CN109873763A

CN109873763A - A kind of communication means and equipment

Info

Publication number: CN109873763A
Application number: CN201711270248.XA
Authority: CN
Inventors: 李皆明
Original assignee: Beijing Huawei Digital Technologies Co Ltd
Current assignee: Beijing Huawei Digital Technologies Co Ltd
Priority date: 2017-12-05
Filing date: 2017-12-05
Publication date: 2019-06-11
Anticipated expiration: 2037-12-05
Also published as: CN109873763B

Abstract

A kind of communication means and equipment, under the scene of the MTU for being greater than intermediate interchanger configuration in the MTU that the interface of two configuration of routers is supported, it is also possible that two router normal communications.One of communication means includes: that the first router to the second router sends at least one first probe messages, and the first probe messages encapsulate the first MTU；The first router, which determines, does not receive the first detection feedback message from the second router within the set duration, and the first detection feedback message is the feedback message of the first probe messages；First MTU is cut out the first step-length by the first router, obtains the 2nd MTU；The first router sends at least one second probe messages for encapsulating the 2nd MTU to the second router, until the first router receives detection feedback message from the second router within the set duration；The MTU that the first router is supported the 3rd MTU cut out for the last time as the first router to the transmission path between the second router.

Description

A kind of communication means and equipment

Technical field

This application involves field of communication technology more particularly to a kind of communication means and equipment.

Background technique

In now net operation, it may be communicated by Layer 2 switch network between two core routers, if two The maximum transmission unit (maximum transmission unit, MTU) that the interface of configuration of routers is supported is greater than intermediate friendship Change planes the MTU of configuration, then a router is sent to the message of another router when by intermediate interchanger, interchanger The message can be directly abandoned because that can not support the MTU of the message, cause two routers to cannot achieve communication, thus can Influence the normal normal transmission established with service message of the protocol neighbors relationship between two routers.

Summary of the invention

The embodiment of the present application provides a kind of communication means and equipment, with the MTU supported in the interface of two configuration of routers Under scene greater than the MTU of intermediate interchanger configuration, it is also possible that two router normal communications.

In a first aspect, providing a kind of communication means, this method can be executed by router, and the router for executing this method is The first router.This method comprises: the first router sends at least one first probe messages to the second router, described first Probe messages encapsulate the first MTU, and the first MTU is the MTU that the outgoing interface of the first router is supported, described first visits Text is observed and predicted for detecting whether the message that size is the first MTU can be sent to the second router；The first via It is determined by device and does not receive the first detection feedback message, the first detection feedback report from the second router within the set duration Text is the feedback message of first probe messages；First MTU is cut out the first step-length by the first router, obtains Two MTU；The first router sends at least one second probe messages for encapsulating the 2nd MTU to the second router, Until the first router receives detection feedback message from the second router in the setting duration；Described One router is using the 3rd MTU cut out for the last time as the first router to the biography between the second router The MTU that defeated path is supported.

In the embodiment of the present application, the first router in double layer network can send detection report to the second router Text, such as at least one first probe messages is first had sent, the first probe messages encapsulate the first MTU, if super in timer Constantly the first router does not receive the first detection feedback message from the second router, then the first router can cut the first MTU The first step-length is cut out, the 2nd MTU is obtained, then sends the second probe messages of the 2nd MTU of encapsulation, phase to the second router again again When in, if do not received in timer expiry detection feedback message, so that it may think that the MTU of message is excessive, then the first via by Device can reduce MTU, detect again, in this way, when the MTU of probe messages encapsulation is equal to the MTU that intermediate interchanger is supported, Probe messages can reach the second router, so that the second router can reply detection feedback message, then the first router As long as having received detection feedback message before timer expiry, it will be able to determine that current MTU is the first router and the second tunnel The MTU supported by the transmission path between device, so as to stop detecting.In this way, even if two configuration of routers The MTU that supports of interface be greater than the MTU of intermediate interchanger configuration, router can also be determined by probe messages by between device The MTU that is supported of transmission path, that is, the MTU that intermediate interchanger is supported is determined, so that message is between the routers Can physics it is reachable, guarantee the normal transmission of message, but also the protocol neighbors relationship between two routers can normally be built It is vertical.

In a possible design, when the first router sends at least one first probe messages to the second router, First probe messages can be sent to the second router every the first duration by the first router.

In view of factors such as network qualities, if the first router only sends first probe messages, the first via by Device does not receive the first detection feedback message in timer expiry, it may be possible to because the reason of MTU, it is also possible to because network passes The reasons such as transmission quality, such as packet loss or time delay are excessive etc., it, may be not accurate enough if thus reducing MTU to determine.Therefore exist In the embodiment of the present application, the first router can send first probe messages to the second router, in this way for the first via It is smaller by being born for device, or consider network quality, the first router can also send multiple first to the second router Probe messages.

In a possible design, first probe messages and second probe messages can be respectively ping report Text.

The embodiment of the present application can detect mechanism by ping to realize the detecting to MTU.But ping detection mechanism is A kind of optional mechanism, the embodiment of the present application are not intended to limit detection mechanism.

In a possible design, the first router outgoing interface of the first router is supported described the One MTU is adjusted to the 3rd MTU；The first router sends service message, the business report to the second router The MTU of text is the 3rd MTU.

The MTU that interchanger is supported finally has been determined in the first router, that is, the first router and the second router has been determined Between path mtu after, when the first router retransmits service message, the MTU of the service message can be the first via by The path mtu between the first router and the second router that device finally determines, such as the path mtu is known as the 3rd MTU, from And guarantee the normal transmission of service message.Wherein, which can be the first router generation, or be also possible to it What his equipment was forwarded by the first router.If the service message is that the first router generates, the MTU of the service message It is the first router to be arranged, the first router can be directly disposed as the 3rd MTU, and if the service message is other equipment It is forwarded by the first router, then the MTU of the service message can be other equipment to be arranged.For example, the first router is true After having determined the 3rd MTU, the 3rd MTU can be notified to the other equipment of the first router upstream, so that other equipment are rear When the continuous transmission service message by the first router, so that it may know to set the 3rd MTU for the MTU of service message.

Second aspect provides a kind of communication means, and this method can be executed by router, and the router for executing this method can also To be the first router.This method comprises: the first router sends probe messages, the probe messages encapsulation to the second router First MTU, the first MTU are the MTU that the outgoing interface of the first router is supported, the probe messages are big for detecting Whether the small message for the first MTU can be sent to the second router；The first router is determined in setting Detection feedback message is not received from the second router in long, the detection feedback message is the feedback report of the probe messages Text；The first router sends loopback message to the second router, and the loopback message is for requesting the first via The MTU supported by device to the transmission path the second router；The first router receives loopback and feeds back message, The loopback feedback message is the feedback message of the loopback message；The first router obtains the loopback and feeds back message institute The 2nd MTU indicated, the 2nd MTU are supported by the first router to the transmission path the second router MTU.

Correspondingly, the third aspect, provides a kind of communication means, this method can be executed by interchanger.This method comprises: exchange Machine receives loopback message from the first router, and the loopback message is for requesting the first router between the second router The MTU that is supported of transmission path, transmission of the interchanger between the first router and the second router On path；The interchanger adds the 2nd MTU in the loopback message, obtains loopback feedback message, the 2nd MTU is institute State the MTU that interchanger is supported；Loopback feedback message is sent to the first router by the interchanger.

In the embodiment of the present application, the first router is if it is determined that probe messages transmission failure, then can directly transmit ring Return text, the MTU that the transmission path so as to directly obtain between the first router and the second router is supported are solved The problem of MTU is found in double layer network, without excessive detection process, accelerates the speed of detection.And so that the first via by The protocol neighbors relationship of device and the second router can be established normally, but also message can be in the first router and secondary route It is transmitted between device.

In a possible design, the first router outgoing interface of the first router is supported described the One MTU is adjusted to the 2nd MTU；The first router sends service message, the business report to the second router The MTU of text is the 2nd MTU.

The MTU that interchanger is supported, that is, after the 2nd MTU has been determined, the first router has finally been determined in the first router When retransmiting service message, the MTU of the service message can be the 2nd MTU, to guarantee the normal transmission of service message.Its In, which can be the first router generation, or be also possible to what other equipment were forwarded by the first router. If the service message be the first router generate, the MTU of the service message is the first router to be arranged, the first via by Device can be directly disposed as the 2nd MTU, and if the service message is that other equipment are forwarded by the first router, the industry The MTU of business message can be other equipment to be arranged.For example, after the first router has determined the 2nd MTU, it can be by second MTU is notified to the other equipment of the first router upstream, so that other equipment are sending business report subsequently through the first router Wen Shi, so that it may know to set the three or two MTU for the MTU of service message.

In a possible design, loopback message is ECHO message.

Loopback message can be realized in the embodiment of the present application by ECHO message.Certain the embodiment of the present application can also lead to Cross other messages to realize loopback message, with no restriction.

In a possible design, the destination address of the loopback message is the ground of the outgoing interface of the first router Location.

Since being loopback message, then destination address can be set to the address of the outgoing interface of the first router, then 2nd MTU is added to after loopback message by interchanger retransmits loopback message, and according to the destination address, loopback message directly can To return to the first router, regenerates message again without interchanger and is sent to the first router, mitigate the burden of interchanger, More meet the working mechanism of interchanger.

Fourth aspect provides a kind of router.The router, which has, realizes the first router in above method design Function.These functions can also execute corresponding software realization by hardware realization by hardware.The hardware or software Including one or more units corresponding with above-mentioned function.

In a possible design, the specific structure of the router may include processor and transceiver.Processor and receipts The corresponding function in method provided by any one possible design of above-mentioned first aspect or first aspect can be performed in hair device.

5th aspect, provides a kind of router.The router, which has, realizes the first router in above method design Function.These functions can also execute corresponding software realization by hardware realization by hardware.The hardware or software Including one or more units corresponding with above-mentioned function.

In a possible design, the specific structure of the router may include processor and transceiver.Processor and receipts The corresponding function in method provided by any one possible design of above-mentioned second aspect or second aspect can be performed in hair device.

6th aspect, provides a kind of interchanger.The interchanger has interchanger (the first friendship realized in above method design Change planes) function.These functions can also execute corresponding software realization by hardware realization by hardware.It is described hard Part or software include one or more units corresponding with above-mentioned function.

In a possible design, the specific structure of the interchanger may include processor and transceiver.Processor and receipts The corresponding function in method provided by any one possible design of the above-mentioned third aspect or the third aspect can be performed in hair device.

7th aspect, provides a kind of router.The router, which has, realizes the first router in above method design Function.These functions can also execute corresponding software realization by hardware realization by hardware.The hardware or software Including one or more units corresponding with above-mentioned function.

In a possible design, the specific structure of the router may include processing module and transceiver module.Handle mould Block and transceiver module can be performed in method provided by any one possible design of above-mentioned first aspect or first aspect Corresponding function.

Eighth aspect provides a kind of router.The router, which has, realizes the first router in above method design Function.These functions can also execute corresponding software realization by hardware realization by hardware.The hardware or software Including one or more units corresponding with above-mentioned function.

In a possible design, the specific structure of the router may include processing module and transceiver module.Handle mould Block and transceiver module can be performed in method provided by any one possible design of above-mentioned second aspect or second aspect Corresponding function.

9th aspect, provides a kind of interchanger.The interchanger has interchanger (the first friendship realized in above method design Change planes) function.These functions can also execute corresponding software realization by hardware realization by hardware.It is described hard Part or software include one or more units corresponding with above-mentioned function.

Tenth aspect, provides a kind of communication device.The communication device can be designed for the above method in the first router, Or for the chip in the first router is arranged in.The communication device includes: memory, for storing computer executable program Code；And processor, processor are coupled with memory.The program code that wherein memory is stored includes instruction, works as processing When device executes described instruction, communication device is made to execute in any one possible design of above-mentioned first aspect or first aspect the Method performed by one router.

On the one hand tenth, provides a kind of communication device.The communication device can be designed for the above method in the first via by Device, or for the chip in the first router is arranged in.The communication device includes: memory, executable for storing computer Program code；And processor, processor are coupled with memory.The program code that wherein memory is stored includes instruction, when When processor executes described instruction, communication device is made to execute any one possible design of above-mentioned second aspect or second aspect Method performed by middle the first router.

12nd aspect, provides a kind of communication device.The communication device can be designed for the above method in interchanger ( One interchanger), or the chip to be arranged in interchanger (the first interchanger).The communication device includes: memory, for depositing Store up computer executable program code；And processor, processor are coupled with memory.The wherein program generation that memory is stored Code includes instruction, when processor executes described instruction, communication device is made to execute any of above-mentioned second aspect or second aspect A kind of method performed by interchanger (the first interchanger) in possible design.

13rd aspect, provides a kind of communication system, including the first router and interchanger.Wherein, the first router is used In sending probe messages to the second router, the probe messages encapsulate the first MTU, and the first MTU is the first via The MTU supported by the outgoing interface of device, the probe messages are used to detect whether the message that size is the first MTU can to send To the second router, determines and do not receive detection feedback message, the detection from the second router within the set duration Feedback message is the feedback message of the probe messages, and Xiang Suoshu the second router sends loopback message, and the loopback message is used In the MTU for requesting the first router to be supported to the transmission path between the second router, loopback feedback report is received Text, the loopback feedback message are the feedback message of the loopback message, are obtained second indicated by the loopback feedback message MTU, the MTU that the 2nd MTU is supported by the first router to the transmission path the second router；Exchange Machine, for receiving loopback message from the first router, the loopback message is for requesting the first router to second The MTU that transmission path between router is supported, the interchanger are located at the first router and the second router Between transmission path on, in the loopback message add the 2nd MTU, obtain loopback feedback message, the 2nd MTU is institute The MTU that interchanger is supported is stated, loopback feedback message is sent to the first router.

Fourteenth aspect provides a kind of computer storage medium, instruction is stored in the computer readable storage medium, When run on a computer, so that computer executes any one possible design of above-mentioned first aspect or first aspect Described in method.

15th aspect, provides a kind of computer storage medium, instruction is stored in the computer readable storage medium, When run on a computer, so that computer executes any one possible design of above-mentioned second aspect or second aspect Described in method.

16th aspect, provides a kind of computer storage medium, instruction is stored in the computer readable storage medium, When run on a computer, so that computer executes any one possible design of the above-mentioned third aspect or the third aspect Described in method.

17th aspect, provides a kind of computer program product comprising instruction, stores in the computer program product Have instruction, when run on a computer so that computer execute above-mentioned first aspect or first aspect any one can Method described in the design of energy.

18th aspect, provides a kind of computer program product comprising instruction, stores in the computer program product Have instruction, when run on a computer so that computer execute above-mentioned second aspect or second aspect any one can Method described in the design of energy.

19th aspect, provides a kind of computer program product comprising instruction, stores in the computer program product Have instruction, when run on a computer so that computer execute the above-mentioned third aspect or the third aspect any one can Method described in the design of energy.

The embodiment of the present application supplement extends the technology of network path MTU study discovery, and providing one kind can be efficiently fast The discovery technique of the path mtu of speed detecting double layer network.

Detailed description of the invention

Figure 1A is the form schematic diagram of the unreachable message of ICMP；

When Figure 1B is the MTU that the MTU that the interface of two configuration of routers is supported is greater than intermediate interchanger configuration, interchanger The schematic diagram of dropping packets；

Fig. 2 is a kind of application scenarios schematic diagram of the embodiment of the present application；

Fig. 3 is a kind of flow chart of communication means provided by the embodiments of the present application；

Fig. 4 A is another application scenarios schematic diagram of the embodiment of the present application；

Fig. 4 B is the flow chart of another communication means provided by the embodiments of the present application；

Fig. 5 is a kind of structural schematic diagram of the first router provided by the embodiments of the present application；

Fig. 6 is a kind of structural schematic diagram of the first router provided by the embodiments of the present application；

Fig. 7 is a kind of structural schematic diagram of interchanger provided by the embodiments of the present application；

Fig. 8 A- Fig. 8 B is two kinds of structural schematic diagrams of communication device provided by the embodiments of the present application.

Specific embodiment

In order to keep the purposes, technical schemes and advantages of the embodiment of the present invention clearer, below in conjunction with attached drawing to this hair Bright embodiment is described in further detail.

Hereinafter, the part term in the embodiment of the present application is explained, in order to those skilled in the art understand that.

1) router (router) is the equipment for connecting each local area network, wide area network in internet (internet), routing hair The raw third layer in open system interconnection (open system interconnection, OSI) reference model is (also known as For three-layer network), i.e. network layer, router can automatically select and set routing according to the case where channel, with optimal path, before pressing Sequence sends signal afterwards.

Router also is understood as gateway (gateway), for connecting multiple logically separate networks.It is so-called Logical network represents an individual network or a subnet.When data is transferred from one subnet to another subnet, may be used It is completed by the routing function of router.Therefore, router, which has, judges network address and selection Internet protocol The function in the path (internet protocol, IP), it can establish flexible connection, can be finished in a multi-network interconnection environment Complete different data grouping connects various subnets with media access method, and router only receives source station or the letter of other routers Breath, belongs to a kind of InterWorking Equipment of network layer.

2) interchanger (switch) is a kind of based on media access control (media access control, MAC) (network interface card Hardware address) identification, can complete encapsulate forward data packet function the network equipment.Interchanger " can learn " MAC Address, and The MAC Address of study is stored in internal address table, it is interim by being established between the originating terminal and target side of data frame Switching path, so that data frame is directly arrived at the destination location by source address.Interchanger includes work in OSI Reference Model Three-tier switch of the Layer 2 switch and work of the second layer (herein also referred to as double layer network) in three-layer network, three-tier switch Or the interchanger of higher.Three-tier switch can equally have the function of routing, and than the forwarding rate of low end router Faster.It is mainly characterized by: primary routing repeatedly forwards.What the embodiment of the present application mainly discussed is Layer 2 switch.

3) MTU refers to the size for the maximum data packet that can pass through on a kind of a certain layer of communication protocol, is with byte Unit.Maximum transmission unit is usually related with communication interface, such as network interface card or serial ports etc..Such as the embodiment of the present application meeting The MTU that the outgoing interface of router is supported is discussed.

4) term in the embodiment of the present application " system " and " network " can be used interchangeably." multiple " refer to two or two More than, in consideration of it, " multiple " can also be interpreted as " at least two " in the embodiment of the present application."and/or" describes affiliated partner Incidence relation, indicate may exist three kinds of relationships, for example, A and/or B, can indicate: individualism A exists simultaneously A and B, These three situations of individualism B.In addition, character "/", unless otherwise specified, typicallying represent forward-backward correlation object is a kind of "or" Relationship.

And unless indicated to the contrary, the embodiment of the present application refers to that the ordinal numbers such as " first ", " second " are for more A object distinguishes, and is not used in sequence, timing, priority or the significance level for limiting multiple objects.

The embodiment of the present application can be adapted for long term evolution (long term evolution, LTE) system or the 5th generation New wireless (new radio, the NR) system of mobile communication technology (5G), or it is readily applicable to other similar communication system, Such as next generation communication system etc..

Technical solution provided by the embodiments of the present application in order to better understand first introduces the technology of the embodiment of the present application below Background.

In three-layer network, MTU can be found.For example, the MTU when the received message of router has been more than next The MTU of network is jumped, and the message cannot be split, then router needs to return to a control message to the source device for sending the message Agreement (internet control message protocol, ICMP) the unreachable message of purpose (such as be known as ICMP can not Up to message), A, is the format of the unreachable message of ICMP referring to Figure 1.The unreachable message of ICMP include type, code, verification and Preceding 64 bit (bit) in header field, internet header field (or being interpreted as IP)+original message, original message The message that the as received MTU of router has been more than the MTU of next-hop network.

Wherein, type and code show for determining the type of icmp packet, such as type=3 and code=4 jointly Unreachable message for the purpose of the ICMP.For support path MTU discovery technique, router can be in the stem of the unreachable message of ICMP It include the MTU of next-hop network in the 16bit of low sequence in field, this field is marked as " being not used " in ICMP standard. The 16bit of high order is remained unused, and is set as 0.After then source device receives the unreachable message of the ICMP, it is unreachable to can get the ICMP The MTU for the next-hop network that the 16bit of low sequence includes in the header field of message, thus according to the MTU regenerate message come It sends.

But current standard is defined just for the MTU discovery of three-tier message, for double layer network, is not had also at present There are standard and corresponding technology to find MTU.

Such as B referring to Figure 1, it may be communicated by switch A and switch b between router A and router B, Switch A and switch b are Layer 2 switch.The MTU of the incoming interface of the outgoing interface of router A and router B configuration is 1500, the MTU of the incoming interface configuration of the outgoing interface and switch b of switch A is 1000.Router A is sent to the report of router B For text when by switch A, switch A can directly abandon the message because that can not support the MTU of the message, lead to router A and router B cannot achieve communication, thus will affect normally building for the protocol neighbors relationship between router A and router B Vertical and service message normal transmission.

In consideration of it, the technical solution of the embodiment of the present application is provided, it is big with the MTU supported in the interface of two configuration of routers Under the scene of the MTU of intermediate interchanger configuration, it is also possible that two router normal communications.

Fig. 2 is referred to, a kind of application scenarios of the embodiment of the present application are introduced.Including the first router and secondary route Device includes the first interchanger and second positioned at double layer network in the transmission path between the first router and the second router Interchanger.Wherein, the IP address of the outgoing interface of the first router is, for example, 10.1.1.1, the IP of the incoming interface of the second router Location is, for example, 10.1.1.2.The MTU of the incoming interface configuration of the outgoing interface and the second router of the first router is, for example, 1500, the The MTU of the incoming interface configuration of the outgoing interface and second switch of one interchanger is, for example, 1000.That is, first as protocol neighbors It is double layer network between router and the second router, and the MTU that the link for being located at the interchanger interconnection of double layer network allows is small In the interface mtu of both ends router.

Wherein, the MTU (or interchanger support MTU) that the first interchanger is supported, the first router and the second router it Between the MTU that is supported of transmission path, the path mtu between the first router and the second router, the first router and second The MTU that double layer network between router is supported, these types of concept are herein defined as meaning of the same race, can be substituted for one another.About These types of concept will have been described below.

Fig. 3 is referred to, the embodiment of the present application provides a kind of communication means, during introduction below, by this method For application scenarios shown in Fig. 2.The process of this method is described below.

S301, the first router send at least one first probe messages to the second router, then the first interchanger receives At least one first probe messages, the first probe messages encapsulate the first MTU, and the first MTU is the outgoing interface branch of the first router The MTU held, the first probe messages are used to detect whether the message that size is the first MTU can be sent to the second router, and first It include the equipment positioned at double layer network in transmission path between router and the second router；

S302, the first interchanger determine the size relation between the first MTU and the 3rd MTU, if it is determined that the first MTU is greater than 3rd MTU, then the first interchanger abandons at least one first probe messages, the MTU that the 3rd MTU is supported by the first interchanger (S302 is as example)；And if it is determined that the first MTU is equal to the 3rd MTU, then next-hop of first interchanger in transmission path At least one first probe messages of device forwards；

If S303, the first interchanger abandon at least one first probe messages, the first router is determined in setting The first detection feedback message is not received from the second router in long, the first detection feedback message is the feedback report of the first probe messages Text；

First MTU is cut out the first step-length by S304, the first router, obtains the 2nd MTU；

S305, the transmission path institute determined between the first router and the second router is not yet detected because of the first router The MTU of support, therefore the first router continues detection process, such as the first router encapsulates second to the second router transmission At least one second probe messages of MTU, then the first interchanger receives at least one second probe messages；

Then, the first interchanger at least one the second probe messages processing mode be similar to at least one first The processing mode of probe messages, the first interchanger determines the size relation between the 2nd MTU and the 3rd MTU, such as determines second MTU is greater than the 3rd MTU, then the first interchanger abandons at least one second probe messages, the processing mode of subsequent the first router See also S304 and S305, that is to say, that the first router continues to execute detection process, and centre omits more wheels and passes through detection report The process that text is detected.

Until after N takes turns detection process, in N+1 wheel detection process, S306, the first router are to the second router At least one probe messages (the present embodiment is known as third probe messages) is sent, at least one third probe messages encapsulates Four MTU, then the first interchanger receives at least one third probe messages；

S307, the first interchanger determine the size relation between the 4th MTU and the 3rd MTU, if it is determined that the 4th MTU is greater than 3rd MTU, then the first interchanger abandons at least one first probe messages, and if it is determined that the 4th MTU is equal to the 3rd MTU, then Next-hop device of first interchanger in transmission path forwards at least one third probe messages (S307 is as example)；Transmission Next-hop device on path is, for example, second switch, then second switch receives at least one third probe messages；

S308, second switch send at least one third probe messages to the second router, then the second router receives At least one third probe messages；

S309, the second router generate at least one third detection feedback message, and third detection feedback message is that third is visited Observe and predict the feedback message of text；Wherein, one third detection feedback message of the every reception of the second router can generate a third Detection feedback message；

S310, the second router send at least one third detection feedback message to the first router, then the first router Receive at least one third detection feedback message；

Wherein, the every third detection feedback message that generates of the second router can send one the to the first router Three detection feedback messages, that is, if the second router generates multiple third detection feedback messages, multiple third detection feedback reports The sending time of text may be different；

In addition, it includes three processes that the second router, which sends at least one third detection feedback message to the first router, That is 3 processes of S310 in Fig. 3 are respectively as follows: the second router to second switch and send at least one third detection feedback report Text, second switch receive at least one third detection feedback message, and second switch sends at least one to the first interchanger Third detection feedback message, the first interchanger receive at least one third detection feedback message, the first interchanger to the first via by Device sends at least one third detection feedback message, and the first router receives at least one third detection feedback message；

S311, the first router determine has received at least one third detection feedback message within the set duration, it is determined that The MTU that transmission path between the first router and the second router is supported is the 4th MTU, the 4th MTU i.e. the first via The MTU cut out by device last time, and the 4th MTU namely the 3rd MTU.So far, the detecting process of MTU is terminated.

Wherein, the arrow in the S31 and S35 in Fig. 3 further includes the dotted line arrow that the second router is directed toward from the first interchanger Head, shows at least one first probe messages and at least one second probe messages is actually to be sent to the second router, Certainly the second router is different surely receives, so the dotted arrow in figure is only illustrated.And at least one third detection report Text is destined to the second router, and the second router can also receive, therefore is solid arrow in Fig. 3.

By taking scene shown in Fig. 2 as an example, because the first interchanger and second switch are located in double layer network, according to Current standard, the first router can not find the MTU that the first interchanger is supported.So in the embodiment of the present application, for two layers Network proposes by way of detecting MTU, to enable the first router finally to know that the first interchanger is supported probe messages MTU, and the transmission path between the MTU i.e. the first router and the second router that first interchanger is supported is supported MTU, in other words, the path mtu between MTU i.e. the first router and the second router that the first interchanger is supported are so-called Path mtu, refer in an internet transmissions path, from source address (this refers to the addresses of the first router) to destination The minimum for the maximum transmission unit that all IP in the transmission path that location (this refers to the addresses of the second router) is passed through are jumped Value, or from the point of view of another angle, path mtu is exactly to be not necessarily to message progress fragment processing can pass through this transmission road The maximum value of the maximum transmission unit of diameter.

MTU is detected using mode provided by the embodiments of the present application, is a kind of function of router, is come as the first router It says, can choose and open this function, also can choose and close this function.So, if the first router will select to open This function, then the specified outgoing interface of the first router is needed in available (UP) state, what the first router here was specified Outgoing interface is exactly the interface that the first router sends probe messages provided by the embodiment of the present application.In addition, the first router is such as Fruit will select to open this function, then also need the first router and the second router that can learn to the address to end interface Analysis protocol (address resolution protocol, ARP) list item, to guarantee that network is that physics is reachable.

Because to be detected in double layer network in the embodiment of the present application, then as an example, probe messages can To be realized by ping message, that is, can realize the detection to MTU by ping testing mechanism.Certainly ping message is used Be a kind of example as probe messages, can also perhaps be realized by the special probe messages of detection to(for) MTU or The detection for MTU can also be realized using other mechanism, the embodiment of the present application is with no restriction.Below introduce process In, by taking probe messages are realized by ping message as an example, then foregoing first probe messages, the second probe messages and the Three probe messages etc. can be ping message.

In addition, the first router send probe messages after, if the probe messages encapsulation MTU be equal to the first router and The MTU that transmission path between the second router is supported, that is, equal to the path between the first router and the second router MTU (the present embodiment is known as the 3rd MTU), then the second router can receive the probe messages, and the second router receives detection After message, the feedback message for the probe messages can be generated, is known as the feedback message of probe messages to detect feedback report herein Text, then detection feedback message can be sent to the first router by the second router, then the first router receives detection feedback message Afterwards, it just can determine that the probe messages are sent successfully.Otherwise, after the first router sends probe messages, if the probe messages are sealed The MTU of dress is greater than the MTU that the transmission path between the first router and the second router is supported, that is, is greater than the first router Path mtu between the second router, then the first intermediate exchange opportunity abandons the probe messages, and the first interchanger, which abandons, to be visited Detection feedback message will not be replied to the first router after observing and predicting text, then the first router would not receive detection feedback message. So, if not receiving detection feedback message after a period of time, the first router just can determine that the probe messages send failure.This Apply, in order to allow the first router that can specify whether probe messages send failure, timer can be set in embodiment, that is, Timer can be set in the first router, and provides: in the timer expiry, if the first router not yet receive it is transmitted Probe messages feedback message, it is determined that be to be dropped because the MTU that encapsulates of transmitted probe messages is excessive, then first Router can reduce MTU, and retransmit the probe messages for encapsulating the MTU after reducing.The timing length of the timer is To set duration as previously described, which can be empirically determined, such as the timing length of settable timer are as follows: When the MTU for the message that the first router is sent is equal to path mtu between the first router and the second router, the first via by Device is from message is sent to duration experienced the feedback message for receiving the message.It can certainly set by other means The timing length of timer is set, the embodiment of the present application is with no restriction.It in addition, can also root after the timing length of setting timer The timing length is adjusted according to demand dynamic.

For example, the first router needs to detect the MTU of the support of the double layer network between the first router and the second router, Then the first router can enable two layers of path mtu (pathmtu) detection function for the outgoing interface of the first router, thus open The detecting function of MTU is moved, in the embodiment of the present application for realizing the detection of MTU by ping testing mechanism, therefore in this way It is equivalent to start ping detection.

During detecting MTU, the first router generates the first probe messages, and the source IP address of the first probe messages is The IP address of the outgoing interface of the first router, the source MAC of the first probe messages are also the MAC of the outgoing interface of the first router Address, the purpose IP address of the first probe messages are the IP address of the incoming interface of the second router, the purpose of the first probe messages MAC Address is also the MAC Address of the incoming interface of the second router.Such as first probe messages be the first router in starting MTU Detection after transmitted first probe messages, then in the first probe messages, the MTU of the first router encapsulation can be the The MTU encapsulated in first probe messages is known as the first MTU herein by the MTU that the outgoing interface of one router is supported, with Fig. 2 institute For the scene shown, then the first MTU is equal to 1500.And the first router is by the not fragment (don't in the first probe messages Fragment, DF) value of flag bit is set to 1, show that the first probe messages cannot be split transmission.

In view of factors such as network qualities, the first router can send at least one first detection report to the second router Text, if only sending first probe messages, the first router does not receive the first detection feedback report in timer expiry Text, it may be possible to because the reason of MTU, it is also possible to because the reasons such as network transmission quality, such as packet loss or time delay are excessive etc., such as Thus fruit determines reduces MTU, may be not accurate enough.Therefore in the embodiment of the present application, the first router can be to second Router sends first probe messages, or multiple first probe messages can also be sent to the second router, such as the One router just sends first probe messages to the second router every the first duration, is sending first first detection report Wen Shi, the first router can star timer, before timer expiry, that is, within the set duration, as long as the first router connects The the first detection feedback message narrowed to the first probe messages of any one sent during this period, is considered as the first probe messages It sends successfully.Wherein, the first duration can be arranged by the first router, such as be set as 1 second, or when may be set to be other It is long.In addition after the first duration is set, the first duration can also be dynamically adjusted according to demand.

So, since the first router can send at least one first probe messages to the second router, then it is used as one Kind example, the timing length of timer can also be controlled according to the quantity of the probe messages of transmission.For example, in order to reduce network The quantity and pressure of midamble set the first duration to 1 second, set 5 seconds for the timing length of timer, then the first via First probe messages were sent to the second router every 1 second from device, the first router can send 5 within 5 seconds time First probe messages.And 5 seconds time reach when, if the first router do not receive it is any for being sent in this 5 seconds First detection feedback message of one the first probe messages, then the first router determines that the first probe messages send failure.

By taking scene shown in Fig. 2 as an example, the MTU that the double layer network where the first interchanger and second switch is supported is 1000, it is clear that less than the MTU of the outgoing interface support of the first router.After so the first interchanger receives the first probe messages, because What the double layer network where being greater than the first interchanger and second switch by the first MTU of the first probe messages encapsulation was supported MTU, the first exchange opportunity abandon the first probe messages.Such first probe messages obviously can not reach the second router, and One interchanger will not reply detection feedback message to the first router, then the first router would not receive detection feedback message. Such as first interchanger just start timer when sending the first probe messages, then the first interchanger in timer expiry Detection feedback message (the first detection feedback message will be known as the feedback message of the first probe messages herein) will not be received, that The first router determines that the first probe messages send failure, can retransmit probe messages.The probe messages of retransmission In obviously cannot encapsulate the first MTU again, in the embodiment of the present application, the first MTU can be cut out the first step-length by the first router, be obtained To the 2nd MTU, after determining that the first probe messages send failure, the first router generates the second probe messages, the second detection report The source IP address of text is the IP address of the outgoing interface of the first router, the source MAC of the second probe messages be also the first via by The MAC Address of the outgoing interface of device, the purpose IP address of the second probe messages are the IP address of the incoming interface of the second router, second The target MAC (Media Access Control) address of probe messages is also the MAC Address of the incoming interface of the second router, unlike the first probe messages, That encapsulate in the second probe messages is the 2nd MTU rather than the first MTU.Equally, the first router can be sent to the second router At least one second probe messages.That is, the first router can gradually reduce spy if probe messages transmission is unsuccessful The MTU encapsulated in text is observed and predicted, repeatedly, the probe messages (the i.e. in the present embodiment that certain sends until the first router Three probe messages) encapsulation MTU (the 4th MTU i.e. in the present embodiment) be equal to the first interchanger and where second switch two When the MTU that layer network is supported, the first router will receive the detection feedback of the second router transmission before timer expiry Message (the third detection feedback message i.e. in the present embodiment), then the first router determines that detection process terminates, and the detection is anti- The MTU encapsulated in probe messages corresponding to feedback message, is exactly the transmission path institute between the first router and the second router The MTU of support, i.e. the 3rd MTU described in the present embodiment, then the first router enables the 3rd MTU in the outgoing interface of the first router It comes into force, or is interpreted as, the MTU that the outgoing interface of the first router is supported is adjusted to third from the first MTU by the first router MTU。

Wherein, the first step-length can be arranged by the first router, such as in order to enable granularity of successively decreasing is thinner, avoid passing as far as possible Subtracting excessive and misses correct MTU, the first step-length may be configured as 1, alternatively, detected as early as possible successfully to accelerate detection process, First step-length can be arranged larger.How the embodiment of the present application is specifically set with no restriction.

Later, if the first router sends service message to the second router, the MTU of the service message just uses the Three MTU.Wherein, which may be what the first router generated, or be also possible to other equipment by the first via by Device forwarding.So, the first router can also send notice message to the other equipment of the first router upstream, such as send The unreachable message of ICMP, encapsulates the 3rd MTU in the notice message, then after other equipment receive the notice message, so that it may The service message of subsequent transmission is determined using the 3rd MTU, to improve the success rate of message transmissions.

In the embodiment of the present application, the first router passes through transmission probe messages and the MTU of probe messages of gradually successively decreasing encapsulation Mode, it will be able to obtain the MTU that the transmission path between the first router and the second router is supported, solve at two layers The problem of MTU is found in network, enables the protocol neighbors relationship of the first router and the second router normally to establish, also makes Obtaining message can transmit between the first router and the second router, and implementation is relatively simple.

The scheme that embodiment according to Fig.3, provides, the first router is by sending probe messages and spy of gradually successively decreasing Observe and predict the mode of the MTU of text encapsulation, it will be able to obtain what the transmission path between the first router and the second router was supported MTU solves the problems, such as to find MTU in double layer network.And on how to find MTU in double layer network, it is not limited to Fig. 3 institute Scheme provided by the embodiment shown.

Fig. 4 A is referred to, another application scenarios of the embodiment of the present application are introduced.Including the first router and second Router, include in the transmission path between the first router and the second router positioned at double layer network the first interchanger and Second switch.Wherein, the IP address of the outgoing interface of the first router is, for example, 10.1.1.1, the incoming interface of the second router IP address is, for example, 10.1.1.2.The outgoing interface of the first router and the MTU of the incoming interface of the second router configuration are, for example, 1500, the MTU of the incoming interface configuration of the outgoing interface and second switch of the first interchanger is, for example, 1000.That is, as agreement neighbour It is double layer network between the first router and the second router in residence, and the link that the interchanger for being located at double layer network interconnects allows MTU be less than both ends router interface mtu.

Fig. 4 B is turned next to, the embodiment of the present application also provides a kind of communication means, is equally able to solve in double layer network The problem of middle discovery MTU.During introduction below, by taking the communication means is applied to application scenarios shown in Fig. 4 A as an example. The process of this method is described below.

S41, the first router send probe messages to the second router, then interchanger receives the probe messages, the detection Message encapsulates the first MTU, and the first MTU is the MTU that the outgoing interface of the first router is supported, probe messages are for detecting size Whether the message of the first MTU can be sent to the second router, in the transmission path between the first router and the second router Equipment including being located at double layer network；

S42, interchanger determine that the first MTU is greater than the 2nd MTU, then interchanger abandons probe messages, and the 2nd MTU is interchanger The MTU supported；

S43, the first router, which determine, does not receive detection feedback message, detection feedback from the second router within the set duration Message is the feedback message of probe messages；

S44, the first router send loopback message, then interchanger receives the loopback message, and the loopback message is for requesting The MTU that the first router is supported to the transmission path between the second router；

S45, interchanger add the 2nd MTU in loopback message, obtain loopback feedback message, it is loopback that loopback, which feeds back message, The feedback message of message；

Loopback feedback message is sent to the first router by S46, interchanger, then the first router receives loopback feedback report Text；

S47, the first router obtain the 2nd MTU indicated by loopback feedback message, and the 2nd MTU is the first router to the The MTU that transmission path between two routers is supported.

Interchanger as described in the examples shown in Fig. 4 B can be the first interchanger in scene shown in Fig. 4 A.Its In, for the scene shown in Fig. 4 A, because the process of embodiment shown in Fig. 4 B is temporarily not directed to the second switch in Fig. 4 A, Therefore second switch is not drawn into Fig. 4 B.In addition, the arrow in S41 in Fig. 4 B further includes being directed toward second from the first interchanger The dotted arrow of router shows that probe messages are actually to be sent to the second router, and certain the second router is not necessarily It can receive, so the dotted arrow in figure is only illustrated.

In the embodiment of the present application, for double layer network, it again may be by probe messages to detect MTU, so that the first via The MTU that first interchanger is supported can finally be known by device, and the MTU i.e. the first router and that the first interchanger is supported The MTU that transmission path between two routers is supported, in other words, the MTU i.e. the first router that the first interchanger is supported Path mtu between the second router.

Similarly with embodiment shown in Fig. 3, MTU is detected using mode provided by the embodiments of the present application, is the one of router Kind function can choose for the first router and open this function, also can choose and closes this function.So, If a router will select to open this function, the specified outgoing interface of the first router is needed in UP state, here The specified outgoing interface of the first router, is exactly the interface that the first router sends probe messages provided by the embodiment of the present application. If also needing the first router and the second router that can learn in addition, the first router will select to open this function The ARP entry to end interface is practised, to guarantee that network is that physics is reachable.

Because to be detected in double layer network in the embodiment of the present application, then as an example, probe messages can To be realized by ping message, it can realize the detection to MTU by ping testing mechanism.Certainly made using ping message It is a kind of example for probe messages, or can also realizes the detection for MTU, Huo Zheye by special probe messages The detection for MTU can be realized using other mechanism, the embodiment of the present application is with no restriction.Below introduce process In, by taking probe messages are realized by ping message as an example.

In addition, the first router send probe messages after, if the probe messages encapsulation MTU be equal to the first router and The MTU that transmission path between the second router is supported, that is, equal to the path between the first router and the second router MTU, then the second router can receive the probe messages and can generate after the second router receives probe messages for the spy The feedback message of text is observed and predicted, is known as the feedback message of probe messages to detect feedback message herein, then the second router can will be visited It surveys feedback message and is sent to the first router, then after the first router receives detection feedback message, just can determine that the probe messages It sends successfully.Otherwise, after the first router sends probe messages, if the MTU of probe messages encapsulation is greater than the first router The MTU that transmission path between the second router is supported, that is, greater than the path between the first router and the second router MTU, then the first intermediate exchange opportunity abandons the probe messages, the first interchanger abandon after probe messages will not to the first via by Device replys detection feedback message, then the first router would not receive detection feedback message.So, if do not connect after a period of time Detection feedback message is received, the first router just can determine that the probe messages send failure.In the embodiment of the present application, in order to allow first Router can specify whether probe messages send failure, and timer can be set, that is, timing can be set in the first router Device, the timing length of timer is foregoing setting duration, and is provided: in the timer expiry, that is, in setting In length, if the first router not yet receives the feedback message of transmitted probe messages, it is determined that be the spy because transmitted The MTU for observing and predicting text encapsulation is excessive and be dropped, then the first router can send loopback message to the second router.The timer The setting of timing length can refer to the related introduction of embodiment shown in Fig. 3, seldom repeat.

For example, the first router needs to detect the MTU of the support of the double layer network between the first router and the second router, Then the first router can enable two layers of pathmtu detection function for the outgoing interface of the first router, thus start MTU's Detecting function in the embodiment of the present application for realizing the detection of MTU by ping testing mechanism, therefore is equivalent to open in this way Ping detection is moved.

During detecting MTU, the first router generates probe messages, and the source IP address of the probe messages is the first via By the IP address of the outgoing interface of device, the source MAC of the probe messages is also the MAC Address of the outgoing interface of the first router, should The purpose IP address of probe messages is the IP address of the incoming interface of the second router, and the target MAC (Media Access Control) address of the probe messages is also The MAC Address of the incoming interface of the second router.In the probe messages, the MTU of the first router encapsulation is the first router The MTU encapsulated in probe messages is known as the first MTU herein by the MTU that outgoing interface is supported, for the scene shown in Fig. 4 A, Then the first MTU is equal to 1500.And the value of the DF flag bit in the probe messages is set to 1 by the first router, shows the detection report Text cannot be split transmission.

In view of factors such as network qualities, the first router can send at least one probe messages, example to the second router If the first router sends a probe messages to the second router if the first duration, when sending first probe messages The first router can start timer, before the timer expiry, as long as soon as the first router receives a detection feedback message, Think that probe messages are sent successfully.The description as described in this partial content can refer to the related introduction in embodiment shown in Fig. 3, no It repeats more.

Then interchanger receives at least one probe messages, here with interchanger to the processing mode of one of probe messages For introduce, such as the probe messages are received first probe messages of interchanger.Then interchanger uplink learns the first via By the MAC Address of device outgoing interface, and in downlink, the MTU that can be encapsulated due to the probe messages is excessive and abandons the probe messages.This When, interchanger can record the corresponding MTU of the MAC Address, which is the MTU of the outgoing interface of interchanger, and as interchanger is supported The MTU that transmission path between MTU and the first router and the second router is supported.Such as interchanger can will record MAC Address and MTU between mapping relations be mapped in the MAC forwarding table of interchanger.

In timer expiry, it is clear that the first router does not receive the detection feedback message of the second router transmission, then and the One router generates loopback message, and as an example, loopback message is for example realized by echo (ECHO) message.Loopback message Encapsulation for example are as follows: in the source MAC and target MAC (Media Access Control) address of data link layer encapsulation be the first router outgoing interface MAC Address, 00-E0-FC-01-01-22 shown in for example, Fig. 4 A, in the source IP address of network layer encapsulation and destination IP Location is the IP address of the outgoing interface of the first router, and what it is in transport layer encapsulation is the unreachable message of ICMP, unreachable in ICMP In message, next-hop MTU extends this as 0.

The first router sends loopback message to the second router, then interchanger receives the loopback message.Interchanger passes through MAC forwarding table is inquired, MTU corresponding with the MAC Address of the outgoing interface of the first router can be obtained, then interchanger is by the MTU It is added in loopback message, such as interchanger is filled up to the MTU in the unreachable message of ICMP encapsulated in ECHO message In next-hop mtu field, loopback feedback message is obtained, loopback is fed back into the MTU in message herein and is known as the 2nd MTU.

Interchanger sends loopback and feeds back message, since the purpose IP address of loopback message is the IP address of the first router, Target MAC (Media Access Control) address is also the MAC Address of the first router, therefore loopback feedback message can return to the first router, Huo Zheli Loopback feedback message is sent to the first router by Xie Wei, interchanger, then the first router receives loopback feedback message, such as Fig. 4 A In loopback arrow shown in.The first router feeds back message by parsing loopback, so that it may the 2nd MTU wherein encapsulated is obtained, To which the first router can be according to the MTU of the outgoing interface of the 2nd MTU dynamic adjustment the first router, it will be appreciated that be the first via The MTU that the outgoing interface of the first router is supported is adjusted to the 2nd MTU by device.

In addition, loopback message is triggered from probe messages time-out to the first router, if the time interval between this is too long, The MAC forwarding table aging that then may cause intermediate switch device can not continue connecing out for the first router of storage record The mapping relations between MTU that the MAC Address and interchanger of mouth are supported.In consideration of it, it can be stated that probe messages time-out after, The first router needs to enter within the second duration ECHO process, i.e. the first router triggers ECHO message, to guarantee to detect Continue.Second duration is, for example, 3 minutes, or may be alternatively provided as other durations, specifically can be according to the aging of MAC forwarding table The factors such as speed determine, in addition can also carry out dynamic adjustment according to demand after setting.

Later, if the first router sends service message to the second router, the MTU of the service message just uses the Two MTU.Wherein, which may be what the first router generated, or be also possible to other equipment by the first via by Device forwarding.So, the first router can also send notice message to the other equipment of the first router upstream, such as send The unreachable message of ICMP, wherein the ICMP that the unreachable message of the ICMP can be packaged in loopback feedback message is unreachable Message, be equivalent to the first router can directly parse loopback feedback message obtain the unreachable message of ICMP, directly by the ICMP Unreachable message is sent to the other equipment of the first router upstream, without regenerating the unreachable message of ICMP again, subtracts Few process flow.After then other equipment receive the notice message, so that it may determine that the service message of subsequent transmission uses second MTU, to improve the success rate of message transmissions.

The embodiment of the present application supplement extends the technology of network path MTU study discovery, and providing one kind can be efficiently fast The discovery technique of the path mtu of speed detecting double layer network.In the embodiment of the present application, the first router is if it is determined that probe messages Failure is sent, then loopback message can be directly transmitted, so as to directly obtain between the first router and the second router The MTU that transmission path is supported solves the problems, such as to find that MTU is accelerated without excessive detection process in double layer network The speed of detection.And the protocol neighbors relationship of the first router and the second router is normally established, but also message It can be transmitted between the first router and the second router.

Equipment provided by the embodiments of the present application is introduced with reference to the accompanying drawing.

Fig. 5 shows a kind of structural schematic diagram of router 500.The router 500 may be implemented above involved in the The function of one router.The router 500 can be the above the first router, or can be setting hereinbefore Chip in the first router.The router 500 may include processor 501 and transceiver 502.Wherein, processor 501 can be used for executing S303, S304 and S311 in embodiment shown in Fig. 3, and/or for supporting skill described herein Other processes of art.Transceiver 502 can be used for executing S301, S305, S306 and S310 in embodiment shown in Fig. 3, and/ Or other processes for supporting techniques described herein.

For example, transceiver 502, for sending at least one first probe messages, first detection to the second router Message encapsulates the first MTU, and the first MTU is the MTU that the outgoing interface of the router is supported, first probe messages are used Whether the second router can be sent in the message that detection size is the first MTU；

Processor 501 does not receive the first detection feedback message from the second router within the set duration for determining, The first detection feedback message is the feedback message of first probe messages；

Processor 501 is also used to the first MTU cutting out the first step-length, obtains the 2nd MTU；

Transceiver 502 is also used to send at least one the second detection report for encapsulating the 2nd MTU to the second router Text, until the transceiver module receives detection feedback message from the second router in the setting duration；

Processor 501, the 3rd MTU for being also used to cut out for the last time is as the first router to described The MTU that transmission path between two routers is supported.

Wherein, all related contents for each step that above method embodiment is related to can quote corresponding function module Function description, details are not described herein.

Fig. 6 shows a kind of structural schematic diagram of router 600.The router 600 may be implemented above involved in the The function of one router.The router 600 can be the above the first router, or can be setting hereinbefore Chip in the first router.The router 600 may include processor 601 and transceiver 602.Wherein, processor 601 can be used for executing S43 and S47 in embodiment shown in Fig. 4, and/or for support techniques described herein its Its process.Transceiver 602 can be used for executing S41, S44 and S46 in embodiment shown in Fig. 4, and/or for supporting herein Other processes of described technology.

For example, transceiver 602, for sending probe messages to the second router, the probe messages encapsulate first MTU, the first MTU are the MTU that the outgoing interface of the router is supported, the probe messages are described for detecting size Whether the message of one MTU can be sent to the second router；

Processor 601 does not receive detection feedback message from the second router within the set duration for determining, described Detection feedback message is the feedback message of the probe messages；

Transceiver 602, is also used to send loopback message to the second router, and the loopback message is described for requesting The MTU that router is supported to the transmission path between the second router；

Transceiver 602, is also used to receive loopback feedback message, and the loopback feedback message is the feedback of the loopback message Message；

Processor 601 is also used to obtain the 2nd MTU indicated by the loopback feedback message, and the 2nd MTU is described The MTU that router is supported to the transmission path between the second router.

Fig. 7 shows a kind of structural schematic diagram of interchanger 700.The interchanger 700 may be implemented above involved in friendship It changes planes the function of (the first interchanger).The interchanger 700 can be the above interchanger (the first interchanger), Huo Zheke To be the chip being arranged in the interchanger (the first interchanger) being described above.The interchanger 700 may include processor 701 With transceiver 702.Wherein, processor 701 can be used for executing S42 and S45 in embodiment shown in Fig. 4, and/or for branch Hold other processes of techniques described herein.Transceiver 702 can be used for executing S41, S44 in embodiment shown in Fig. 4 And S46, and/or other processes for supporting techniques described herein.

For example, transceiver 702, for receiving loopback message from the first router, the loopback message is described for requesting The MTU that the first router is supported to the transmission path between the second router, the interchanger are located at the first router In transmission path between the second router；

Processor 701, be also used in the loopback message add the 2nd MTU, obtain loopback feedback message, described second The MTU that MTU is supported by the interchanger；

Transceiver 702 is also used to loopback feedback message being sent to the first router.

In a simple embodiment, those skilled in the art is it is contemplated that can also be by router 500, routing Device 600 or interchanger 700 are realized by the structure of communication device 800 as shown in Figure 8 A.The communication device 800 may be implemented The function of the network equipment involved in text or communication equipment.The communication device 800 may include processor 801.Wherein, logical at this T unit 800 for realizing the first router in embodiment shown in Fig. 3 function when, processor 801 can be used for executing Fig. 3 Shown in S303, S304 and S311 in embodiment, and/or other processes for supporting techniques described herein.At this Communication device 800 for realizing the first router in embodiment shown in Fig. 4 function when, processor 801 can be used for executing S43 and S47 in embodiment shown in Fig. 4, and/or other processes for supporting techniques described herein.In the communication Device 800 for realizing the interchanger (the first interchanger) in embodiment shown in Fig. 4 function when, processor 801 can be used S42 and S45 in execution embodiment shown in Fig. 4, and/or other processes for supporting techniques described herein.

Wherein, communication device 800 can pass through field programmable gate array (field-programmable gate Array, FPGA), special integrated chip (application specific integrated circuit, ASIC), system core Piece (system on chip, SoC), central processing unit (central processor unit, CPU), network processing unit (network processor, NP), digital signal processing circuit (digital signal processor, DSP), microcontroller Device (micro controller unit, MCU), can also be programmable controller (programmable logic device, PLD) or other integrated chips realize that then communication device 600 may be placed at the network equipment of the embodiment of the present application or communication is set In standby, so that the method that the network equipment or communication equipment realize transmission message provided by the embodiments of the present application.

In a kind of optional implementation, which can also include memory 802, can refer to Fig. 8 B, In, memory 802 for storing computer program or instruction, processor 801 for decode and execute these computer programs or Instruction.It should be understood that these computer programs or instruction may include the function of above-mentioned the first router or interchanger (the first interchanger) It can program.When the function program of the first router is decoded and executed by processor 801, the first router may make to realize this Shen Please in communication means provided by embodiment embodiment shown in Fig. 3 or embodiment shown in Fig. 4 the first router function.When When the function program of interchanger (the first interchanger) is decoded and executed by processor 801, interchanger (the first interchanger) may make Realize the function of interchanger (the first interchanger) in communication means provided by the embodiment shown in Fig. 4 of the embodiment of the present application.

In another optional implementation, the function program of these the first router or interchanger (the first interchanger) is deposited Storage is in the memory outside communication device 800.When the function program of the first router is decoded and is executed by processor 801, Some or all of the function program of above-mentioned the first router content is temporarily stored in memory 802.When interchanger (the first exchange Machine) function program when being decoded and executed by processor 801, (the first exchange of above-mentioned interchanger is temporarily stored in memory 802 Machine) some or all of function program content.

In another optional implementation, the function program quilt of these the first router or interchanger (the first interchanger) It is set in the memory 802 being stored in inside communication device 800.It is stored in memory 802 inside communication device 800 When the function program of the first router, communication device 800 be may be disposed in the first router of the embodiment of the present application.Work as communication When being stored with the function program of interchanger (the first interchanger) in the memory 802 inside device 800, communication device 800 can quilt It is arranged in the interchanger (the first interchanger) of the embodiment of the present application.

In another optional implementation, the partial content of the function program of these the first router is stored in communication dress It sets in the memory outside 800, the other parts content of the function program of these the first router is stored in communication device 800 In the memory 802 in portion.Or, the partial content of the function program of these interchangers (the first interchanger) is stored in communication device In memory outside 800, the other parts content of the function program of these interchangers (the first interchanger) is stored in communication dress It sets in the memory 802 inside 800.

In the embodiment of the present application, the corresponding each function of router 500,600 interchanger 700 of router and communication device 800 The form of each functional module can be divided to present, alternatively, can be using the form of the integrated each functional module of model split To present.Here " module " can refer to ASIC, execute the processor and memory of one or more softwares or firmware program, collection At logic circuit and/or other device of above-mentioned function can be provided.

In addition, the router 500 that embodiment shown in fig. 5 provides can also be realized by other forms.Such as the routing Device includes processing module and transceiver module.Such as processing module can realize that transceiver module can pass through transceiver by processor 501 502 realize.Wherein, processing module can be used for executing S303, S304 and S311 in embodiment shown in Fig. 3, and/or be used for Support other processes of techniques described herein.Transceiver module can be used for executing S301 in embodiment shown in Fig. 3, S305, S306 and S310, and/or other processes for supporting techniques described herein.

For example, transceiver module, for sending at least one first probe messages, the first detection report to the second router Text encapsulates the first MTU, and the first MTU is the MTU that the outgoing interface of the router is supported, first probe messages are used for Whether the message that detection size is the first MTU can be sent to the second router；

Processing module does not receive the first detection feedback message from the second router within the set duration for determining, The first detection feedback message is the feedback message of first probe messages；

Processing module is also used to the first MTU cutting out the first step-length, obtains the 2nd MTU；

Transceiver module is also used to send at least one the second detection report for encapsulating the 2nd MTU to the second router Text, until the transceiver module receives detection feedback message from the second router in the setting duration；

Processing module, the 3rd MTU for being also used to cut out for the last time is as the first router to described The MTU that transmission path between two routers is supported.

The router 600 that embodiment shown in fig. 6 provides can also be realized by other forms.Such as the router includes Processing module and transceiver module.Such as processing module can be realized by processor 601, transceiver module can be real by transceiver 602 It is existing.Wherein, processing module can be used for executing S43 and S47 in embodiment shown in Fig. 4, and/or for supporting to be retouched herein The other processes for the technology stated.Transceiver module can be used for executing S41, S44 and S46 in embodiment shown in Fig. 4, and/or For supporting other processes of techniques described herein.

For example, transceiver module, for sending probe messages to the second router, the probe messages encapsulate the first MTU, First MTU is the MTU that the outgoing interface of the router is supported, the probe messages are described first for detecting size Whether the message of MTU can be sent to the second router；

Processing module does not receive detection feedback message from the second router within the set duration for determining, described Detection feedback message is the feedback message of the probe messages；

Transceiver module, is also used to send loopback message to the second router, and the loopback message is described for requesting The MTU that router is supported to the transmission path between the second router；

Transceiver module, is also used to receive loopback feedback message, and the loopback feedback message is the feedback of the loopback message Message；

Processing module is also used to obtain the 2nd MTU indicated by the loopback feedback message, and the 2nd MTU is described The MTU that router is supported to the transmission path between the second router.

The interchanger 700 that embodiment shown in Fig. 7 provides can also be realized by other forms.Such as the interchanger includes Processing module and transceiver module.Such as processing module can be realized by processor 701, transceiver module can be real by transceiver 702 It is existing.Wherein, processing module can be used for executing S42 and S45 in embodiment shown in Fig. 4, and/or for supporting to be retouched herein The other processes for the technology stated.Transceiver module can be used for executing S41, S44 and S46 in embodiment shown in Fig. 4, and/or For supporting other processes of techniques described herein.

For example, transceiver module, for receiving loopback message from the first router, the loopback message is for requesting described the The MTU that one router is supported to the transmission path between the second router, the interchanger be located at the first router and In transmission path between the second router；

Processing module, be also used in the loopback message add the 2nd MTU, obtain loopback feedback message, described second The MTU that MTU is supported by the interchanger；

Transceiver module is also used to loopback feedback message being sent to the first router.

Since router 500 provided by the embodiments of the present application, router 600, interchanger 700 and communication device 800 can be used In the method provided by embodiment shown in Fig. 3 or embodiment shown in Fig. 4 that executes, thus its can be obtained technical effect can With reference to above method embodiment, details are not described herein.

The embodiment of the present application is referring to the method, equipment (system) and computer program product according to the embodiment of the present application Flowchart and/or the block diagram describe.It should be understood that can be realized by computer program instructions in flowchart and/or the block diagram The combination of process and/or box in each flow and/or block and flowchart and/or the block diagram.It can provide these calculating Processing of the machine program instruction to general purpose computer, special purpose computer, Embedded Processor or other programmable data processing devices Device is to generate a machine, so that being generated by the instruction that computer or the processor of other programmable data processing devices execute For realizing the function of being specified in one or more flows of the flowchart and/or one or more blocks of the block diagram Device.

In the above-described embodiments, can come wholly or partly by software, hardware, firmware or any combination thereof real It is existing.When implemented in software, it can entirely or partly realize in the form of a computer program product.The computer program Product includes one or more computer instructions.When loading on computers and executing the computer program instructions, all or It partly generates according to process or function described in the embodiment of the present application.The computer can be general purpose computer, dedicated meter Calculation machine, computer network or other programmable devices.The computer instruction can store in computer readable storage medium In, or from a computer readable storage medium to the transmission of another readable storage medium storing program for executing, for example, the computer instruction can To pass through wired (such as coaxial cable, optical fiber, Digital Subscriber Line from a web-site, computer, server or data center (digital subscriber line, DSL)) or wireless (such as infrared, wireless, microwave etc.) mode to another website station Point, computer, server or data center are transmitted.The computer readable storage medium can be computer and can access Any usable medium either include that the data storages such as one or more usable mediums integrated server, data center are set It is standby.The usable medium can be magnetic medium, and (for example, floppy disk, hard disk, tape), optical medium are (for example, digital versatile disc (digital versatile disc, DVD)) or semiconductor medium (for example, solid state hard disk (solid state disk, SSD)) etc..

Obviously, those skilled in the art can carry out various modification and variations without departing from this Shen to the embodiment of the present application Spirit and scope please.In this way, if these modifications and variations of the embodiment of the present application belong to the claim of this application and its wait Within the scope of technology, then the application is also intended to include these modifications and variations.

Claims

1. a kind of communication means characterized by comprising

The first router sends at least one first probe messages to the second router, and first probe messages encapsulate first Maximum transmission unit MTU, the first MTU are the MTU that the outgoing interface of the first router is supported, first probe messages For detecting whether the message that size is the first MTU can be sent to the second router；

The first router, which determines, does not receive the first detection feedback message from the second router within the set duration, described First detection feedback message is the feedback message of first probe messages；

First MTU is cut out the first step-length by the first router, obtains the 2nd MTU；

The first router sends at least one second probe messages for encapsulating the 2nd MTU to the second router, directly Until the first router receives detection feedback message from the second router in the setting duration；Described first Router is using the 3rd MTU cut out for the last time as the first router to the transmission between the second router The MTU that path is supported.

2. the method as described in claim 1, which is characterized in that the first router to the second router send at least one first Probe messages, comprising:

The first router sends first probe messages to the second router every the first duration.

3. method according to claim 2, which is characterized in that first probe messages and second probe messages are Ping message.

4. method a method according to any one of claims 1-3, which is characterized in that the method also includes:

The first MTU that the outgoing interface of the first router is supported is adjusted to the 3rd MTU by the first router；

The first router sends service message to the second router, and the MTU of the service message is the third MTU。

5. a kind of communication means characterized by comprising

The first router sends probe messages to the second router, and the probe messages encapsulate the first maximum transmission unit MTU, First MTU is the MTU that the outgoing interface of the first router is supported, the probe messages are described for detecting size Whether the message of one MTU can be sent to the second router；

The first router, which determines, does not receive detection feedback message, the detection from the second router within the set duration Feedback message is the feedback message of the probe messages；

The first router sends loopback message to the second router, and the loopback message is for requesting the first via The MTU supported by device to the transmission path the second router；

The first router receives loopback and feeds back message, and the loopback feedback message is the feedback message of the loopback message；

The first router obtains the 2nd MTU indicated by the loopback feedback message, and the 2nd MTU is the first via The MTU supported by device to the transmission path the second router.

6. method as claimed in claim 5, which is characterized in that the method also includes:

The first MTU that the outgoing interface of the first router is supported is adjusted to the 2nd MTU by the first router；

The first router sends service message to the second router, and the MTU of the service message is described second MTU。

7. a kind of communication means characterized by comprising

Interchanger receives loopback message from the first router, and the loopback message is for requesting the first router to described the The MTU that transmission path between two routers is supported, the interchanger are located at the first router and the secondary route In transmission path between device；

The interchanger adds the 2nd MTU in the loopback message, obtains loopback feedback message, the 2nd MTU is described The MTU that interchanger is supported；

Loopback feedback message is sent to the first router by the interchanger.

8. the method as described in claim 5-7 is any, which is characterized in that the loopback message is echo ECHO message.

9. the method as described in claim 5-8 is any, which is characterized in that the destination address of the loopback message is described first The address of the outgoing interface of router.

10. a kind of router characterized by comprising

Transceiver module, for sending at least one first probe messages to the second router, first probe messages are encapsulated First maximum transmission unit MTU, the first MTU is the MTU that the outgoing interface of the router is supported, first probe messages For detecting whether the message that size is the first MTU can be sent to the second router；

Processing module does not receive the first detection feedback message from the second router within the set duration for determining, described First detection feedback message is the feedback message of first probe messages；

The processing module is also used to the first MTU cutting out the first step-length, obtains the 2nd MTU；

The transceiver module is also used to send at least one the second detection report for encapsulating the 2nd MTU to the second router Text, until the transceiver module receives detection feedback message from the second router in the setting duration；

The processing module, the 3rd MTU for being also used to cut out for the last time is as the first router to described The MTU that transmission path between two routers is supported.

11. router as claimed in claim 10, which is characterized in that the transceiver module sends at least one to the second router When a first probe messages, it is specifically used for:

First probe messages are sent to the second router every the first duration.

12. router as claimed in claim 11, which is characterized in that first probe messages and second probe messages For ping message.

13. the router as described in claim 10-12 is any, which is characterized in that

The processing module is also used to the first MTU that the outgoing interface of the router is supported being adjusted to the third MTU；

The transceiver module, is also used to send service message to the second router, and the MTU of the service message is described the Three MTU.

14. a kind of router characterized by comprising

Transceiver module, for sending probe messages to the second router, the probe messages encapsulate the first maximum transmission unit MTU, the first MTU are the MTU that the outgoing interface of the router is supported, the probe messages are described for detecting size Whether the message of one MTU can be sent to the second router；

Processing module does not receive detection feedback message, the detection from the second router within the set duration for determining Feedback message is the feedback message of the probe messages；

The transceiver module, is also used to send loopback message to the second router, and the loopback message is described for requesting The MTU that router is supported to the transmission path between the second router；

The transceiver module, is also used to receive loopback feedback message, and the loopback feedback message is the feedback of the loopback message Message；

The processing module is also used to obtain the 2nd MTU indicated by the loopback feedback message, and the 2nd MTU is described The MTU that router is supported to the transmission path between the second router.

15. router as claimed in claim 14, which is characterized in that

The processing module is also used to the first MTU that the outgoing interface of the router is supported being adjusted to described second MTU；

The transceiver module, is also used to send service message to the second router, and the MTU of the service message is described the Two MTU.

16. the router as described in claims 14 or 15, which is characterized in that the loopback message is echo ECHO message.

17. the router as described in claim 14-16 is any, which is characterized in that the destination address of the loopback message is institute State the address of the outgoing interface of the first router.

18. a kind of interchanger characterized by comprising

Transceiver module, for receiving loopback message from the first router, the loopback message is for requesting the first router The MTU supported to the transmission path between the second router, the interchanger are located at the first router and described second In transmission path between router；

Processing module obtains loopback feedback message, the 2nd MTU is institute for adding the 2nd MTU in the loopback message State the MTU that interchanger is supported；

The transceiver module is also used to loopback feedback message being sent to the first router.

19. interchanger as claimed in claim 18, which is characterized in that the loopback message is echo ECHO message.

20. the interchanger as described in claim 18 or 19, which is characterized in that the destination address of the loopback message is described the The address of the outgoing interface of one router.

21. a kind of computer readable storage medium, which is characterized in that the computer-readable recording medium storage program refers to It enables, when described program or instruction are run by one or more processors, realizes method as described in claim 1-4 is any.

22. a kind of computer readable storage medium, which is characterized in that the computer-readable recording medium storage program refers to It enables, when described program or instruction are run by one or more processors, realizes method as described in claim 5,6,8 or 9.

23. a kind of computer readable storage medium, which is characterized in that the computer-readable recording medium storage program refers to It enables, when described program or instruction are run by one or more processors, realizes method as described in claim 7-9 is any.