CN110351127A

CN110351127A - A kind of method of Graceful Restart, equipment and system

Info

Publication number: CN110351127A
Application number: CN201910564049.2A
Authority: CN
Inventors: 胡雅庆
Original assignee: Maipu Communication Technology Co Ltd
Current assignee: Maipu Communication Technology Co Ltd
Priority date: 2019-06-28
Filing date: 2019-06-28
Publication date: 2019-10-18
Anticipated expiration: 2039-06-28
Also published as: CN110351127B

Abstract

The embodiment of the invention discloses a kind of method of Graceful Restart, equipment and systems, are related to data communication field, realize the uninterrupted forwarding of service traffics.This method comprises: after the MLAG process of local terminal network equipment is restarted, load MLAG configuration, by the initial port state recording of the port LAG of this equipment into interim table；Negotiation packet is sent to the peer network device in the place domain MLAG to re-establish pairing relationship with the peer network device；The local terminal network equipment starts timer, with the peer network device synchronisation message, calculates the current port status in the port LAG, and update into the interim table；If the timer expiry, the list item corresponding with the port LAG in the external setting database of this equipment of the corresponding list item in the port LAG in the interim table is compared by the local terminal network equipment, to determine whether to update the hardware Forwarding plane and the external setting database of this equipment.

Description

A kind of method of Graceful Restart, equipment and system

Technical field

The invention belongs to data communication field more particularly to a kind of methods of Graceful Restart, equipment and system.

Background technique

Striding equipment link aggregation group (Multi-Chassis Link Aggregation Group, referred to as: MLAG) technology It is a kind of link aggregation technology of striding equipment, two physical equipments is invented into an equipment in polymerization level to realize striding equipment Link aggregation, to provide device level redundancy protecting and flow load.In the network topology of MLAG technology, in a domain MLAG Comprising two pairing network equipments, in such network topology, if any network is set in two pairing network equipments in the domain MLAG Standby upper MLAG process is restarted, how to realize in MLAG process restarting process, by the service traffics of the network equipment Uninterrupted forwarding is a urgent problem to be solved.

Summary of the invention

The present invention provides a kind of Graceful Restart method, equipment and systems, to solve any network equipment in the domain MLAG MLAG process restart after, the forwarding problems of service traffics.

In order to achieve the above object, in a first aspect, the embodiment of the invention provides a kind of Graceful Restart method, the method Include:

After the striding equipment link aggregation group MLAG process of local terminal network equipment is restarted, load MLAG configuration, by this equipment The initial port state recording of the port link aggregation group LAG is into interim table；Wherein, the interim table is for recording the port LAG Port status information, a port LAG corresponding list item in the interim table；

Negotiation packet is sent to the peer network device in the place domain MLAG to match to re-establish with the peer network device To relationship；

The local terminal network equipment starting timer calculates the LAG with the peer network device synchronisation message The current port status in port, and update into the interim table；

If the timer expiry, the local terminal network equipment is by the corresponding list item in the port LAG in the interim table and originally The corresponding list item in the port LAG is compared in the external setting database of equipment, to determine whether that the hardware for updating this equipment turns Send out plane and the external setting database；Wherein, MLAG process is had recorded to the hardware in the external setting database The port status information for all ports LAG that Forwarding plane issues.

Second aspect, the embodiment of the invention provides a kind of equipment of Graceful Restart, the equipment includes configuration module, hair Module, receiving module, comparison module and update module are sent,

The configuration module, after the striding equipment link aggregation group MLAG process for this equipment is restarted, load MLAG configuration, By the initial port state recording of the port link aggregation group LAG of this equipment into interim table；Wherein, the interim table is for remembering Record the port status information of the port LAG, a port LAG corresponding list item in the interim table；

The sending module, for the peer network device in the place domain MLAG send negotiation packet with the opposite end net Network equipment re-establishes pairing relationship；

The configuration module is also used to start timer；

The sending module is also used to send sync message to the peer network device；

The receiving module for calculating the current port status in the port LAG, and is updated into interim table；

The comparison module, if being used for the timer expiry, by the corresponding list item in the port LAG in the interim table and this The corresponding list item in the port LAG is compared in the external setting database of equipment；

The update module is used to determine whether to update the hardware Forwarding plane of this equipment and the external setting data Library；Wherein, all ports LAG that MLAG process is issued to the hardware Forwarding plane are had recorded in the external setting database Port status information.

The third aspect, the embodiment of the invention provides a kind of system of Graceful Restart, the system includes at least local terminal net It is poly- that the same striding equipment link is added in network equipment and peer network device, the local terminal network equipment and the peer network device The domain MLAG, the local terminal network equipment or the peer network device are combined using equipment described in second aspect.

Method, equipment and the system of a kind of Graceful Restart provided in an embodiment of the present invention, in MLAG process restarting process, Only the current port status in the calculated port LAG is recorded in interim table, at this time and hardware Forwarding plane is not provided with, keeps away The some intermediate transitory states exempted from convergence process have an impact service traffics, realize the uninterrupted of service traffics and turn Hair.It is current by the port LAG for changing originating port state in MLAG process restarting process after MLAG process is restarted and stablized Port status information update to hardware Forwarding plane.If after MLAG process is restarted, the port status of the port LAG does not change Become, then without updating hardware Forwarding plane, avoids overhead caused by resetting hardware Forwarding plane and cutout risk.

Detailed description of the invention

In order to illustrate the technical solution of the embodiments of the present invention more clearly, below will be in embodiment or description of the prior art Required attached drawing is briefly described, it should be apparent that, the accompanying drawings in the following description is only some realities of the invention Example is applied, it for those of ordinary skill in the art, without creative efforts, can also be according to these attached drawings Obtain other attached drawings.

Fig. 1 is a kind of method flow diagram of Graceful Restart provided in an embodiment of the present invention；

Fig. 2 is a kind of equipment schematic diagram of Graceful Restart provided in an embodiment of the present invention；

Fig. 3 is a kind of network topological diagram of exemplary MLAG technical application；

Fig. 4 is a kind of network topological diagram of exemplary MLAG technical application；

Fig. 5 is a kind of system schematic of Graceful Restart provided in an embodiment of the present invention.

Specific embodiment

Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, complete Site preparation description, it is clear that embodiment as described herein is only a part of the embodiments of the present invention, rather than whole implementation Example.Based on the embodiments of the present invention, obtained by those of ordinary skill in the art without making creative efforts Every other embodiment, shall fall within the protection scope of the present invention.

The system architecture and business scenario of description of the embodiment of the present invention are to more clearly illustrate implementation of the present invention The technical solution of example, does not constitute the restriction for technical solution provided in an embodiment of the present invention, those of ordinary skill in the art It is found that technical solution provided in an embodiment of the present invention is for similar with the differentiation of system architecture and the appearance of new business scene The technical issues of, it is equally applicable.

The above method is described in detail combined with specific embodiments below.

Striding equipment link aggregation group MLAG technology be to link aggregation group (Link Aggregation Group, referred to as: LAG) the supplement of technology can be realized the link aggregation of striding equipment, in the practical application scene of MLAG technology, it will usually encounter The case where MLAG process of a certain network equipment is restarted in two pairing network equipments in the domain MLAG, such as MLAG version It updates, needs to close the MLAG process of legacy version at this time and enable the MLAG process or equipment debugging occasion needs of new version It is artificial MLAG process is restarted or MLAG process exception after be restarted automatically.It should be strongly noted that of the invention real It applies in example, the active and standby master control processing unit (Main Process Unit, abbreviation MPU) of dual master control equipment needs to close when switching MLAG process on primary MPU and process the restarting similar to MLAG process for starting MLAG process on spare MPU, can also answer With the scheme provided in an embodiment of the present invention for solving to guarantee Graceful Restart in MLAG process restarting process.

The embodiment of the invention provides a kind of method of Graceful Restart, this method is used to solve the application in MLAG technology In, after the MLAG processes in two pairing network equipments on any network equipment are restarted, the forwarding problems of service traffics, due to In the embodiment of the present invention, two pairing network equipments can be realized excellent using Graceful Restart method provided in an embodiment of the present invention It is refined to restart, here only it is exemplary with wherein network equipment (local terminal network equipment is chosen here to be illustrated, it is clear that, " this End " and " opposite end " belong to relative concept, do not form the restriction to the embodiment of the present invention) MLAG process restart for into Row is described in detail.

In embodiments of the present invention, when local terminal network equipment operates normally, the MLAG process of local terminal network equipment passes through Peer-Link interacts negotiation packet with the peer network device in the place domain MLAG, is closed with establishing pairing with the peer network device System, and by with peer network device synchronisation (SYNC) message, to calculate the end of the port LAG of local terminal network equipment Mouth state, and call driving interface that the port status of the port LAG is updated to the hardware Forwarding plane to this equipment；Meanwhile by LAG The port status of port is recorded in the external setting database of this equipment.Here the port status of the port LAG is updated to this The port status of the port LAG, is as issued in the hardware chip of this equipment by the hardware Forwarding plane of equipment.In the present invention In embodiment, comprising at least one LAG, (LAG here can also be stated as in some cases in a domain MLAG MLAG), comprising two ports LAG, (port LAG here, is the concept of aggregation port, and port LAG can be in a LAG It is polymerized by multiple physical member ports), the two ports LAG are located at local terminal network equipment in the domain MLAG and right It holds on the network equipment.

In embodiments of the present invention, when the MLAG process of local terminal network equipment starts for the first time, an externally setting can be established Database, database purchase is externally arranged in Installed System Memory database in this, Installed System Memory database independently of each business into Journey (such as MLAG process) and exist, for each business process store information.In the external setting database of the embodiment of the present invention Port status of the MLAG process to the port all LAG set by hardware Forwarding plane is had recorded, hardware forwarding is considered as One image of plane.In the active and standby MPU system of dual master control equipment, the Installed System Memory database of primary MPU is with spare MPU's It is synchronous to will do it data between Installed System Memory database, therefore, in active and standby MPU switching, the MLAG process of spare MPU can also be answered With the method for Graceful Restart provided in an embodiment of the present invention.One port LAG corresponding list item in externally setting database, The LAG port numbers comprising the port LAG are removed in every list item, enabled state, isolation, the Peer-Link port numbers of isolation, are turned Outside the fields such as hair-like state, also comprising verification and and whether effective field.Wherein, checksum field is to enabled state, isolation What state, the Peer-Link port numbers of isolation and forwarding state were verified and were calculated, specific verification and calculating side Formula does not limit here, such as can be the cumulative summation to the binary string of above-mentioned field, perhaps can be CRC or MD5 The checksum algorithms such as calculating.Obvious, other fields in list item can also be also added to school according to the difference of application scenarios In testing and calculating, exhaustion is not done here.

In embodiments of the present invention, when the MLAG process in local terminal network equipment operates normally, the local terminal network equipment period The port status of all ports LAG by this equipment of property is synchronized to peer network device, alternatively, in local terminal network equipment When the port status of the port LAG changes, the new port status of the port LAG is synchronized to pair immediately by sync message The network equipment is held, allows peer network device that can know the current port status in the port LAG of local terminal network equipment in time.Equally , the port status of all ports LAG of this equipment also periodically can be synchronized to local terminal network equipment by peer network device, Alternatively, when the port status in the port LAG of peer network device changes, by sync message by the new of the port LAG Port status be synchronized to local terminal network equipment immediately, allow local terminal network equipment that can know the LAG of peer network device in time The current port status in port.In embodiments of the present invention, if local terminal network equipment receives peer network device and periodically sends out The sync message sent, and judge that the port status of the port LAG of the peer network device carried in the sync message changes, Then the port status current according to the port LAG of peer network device in the sync message is set in this equipment with the correspondent network The port status that the standby port LAG belongs to the port LAG of same LAG is updated, and calls driving interface will be in this equipment The current port status in the port LAG is updated to hardware Forwarding plane；Meanwhile the current port status in the port LAG being recorded Externally in setting database in the corresponding list item in the port LAG, and calculate the corresponding list item in the port LAG verification and, by this The corresponding list item in the port LAG whether effective field is set to effective True.If local terminal network equipment receives peer network device The sync message of periodicity sending, and judge the port shape of the port LAG of the peer network device carried in the sync message State is unchanged, then is not necessarily to update the port status of the port LAG in this equipment, since the port status of the port LAG does not change, Then without updating hardware Forwarding plane, also just need to update externally setting database.

As shown in Figure 1, a kind of method of Graceful Restart provided in an embodiment of the present invention, comprising:

After step 101, the MLAG process of local terminal network equipment are restarted, load MLAG configuration, by the port LAG of this equipment Initial port state recording is into interim table；Wherein, interim table is used to record the port status information of the port LAG, an end LAG Mouth corresponding list item in the interim table.In embodiments of the present invention, it after the MLAG process initiation of local terminal network equipment, builds An interim table is found, which does not work when MLAG process operates normally, only act as in MLAG process restarting process With.In MLAG process restarting process, the port LAG is current in this equipment for recording in MLAG process restarting process for the interim table Port status, a port LAG corresponding list item in the interim table；In the interim table without whether effective field, other Field is identical with external setting database, i.e., includes the LAG port numbers of the port LAG in every list item in interim table, enables State, isolation, Peer-Link port numbers, forwarding state and the checksum field of isolation, wherein checksum field is Enabled state, isolation, the Peer-Link port numbers of isolation and forwarding state are verified and be calculated, is had The verification and calculation of body, do not limit here, such as can be the cumulative summation to the binary string of above-mentioned field, Huo Zheke To be the checksum algorithms such as CRC or MD5 calculating.It should be noted that interim table and the verification that externally setting database uses It is identical with algorithm needs.

In embodiments of the present invention, the port status of the port LAG includes enabled state, isolation and forwarding state, In, enabled state includes being not enabled on Disabled state and enabled Enabled state, the port LAG in Disabled state It is not involved in physics negotiation, link state Down；The port LAG and access device in Enabled state are assisted by physics Shang Hou, link state can be Up.Isolation includes isolation Isolated state and non-isolated Unisolated state, is in The LAG port blocking of Isolated state is forwarded from the flow of Peer-Link to the port LAG；In Unisolated shape The port LAG of state allows the flow from Peer-Link to forward to the port LAG.Forwarding state includes obstruction Blocked state With forwarding Forwarding state, the port LAG in Blocked state is unable to converting flow；In Forwarding state The port LAG can with converting flow, but if in Forwarding state the port LAG isolation be Isolated shape State then still forbids forwarding the flow from Peer-Link, can forward other flows, such as the flow from access device.

When initial, the enabled state of the port LAG is Disabled state；If the pairing relationship of pairing LA Management Room is built Vertical, then the enabled state of the port LAG is from Disabled state transition to Enabled state；If matching the pairing of LA Management Room Relationship keep-alive failure, then the enabled state of the port LAG is from Enabled state transition to Disabled state.

When initial, the isolation of the port LAG is Isolated state；If belonging to another port LAG in a LAG Link state be Down, then the isolation of the port LAG is from Isolated state transition to Unisolated state；If same The link state for belonging to another port LAG in a LAG is Up, then the isolation of the port LAG is from Unisolated shape State moves to Isolated state.

When initial, the forwarding state of the port LAG is Blocked state；If the link state of the port LAG is Up, and Belong to another port LAG in a LAG isolation be Isolated state, then the forwarding state of the port LAG from Blocked state transition is to Forwarding state；If the link state of the port LAG is Down, or belongs to a LAG In the isolation of another port LAG be Unisolated state, then the forwarding state of the port LAG is from Forwarding shape State moves to Blocked state.

In embodiments of the present invention, it in the MLAG process restarting process of local terminal network equipment, is set without closing the network Standby all ports LAG, but maintain hardware Forwarding plane constant, i.e., if before MLAG process restarts, the hardware shape of the port LAG State is in forwarding state, then in MLAG process restarting process, the hardware state of the port LAG still maintains forwarding state, because Without will lead to flow interrupt, the uninterrupted forwarding of service traffics is realized.

Step 102, to the peer network device in the place domain MLAG send negotiation packet with the peer network device again Establish pairing relationship；Wherein, negotiation packet here can be heartbeat Heartbeat message or hello packet of shaking hands, can also To be other negotiation packets.

After the peer network device in local terminal network equipment Yu the domain place MLAG re-establishes pairing relationship, starting timing Device.After the time-out time of the timer indicates that MLAG process restarts and re-establishes pairing relationship, the end LAG of this equipment is calculated The maximum duration of the current port status of mouth.The time-out time of timer customized can be arranged, and such as can choose empirical value, such as 60 seconds.

In embodiments of the present invention, the peer network device in local terminal network equipment Yu the domain place MLAG re-establishes pairing After relationship, the enabled state of the port LAG of local terminal network equipment becomes Enabled state, is recorded in interim table, and pass through Negotiate with the physics of third party's access device, after the link state of the port LAG of local terminal network equipment all becomes Up, local terminal network New link state is synchronized to peer network device by equipment.

Step 103, starting timer calculate the current port shape in the port LAG with peer network device synchronisation message State, and update into interim table.

In this step, with peer network device synchronisation message, the current port status in the port LAG is calculated, and more Newly into the interim table, specifically include:

Local terminal network equipment carries the current link state in the port LAG of this equipment and isolation in sync message In, it is sent to peer network device；

Peer network device is arranged in this equipment according to the current link state in the port LAG to be belonged to together with the port LAG The current isolation in the port LAG of one LAG；

The peer network device isolation current according to the port LAG, is arranged in this equipment and belongs to together with the port LAG The current forwarding state in the port LAG of one LAG；

Peer network device link state and isolation that the port LAG for belonging to same LAG with the port LAG is current It carries in sync message, is sent to local terminal network equipment；In this step, can be periodically will be with for peer network device The port LAG belongs to the current link state in the port LAG of same LAG and isolation carrying is sent to this in sync message The network equipment is held, when being also possible to the port status current in the port LAG for belonging to same LAG with the port LAG and changing, Actively the current link state in the port LAG for belonging to same LAG with the port LAG and isolation are carried in sync message It is sent to local terminal network equipment.

Local terminal network equipment is according to the port LAG for belonging to same LAG on peer network device with the port LAG of this equipment The current isolation in the port LAG of this equipment is arranged in current link state；

Local terminal network equipment is according to the port LAG for belonging to same LAG on peer network device with the port LAG of this equipment The current forwarding state in the port LAG of this equipment is arranged in current isolation；

The current isolation in the port LAG and forwarding state are recorded in the interim table local terminal network equipment In the corresponding list item in the port LAG, and calculate the corresponding list item in the port LAG verification and.

In embodiments of the present invention, in the MLAG process restarting process of local terminal network equipment, only by the calculated end LAG Mouthful current port status is recorded in interim table, and calculate verification and.Even if the current end in the calculated port LAG at this time Mouthful state has occurred and that changes, also never calls driving interface update hardware Forwarding plane, also not compared with before MLAG process is restarted It is recorded in externally setting database.The current port status in the calculated port LAG is not updated to hardware to forward herein and be put down Face, some intermediate transitory states avoided in convergence process have an impact service traffics, realize effective guarantee MLAG process In restarting process, the uninterrupted forwarding of service traffics.

If step 104, timer expiry, local terminal network equipment is by the corresponding list item in the port LAG in interim table and this equipment External setting database in the corresponding list item in the port LAG be compared, it is flat with the hardware forwarding for determining whether to update this equipment Face and externally setting database；Wherein, the institute that MLAG process is issued to hardware Forwarding plane externally is had recorded in setting database There is the port status information of the port LAG.

In this step, reduce comparing expense by verification and mechanism (this there are hundreds and thousands of a ports LAG When it is extremely obvious).If after MLAG process is restarted, the port status of the port LAG does not change, then end LAG in interim table Mouthful corresponding list item and the verification of the corresponding list item in the port LAG in externally setting database and identical, at this time without updating firmly Part Forwarding plane；If after MLAG process is restarted, the port status of the port LAG changes, then the port LAG is corresponding in interim table List item list item corresponding with the port LAG in external setting database verification and difference, originating port state is changed at this time Hardware Forwarding plane is wanted in the new port status update of the port LAG of change, i.e., is issued to the new port status of the port LAG firmly In part chip.Avoid overhead caused by resetting hardware Forwarding plane and cutout risk.In fact, more in number big absolutely Under occasion, MLAG process, which restarts front and back network topology, all be will not change, then MLAG process restarts the calculated port LAG in front and back Port status is identical, and also just without any variation, network flow is not also just affected hardware Forwarding plane, realizes really Uninterrupted forwarding.

In this step, local terminal network equipment is by the external setting of the corresponding list item in the port LAG and this equipment in interim table The corresponding list item in the port LAG is compared in database, to determine whether to update the hardware Forwarding plane of this equipment and to peripheral hardware Database is set, is specifically included:

Local terminal network equipment by the corresponding list item in the ports LAG all in external setting database whether effective field is set to In vain, i.e., initially think that all list items being externally arranged in database are all invalid.

The interim table is traversed, if network topology does not change in the MLAG process restarting process of local terminal network equipment, and The port LAG in MLAG configuration does not also change.Even there are corresponding first list items in interim table for the port LAG, right There are corresponding second list item in outer setting database, and the first list item and the verification of the second list item and identical, by second table In whether effective field is set to effectively；

If the port LAG in interim table there are corresponding first list item, there are corresponding the in externally setting database Two list items, and the verification and difference of the first list item and the second list item, the then port status current according to the port LAG in the first list item Update hardware Forwarding plane, and the port status and verification and update second list item current according to the port LAG in the first list item In the current port status in the port LAG and verification and after, by the second list item whether effective field is set to effectively.At this In step, it can also further determine which port status of the specifically port LAG in the first list item and the second list item is different It causes, and only updates to hardware to forward by that one or more port status inconsistent in the first list item and in the second list item and put down Face, to reduce the operation overhead to hardware Forwarding plane.

It is exemplary, every list item LAG-Port-i (i is customized port numbers) in interim table is traversed, is judged to peripheral hardware It sets with the presence or absence of the corresponding list item of the LAG-Port-i in database, if externally there are this LAG-Port-i pairs in setting database The list item answered, and verify and identical, show that the port status of the port LAG does not change, will externally be arranged in database should In the corresponding list item of LAG-Port-i whether effective field is updated to True.If externally there are the LAG- in setting database The corresponding list item of Port-i, but verification and difference, show that the port status of the port LAG has occurred and that change, will be in interim table Port status in the corresponding list item of the LAG-Port-i calls driving interface to update to hardware Forwarding plane, and will be in interim table Port status in the corresponding list item of the LAG-Port-i updates the corresponding table of the LAG-Port-i into external setting database Xiang Zhong, at the same update the verification in externally setting database in the corresponding list item of the LAG-Port-i and, and will whether effective word Section is updated to True.

Optionally, if when the MLAG process on the network equipment is restarted, there is increase in the port LAG in MLAG configuration, i.e., If the port LAG is in interim table, there are corresponding first list items, corresponding list item are not present in externally setting database, then foundation The port status that the port LAG is current in first list item updates hardware Forwarding plane, and increases one newly in externally setting database Third list item corresponding with the port LAG, the port status and verification and update current according to the port LAG in the first list item In third list item the current port status in the port LAG and verification and after, by third list item whether effective field is set to Effectively.

If the port LAG in MLAG configuration is reduced, i.e., traversal is completed when the MLAG process on the network equipment is restarted Afterwards, it if having whether effective field is the 4th invalid list item in the external setting database, is deleted from hardware Forwarding plane The 4th list item is deleted except the port status of the port LAG in the 4th list item, and from the external setting database.

It is exemplary, every list item LAG-Port-i (i is customized port numbers) in interim table is traversed, is judged to peripheral hardware It sets with the presence or absence of the corresponding list item of the LAG-Port-i in database, if the LAG-Port-i externally is not present in setting database Corresponding list item then calls the port status of the LAG-Port-i of the corresponding list item record of the LAG-Port-i in interim table Driving interface is arranged to hardware Forwarding plane, and increases the corresponding table of the LAG-Port-i newly in externally setting database , the corresponding list item information of the LAG-Port-i in interim table is updated to the LAG- increased newly into external setting database In the corresponding list item of Port-i, while calculating in the corresponding list item of the LAG-Port-i increased newly in externally setting database Verification and, will whether effective field be set to True.

After the completion of traversal, if externally setting database in exist whether effective field be still invalid False list item, will Externally whether effective field is all list items of False in setting database, and driving interface is called to delete from hardware Forwarding plane Whether effective field be False the corresponding port LAG of list item port status, and delete externally setting database in whether have Imitate all list items that field is False.

In embodiments of the present invention, the traversal to interim table is completed, and has updated hardware Forwarding plane and externally setting number Behind library, interim table can be emptied or delete, MLAG process restarts end.

As a kind of special circumstances of the embodiment of the present invention, if after the MLAG process of local terminal network equipment is restarted, new MLAG Process can not re-establish pairing relationship with peer network device, then can not start timer after pairing relationship foundation, at this point, The port status of the port LAG of local terminal network equipment is original state, if needed at this time by the initial port state of the port LAG Hardware Forwarding plane is updated, can be arranged before load MLAG configuration after the MLAG process of local terminal network equipment is restarted One timer, the time-out time of the timer are greater than the time-out time of the timer started after pairing relationship is established；The timing The time-out time of device customized can be arranged, and such as can choose empirical value, and such as 300 seconds.Therefore, in embodiments of the present invention, if New MLAG process cannot re-establish pairing relationship, then after the timer expiry started before load MLAG configuration, foundation is faced When table in the port LAG initial port state, it is determined whether update hardware Forwarding plane and externally setting database.

It in embodiments of the present invention, can be periodically through Peer-Link and opposite end net when local terminal network equipment operates normally Network equipment interaction heartbeat message carries out neighbor keep-alive, includes keep-alive time field in heartbeat message, for indicating expectation opposite end net The keep-alive time of network equipment, the keep-alive time customized can be arranged.Before the MLAG process of local terminal network equipment is restarted, Ke Yitong The Graceful Restart function that MLAG process is opened in configuration is crossed, that is, the keep-alive time of heartbeat message, the keep-alive time being arranged at this time are set The keep-alive time when network equipment operates normally should be greater than, avoid local terminal network equipment right in MLAG process restarting process The end network equipment is mistakenly considered aging.Exemplary, keep-alive time when local terminal network equipment A is operated normally is 15 seconds, then opposite end Network equipment B interior does not receive heartbeat message for 15 seconds, then it is assumed that network equipment A aging, therefore can be set in network Before the MLAG process of standby A is restarted, set the keep-alive time to 150 seconds, network equipment B is continuing not receive the heart in 150 seconds Message is jumped, just will be considered that network equipment A aging.The keep-alive time is lengthened to avoid in the MLAG process of local terminal network equipment A It is mistakenly considered in restarting process by peer network device B weathered.

A kind of method of Graceful Restart provided in an embodiment of the present invention will only calculate in MLAG process restarting process The current port status in the port LAG be recorded in interim table, at this time and be not provided with hardware Forwarding plane, avoid and restrained Some intermediate transitory states in journey have an impact service traffics, realize the uninterrupted forwarding of service traffics.MLAG into After Cheng Chongqi stablizes, pass through the current port status in the port LAG for changing originating port state in MLAG process restarting process Information update is to hardware Forwarding plane.If after MLAG process is restarted, the port status of the port LAG does not change, then it is not necessarily to Hardware Forwarding plane is updated, overhead caused by resetting hardware Forwarding plane and cutout risk are avoided.

It is exemplary, as shown in Fig. 2, being a kind of network topological diagram of exemplary MLAG technical application, network equipment A and network Equipment B forms the domain MLAG, and access device D1 and access device D2 dual homed access the domain MLAG, form two striding equipment link aggregations Group LAG1 and LAG2, LAG port of the LAG1 on network equipment A are Port-A1, and the port LAG on network equipment B is Port-B1；LAG port of the LAG2 on network equipment A is Port-A2, and the port LAG on network equipment B is Port-B2； It there are direct-connected aggregated links Peer-Link, Port-APL is the Peer- of network equipment A between network equipment A and network equipment B The port Link, Port-BPL are the ports Peer-Link of network equipment B.When initial, Port-A1, Port-A2, Port-B1 with And the enabled state of Port-B2 is all Disabled state, isolation is all Isolated state, and forwarding state is all Blocked state.After MLAG process initiation, network equipment A and network equipment B pass through interaction negotiation packet, judge the domain MLAG ID, After the parameters such as virtual mac address are consistent, the pairing relationship of network equipment A and network equipment B are established, Port-A1, Port-A2, The enabled state of Port-B1 and Port-B2 becomes Enabled state.By the object with access device D1 and access device D2 Reason is negotiated, and the link state of Port-A1, Port-A2, Port-B1 and Port-B2 all become Up, and network equipment A and network are set New link state is synchronized to opposite end by standby B.Specifically, network equipment A is actively current to the synchronous port LAG network equipment B Port status situation, be implemented as follows:

Network equipment A carries the link state (Up) of Port-A1 and Port-A2 and isolation (Isolated) Network equipment B is sent in SYNC message, after network equipment B receives SYNC message, according to Port-A1 in the SYNC message and The link state (Up) of Port-A2, remains Isolated state for the isolation of Port-B1 and Port-B2, according to this The isolation (Isolated) of Port-A1 and Port-A2, the forwarding state of Port-B1 and Port-B2 are set in SYNC message It is set to Forwarding state.

Similarly, network equipment B is actively to the situation of the current port status in the network equipment A step port LAG, specific implementation It is as follows:

Network equipment B carries the link state (Up) of Port-B1 and Port-B2 and isolation (Isolated) SYNC message is sent to network equipment A, after network equipment A receives SYNC message, according to Port-B1 in the SYNC message and The link state (Up) of Port-B2, remains Isolated state for the isolation of Port-A1 and Port-A2, according to this The isolation (Isolated) of Port-B1 and Port-B2, the forwarding state of Port-A1 and Port-A2 are set in SYNC message It is set to Forwarding state.

In embodiments of the present invention, respective hardware Forwarding plane and right is all corresponding on network equipment A and network equipment B Outer setting database, when MLAG process operates normally, after Port-A1, Port-A2 current port status is provided with, network The current port status of Port-A1, Port-A2 is issued to the hardware Forwarding plane of this equipment by equipment A calling driving interface；It will Port-A1, Port-A2 current port status is recorded in the external setting database of this equipment, and updates externally setting number According to the corresponding list item of Port-A1, Port-A2 in library verification and.Likewise, Port-B1, Port-B2 current port status After being provided with, network equipment B calls driving interface to be issued to the current port status of Port-B1 and Port-B2 and originally sets Standby hardware Forwarding plane；The current port status of Port-B1, Port-B2 is recorded to the external setting database of this equipment In, and update externally setting database in the corresponding list item of Port-B1, Port-B2 verification and.

We assume here that the MLAG process needs on network equipment A are restarted due to MLAG version updating, at this point it is possible to It sets the keep-alive time field of Heartbeat message to 150 seconds, is greater than when the network equipment operates normally the keep-alive time 15 seconds, After MLAG process on network equipment A is restarted, the external setting database on network equipment A is still had, because of externally setting Database purchase in Installed System Memory database, deposit independently of each business process (such as MLAG process) by Installed System Memory database So externally setting database will not restart because of MLAG process and be disappeared.

After MLAG process on network equipment A is restarted, load MLAG configuration creates interim table, LAG port status is arranged For original state, (enabled state of Port-A1 and Port-A2 are all Disabled state, and isolation is all Isolated shape State, forwarding state are all Blocked state), it is only recorded in interim table, never calls driving interface and issue hardware Forwarding plane, Negotiation packet, which is interacted, with network equipment B re-establishes pairing relationship.Pairing relationship establish after, on network equipment A new MLAG into Cheng Qidong timer interacts SYNC message with network equipment B, the port status of each port LAG is calculated, in timer expiry Before, the setting of port status is only recorded in interim table in network equipment A, and updates checksum field, never calls driving interface Hardware Forwarding plane is issued, is not also recorded in externally setting database.

Specifically, new MLAG process initiation timer T1 (T1=60 seconds), network equipment A will after pairing relationship is established Enabled state is arranged in the enabled state of Port-A1 and Port-A2, and is recorded in interim table.Before MLAG process is restarted, The link state of Port-A1 and Port-A2 has been Up.Network equipment A is by the link state (Up) of Port-A1 and Port-A2 Network equipment B is sent in SYNC message with isolation (Isolated) carrying, after network equipment B receives SYNC message, According to the link state (Up) of Port-A1 and Port-A2 in the SYNC message, the isolation of Port-B1 and Port-B2 is protected It holds as Isolated state, according to the isolation (Isolated) of Port-A1 and Port-A2 in the SYNC message, by Port- The forwarding state of B1 and Port-B2 remains Forwarding state.

Network equipment B carries the link state (Up) of Port-B1 and Port-B2 and isolation (Isolated) SYNC message is sent to network equipment A, after network equipment A receives SYNC message, according to Port-B1 in the SYNC message and The link state (Up) of Port-B2, remains Isolated state for the isolation of Port-A1 and Port-A2, according to this The isolation (Isolated) of Port-B1 and Port-B2, the forwarding state of Port-A1 and Port-A2 are set in SYNC message It is set to Forwarding state, and is recorded in interim table.

In embodiments of the present invention, after restarting before being restarted due to MLAG process with MLAG process, the Port- of network equipment A After the port status of A1 and Port-A2 does not change, therefore MLAG process is restarted, recorded in the interim table of network equipment A Port-A1 and Port-A2 in the external setting database of Port-A1 and Port-A2 current port status and network equipment A Port status is identical, therefore interim table list item corresponding with calculated Port-A1 and Port-A2 in external setting database It verifies and also identical.

Timer T1 time-out, by the corresponding list item of Port-A1 and Port-A2 in the external setting database of network equipment A In whether effective field is all set to False, new MLAG process traverses every list item in interim table, Port-A1 and Port- There is corresponding list item in interim table and externally setting database in A2, and verify and identical, i.e., after MLAG process is restarted, The port status of Port-A1 and Port-A2 does not change, then it is corresponding that Port-A1 and Port-A2 in database will externally be arranged List item in whether effective field is set to True, do not update hardware Forwarding plane at this time.After the completion of traversal, on network equipment A External setting database in be not present whether effective field be False list item, without separately processing.On network equipment A All list items in the new interim table of MLAG process-kill complete MLAG process Graceful Restart.

In above-mentioned MLAG process restarting process, since MLAG network topology and configuration are unchanged, MLAG process weight Qi Hou, the port status of each port LAG that new MLAG process is calculated and MLAG process restart before each port LAG Port status be identical, so verification and be also it is identical, therefore do not need update hardware Forwarding plane, so hardware turn Hair plane is not any change yet, and network flow would not also be affected in entire MLAG process restarting process, realize The uninterrupted forwarding of service traffics.

As shown in Figure 3, it is assumed that in the MLAG process restarting process of network equipment A, network equipment B and access device D1 it Between link disconnected due to failure, the link state of Port-B1 becomes Down, sets the forwarding state of Port-B1 to Blocked。

Specifically, new MLAG process initiation timer T1 (T1=60 seconds), network equipment A will after pairing relationship is established Enabled state is arranged in the enabled state of Port-A1 and Port-A2, and is recorded in interim table.Before MLAG process is restarted, The link state of Port-A1 and Port-A2 has been Up.Network equipment A is by the link state (Up) of Port-A1 and Port-A2 Network equipment B is sent in SYNC message with isolation (Isolated) carrying, after network equipment B receives SYNC message, According to the link state (Up) of Port-A1 and Port-A2 in the SYNC message, the isolation of Port-B1 and Port-B2 is protected It holds as Isolated state, according to Port-A1 isolation (Isolated) in the SYNC message, by the forwarding shape of Port-B1 State remains Blocked state (because the link state of Port-B1 is Down), is isolated according to Port-A2 in the SYNC message The forwarding state of Port-B2 is remained Forwarding state by state (Isolated).

Network equipment B is by the link of the link state (Down) of Port-B1 and isolation (Isolated) and Port-B2 State (Up) and isolation (Isolated), which are carried, is sent to network equipment A in SYNC message, and network equipment A receives SYNC report Wen Hou sets Port-A1 isolation to according to the link state (Down) of Port-B1 in the SYNC message Unisolated state, and being recorded in interim table, according to the isolation (Isolated) of Port-B1 in the SYNC message, Forwarding state is set by Port-A1 forwarding state, and is recorded in interim table, according to Port- in the SYNC message The link state (Up) of B2, remains Isolated state for Port-A2 isolation, according to Port-B2 in the SYNC message Isolation (Isolated), set Forwarding state for Port-A2 forwarding state, and be recorded in interim table.

In embodiments of the present invention, due in the MLAG process restarting process of network equipment A, the port status of Port-A2 Do not change, therefore after MLAG process is restarted, the Port-A2 recorded in the interim table of network equipment A current port status with The port status of Port-A2 is identical in the external setting database of network equipment A, therefore, interim table and externally setting database In the verification of the corresponding list item of calculated Port-A2 and also identical.But the port status of Port-A1 changes, therefore After MLAG process is restarted, pair of the Port-A1 recorded in the interim table of network equipment A current port status and network equipment A The port status of Port-A1 is different in outer setting database, therefore, calculated in interim table and externally setting database The verification of the corresponding list item of Port-A1 and also difference.

Timer T1 time-out, by the corresponding list item of Port-A1 and Port-A2 in the external setting database of network equipment A In whether effective field is all set to False, new MLAG process traverses every list item in interim table, and Port-A1 is interim There is corresponding list item, and verification and difference in table and externally setting database, by the corresponding list item of Port-A1 in interim table In the current port status of Port-A1 call driving interface to update to hardware Forwarding plane, it should be noted that due to here Can be by further it was found that Port-A1 only has isolation to change, thus it can be only current by Port-A1 Isolation is updated to hardware Forwarding plane, and Port-A1 current port status is updated into external setting database In the corresponding list item of Port-A1, and calculate verification and, will be in the corresponding list item of Port-A1 in setting database externally No effective field is set to True.

There is corresponding list item in interim table and externally setting database in Port-A2, and verify and identical, then will be right In outer setting database in the corresponding list item of Port-A2 whether effective field is set to True, at this time without update hardware forwarding Plane.After the completion of traversal, be not present in the external setting database on network equipment A whether effective field be False table , without separately processing.All list items on network equipment A in the new interim table of MLAG process-kill, complete entire MLAG into Journey Graceful Restart.

MLAG process weight in above-mentioned MLAG process restarting process, since MLAG network topology changes, on network equipment A The port status of Qi Hou, the new calculated Port-A1 of MLAG process change, and lead to calculated verification and difference, because This, needs to update the port status of Port-A1 to hardware Forwarding plane；And the new calculated Port-A2 of MLAG process Port status does not change, calculated verification and identical, it is therefore not necessary to update the port status of Port-A2 to hardware Forwarding plane.That is, if the port status of the port LAG changes in MLAG process restarting process, it is only necessary to will send out The new port status for the port LAG that raw port status changes is updated to hardware Forwarding plane, if the port status of the port LAG is not It changes, then without updating hardware Forwarding plane, ensure that the stability and reliability of hardware Forwarding plane.

As shown in figure 4, the equipment 40 includes configuration module the embodiment of the invention provides a kind of equipment of Graceful Restart 401, sending module 402, receiving module 403, comparison module 404 and update module 405,

The configuration module 401, after the striding equipment link aggregation group MLAG process for this equipment is restarted, load MLAG matches It sets, by the initial port state recording of the port link aggregation group LAG of this equipment into interim table；Wherein, the interim table is used Port status information in the record port LAG, a port LAG corresponding list item in the interim table；

The sending module 402, for the peer network device in the place domain MLAG send negotiation packet with it is described right The end network equipment re-establishes pairing relationship；

The configuration module 401, is also used to start timer；

The sending module 402 is also used to send sync message to the peer network device；

The receiving module 403 for calculating the current port status in the port LAG, and is updated into interim table；

The comparison module 404, if the timer expiry is used for, by the corresponding list item in the port LAG in the interim table List item corresponding with the port LAG in the external setting database of this equipment is compared；

The update module 405 is used to determine whether to update the hardware Forwarding plane of this equipment and the external setting number According to library；Wherein, all ends LAG that MLAG process is issued to the hardware Forwarding plane are had recorded in the external setting database The port status information of mouth.

The sending module 402, specifically for the port LAG by this equipment current link state and isolation It carries in sync message, the peer network device is sent to, so that the chain that peer network device is current according to the port LAG The current isolation in the port LAG for belonging to same LAG with the port LAG on line state setting peer network device, and according to The port LAG for belonging to same LAG with the port LAG on the current isolation setting peer network device in the port LAG is current Forwarding state；

The receiving module 403, specifically for receiving the carrying and the port LAG that the peer network device is sent After belonging to the sync message of the current link state and isolation in the port LAG of same LAG, according to this and the port LAG The current isolation in the port LAG is arranged in the current link state in the port LAG for belonging to same LAG；According to this with it is described The current forwarding state in the port LAG is arranged in the current isolation in the port LAG that the port LAG belongs to same LAG；

The receiving module 403, specifically for this is recorded in the port LAG current isolation and forwarding state In the corresponding list item in the port LAG described in the interim table of equipment, and calculate the corresponding list item in the port LAG verification and.

The comparison module 404, specifically for by the corresponding list item in all ports LAG in the external setting database Whether effective field is set in vain；The interim table is traversed, there are corresponding first if the port LAG is in the interim table List item, there are corresponding second list item in the external setting database, and first list item and second list item It verifies and identical, then triggers the update module；

The update module 405, specifically for by second list item whether effective field is set to effectively；

The comparison module 404, if being specifically also used to the port LAG, there are corresponding first tables in the interim table , there are corresponding second list item in the external setting database, and the school of first list item and second list item It tests and different, then triggers the update module 405；

The update module 405, more specifically for the port status current according to the port LAG described in first list item The new hardware Forwarding plane, and the port status and verification current according to the port LAG described in first list item and more The current port status in the port LAG described in new second list item and verification and after, by second list item whether Effective field is set to effectively.

The comparison module 404, if being specifically also used to the port LAG, in the interim table, there are corresponding first tables , corresponding list item is not present in the external setting database, then triggers the update module 405；

The update module 405 is specifically also used to the port status current according to the port LAG described in first list item Hardware Forwarding plane is updated, and increases a third list item corresponding with the port LAG newly in the external setting database, Described in the port status and verification and the update third list item current according to the port LAG described in first list item The current port status in the port LAG and verification and after, by the third list item whether effective field is set to effectively；

The update module 405, is specifically also used to after the completion of traversal, if whether exist in the external setting database has Imitating field is the 4th invalid list item, then the port status of the port LAG in the 4th list item is deleted from hardware Forwarding plane, and The 4th list item is deleted from the external setting database.

The peer network device periodically sends sync message to the local terminal network equipment.

A kind of equipment of Graceful Restart provided in an embodiment of the present invention will only calculate in MLAG process restarting process The current port status in the port LAG be recorded in interim table, at this time and be not provided with hardware Forwarding plane, avoid and restrained Some intermediate transitory states in journey have an impact service traffics, realize the uninterrupted forwarding of service traffics.MLAG into After Cheng Chongqi stablizes, pass through the current port status in the port LAG for changing originating port state in MLAG process restarting process Information update is to hardware Forwarding plane.If after MLAG process is restarted, the port status of the port LAG does not change, then it is not necessarily to Hardware Forwarding plane is updated, overhead caused by resetting hardware Forwarding plane and cutout risk are avoided.

The embodiment of the invention provides a kind of systems of Graceful Restart, as shown in figure 5, the system includes at least local terminal net Network equipment 501 and peer network device 502, the local terminal network equipment 501 are added same with the peer network device 502 The domain striding equipment link aggregation group MLAG, the local terminal network equipment 501 or the peer network device 502 are implemented using the present invention A kind of equipment for Graceful Restart that example provides.

A kind of system of Graceful Restart provided in an embodiment of the present invention will only calculate in MLAG process restarting process The current port status in the port LAG be recorded in interim table, at this time and be not provided with hardware Forwarding plane, avoid and restrained Some intermediate transitory states in journey have an impact service traffics, realize the uninterrupted forwarding of service traffics.MLAG into After Cheng Chongqi stablizes, pass through the current port shape in the port LAG for changing originating port state in MLAG process restarting process State information update is to hardware Forwarding plane.If after MLAG process is restarted, the port status of the port LAG does not change, then without Hardware Forwarding plane need to be updated, overhead caused by resetting hardware Forwarding plane and cutout risk are avoided.

In several embodiments provided by the present invention, it should be understood that disclosed system and method can pass through it Its mode is realized.For example, system embodiment described above is only schematical, for example, the division of module, only A kind of logical function partition, there may be another division manner in actual implementation, for example, multiple module or components can combine or Person is desirably integrated into another system, or some features can be ignored or not executed.

Finally, it should be noted that the above embodiments are merely illustrative of the technical solutions of the present invention, rather than its limitations；Although Present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that: it still may be used To modify the technical solutions described in the foregoing embodiments or equivalent replacement of some of the technical features； And these are modified or replaceed, it does not separate the essence of the corresponding technical solution the scope of the present invention.

Claims

1. a kind of method of Graceful Restart, which is characterized in that the described method includes:

After the striding equipment link aggregation group MLAG process of local terminal network equipment is restarted, load MLAG configuration, by the link of this equipment The initial port state recording of the port aggregation group LAG is into interim table；Wherein, the interim table is used to record the end of the port LAG Mouth status information, a port LAG corresponding list item in the interim table；

Negotiation packet is sent to the peer network device in the place domain MLAG to close to re-establish pairing with the peer network device System；

The local terminal network equipment starting timer calculates the port LAG with the peer network device synchronisation message Current port status, and update into the interim table；

If the timer expiry, the local terminal network equipment is by the corresponding list item in the port LAG in the interim table and this equipment External setting database in the corresponding list item in the port LAG be compared, it is flat with the hardware forwarding for determining whether to update this equipment Face and the external setting database；Wherein, MLAG process is had recorded in the external setting database to forward to the hardware The port status information for all ports LAG that plane issues.

2. the method according to claim 1, wherein described with the peer network device synchronisation message, The current port status in the port LAG is calculated, and is updated into the interim table, is specifically included:

The local terminal network equipment carries the current link state in the port LAG of this equipment and isolation in sync message In, it is sent to the peer network device；

The peer network device link state current according to the port LAG is arranged in this equipment and belongs to the port LAG In the current isolation in the port LAG of same LAG；

The peer network device isolation current according to the port LAG is arranged in this equipment and belongs to the port LAG In the current forwarding state in the port LAG of same LAG；

The peer network device link state and barrier-like that the port LAG for belonging to same LAG with the port LAG is current State carries in sync message, is sent to the local terminal network equipment；

The local terminal network equipment is according to the end LAG for belonging to same LAG on peer network device with the port LAG of this equipment The current isolation in the port LAG of this equipment is arranged in mouthful current link state；

The local terminal network equipment is according to the end LAG for belonging to same LAG on peer network device with the port LAG of this equipment The current forwarding state in the port LAG of this equipment is arranged in mouthful current isolation；

Institute in the interim table is recorded in the port LAG current isolation and forwarding state by the local terminal network equipment State in the corresponding list item in the port LAG, and calculate the corresponding list item in the port LAG verification and.

3. according to the method described in claim 2, it is characterized in that, the local terminal network equipment is by the end LAG in the interim table The corresponding list item of mouth list item corresponding with the port LAG in the external setting database of this equipment is compared, to determine whether more The hardware Forwarding plane and the external setting database of this new equipment, specifically include:

The local terminal network equipment by the external setting database the corresponding list item in all ports LAG whether effective field It is invalid to be set to；

The interim table is traversed, if there are corresponding first list items in the interim table for the port LAG, described to peripheral hardware It sets in database there are corresponding second list item, and first list item and the verification of second list item and identical, it will be described In second list item whether effective field is set to effectively；

If there are corresponding first list items in the interim table for the port LAG, exist in the external setting database Corresponding second list item, and the verification and difference of first list item and second list item, then according in first list item The current port status in the port LAG updates hardware Forwarding plane, and current according to the port LAG described in first list item Port status and verification and update the current port status in the port LAG described in second list item and verification and after, By in second list item whether effective field is set to effectively.

4. according to the method described in claim 3, it is characterized in that, the method also includes:

If the port LAG is in the interim table, there are corresponding first list items, are not present in the external setting database Corresponding list item, then the port status current according to the port LAG described in first list item updates hardware Forwarding plane, and A third list item corresponding with the port LAG is increased in the external setting database newly, according to institute in first list item It states the current port status in the port LAG and verification and updates the current port status in the port LAG described in the third list item And verification and after, by the third list item whether effective field is set to effectively.

After the completion of traversal, if existing in the external setting database, whether effective field is the 4th invalid list item, from hard Part Forwarding plane deletes the port status of the port LAG in the 4th list item, and deletes institute from the external setting database State the 4th list item.

5. a kind of equipment of Graceful Restart, which is characterized in that the equipment includes configuration module, sending module, receiving module, ratio Compared with module and update module,

The configuration module, after the striding equipment link aggregation group MLAG process for this equipment is restarted, load MLAG configuration incite somebody to action this The initial port state recording of the port link aggregation group LAG of equipment is into interim table；Wherein, the interim table is for recording The port status information of the port LAG, a port LAG corresponding list item in the interim table；

The sending module, for sending negotiation packet to the peer network device in the place domain MLAG to set with the correspondent network It is standby to re-establish pairing relationship；

The configuration module is also used to start timer；

The comparison module, if the timer expiry is used for, by the corresponding list item in the port LAG in the interim table and this equipment External setting database in the corresponding list item in the port LAG be compared；

The update module is used to determine whether to update the hardware Forwarding plane of this equipment and the external setting database；Its In, the end for all ports LAG that MLAG process is issued to the hardware Forwarding plane is had recorded in the external setting database Mouth status information.

6. equipment according to claim 5, which is characterized in that

The sending module is carried specifically for the current link state in the port LAG by this equipment and isolation In sync message, it is sent to the peer network device；

The receiving module belongs to together specifically for receiving the carrying that the peer network device is sent with the port LAG After the sync message of the port LAG of one LAG current link state and isolation, belonged to together according to this with the port LAG The current isolation in the port LAG is arranged in the current link state in the port LAG of one LAG；According to this and the port LAG The current forwarding state in the port LAG is arranged in the current isolation in the port LAG for belonging to same LAG；

The receiving module, specifically for this equipment is recorded in the port LAG current isolation and forwarding state In the corresponding list item in the port LAG described in interim table, and calculate the corresponding list item in the port LAG verification and.

7. equipment according to claim 6, which is characterized in that

The comparison module, specifically for whether all corresponding list items in the port LAG in the external setting database have Effect field is set in vain；Traverse the interim table, if the port LAG in the interim table there are corresponding first list item, There are corresponding second list item in the external setting database, and the verification of first list item and second list item and It is identical, then trigger the update module；

The update module, specifically for by second list item whether effective field is set to effectively；

The comparison module, if being specifically also used to the port LAG, there are corresponding first list items in the interim table, in institute It states in externally setting database there are corresponding second list item, and the verification of first list item and second list item and not Together, then the update module is triggered；

The update module, specifically for described in the port status update current according to the port LAG described in first list item Hardware Forwarding plane, and described in the port status and verification and update current according to the port LAG described in first list item The current port status in the port LAG described in second list item and verification and after, by second list item whether effective word Section is set to effectively.

8. equipment according to claim 7, which is characterized in that the comparison module, if being specifically also used to the port LAG In the interim table, there are corresponding first list items, and corresponding list item is not present in the external setting database, then triggers The update module；

The update module is specifically also used to the port status current according to the port LAG described in first list item and updates firmly Part Forwarding plane, and increase a third list item corresponding with the port LAG newly in the external setting database, according to institute State the port status and verification and update the port LAG described in the third list item that the port LAG is current described in the first list item Current port status and verification and after, by the third list item whether effective field is set to effectively；

The update module, is specifically also used to after the completion of traversal, if in the external setting database exist whether effective field For the 4th invalid list item, then the port status of the port LAG in the 4th list item is deleted from hardware Forwarding plane, and from described Externally the 4th list item is deleted in setting database.

9. according to the described in any item equipment of claim 6-8, which is characterized in that the peer network device is periodically to described Local terminal network equipment sends sync message.

10. a kind of system of Graceful Restart, which is characterized in that the system includes at least local terminal network equipment and correspondent network is set It is standby, the local terminal network equipment and the same domain striding equipment link aggregation group MLAG of peer network device addition, described The network equipment or the peer network device is held to use such as the described in any item equipment of claim 5-9.