CN113938446A

CN113938446A - Multicast table item synchronization method and device based on MLAG environment

Info

Publication number: CN113938446A
Application number: CN202111115608.5A
Authority: CN
Inventors: 潘天宇
Original assignee: Inspur Cisco Networking Technology Co Ltd
Current assignee: Inspur Cisco Networking Technology Co Ltd
Priority date: 2021-09-23
Filing date: 2021-09-23
Publication date: 2022-01-14
Anticipated expiration: 2041-09-23
Also published as: CN113938446B

Abstract

The embodiment of the specification discloses a multicast table item synchronization method and equipment based on an MLAG environment, wherein the method comprises the following steps: when the appointed equipment is accessed to the multicast group, the MLAG equipment receives an IGMPreport message sent by the appointed equipment; after receiving the IGMP report message, the MLAG device sets the table entry state of the MLAG device to a first state from an initial state, generates a multicast MAC table entry according to the IGMP report message, and does not access any device at a designated port of the MLAG device for receiving the IGMP report message in the initial state; in the first state, the specific information of the IGMP report message is sent to the opposite terminal equipment through Peer-link, so that the table entry state is set to be a second state from the initial state after the opposite terminal equipment receives the specific information, and the opposite terminal equipment generates a multicast MAC table entry according to the specific information of the IGMP report message in the second state, thereby realizing the synchronous multicast MAC table entry in MLAG equipment and the opposite terminal equipment and ensuring that the specified equipment normally receives the multicast group flow.

Description

Multicast table item synchronization method and device based on MLAG environment

Technical Field

The present disclosure relates to the field of network communication technologies, and in particular, to a multicast entry synchronization method and device based on an MLAG environment.

Background

The Multi-Chassis Link Aggregation (MLAG) is a technique of performing cross-device Link Aggregation on interfaces of two Aggregation switches, and connecting the two Aggregation switches through a Peer-Link to logically serve as one device, where ports of the two devices together form an Aggregation port, so that all the ports participate in data traffic forwarding.

The two devices simultaneously start the IGMP snooping function, and for the devices joining the same multicast group, the problem that some devices cannot receive multicast flow is caused because the synchronization of multicast table items is lacked. When the device wants to receive the multicast traffic, the sending message is only sent to one switch due to link aggregation, the switch locally generates a multicast MAC table entry, if the device joins the multicast group ip traffic, the multicast MAC table entry is forwarded to the other switch, and because the other switch does not have the multicast table entry, the multicast traffic is processed as broadcast, and is flooded in the vlan, so that bandwidth resources are wasted.

Disclosure of Invention

One or more embodiments of the present specification provide a multicast entry synchronization method and apparatus based on MLAG environment, so as to solve the following technical problems: the problems that some devices cannot receive the flow and broadband resources are wasted due to the fact that multicast table items cannot be synchronized.

One or more embodiments of the present disclosure adopt the following technical solutions:

one or more embodiments of the present specification provide a multicast entry synchronization method based on an MLAG environment, where the method includes: when a designated device accesses a multicast group, an MLAG device receives an IGMP report message sent by the designated device; after receiving the IGMP report message, the MLAG device sets the entry state of the MLAG device from an initial state to a first state, and generates a multicast MAC entry according to the IGMP report message, where in the initial state, no device is accessed to a designated port of the MLAG device receiving the IGMP report message; under the first state, the specific information of the IGMP report message is sent to opposite terminal equipment through Peer-link, so that the opposite terminal equipment receives the table entry state after the specific information, the initial state is set to be a second state, the opposite terminal equipment generates a multicast MAC table entry under the second state according to the specific information of the IGMP report message, and the multicast MAC table entry is synchronized in the MLAG equipment and the opposite terminal equipment to ensure that the specified equipment normally receives the multicast group flow.

Further, the sending the specific information of the IGMP report to the Peer device through the Peer-link specifically includes: after receiving the IGMP report message, the MLAG device screens out specific information in the IGMP report message to generate an MLAG message, wherein the specific information is used for generating the multicast MAC table item; and the MLAG equipment sends the MLAG message to the opposite terminal equipment through the Peer-link.

Further, when the information type of the MLAG packet is add information, the method screens out specific information in the IGMP report packet to generate an MLAG packet, and specifically includes: and after the MLAG device determines that the IGMP report message conforms to a preset rule of the MLAG device, the MLAG device extracts IGMP add information in the IGMP report message and generates corresponding MLAG message information according to the IGMP add information.

Further, after the designated device normally receives the multicast group traffic, the method further includes: the designated device sends an IGMP report message to any one of the MLAG device and the opposite terminal device according to the received IGMP query message, wherein the IGMP query message is periodically sent by a service device in an MLAG networking environment; when the MLAG device receives the IGMP report message, refreshing a group timer of the first state multicast MAC table item to ensure that the group timer does not exceed preset time, wherein the group timer performs timing according to the received IGMP report message; when the opposite terminal equipment receives the IGMP report message, refreshing a group timer of the second state multicast MAC table item, generating an MLAG message according to IGMPupdate information in the IGMP report message, sending the MLAG message to the MLAG equipment through peerlink, and updating the group timer of the MLAG equipment so as to ensure that the group timer does not exceed preset time.

Further, after the designated device normally receives the multicast group traffic, the method further includes: if the MLAG device enables a fast away enabled mechanism and any of the following conditions exist: the group timer of the multicast MAC entry in the first state of the MLAG device exceeds a preset time, or the MLAG device receives an IGMP leave message sent by the designated device; the MLAG device deletes the first state multicast MAC table item, and the first state is converted into the initial state to generate IGMP del information; and generating an MLAG message according to the IGMP del information, sending the MLAG message to the opposite terminal equipment through Peer-link, and deleting the second state multicast MAC table item by the opposite terminal equipment according to the corresponding IGMP del information in the MLAG message information.

Further, if the MLAG device enables the fast away enabled mechanism and the group timer of the first-state multicast MAC entry does not exceed a preset time, the method further includes: when the opposite terminal equipment receives the IGMP leave message sent by the appointed equipment, the opposite terminal equipment deletes the second state multicast MAC table entry of the opposite terminal equipment according to the IGMP leave message, and generates IGMP del information; and generating an MLAG message according to the IGMP del information, and sending the MLAG message to the MLAG equipment through Peer-link, so that the MLAG equipment deletes the first state multicast MAC table item according to the corresponding IGMP del information in the MLAG message information.

Further, when the MLAG device does not enable the fast away enabled mechanism, the method further comprises: when the table entry group timer in the first state exceeds a preset time, the first state is switched to a third state, wherein the MLAG device sends a specific group query message to the designated device in the third state, and the specific group query message is used for checking the member state; after receiving the specific group query message, the designated device sends an IGMP report message to the MLAG device; if the MLAG device does not receive the IGMP report message, deleting the first state multicast MAC table item and generating IGMP del information; and generating an MLAG message according to the IGMP del information, sending the MLAG message to the opposite terminal equipment through Peer-link, and deleting the second state multicast MAC table entry of the opposite terminal equipment by the opposite terminal equipment according to the IGMP del information in the MLAG message.

Further, before the designated device accesses the multicast group, the method further includes: the MLAG device and the opposite terminal device construct an MLAG environment through a Peer-link, wherein the MLAG device, the opposite terminal device and a service device form cross-device link aggregation, the service device is used for sending multicast traffic, and both the MLAG device and the opposite terminal device are aggregation switches; when the designated device is one, the connection mode between the designated device and the MLAG device and the opposite device includes any one of dual-homing access and single-homing access; when the designated device is multiple, the connection mode between the designated device and the MLAG device and the peer device includes: the mobile terminal can be any one of dual homing access, single homing access and single-dual homing hybrid access.

Further, before the MLAG device receives the IGMP report packet sent by the designated device, the method further includes: and starting the IGMP snooping functions of the MLAG equipment and the opposite terminal equipment.

One or more embodiments of the present specification provide a multicast entry synchronization apparatus based on an MLAG environment, including:

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:

when a designated device accesses a multicast group, an MLAG device receives an IGMP report message sent by the designated device;

after receiving the IGMP report message, the MLAG device sets the entry state of the MLAG device from an initial state to a first state, and generates a multicast MAC entry according to the IGMP report message, where in the initial state, no device is accessed to a designated port of the MLAG device receiving the IGMP report message;

under the first state, the specific information of the IGMP report message is sent to opposite terminal equipment through Peer-link, so that the opposite terminal equipment receives the table entry state after the specific information, the initial state is set to be a second state, the opposite terminal equipment generates a multicast MAC table entry under the second state according to the specific information of the IGMP report message, and the multicast MAC table entry is synchronized in the MLAG equipment and the opposite terminal equipment to ensure that the specified equipment normally receives the multicast group flow.

One or more embodiments of the present specification provide a non-transitory computer storage medium storing computer-executable instructions configured to:

when a designated device accesses a multicast group, an MLAG device receives an IGMP report message sent by the designated device; after receiving the IGMP report message, the MLAG device sets the entry state of the MLAG device from an initial state to a first state, and generates a multicast MAC entry according to the IGMP report message, where in the initial state, no device is accessed to a designated port of the MLAG device receiving the IGMP report message; under the first state, the specific information of the IGMP report message is sent to opposite terminal equipment through Peer-link, so that the opposite terminal equipment receives the table entry state after the specific information, the initial state is set to be a second state, the opposite terminal equipment generates a multicast MAC table entry under the second state according to the specific information of the IGMP report message, and the multicast MAC table entry is synchronized in the MLAG equipment and the opposite terminal equipment to ensure that the specified equipment normally receives the multicast group flow.

The embodiment of the specification adopts at least one technical scheme which can achieve the following beneficial effects: the method comprises the steps of converting the state of a state machine of an MLAG device for processing messages according to different IGMP report sources, when a specified device is added into a multicast group for the first time, sending specific information of the IGMP report messages to an opposite terminal device through Peer-link, converting the state of an item of the opposite terminal device from the initial state into a second state, generating a multicast MAC (media access control) item according to the specific information of the IGMP report messages, realizing synchronization of the multicast item, enabling an MLAG scene to support two-layer multicast, not using the multicast as broadcast processing, and not generating the condition of flow blockage under the condition of complex topology.

Drawings

In order to more clearly illustrate the embodiments of the present specification or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, it is obvious that the drawings in the following description are only some embodiments described in the present specification, and for those skilled in the art, other drawings can be obtained according to the drawings without any creative effort. In the drawings:

fig. 1 is a schematic diagram of an MLAG networking environment provided in an embodiment of the present disclosure;

fig. 2 is a flowchart illustrating a multicast entry synchronization method based on an MLAG environment according to an embodiment of the present disclosure;

fig. 3 is a schematic diagram of a raw IGMP route management state machine according to an embodiment of the present disclosure;

fig. 4 is a schematic diagram of a routing management state machine for IGMP in an MLAG environment according to an embodiment of the present disclosure;

fig. 5 is a schematic diagram of an MLAG multicast MAC synchronization packet encapsulation format according to an embodiment of the present disclosure;

fig. 6 is a schematic structural diagram of a multicast entry synchronization apparatus based on an MLAG environment according to an embodiment of the present disclosure.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present specification, the technical solutions in the embodiments of the present specification will be clearly and completely described below with reference to the drawings in the embodiments of the present specification, and it is obvious that the described embodiments are only a part of the embodiments of the present specification, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present specification without any creative effort shall fall within the protection scope of the present specification.

The Multi-Chassis Link Aggregation (MLAG) performs cross-device Link Aggregation on interfaces on two Aggregation switches, so as to promote devices from a single board level to a device level, thereby forming an Active-Active system. And connecting the two aggregation switches through a Peer-Link Link in the middle to make the aggregation switches logically like a device. The ports of the two devices together form an aggregation port, so that all the ports participate in data traffic forwarding. Compared with stacking, the devices forming the MLAG still need to be managed respectively in management, but the MLAG configuration is relatively simple, the devices do not need to be restarted after the configuration is completed, the forwarding decision is local, the flow does not need to go through the interconnection path between the devices under normal conditions, the bandwidth of the interconnection path is prevented from becoming a bottleneck, and meanwhile, the delay is reduced. Compared with the traditional network, the MLAG provides higher bandwidth and higher reliability when the network flow is increased. And use static LAG or LACP to connect other switches or servers, enabling cross device link aggregation. In addition, the MLAG realizes redundant backup and provides two-layer redundant protection of Active-Active. The two devices can be upgraded independently, so that one device can be ensured to work normally only by forwarding, and the running service is hardly influenced.

As shown in fig. 1, a device SWA and a device SWB establish an MLAG through Peer-link links, where port 1 of the device SWA and port 1 of the device SWB respectively form a cross-device link aggregation AGG1 with port 1 and port 2 of the device SERVER, port 1 and port 2 of the device C respectively form a cross-device link aggregation AGG2 with port 3 of the SWA and SWB, and port 1 of the device D is directly connected to port 3 of the SWB.

The device SERVER sends the multicast traffic, and both the device C and the device D want to receive the multicast traffic, and therefore both send the IGMP report message to the outside to join the multicast group. The device SWB starts an IGMP snooping function, and the port 3 of the device SWB receives an IGMP report message of the device D, processes the message, and generates a corresponding multicast MAC entry. The device SWA also starts the IGMP snooping function, but since the port 1 and the port 2 of the device C are in the same aggregation, after the port 1 of the device C sends an IGMP report message, the SWA receives and processes the message, and generates a corresponding multicast MAC entry. After the SERVER sends the multicast traffic, the traffic is sent from the port 2 due to port aggregation, the traffic can only be sent to the device D after the SWB, and the device C added to the same group cannot receive the traffic. That is to say, in a networking environment of MLAG single-dual home hybrid access, two devices simultaneously start the IGMP snooping function, and for devices joining the same multicast group, there is a problem that some devices cannot receive multicast traffic because of lack of synchronization of multicast entries.

The device SERVER sends multicast traffic, when the device C wants to receive the multicast stream, the device C sends an igmp report, only sends the multicast MAC entry to the SWA due to link aggregation, and the SWA locally generates a multicast MAC entry, at this time, the SERVER sends a destination multicast ip, which is the multicast group ip traffic added by the device C, and forwards the multicast group ip traffic to the SWB from the port 2 of the SERVER, and because the SWB does not have a multicast entry, the multicast traffic is treated as broadcast, and is flooded in the vlan, which wastes bandwidth resources.

The embodiment of the present specification provides a multicast entry synchronization method and device based on an MLAG environment, and for a switch, generating a multicast MAC address may be implemented in an IGMP snooping/GMRP manner, and the synchronization of generating a multicast MAC entry based on IGMP snooping in an MLAG environment provided in the embodiment of the present specification uses an IGMPv2 mode as a default. In addition, it needs to be clear to those skilled in the art that when a host joins a multicast group or when it receives a conventional query message sent by a querier, the host will send a membership report message, i.e. an IGMP report message.

The embodiments of the present specification will be described below with reference to the accompanying drawings.

Fig. 2 is a schematic flowchart of a multicast entry synchronization method based on an MLAG environment according to an embodiment of the present disclosure, and as shown in fig. 2, the method mainly includes the following steps:

step S201, when the designated device accesses the multicast group, the MLAG device receives an IGMP report message sent by the designated device.

Before a designated device accesses a multicast group, an MLAG environment is constructed by the MLAG device and an opposite terminal device through a Peer-link, wherein the MLAG device, the opposite terminal device and a service device form cross-device link aggregation, the service device is used for sending multicast flow, and both the MLAG device and the opposite terminal device are aggregation switches; when the designated equipment is one, the connection mode of the designated equipment, the MLAG equipment and the opposite terminal equipment comprises any one of dual-homing access or single-homing access; when a plurality of designated devices are provided, the connection mode between the designated devices and the MLAG device and the peer device includes: the mobile terminal can be any one of dual homing access, single homing access and single-dual homing hybrid access.

It should be noted that the MLAG device may be the device SWA in fig. 1, the peer device may be the device SWB in fig. 1, the service device corresponds to the SERVER in fig. 1, and the specified device may be the device C or the device D. The device C is a dual-homed access, and the device D is a single-homed access. The IGMP snooping functions of the device SWA and the device SWB are turned on.

Step S202, after receiving the IGMPreport message, the MLAG device sets the table entry state of the MLAG device from the initial state to a first state, and generates a multicast MAC table entry according to the IGMP report message.

It should be noted that, in the initial state, no device has been accessed at the designated port where the MLAG device receives the IGMP report message. The initial state corresponds to the No Members Present state in fig. 4, and the first state corresponds to the Mlag Output Members Present state, MO state for short, in fig. 4.

Step S203, in the first state, the specific information of the IGMP report message is sent to the opposite terminal equipment through Peer-link.

Specifically, after receiving an IGMP report message, the MLAG device screens out specific information in the IGMP report message to generate an MLAG message, where the specific information is used to generate a multicast MAC entry; and the MLAG equipment sends the MLAG message to opposite-end equipment through a Peer-link.

When the information type of the MLAG message is add information, after determining that the IGMP report message conforms to the preset rule of the MLAG device, the MLAG device extracts the IGMP add information in the IGMP report message, and generates corresponding MLAG message information according to the IGMP add information.

Step S204, after receiving the specific information, the opposite terminal device sets the table entry state from the initial state to a second state, and in the second state, the opposite terminal device generates a multicast MAC table entry according to the specific information of the IGMP report message.

It should be noted that the second state corresponds to the Mlag Input Members Present state in fig. 4, which is abbreviated as MI state.

Step S205, implement synchronization of multicast MAC entries in the MLAG device and the peer device, so as to ensure that the designated device normally receives the multicast group traffic.

After the designated device receives the multicast group traffic normally, maintenance operation needs to be performed on the designated device. Wherein the maintenance operation is as follows:

the method comprises the steps that service equipment in an MLAG networking environment periodically sends IGMP query messages, designated equipment sends IGMP report messages to any one of MLAG equipment and opposite-end equipment according to the received IGMP query messages, and when the MLAG equipment receives the IGMP report messages, a group timer of a first-state multicast MAC table item of the MLAG equipment is refreshed, and the group timer is guaranteed not to exceed preset time, wherein the group timer performs timing according to the received IGMP report messages; and when the received IGMP report message is the opposite terminal equipment, refreshing the group timer of the second state multicast MAC table item, generating an MLAG message according to IGMPupdate information in the IGMP report message, sending the MLAG message to the MLAG equipment through peerlink, and updating the group timer of the MLAG equipment so as to ensure that the group timer does not exceed the preset time.

After the specified device normally receives the multicast group traffic, the table entry deletion operation is also required to be synchronized. Wherein the deletion operation is as follows:

if the MLAG device starts the enabling fast leaving mechanism, and the group timer of the multicast MAC table item in the first state of the MLAG device exceeds the preset time; or, the MLAG device enables the enable fast leave mechanism, and the MLAG device receives the IGMP leave packet sent by the specified device, and performs the following operations: the MLAG device deletes the first state multicast MAC table item, and the first state is changed into an initial state to generate IGMP del information; and generating an MLAG message according to the IGMP del information, sending the MLAG message to the opposite terminal equipment through Peer-link, and deleting the second state multicast MAC table item by the opposite terminal equipment according to the corresponding IGMP del information in the MLAG message information.

If the MLAG device starts an enabling rapid exit mechanism and a group timer of a first state multicast MAC table item does not exceed preset time, and when the opposite terminal device receives an IGMP leave message sent by the appointed device, deleting a second state multicast MAC table item of the opposite terminal device according to the IGMP leave message, and generating IGMP del information; and generating an MLAG message according to the IGMP del information, and sending the MLAG message to MLAG equipment through Peer-link so that the MLAG equipment deletes the first-state multicast MAC table item according to the corresponding IGMP del information in the MLAG message information.

Under the condition that the MLAG equipment does not start an enabling rapid exit mechanism, when the table item group timer in the first state exceeds preset time, the first state is converted into a third state, wherein the MLAG equipment sends a specific group query message to specified equipment under the third state, and the specific group query message is used for checking the member state; after receiving the specific group query message, the designated device sends an IGMP report message to the MLAG device; if the MLAG device does not receive the IGMP report message, deleting the first state multicast MAC table item and generating IGMP del information; generating an MLAG message according to the IGMP del information, sending the MLAG message to the opposite terminal equipment through Peer-link, and deleting the second state multicast MAC table item of the opposite terminal equipment by the opposite terminal equipment according to the IGMP del information in the MLAG message. It should be noted that the third state corresponds to the Checking Membership state in fig. 4.

A second embodiment of the present specification provides a multicast entry synchronization method based on an MLAG environment during dual-homing access, and the second embodiment is described with reference to fig. 1 and fig. 3 to 5, taking an AGG2 of a device C as a dual-homing access device SWA and a device SWB as an example.

The IGMP snooping functions of the device SWA and the device SWB are turned on. In MLAG environment, when a device C wants to join a multicast group, a port 1 or a port 2 sends IGMP report messages to the SWA and the SWB through the AGG2, and the following description will be given by taking the AGG2 of the device C as the dual-homed access device SWA and the device SWB.

First, the table entry synchronization at the time of multicast MAC table entry addition. In the MLAG environment of fig. 1, when a device C joins a multicast group for the first time, no other device exists at a port of a switch to which the device C is to join, an IGMP report message is sent out through AGG2, and a port 1 of the device C sends the IGMP report message to a device SWA through AGG2 as an example. When a port 1 sends a message to the SWA due to link aggregation, the SWA receives an IGMP report message reported from the inner core at the moment, and when a protocol stack of the switch receives the IGMP report message uploaded by the inner core of the switch, after the received message is confirmed to be legal and a table entry can be generated, IGMP add information is generated.

After receiving the IGMP report message reported from the kernel, the SWA changes its state from the No Members Present state to the Mlag Output Members Present state, and generates a corresponding multicast MAC address. It should be noted that the states of the original route management state machine for processing the packet by using the IGMP protocol include a No Members Present state, a Members Present state, and a Checking Members state, as shown in fig. 3. In the embodiment of the Present description, the original member Present state of the state machine is divided into an Mlag Output member Present state and an Mlag Input member Present state according to the source of the report packet, as shown in fig. 4, fig. 4 shows a routing management state machine for IGMP in an Mlag environment provided by the embodiment of the Present description, and provides a processing method for packets in each state. If the previous state is still used, the SWA and the SWB independently run an IGMP protocol state machine, and the original Members Present state is divided into an Mlag Output Members Present state and an Mlag Input Members Present state, so that the table items are consistent in the MLAG environment.

After the state of the SWA is converted from the No Members Present state to the Mlag Output Members Present state, specific information is extracted from the report message, an MLAG message is generated for packaging IGMP add information in the adding step, and the MLAG message is sent to the opposite terminal device SWB through a peerlink port. The device SWB decapsulates the MLAG message to obtain IGMP add information, the state of the device SWB is converted from the No Members Present state to the Mlag Input Members Present state, and a corresponding multicast MAC address is generated. Through the steps, synchronization of multicast table entries is realized in the device SWA and the device SWB, and when the SERVER sends traffic to any device of the device SWA and the device SWB, the device SWA and the device SWB can both realize the purpose of forwarding the traffic to the device C.

If the port 2 of the device C sends an IGMP report message to the SWB, after receiving the IGMP report message, the SWB changes from the No Members Present state to the Mlag Output Members Present state, extracts specific information from the report message, generates an Mlag message for encapsulating IGMP add information in the adding step, and sends the Mlag message to the opposite-end device SWA through a peerlink port. The device SWA decapsulates the MLAG message to obtain IGMP add information, the state of the device SWA is converted from the No Members Present state to the Mlag Input Members Present state, a corresponding multicast MAC address is generated, and the same multicast MAC table entry is ensured in AGG2 of the SWA and the SWB.

Secondly, multicast MAC table entries need to be maintained. The original state needs to be maintained by each switch independently, but the maintenance operation needs to be maintained according to the report message sent by the device C, and because of the MLAG cross-device aggregation environment, a situation that the report message is only sent to any one of the SWA or the SWB may occur, which causes the original state of the switch which is not received to be aged, and affects subsequent traffic reception.

In the MLAG environment of fig. 1, the table entry of IGMP maintains an IGMP query message sent according to a SERVER cycle, and after receiving the IGMP query message, the device C sends an IGMP report message through the AGG 2. When the device C sends an IGMP report message through the port 1, and when the port 1 sends a message to the SWA due to link aggregation, the SWA receives the IGMP report message reported by the kernel, and refreshes the group timer of the mo (mlag output) entry to ensure that the group timer does not time out. Since the MI (Mlag input) table entry of the SWB does not receive the report message, the group timer is overtime, but the table entry is not deleted at the moment, and only the flag is set to be in an overtime state.

When the device C sends the IGMP query message from the port 2, the SWB receives the IGMP query message reported by the inner core, refreshes the group timer of the MI table item, encapsulates the Update information and sends the encapsulated Update information to the SWA through the peerlink port, the SWA receives the Update information decapsulated by the MLAG, and the group timer of the MO table item is updated to ensure that the group timer cannot be overtime.

On the other hand, when the device C leaves the multicast group, the table item deletion operation needs to be synchronized between the device SWA and the device SWB, thereby avoiding the situation of wasting bandwidth resources. In MLAG environment, there are two stages for a member to leave a multicast group, one is that the member running IGMPv2 sends an IGMP leave message to notify the IGMP querier that it leaves a certain multicast group. The other is that after receiving IGMP leave message, IGMP enquirer resolves multicast group address and sends IGMP specific group enquiry message/IGMP specific source group enquiry message to the multicast group through receiving interface.

In this embodiment, if IGMP snooping enables the fast leaving mechanism, and the MO entry group timer of SWA is over time, the deletion process is directly performed, meanwhile, the IGMP del information is encapsulated and sent to the opposite end through the peerlink port, and the opposite end device deletes the MI entry after receiving the del information. If the device C belongs to the IGMP snooping enabled fast leaving mechanism and the MO entry group timer is not timed out, there may be a case where the device C sends a leave message to the device SWA and the device C sends a leave message to the device SWB. When SWA receives leave message, it directly deletes flow, at the same time, packaging IGMP del information and sending it to opposite end through peerlink port, and after SWB receives del information, it deletes MI table of SWB. And when receiving the leave message, the SWB encapsulates IGMP del information and sends the information to the opposite end SWA through the peerlink port, and after receiving the del information, the opposite end SWA performs a deletion process to delete the MO table entry of the SWA.

If the device belongs to the IGMP snooping mechanism which does not enable the quick exit, the MO table entry group timer of the SWA is overtime and then is converted into a Checking Membership state, a specific group query message is sent, and the robust value is repeated for times. During the period, if the device SWA does not receive the IGMP report message sent by the device C, the entry is deleted, meanwhile, the encapsulated IGMP del information is sent to the opposite end through the peerlink port, and the MI entry is deleted after the opposite end device receives the del information. It should be noted that, when the device C sends the GMP report, the GMP report may be sent to the device SWA or the device SWB; when sending to the device SWB, the device SWB encapsulates the IGMPdel information and sends it to the device SWA, so that the IGMP report message sent by the device C here includes the decapsulated and received by the kernel.

Finally, the device C is a dual-homed access, and if the dual-homed access is changed to a single-homed access, the corresponding synchronization operations are as follows: in the MLAG environment of fig. 1, if the device C sends an IGMP report message to the device SWA through the port 1, the SWB port 2 is down, the SWA changes from dual-homed to single-homed, and at this time, the MI entry of the SWB updates the port from the AGG2 to the peerlink port, and the state is not changed. If the device C sends an IGMP report message to the device SWB through the port 2, the SWA port 2 is down, the SWB is changed from dual-homing to single-homing, and the MO table entry on the AGG2 of the SWA is updated to the peerlink port, and the state is unchanged.

With reference to the foregoing embodiment and fig. 4 in the description, it should be noted that the method for processing packets in the Mlag Output Members Present state and the Mlag Input Members Present state is determined according to whether the IGMP report packet is received for the first time and the state of the current switch. When the device to be added into the multicast group is added for the first time, the IGMP report message sent by the device is sent for the first time, the switch is in a No number Present state before receiving the message, the IGMP report message is converted into an Mlag Output number Present state after receiving the IGMP report message reported by the inner core, and the message is extracted, packaged and sent to the opposite terminal device. When receiving an IGMP report message in the MAC address deletion process, the switch is already in the Mlag Output Members Present state at this time, and it receives the IGMP report message for the non-first time, and the Mlag Output Members Present state performs an operation of not extracting and encapsulating information of the message and transmitting the message to the opposite end.

Similarly, when adding the MAC address, the switch is in the No Members Present state, and generates the corresponding multicast address after receiving the encapsulated packet, that is, in this case, the Mlag Input Members Present state does not perform the operations of extracting, encapsulating, and sending to the peer. However, in the MAC address deletion process, the state of the switch is already the Mlag Input Members Present state, and the received IGMP report message is received for the first time, and the message is subjected to information extraction, encapsulation, and is sent to the peer device. That is, in the Mlag Output Members Present state and the Mlag Input Members Present state, if the IGMP report packet is received for the first time, the packet is subjected to the operations of information extraction, encapsulation, and forwarding to the opposite end.

A third embodiment of this specification provides a multicast entry synchronization method based on an MLAG environment during single-homing access, and the third embodiment is described with reference to fig. 1 and fig. 3 to 5, taking an AGG2 of a device C as a dual-homing access device SWA and a device SWB as examples.

First, the table entry synchronization at the time of multicast MAC table entry addition. In the MLAG environment of fig. 1, a port 1 of a device D is connected to a port 3 of an SWB, when the device D joins a certain multicast group for the first time, No other device is Present at the port of an exchange to which the device D is to join, an IGMP report message is sent to the SWB, the SWB receives an IGMP report reported from a kernel, converts from a No Members Present state to an MLAG Output Members Present state, and generates a corresponding multicast MAC address; when a protocol stack of the switch receives an IGMP report message uploaded by a switch kernel, after the received message is confirmed to be legal and a table entry can be generated, IGMP add information is generated.

After the state of the SWA is converted from the No Members Present state to the Mlag Output Members Present state, specific information is extracted from the report message, an MLAG message is generated for packaging IGMP add information in the adding step, and the MLAG message is sent to the opposite terminal equipment SWA through a peerlink port. The equipment SWA decapsulates the MLAG message to obtain IGMP add information, the state of the equipment SWA is converted from the No Members Present state to the Mlag Input Members Present state, and a corresponding multicast MAC address is generated. Through the steps, synchronization of multicast table entries is realized in the device SWA and the device SWB, and when the SERVER sends traffic to any device of the device SWA and the device SWB, the device SWA and the device SWB can both realize the purpose of forwarding the traffic to the device D.

Secondly, multicast MAC table entries need to be maintained. In the MLAG environment of fig. 1, the table entry of the IGMP maintains the IGMP query packet sent according to the SERVER cycle, and after receiving the IGMP query packet, the device D sends an IGMP report packet to the SWB. The SWB receives an IGMP report message reported by the kernel, and refreshes a group timer of an MO (mlag output) table entry to ensure that the group timer cannot be overtime. Since the MI (Mlag input) table entry of the SWB does not receive the report message, the group timer is overtime, but the table entry is not deleted at the moment, and only the flag is set to be in an overtime state.

On the other hand, when the device D opens the multicast group, it is necessary to synchronize the entry deletion operations in the device SWA and the device SWB, thereby avoiding the situation of wasting bandwidth resources. If IGMP snooping enables a quick exit mechanism and the MO table entry group timer of the SWB is overtime, the deletion process is directly carried out, meanwhile, IGMP del information is packaged and sent to the opposite end through a peerlink port, and the MI table entry is deleted after the opposite end equipment receives the del information.

If the device D belongs to the IGMP snooping enabled fast leaving mechanism and the MO entry group timer is not timed out, there may be a case where the device D sends a leave message to the device SWB. And after receiving the leave message, operating the same as the overtime process.

If the device belongs to the IGMP snooping mechanism which does not enable the quick exit, the MO table entry group timer of the device SWB is overtime and then is converted into a Checking Membership state, a specific group query message is sent, and the robust value is repeated for times. During the period, if the device SWB has not received the IGMP report message sent by the device C, the entry is deleted, meanwhile, the encapsulated IGMP del information is sent to the opposite end through the peerlink port, and the opposite end device deletes the MI entry after receiving the del information.

And finally, the device D is in single-homing access, and if the single-homing access is changed into double-homing access, the corresponding synchronous operation is as follows: in the MLAG environment of fig. 1, port 2 of SWB is down, and device C can only be single-homed accessed through port 1 and SWA port 2, at this time, port 2 of SWB is UP, and at this time, single-homed access is changed to dual-homed access, and at this time, MI table entry of SWB is updated from peerlink port to AGG2 port, and the state is unchanged.

In both access scenarios provided in the second and third embodiments, the IGMP report packet received by the MLAG device port is encapsulated in the MLAG protocol after being locally generated into the multicast MAC entry, and is sent to the peer device through the peerlink port, and the peer device parses the relevant processing information from the received MLAG protocol packet, and then sends the parsed information to the state machine process.

In an embodiment of the present specification, an encapsulation format of a synchronous multicast packet of an MLAG is shown in fig. 5, and includes the following information: the device comprises an Mlag version, a Message Type, a Message len, an Action, an Mlag id, a Vlan id, an Interface and a Group-address, wherein the Mlag version refers to a protocol version number and is used for identifying an M-LAG version operated by the device. The Message Type is a Message Type and is used for identifying the Type of the Message, namely, an fdb or multicast MAC synchronous Message. Message len means the total length of the Message. Action refers to the type of information, including ADD/DEL/UPDATE/LEAVE/CLEAR _ ALL/CLEAR _ VLAN. The Mlag ID is the Mlag member where the identified port is located (the identification is the actual Mlag member ID in case of dual-homing access, and the value is 0 in case of single-homing access). The Vlan id refers to the Vlan id of the entry. Interface refers to the egress Interface of the table entry. The Group-address refers to a multicast Group IP address.

In an embodiment of this specification, in a synchronization method of multicast MAC entries in an MLAG networking environment, entries are divided into two states for respective processing, so as to achieve the purpose that multicast traffic in the MLAG environment can be forwarded normally. When multiple single devices join the same multicast group, ref _ cnt needs to be added to the multicast MAC generated by peerlink at the MLAG peer to determine when the entry can be deleted. In addition, after the equipment is restarted, the MLAG equipment is reconnected, all MI table entries of normal equipment are deleted, MO table entries are reserved, and MO table entries are synchronized to the opposite end after the MLAG connection is reestablished.

One or more embodiments of the present specification provide a multicast entry synchronization apparatus based on an MLAG environment, as shown in fig. 6, including: at least one processor; and a memory communicatively coupled to the at least one processor; wherein the memory stores instructions executable by the at least one processor to enable the at least one processor to: when the appointed equipment is accessed to the multicast group, the MLAG equipment receives an IGMP report message sent by the appointed equipment; after receiving the IGMP report message, the MLAG device sets the table entry state of the MLAG device to a first state from an initial state, generates a multicast MAC table entry according to the IGMP report message, and does not access any device at a designated port of the MLAG device for receiving the IGMP report message in the initial state; in the first state, the specific information of the IGMP report message is sent to the opposite terminal equipment through Peer-link, so that the opposite terminal equipment sets the table entry state from the initial state to a second state after receiving the specific information, and the opposite terminal equipment generates a multicast MAC table entry according to the specific information of the IGMP report message in the second state, thereby realizing the synchronous multicast MAC table entry in MLAG equipment and the opposite terminal equipment and ensuring that the specified equipment normally receives the multicast group flow.

One or more embodiments of the present specification provide a non-transitory computer storage medium storing computer-executable instructions configured to: when the appointed equipment is accessed to the multicast group, the MLAG equipment receives an IGMP report message sent by the appointed equipment; after receiving the IGMP report message, the MLAG device sets the table entry state of the MLAG device to a first state from an initial state, generates a multicast MAC table entry according to the IGMP report message, and does not access any device at a designated port of the MLAG device for receiving the IGMP report message in the initial state; in the first state, the specific information of the IGMP report message is sent to the opposite terminal equipment through Peer-link, so that the opposite terminal equipment sets the table entry state from the initial state to a second state after receiving the specific information, and the opposite terminal equipment generates a multicast MAC table entry according to the specific information of the IGMP report message in the second state, thereby realizing the synchronous multicast MAC table entry in MLAG equipment and the opposite terminal equipment and ensuring that the specified equipment normally receives the multicast group flow.

According to the technical scheme in the embodiment of the description, the entries are divided into two states to be processed respectively, so that the purpose that multicast traffic in an MLAG environment can be forwarded normally is achieved, synchronization of multicast entries is achieved, an MLAG scene supports two-layer multicast, multicast is not treated as broadcast, and the situation of traffic obstruction cannot occur under the condition of complex topology.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the embodiments of the apparatus, the device, and the nonvolatile computer storage medium, since they are substantially similar to the embodiments of the method, the description is simple, and for the relevant points, reference may be made to the partial description of the embodiments of the method.

The foregoing description has been directed to specific embodiments of this disclosure. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing may also be possible or may be advantageous.

The above description is merely one or more embodiments of the present disclosure and is not intended to limit the present disclosure. Various modifications and alterations to one or more embodiments of the present description will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement or the like made within the spirit and principle of one or more embodiments of the present specification should be included in the scope of the claims of the present specification.

Claims

1. A multicast table item synchronization method based on MLAG environment is characterized in that the method comprises the following steps:

2. The method according to claim 1, wherein the sending the specific information of the IGMP report to the Peer device via Peer-link specifically includes:

after receiving the IGMP report message, the MLAG device screens out specific information in the IGMP report message to generate an MLAG message, wherein the specific information is used for generating the multicast MAC table item;

and the MLAG equipment sends the MLAG message to the opposite terminal equipment through the Peer-link.

3. The method according to claim 2, wherein when the information type of the MLAG packet is add information, the method for synchronizing the multicast table entry based on the MLAG environment screens out specific information in the IGMP report packet to generate the MLAG packet, and specifically comprises:

and after the MLAG device determines that the IGMP report message conforms to a preset rule of the MLAG device, the MLAG device extracts IGMP add information in the IGMP report message and generates corresponding MLAG message information according to the IGMP add information.

4. The method of claim 2, wherein after the specified device normally receives the multicast group traffic, the method further comprises:

the designated device sends an IGMP report message to any one of the MLAG device and the opposite terminal device according to the received IGMP query message, wherein the IGMP query message is periodically sent by a service device in an MLAG networking environment;

when the MLAG device receives the IGMP report message, refreshing a group timer of the first state multicast MAC table item to ensure that the group timer does not exceed preset time, wherein the group timer performs timing according to the received IGMP report message;

when the opposite terminal equipment receives the IGMP report message, refreshing a group timer of the second state multicast MAC table item, generating an MLAG message according to IGMPupdate information in the IGMP report message, sending the MLAG message to the MLAG equipment through peerlink, and updating the group timer of the MLAG equipment so as to ensure that the group timer does not exceed preset time.

5. The method of claim 2, wherein after the specified device normally receives the multicast group traffic, the method further comprises:

if the MLAG device enables a fast away enabled mechanism and any of the following conditions exist:

the group timer of the multicast MAC entry in the first state of the MLAG device exceeds a preset time, or the MLAG device receives an IGMP leave message sent by the designated device;

the MLAG device deletes the first state multicast MAC table item, and the first state is converted into the initial state to generate IGMP del information;

and generating an MLAG message according to the IGMP del information, sending the MLAG message to the opposite terminal equipment through Peer-link, and deleting the second state multicast MAC table item by the opposite terminal equipment according to the corresponding IGMP del information in the MLAG message information.

6. The method of claim 5, wherein if the MLAG device enables the fast away enabled mechanism and the group timer of the first-state multicast MAC entry does not exceed a preset time, the method further comprises:

when the opposite terminal equipment receives the IGMP leave message sent by the appointed equipment, the opposite terminal equipment deletes the second state multicast MAC table entry of the opposite terminal equipment according to the IGMP leave message, and generates IGMP del information;

and generating an MLAG message according to the IGMP del information, and sending the MLAG message to the MLAG equipment through Peer-link, so that the MLAG equipment deletes the first state multicast MAC table item according to the corresponding IGMP del information in the MLAG message information.

7. The method of claim 5, wherein when the MLAG device does not enable the fast away enabled mechanism, the method further comprises:

when the table entry group timer in the first state exceeds a preset time, the first state is switched to a third state, wherein the MLAG device sends a specific group query message to the designated device in the third state, and the specific group query message is used for checking the member state;

after receiving the specific group query message, the designated device sends an IGMP report message to the MLAG device;

if the MLAG device does not receive the IGMP report message, deleting the first state multicast MAC table item and generating IGMP del information; and generating an MLAG message according to the IGMP del information, sending the MLAG message to the opposite terminal equipment through Peer-link, and deleting the second state multicast MAC table entry of the opposite terminal equipment by the opposite terminal equipment according to the IGMP del information in the MLAG message.

8. The method of claim 1, wherein before the specified device accesses the multicast group, the method further comprises:

the MLAG device and the opposite terminal device construct an MLAG environment through a Peer-link, wherein the MLAG device, the opposite terminal device and a service device form cross-device link aggregation, the service device is used for sending multicast traffic, and both the MLAG device and the opposite terminal device are aggregation switches;

when the designated device is one, the connection mode between the designated device and the MLAG device and the opposite device includes any one of dual-homing access and single-homing access;

when the designated device is multiple, the connection mode between the designated device and the MLAG device and the peer device includes: the mobile terminal can be any one of dual homing access, single homing access and single-dual homing hybrid access.

9. The method of claim 8, wherein before the MLAG device receives the IGMP report packet sent by the designated device, the method further comprises:

and starting the IGMP snooping functions of the MLAG equipment and the opposite terminal equipment.

10. A multicast table item synchronization device based on MLAG environment is characterized by comprising:

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