PE3 determines that the next hop is PE1 or PE2 according to the destination IP carried in the data packet. If PE3 selects the next hop to be PE1, PE3 encapsulates the stored first VPN label before the data packet when encapsulating the first network packet.

It is understood that PE3 also encapsulates an ethernet Header (ETH Header) and a TUNNEL LABEL (TUNNEL LABEL) together before the first VPN LABEL during the encapsulation process.

Similarly, PE2 also issues the two EVPN1 routes to the outside. After receiving the routes, PE1 and PE3 obtain and store the second VPN label of PE2 from them.

In this embodiment of the present application, after PE1 and PE2 allocate their own bypass tags, they also carry bypass tags through a special EVPN AD per ES route, so that the PE receiving the EVPN AD per ES route stores the bypass tags, for example, PE2 stores the bypass tag of PE1, and PE1 stores the bypass tag of PE 2.

The special EVPN AD per ES route further includes ES information, which is specifically the value of ESI. The special EVPN AD per ES route also includes RT, and the value of the RT is the RT aggregation of VPN examples in PE.

Note that the ESI value is 0, which means that the ESI value is independent of any ES link and is only device-dependent. And the PE receiving the special EVPN AD per ES route determines that the EVPN AD per ES route is a route for carrying a bypass label when judging that the ESI value is 0, and the PE stores the bypass label.

Step 220, according to the first VPN label, obtaining a local VPN instance corresponding to the first VPN label, and obtaining a first outgoing interface of the VPN instance.

Specifically, after PE1 obtains the first VPN label from the first network packet, PE1 finds the local VPN instance corresponding to the first VPN label according to the first VPN label, and obtains the first outgoing interface of the VPN instance.

In this embodiment of the present application, a link corresponding to the first outgoing interface is a first link.

Step 230, when it is determined that the first link corresponding to the first egress interface fails, sending a second network packet to the second PE through the bypass link, where the second network packet includes a bypass tag of the second PE and a second VPN tag of the second PE, so that the second PE determines, according to the bypass tag of the second PE, that the second network packet is sent through the bypass link for the first PE belonging to the same multi-homing group, and discards the second network packet when it determines that the corresponding second link fails according to the second VPN tag.

Specifically, when PE1 determines that the first link failed, PE1 obtains the bypass tag of PE2 and the second VPN tag of PE2 locally. PE1 generates a second network packet that includes the bypass label of PE2 and a second VPN label. PE1 sends the second network packet to PE2 via the bypass link.

It is understood that PE1 encapsulates the second VPN label and the bypass label of PE2 after the tunnel label before the data packet in the process of generating the second network packet.

After receiving the second network packet, PE2 obtains the bypass tag and the second VPN tag of PE2 from the second network packet. According to the bypass label of PE2, PE2 determines that the second network packet is sent by a multihomed member in the same multihomed group as the PE2, that is, PE2 determines that the second network packet is sent by a bypass link for PE1 belonging to the same multihomed group. Meanwhile, the PE2 finds the local VPN instance corresponding to the second VPN label according to the second VPN label, and obtains the second outgoing interface of the VPN instance.

In this embodiment of the application, the link corresponding to the second outgoing interface is the second link.

When PE2 determines that the second link failed, PE2 discards the second network packet.

Therefore, by applying the method for avoiding the loop in the EVPN multi-homing networking provided by the present application, after receiving the first network packet carrying the first VPN label of the first PE, the first PE obtains the corresponding local VPN instance and the first outgoing interface of the VPN instance according to the first VPN label. When the first PE determines that the link corresponding to the first output interface fails, a second network message carrying a bypass label of the second PE and a second VPN label of the second PE is sent to the second PE through the bypass link, so that the second PE determines that the second network message is sent through the bypass link for the first PE belonging to the same multi-attribution group according to the bypass label of the second PE, and discards the second network message when determining that the corresponding second link fails according to the second VPN label. In the process of forwarding the network message, the PE can determine the sender of the network message through the bypass label, so that the problems that in the prior art, the PE is not provided with an independent bypass label and cannot identify the source of the network message, so that a short loop in networking is caused, and the PE is provided with an independent bypass label and the number of labels is too large can be solved.

Optionally, PE2 also performs the steps 210-230 when the first network packet sent by PE3 is forwarded to PE 2.

That is, when PE2 determines that the second link corresponding to the second egress interface fails, the third network packet is sent to PE1 through the bypass link. After receiving the third network packet, PE1 obtains the bypass tag and the first VPN tag of PE1 from the third network packet. According to the bypass label of PE1, PE1 determines that the third network packet is sent by a multihomed member in the same multihomed group as the third network packet, that is, PE1 determines that the third network packet is sent by a bypass link for PE2 belonging to the same multihomed group. Meanwhile, the PE1 finds the local VPN instance corresponding to the first VPN label according to the first VPN label, and obtains the first outgoing interface of the VPN instance.

When PE1 determines that the first link failed, PE1 discards the third network packet.

Based on the same inventive concept, the embodiment of the application also provides a device for avoiding the EVPN multi-homing networking loop, which corresponds to the method for avoiding the EVPN multi-homing networking loop. Referring to fig. 4, fig. 4 is a diagram of an apparatus structure for avoiding a loop in an EVPN multihoming networking according to an embodiment of the present application, where the apparatus is applied to a first PE, the first PE is in a multihoming networking, the multihoming networking further includes a CE and a second PE, the CE is connected to the first PE and the second PE through a first link and a second link, respectively, and the first PE is connected to the second PE through a bypass link, and the apparatus includes:

a receiving unit 410, configured to receive a first network packet sent by a far-end PE, where the first network packet includes a first VPN label of the first PE;

an obtaining unit 420, configured to obtain, according to the first VPN label, a local VPN instance corresponding to the first VPN label, and obtain a first outgoing interface of the VPN instance;

a sending unit 430, configured to send, when it is determined that the first link corresponding to the first egress interface fails, a second network packet to the second PE through the bypass link, where the second network packet includes a bypass tag of the second PE and a second VPN tag of the second PE, so that the second PE determines, according to the bypass tag of the second PE, that the second network packet is sent through the bypass link for the first PE belonging to the same multi-homing group, and discards the second network packet when it determines that the corresponding second link fails according to the second VPN tag.

Optionally, the receiving unit 410 is further configured to receive a configuration instruction input by a user, where the configuration instruction is used to instruct the first PE to start a bypass protection function;

the device further comprises: and an allocating unit (not shown in the figure) configured to allocate a bypass tag to the first PE according to the configuration instruction, where the bypass tag is used to identify that a sender of the network packet bearing the bypass tag is a multi-homing member in a multi-homing group.

Optionally, the receiving unit 410 is further configured to receive a first route advertisement packet sent by the second PE, where the first route advertisement packet includes a bypass tag of the second PE and ethernet segment ES information;

the device further comprises: a holding unit (not shown in the figure) for holding the bypass tag of the second PE when the value of the ES information is the first value.

Optionally, the receiving unit 410 is further configured to receive a third network packet sent by the second PE, where the third network packet includes the bypass tag of the first PE and the first VPN tag;

the obtaining unit 420 is further configured to obtain, according to the first VPN label, a local VPN instance corresponding to the first VPN label, and obtain the first outgoing interface;

the device further comprises: a determining unit (not shown in the figure), configured to determine, according to the bypass tag of the first PE, that the third network packet is sent by the second PE;

a discarding unit (not shown in the figure), configured to discard the third network packet when it is determined that the first link corresponding to the first egress interface fails.

Optionally, the sending unit 430 is further configured to send a second route advertisement packet to the second PE, where the second route advertisement packet includes the bypass tag of the first PE and the ES information, so that when the second PE determines that the value of the ES information is the first value, the bypass tag of the first PE is stored.

Optionally, the route advertisement packet is an EVPN 1-type route, and the route advertisement packet includes an extended community attribute field, where the extended community attribute field carries a bypass label of the PE.

Therefore, by applying the device for avoiding the loop in the EVPN multi-homing networking provided by the present application, after receiving the first network packet carrying the first VPN label of the first PE, the device acquires the corresponding local VPN instance and the first outgoing interface of the VPN instance according to the first VPN label. When the first PE determines that the link corresponding to the first output interface fails, the device sends a second network message carrying a bypass label of the second PE and a second VPN label of the second PE to the second PE through the bypass link, so that the second PE determines that the second network message is sent through the bypass link for the first PE belonging to the same multi-attribution group according to the bypass label of the second PE, and discards the second network message when determining that the corresponding second link fails according to the second VPN label. In the process of forwarding the network message, the PE can determine the sender of the network message through the bypass label, so that the problems that in the prior art, the PE is not provided with an independent bypass label and cannot identify the source of the network message, so that a short loop in networking is caused, and the PE is provided with an independent bypass label and the number of labels is too large can be solved.

Based on the same inventive concept, the embodiment of the present application further provides a network device, as shown in fig. 5, including a processor 510, a transceiver 520, and a machine-readable storage medium 530, where the machine-readable storage medium 530 stores machine-executable instructions capable of being executed by the processor 510, and the processor 510 is caused by the machine-executable instructions to perform the method for avoiding loops in EVPN multi-homing networking provided by the embodiment of the present application. The aforementioned EVPN multihoming networking loop avoidance apparatus shown in fig. 5 may be implemented by using a hardware structure of a network device shown in fig. 5.

The computer-readable storage medium 530 may include a Random Access Memory (RAM) or a Non-volatile Memory (NVM), such as at least one disk Memory. Alternatively, the computer-readable storage medium 530 may also be at least one storage device located remotely from the processor 510.

The Processor 510 may be a general-purpose Processor, and includes a Central Processing Unit (CPU), a Network Processor (NP), and the like; the Integrated Circuit can also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or other Programmable logic devices, discrete Gate or transistor logic devices, discrete hardware components.

In an embodiment of the present application, the processor 510 is caused by machine executable instructions to implement the processor 510 itself and the transceiver 520 to perform the method for EVPN multihoming networking loop avoidance described in the foregoing embodiment of the present application by reading the machine executable instructions stored in the machine readable storage medium 530.

Additionally, embodiments of the present application provide a machine-readable storage medium 530, the machine-readable storage medium 530 storing machine executable instructions that, when invoked and executed by the processor 510, cause the processor 510 itself and the invoking transceiver 520 to perform the aforementioned method for EVPN multihoming networking loop avoidance described in embodiments of the present application.

The implementation process of the functions and actions of each unit in the above device is specifically described in the implementation process of the corresponding step in the above method, and is not described herein again.

For the device embodiments, since they substantially correspond to the method embodiments, reference may be made to the partial description of the method embodiments for relevant points. The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the scheme of the application. One of ordinary skill in the art can understand and implement it without inventive effort.

For the EVPN multihoming networking loop avoidance apparatus and the machine-readable storage medium embodiment, since the content of the related method is substantially similar to the foregoing method embodiment, the description is relatively simple, and the relevant points can be referred to the partial description of the method embodiment.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the scope of protection of the present application.

Claims

1. The method for avoiding the loop in the EVPN multi-homing networking is characterized in that the method is applied to a first PE, the first PE is in the multi-homing networking, the multi-homing networking further comprises a CE and a second PE, the CE is respectively connected with the first PE and the second PE through a first link and a second link, and the first PE is connected with the second PE through a bypass link, and the method comprises the following steps:

2. The method according to claim 1, wherein before receiving the first network packet sent by the far-end PE, the method further comprises:

receiving a configuration instruction input by a user, wherein the configuration instruction is used for indicating the first PE to open a bypass protection function;

and according to the configuration instruction, allocating a bypass label to the first PE, wherein the bypass label is used for identifying that a sender of the network message bearing the bypass label is a multi-homing member in a multi-homing group.

3. The method according to claim 1, wherein before receiving the first network packet sent by the far-end PE, the method further comprises:

receiving a first route notification message sent by the second PE, wherein the first route notification message comprises a bypass label of the second PE and Ethernet segment ES information;

and when the value of the ES information is a first value, saving the bypass label of the second PE.

4. The method of claim 1, further comprising:

receiving a third network message sent by the second PE, wherein the third network message comprises a bypass label of the first PE and the first VPN label;

acquiring a local VPN instance corresponding to the first VPN label according to the first VPN label, and acquiring the first output interface;

determining that the third network message is sent by the second PE according to the bypass label of the first PE;

and when the first link corresponding to the first outgoing interface is determined to be in fault, discarding the third network message.

5. The method of claim 1, further comprising:

and sending a second route notification message to the second PE, wherein the second route notification message comprises the bypass label of the first PE and the ES information, so that the bypass label of the first PE is stored when the second PE determines that the value of the ES information is a first value.

6. The method according to any of claims 2 or 4, wherein the route advertisement packet is an EVPN 1-type route, and wherein the route advertisement packet includes an extended community attribute field, and wherein the extended community attribute field carries the bypass label of the PE.

7. The utility model provides a device of EVPN multi-homing network avoids loop, its characterized in that, the device is applied to first PE, first PE is in multi-homing network, multi-homing network still includes CE and second PE, CE respectively through first link, second link with first PE, second PE connect, first PE with connect through bypass link between the second PE, the device includes:

8. The apparatus according to claim 7, wherein the receiving unit is further configured to receive a configuration instruction input by a user, where the configuration instruction is used to instruct the first PE to turn on a bypass protection function;

the device further comprises: and the allocation unit is used for allocating a bypass label to the first PE according to the configuration instruction, wherein the bypass label is used for identifying that a sender of the network message bearing the bypass label is a multi-homing member in a multi-homing group.

9. The apparatus according to claim 7, wherein the receiving unit is further configured to receive a first route advertisement packet sent by the second PE, where the first route advertisement packet includes a bypass tag and ethernet segment ES information of the second PE;

the device further comprises: and the storage unit is used for storing the bypass label of the second PE when the value of the ES information is a first value.

10. The apparatus according to claim 7, wherein the receiving unit is further configured to receive a third network packet sent by the second PE, where the third network packet includes a bypass tag of the first PE and the first VPN tag;

the obtaining unit is further configured to obtain, according to the first VPN label, a local VPN instance corresponding to the first VPN label, and obtain the first outgoing interface;

the device further comprises: a determining unit, configured to determine, according to the bypass tag of the first PE, that the third network packet is sent by the second PE;

and a discarding unit, configured to discard the third network packet when it is determined that the first link corresponding to the first egress interface fails.

11. The apparatus of claim 7, wherein the sending unit is further configured to send a second route advertisement packet to the second PE, where the second route advertisement packet includes a bypass tag of the first PE and ES information, so that when the second PE determines that the value of the ES information is a first value, the bypass tag of the first PE is saved.

12. The apparatus according to any of claims 9 or 11, wherein the route advertisement packet is an EVPN 1-type route, and wherein the route advertisement packet includes an extended community attribute field, and wherein the extended community attribute field carries a bypass label of the PE.