CN111654435B

CN111654435B - Link protection fault processing system and method based on LACP

Info

Publication number: CN111654435B
Application number: CN202010489393.2A
Authority: CN
Inventors: 刘凯; 赵羚钧
Original assignee: CETC Avionics Co Ltd
Current assignee: CETC Avionics Co Ltd
Priority date: 2020-06-02
Filing date: 2020-06-02
Publication date: 2022-03-18
Anticipated expiration: 2040-06-02
Also published as: CN111654435A

Abstract

The invention discloses a link protection fault processing system and method based on LACP, the system includes LACP module, port management module, link fault detection module, the link fault detection module and LACP module run on the same device; the link fault detection module is used for periodically checking the abnormal message statistical information of each port and the link state of each port and detecting whether a link fault exists in real time; when a fault is detected, processing a port corresponding to an abnormal link of the port, triggering to send a protocol message containing fault information to an opposite terminal, and selecting a non-abnormal link with the highest current priority to send the non-abnormal link through the port sending the fault information; and after receiving the information, the opposite terminal starts a standby link or actively eliminates the fault link according to the fault information. The invention ensures the stable transmission of the service message on the link by actively detecting and processing the fault in real time, realizes high reliability and stability, and is particularly suitable for being applied to the aviation field.

Description

Link protection fault processing system and method based on LACP

Technical Field

The invention relates to the technical field of aviation communication, in particular to a link protection fault processing system and method based on LACP.

Background

With the development of communication and network technologies, the demand of users on network bandwidth is increasing day by day, so that the demand on single Link bandwidth is also increasing step by step, under the demand, Link Aggregation provides a cheap means for single Link bandwidth improvement, the Link Aggregation technology is a method for aggregating a plurality of physical ports into one virtual port, thereby realizing Link bandwidth increase, and an IEEE 802.3 ad-based LACP (Link Aggregation Control Protocol) Protocol is a Protocol for realizing dynamic Link Aggregation and de-Aggregation.

According to the definition in the LACP Protocol, a Protocol packet LACPDU (Link Aggregation Control Protocol Data Unit, that is, a Link Aggregation Control Protocol Unit) is directly transmitted at a port, wherein a port which actively transmits is called a home terminal (the Actor), a port which receives a packet is called an opposite terminal (the Actor's Protocol Partner), the home terminal and the opposite terminal transmit information to each other through the LACPDU, and devices at the home terminal and the opposite terminal can identify LACPDU packets received by all ports, determine which ports can form an Aggregation, and implement dynamic Link Aggregation through this way.

The maximum link number of link aggregation is defined in the LACP protocol, if the link in one aggregation exceeds the maximum link number, the link with the lowest priority can be used as a backup link, and an abnormal link can be replaced when the working link is abnormal, so that the link protection function is realized. Whether a port depends on information in a received LACPDU in aggregation or not, if the received LACPDU information does not change and the state of a port link does not change, whether the received LACPDU information is valid or not is judged by the port according to aging time, namely, if the received LACPDU information cannot be received within a certain time (the short timeout is 3 seconds and the long timeout is 90 seconds) the opposite end is considered to be abnormal, so that the link is deleted from the aggregation, the mechanism is a passive mechanism, some link failures cannot be processed, for example, a data message in the link has a probabilistic check error packet, an ultra-long packet, an ultra-short packet and a probabilistic packet loss caused by the unstable link cannot be solved, when the scene appears, not only the service message on the link cannot guarantee stable transmission, but even the link can be repeatedly added and removed from the aggregation, affecting the overall polymerization work, which can have a great impact in some application areas where high reliability is required, such as the aeronautical field.

Disclosure of Invention

The technical problem to be solved by the present invention is that most of the existing link protection failure processing systems and methods in the aviation field adopt a passive mechanism, that is, if an LACPDU message cannot be received within a certain time, the opposite end is considered as abnormal, so that the link is deleted from aggregation, the passive mechanism cannot process some link failures, for example, a probabilistic CRC check error packet, an ultra-long packet, an ultra-short packet and a probabilistic packet loss caused by link instability occur in a data message in a link, which cannot be solved, when the above scenario occurs, not only the service message on the link cannot guarantee stable transmission, but also the link may repeatedly join and leave aggregation, which affects the whole aggregation work, which has a great influence in some application fields (such as the aviation field) that need high reliability.

The invention provides a link protection fault processing system and method based on LACP, which solves the above problems, the system adds a running link fault detection module, the link fault detection module runs on the equipment running LACP protocol, the link fault detection module can detect whether there is link fault in real time by checking the port abnormal message statistical information, the port link state and other modes; when a fault is detected, sending fault information to an opposite terminal through a slow protocol message (namely, the Ether type is 0x8809) of which the subtype field is a reserve field, and after receiving the information, adopting processing means such as starting a standby link or actively eliminating the fault link according to the fault information by the opposite terminal.

The invention is realized by the following technical scheme:

a link protection fault processing system based on LACP comprises an LACP module and a port management module, wherein the LACP module is in bidirectional communication connection with the port management module;

the system also comprises a link fault detection module, wherein the link fault detection module is in bidirectional communication connection with the port management module, the link fault detection module is in unidirectional communication connection with the LACP module, and the link fault detection module and the LACP module run on the same equipment;

the link fault detection module is used for periodically checking the abnormal message statistical information of each port, the link state of the port link (namely the physical state of the port link) and other modes and detecting whether a link fault exists in real time; when a fault is detected, processing a port corresponding to an abnormal link of the terminal, and triggering to send a protocol message containing fault information to an opposite terminal, wherein the processing mode of the terminal is consistent with the processing mode of the opposite terminal after receiving the abnormal information message, and the port sending the fault information of the terminal selects a non-abnormal link with the highest current priority to send; and after receiving the information, the opposite terminal starts a standby link or actively eliminates the fault link according to the fault information.

Further, the protocol message containing the fault information is a slow protocol message;

the protocol message containing the fault information comprises a destination MAC field, a source MAC field, an Ether type field, a subtype field and a plurality of fault information TLV fields; the message realizes the transmission of a plurality of fault information through a plurality of fault information TLV fields; wherein:

the fault information TLV field includes a fault Type, a TLV Length, and a fault information content Value.

Further, in the protocol message containing the fault information, the destination MAC field is 01:80: c2:00:00:02, the source MAC field is the device MAC itself, the ethertype field is 0x8809, and the subtype field (subtype) uses a reserve value of 0 xf;

each fault information TLV field contains all information of one fault, wherein the fault Type comprises a CRC (cyclic redundancy check) error message, a super-long packet and a super-short packet.

On the other hand, the invention also provides a link protection fault processing method based on the LACP, which comprises the following steps:

s1: operating a link fault detection module on equipment operating an LACP protocol;

s2: the link fault detection module periodically checks the abnormal message statistical information of each port, the link state of the port link (namely the physical state of the port link) and other modes, and detects whether a link fault exists in real time;

s3: when the link is abnormal, processing a port corresponding to the abnormal link of the port immediately, triggering to send a protocol message containing fault information to an opposite terminal, wherein the processing mode of the local terminal is consistent with the processing mode of the opposite terminal after receiving the abnormal message, and the port sending the fault information selects a non-abnormal link with the highest current priority to send;

s4: the opposite terminal receives the fault information protocol message and carries out abnormal port processing; indirectly influencing a link in dynamic aggregation through related parameters defined by an LACP protocol; after processing, sending a reply message through the port with the highest priority;

s5: and after the fault information processing is finished at the two ends of the abnormal link, alarming is carried out to prompt that the link has a fault, and the operation and maintenance personnel manually recover the link after removing the fault.

Further, in step S3, the link exception includes:

counting is carried out aiming at the abnormal messages, and when the quantity or the proportion of the abnormal messages exceeds a preset value, the link is considered to be abnormal; the abnormal message statistical information comprises a CRC error check message, a super-long packet and a super-short packet;

and regarding the link state of the port link, when the link oscillation phenomenon occurs, the link is considered to be abnormal.

Further, the opposite end receives the failure information protocol packet in step S4, and performs abnormal port processing; the abnormal port processing does not directly interfere with the operation of the LACP, but indirectly affects the link in the dynamic aggregation through related parameters defined by the LACP, and the method comprises the following specific steps:

when a backup link exists, the priority field of the port corresponding to the abnormal link is directly set as the lowest priority, the LACP protocol is caused to start the backup link to replace the current link, the abnormal link is converted into the backup link, and service data is not forwarded any more, so that the link aggregation can be ensured to work normally;

when a backup link does not exist, firstly, the priority field of the port corresponding to the abnormal link is set as the lowest priority, and meanwhile, when the maximum link number corresponding to the aggregation of the links is greater than 1, the maximum link number supported by the aggregation is set to be the current maximum link number minus 1, namely, if the total number of the current links is 4, and if one of the links is abnormal, the maximum link number is set to be 3.

Further, step S3 includes a protocol packet of the fault information, where the protocol packet is a slow protocol packet;

Further, in the protocol message containing the fault information, the destination MAC field is 01:80: c2:00:00:02, the source MAC field is the device MAC itself, the ethertype field is 0x8809, and the subtype field (subtype) uses a reserve value of 0 xf.

Compared with the prior art, the invention has the following advantages and beneficial effects:

1. the system is additionally provided with an operation link fault detection module, the link fault detection module is operated on equipment operating an LACP protocol, the structure among the modules is shown as the attached drawing 1, and the link fault detection module can detect whether a link fault exists in real time by checking port abnormal message statistical information, port link states and other modes; when a fault is detected, sending fault information to an opposite terminal through a slow protocol message (namely, the Ether type is 0x8809) of which the subtype field is a reserve field, and after receiving the information, adopting processing means such as starting a standby link or actively eliminating the fault link according to the fault information by the opposite terminal;

2. the method of the invention dynamically detects the abnormal link in the link aggregation, automatically realizes the processing of the abnormal link, and can give an alarm to operation and maintenance personnel, thereby ensuring the normal operation of the aggregated link before the abnormal link is repaired; meanwhile, the method is based on the expansion of the standard LACP protocol, and does not modify the LACP protocol, so that the method can be communicated with other equipment only supporting the standard LACP protocol, and the normal work of link aggregation can not be influenced; finally, the method for detecting the fault in the link fault detection module can be expanded without limit, and the characteristic enables the system and the method of the invention to meet the requirements of special network scenes;

3. the system and the method can ensure the stable transmission of the service message on the link when the scenes of a probabilistic CRC error packet, an ultra-long packet, an ultra-short packet and a probabilistic packet loss caused by the instability of the link occur in the data message in the link through active real-time fault detection and processing, realize high reliability and stability, and are particularly suitable for being applied to the field of aviation.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:

fig. 1 is a structural diagram of a link failure detection module and an LACP module in a link protection failure processing system based on LACP according to the present invention.

Fig. 2 is a diagram of a protocol packet structure containing fault information according to the present invention.

Fig. 3 is a flow chart of fault information detection and transmission in the method of the present invention.

Fig. 4 is a flow chart of the fault information protocol message receiving process in the method of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.

Example 1

As shown in fig. 1 to 4, a link protection failure handling system based on LACP of the present invention includes an LACP module and a port management module, where the LACP module and the port management module are connected in a bidirectional communication manner;

After detecting a link failure, the processing flow of the home terminal is as shown in fig. 1, and each step of the processing is as follows:

s1.1: when a link fault is found, the link fault detection module periodically detects the link state of the port (the detection mode is performed according to the actual capability of the chip, and no specific requirement is made in this embodiment), and when a link fault is detected, the link protection fault processing is started.

S1.2: the LACP module controls, when the link failure is detected, the link failure detection module controls the ports in the link aggregation group in the LACP protocol by configuring parameters of the LACP protocol, the control is mainly realized by configuring the priority of the ports and the maximum port number in the aggregation group, and when the standby link needs to be used, the LACP module can be triggered to complete the starting of the standby link by reducing the priority of the failure link and improving the priority of the alternative link; when the links need to be removed, the link removal can be completed by reducing the priority of the failed links and reducing the maximum number of the links.

S1.3: and (4) processing the LACP protocol, wherein after the step S1.2, the LACP module runs the LACP protocol to finish processing because the priority of the link and the maximum link number of the aggregation group are changed.

S1.4: and sending information, wherein after the processing is finished, the fault information needs to be sent to the opposite terminal through a port with the highest priority through a protocol message, so that the opposite terminal also carries out synchronous processing, and the state synchronization of the two terminals is ensured.

After receiving the protocol packet containing the failure information, the opposite end also has a processing flow consistent with that of the home end, as shown in fig. 1, and the processing flow at each step is as follows:

s1.1: and receiving the fault information, wherein the link fault detection module starts the link protection fault processing after receiving the protocol message containing the fault information.

S1.2: the LACP module is controlled, the opposite end can synchronously configure the LACP module according to the fault information in the protocol message, the configuration mode is consistent as S1.2 in the processing flow of the local end, the control is realized by configuring the priority of the port and the maximum port number in the aggregation group, when the standby link is needed to be used, the priority of the fault link is reduced, and the priority of the alternative link is improved, so that the LACP protocol module can be triggered to complete the starting of the standby link; when the links need to be removed, the link removal can be completed by reducing the priority of the failed links and reducing the maximum number of the links.

S1.4: and (5) information reply, namely, after the processing is finished, the protocol message containing the finished processing is sent back to the local terminal through the port with the highest priority.

Specifically, the protocol packet containing the fault information is a slow protocol packet; as shown in fig. 2:

Specifically, in the protocol message containing the fault information, the destination MAC field is 01:80: c2:00:00:02, the source MAC field is the device MAC itself, the ethertype field is 0x8809, and the subtype field (subtype) uses a reserve value of 0 xf;

The working principle is as follows:

most of the existing link protection failure processing systems and methods in the aviation field adopt a passive mechanism, that is, if an LACPDU message cannot be received within a certain time, the opposite end is considered to be abnormal, so that the link is deleted from aggregation, the passive mechanism cannot process some link failures, for example, a data message in the link has a probabilistic CRC check error packet, an ultra-long packet, an ultra-short packet, and a probabilistic packet loss caused by link instability, which cannot be solved, when the scene appears, not only the service message on the link cannot be guaranteed to be stably transmitted, but also the link may repeatedly join and leave aggregation, which affects the whole aggregation work, which has a great influence in some application fields (such as the aviation field) that need high reliability.

Therefore, the system of the invention is additionally provided with an operation link fault detection module, the link fault detection module is operated on equipment operating the LACP protocol, the structure among the modules is shown as the attached drawing 1, and the link fault detection module can detect whether the link fault exists in real time by checking the port abnormal message statistical information, the port link state and other modes; when a fault is detected, sending fault information to an opposite terminal through a slow protocol message (namely, the Ether type is 0x8809) of which the subtype field is a reserve field, and after receiving the information, adopting processing means such as starting a standby link or actively eliminating the fault link according to the fault information by the opposite terminal.

The system can ensure the stable transmission of the service message on the link when the scenes of a probabilistic CRC error packet, an ultra-long packet, an ultra-short packet and a probabilistic packet loss caused by the instability of the link occur in the data message in the link through active real-time fault detection and processing, and is particularly suitable for being applied to the field of aviation.

Example 2

As shown in fig. 2, the difference between this embodiment and embodiment 1 is that this embodiment provides a link protection failure processing method based on LACP, which includes the following steps:

specifically, in step S3, the link exception includes:

Specifically, step S3 includes a protocol packet of the fault information, where the protocol packet is a slow protocol packet; the protocol packet containing the fault information is shown in fig. 2, and includes a destination MAC field, a source MAC field, an ethertype field, a subtype field, and a plurality of TLV fields of the fault information; the message realizes the transmission of a plurality of fault information through a plurality of fault information TLV fields; wherein: the fault information TLV field includes a fault Type, a TLV Length, and a fault information content Value.

In this embodiment, in the protocol packet containing the failure information, the destination MAC field is 01:80: c2:00:00:02, the source MAC field is the device MAC itself, the ethertype field is 0x8809, and the subtype field (subtype) uses a reserve value of 0 xf.

specifically, the opposite end receives the failure information protocol packet in step S4, and performs abnormal port processing; the abnormal port processing does not directly interfere with the operation of the LACP, but indirectly affects the link in the dynamic aggregation through related parameters defined by the LACP, and the method comprises the following specific steps:

S5: after the port receiving the fault information protocol message completes the processing, a fault information protocol message is replied, the type of TLV of the fault information protocol message is processed in an abnormal way so as to ensure a closed loop of abnormal transmission, and if one end of the fault information sending does not receive the reply message within a certain time, the fault information protocol message is retransmitted;

after the fault information processing is completed at the two ends of the abnormal link, an alarm is given to prompt that the link has a fault, the abnormal link cannot automatically recover the operation, and the operation and maintenance personnel need to manually recover the link after removing the fault.

Fig. 3 is a flow chart of fault information detection and transmission, and as shown in fig. 3, the flow chart of fault information detection and transmission includes: the link fault detection module judges whether the link is abnormal or not according to the detection abnormal message statistics and the detection link state abnormity, and if the link is abnormal, the corresponding port of the fault link is processed; otherwise, returning to the statistics of the abnormal detection message and the abnormal link state detection.

Processing the corresponding port of the fault link, forming a fault information protocol message, sending the message through the link with the highest priority, and returning to start the re-detection if the link fault detection module receives the reply within the overtime time; if no reply is received within the overtime time, continuously judging whether the overtime times reach the upper limit, if so, returning to start the redetection, and if not, retransmitting the reply message.

Fig. 4 is a flow chart of a fault information protocol message receiving process, and as shown in fig. 4, the link fault detection module analyzes a message according to a received fault information protocol message to obtain fault information, processes a port corresponding to an abnormal link, and sends a reply message through a port with the highest priority after processing.

When in implementation: starting the LACP function of the equipment, configuring a port to enable dynamic link aggregation, and configuring parameters such as priority, timeout time and the maximum link quantity of link aggregation related to an LACP protocol; then, a link fault detection module is operated on the equipment at the same time to detect the port supporting dynamic link aggregation; and connecting the ports needing the link aggregation to complete the dynamic link aggregation.

By adopting the method, the abnormal link in the link aggregation can be dynamically detected, the processing of the abnormal link can be automatically realized, the alarm prompt can be carried out on operation and maintenance personnel, and the normal operation of the aggregated link before the abnormal link is repaired is ensured; meanwhile, the method is based on the expansion of the standard LACP protocol, and does not modify the LACP protocol, so that the method can be communicated with other equipment only supporting the standard LACP protocol, and the normal work of link aggregation can not be influenced; finally, the method for detecting the fault in the link fault detection module can be expanded without limit, and the characteristic enables the system and the method of the invention to meet the requirements of special network scenes.

The method can ensure the stable transmission of the service message on the link when the scenes of a probabilistic CRC error packet, an ultra-long packet, an ultra-short packet and a probabilistic packet loss caused by the instability of the link occur in the data message in the link through active real-time fault detection and processing, thereby realizing high reliability and stability, and being particularly suitable for the field of aviation.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A link protection fault processing system based on LACP is characterized in that the system comprises a home terminal and an opposite terminal, wherein the home terminal comprises a home terminal LACP module, a home terminal link fault detection module and a home terminal port management module, and the home terminal LACP module is in bidirectional communication connection with the home terminal port management module; the local end link fault detection module is in bidirectional communication connection with the local end port management module, the local end link fault detection module is in unidirectional communication connection with the local end LACP module, and the local end link fault detection module and the local end LACP module run on the same local end device;

the opposite terminal comprises an opposite terminal LACP module, an opposite terminal link fault detection module and an opposite terminal port management module, and the opposite terminal LACP module is in bidirectional communication connection with the opposite terminal port management module; the opposite-end link fault detection module is in bidirectional communication connection with the opposite-end port management module, the opposite-end link fault detection module is in unidirectional communication connection with the opposite-end LACP module, and the opposite-end link fault detection module and the opposite-end LACP module run on the same device at the opposite end;

the local end link failure detection module is used for periodically detecting the link state of a port, and controlling the port in a link aggregation group in the LACP by configuring parameters of the LACP after the link failure is detected; triggering and sending a protocol message containing fault information to the opposite terminal;

the local LACP module is used for realizing control by configuring the priority of the ports and the maximum port number in the aggregation group, and when the standby link is required to be used, the local LACP module can be triggered to complete the starting of the standby link by reducing the priority of the fault link and increasing the priority of the standby link; when links need to be removed, link removal can be completed by reducing the priority of the failed links and reducing the maximum number of the links; and operating the LACP protocol to complete the processing;

the opposite end link fault detection module is used for receiving the protocol message containing the fault information, synchronously configuring an opposite end LACP module according to the fault information in the protocol message, and controlling a port in a link aggregation group in the LACP protocol by configuring parameters of the LACP;

the opposite-end LACP module is used for realizing control by configuring the priority of the ports and the maximum port number in the aggregation group, and when the standby link is required to be used, the opposite-end LACP module can be triggered to complete the starting of the standby link by reducing the priority of the fault link and improving the priority of the standby link; when links need to be removed, link removal can be completed by reducing the priority of the failed links and reducing the maximum number of the links; and operating the LACP protocol to complete the processing;

the protocol message containing the fault information is a slow protocol message;

the protocol message containing the fault information comprises a subtype field, and the subtype field uses a reserve value of 0 xf.

2. The system according to claim 1, wherein the protocol packet containing the failure information further includes a destination MAC field, a source MAC field, an ethertype field, and a plurality of TLV fields for failure information; the message realizes the transmission of a plurality of fault information through a plurality of fault information TLV fields; wherein:

3. The system according to claim 1, wherein in the protocol message containing the failure information, the destination MAC field is 01:80: c2:00:00:02, the source MAC field is the device MAC itself, and the ethertype field is 0x 8809;

4. A method for processing link protection failure based on LACP, which is applied to the system for processing link protection failure based on LACP as claimed in any one of claims 1 to 3, and which comprises the following steps:

after detecting the link failure, the local terminal processes the following steps:

s1.1: and link failure discovery: the link fault detection module of the home terminal periodically detects the state of a port link, and starts link protection fault processing after detecting a link fault;

s1.2: the local end LACP module is controlled, when the link failure is detected, the local end link failure detection module controls the ports in the link aggregation group in the LACP protocol by configuring parameters of the LACP protocol, the control is realized by configuring the priority of the ports and the maximum port number in the aggregation group, and when the standby link needs to be used, the local end LACP module can be triggered to complete the starting of the standby link by reducing the priority of the failed link and improving the priority of the standby link; when links need to be removed, link removal can be completed by reducing the priority of the failed links and reducing the maximum number of the links;

s1.3: LACP protocol processing, after the step S1.2, the priority of the link and the maximum link number of the aggregation group are changed, and the local end LACP module runs the LACP protocol to complete processing;

s1.4: sending information, namely sending fault information to an opposite terminal through a port with the highest priority through a protocol message after the processing is finished, so that the opposite terminal also carries out synchronous processing, and the state synchronization of the two terminals is ensured;

after receiving the protocol message containing the fault information, the opposite terminal processes the following steps:

s1.1: receiving fault information, and starting link protection fault processing after an opposite-end link fault detection module receives a protocol message containing fault information;

s1.2: the opposite terminal LACP module controls, the opposite terminal synchronously configures the opposite terminal LACP module according to the fault information in the protocol message, and the configuration mode is consistent with that of S1.2 in the local terminal processing flow;

s1.3: LACP protocol processing, after the step S1.2, the priority of the link and the maximum link number of the aggregation group are changed, and an opposite end LACP module runs the LACP protocol to complete processing;

5. The method for processing the link protection fault based on the LACP according to claim 4, wherein statistics is performed on abnormal messages, and when the number or the proportion of the abnormal messages exceeds a predetermined value, the link is considered to be abnormal; the abnormal message statistical information comprises a CRC error check message, a super-long packet and a super-short packet;

6. The method for processing the link protection failure based on the LACP according to claim 4, wherein when the standby link exists, the priority field of the port corresponding to the abnormal link is directly set as the lowest priority to cause the LACP protocol to start the standby link to replace the current link, the abnormal link is converted into the standby link, and the service data is not forwarded, so that the link aggregation can work normally;

when the standby link does not exist, the priority field of the port corresponding to the abnormal link is set as the lowest priority, and meanwhile, when the maximum link number corresponding to the aggregation of the links is greater than 1, the maximum link number supported by the aggregation is set to be the current maximum link number minus 1.

7. The method according to claim 4, wherein the protocol packet containing the failure information further includes a destination MAC field, a source MAC field, an ethertype field, and a plurality of TLV fields for failure information; the message realizes the transmission of a plurality of fault information through a plurality of fault information TLV fields; wherein:

8. The method as claimed in claim 7, wherein in the protocol message containing the failure information, the destination MAC field is 01:80: c2:00:00:02, the source MAC field is the device MAC itself, and the ethertype field is 0x 8809;