CN104639433A

CN104639433A - Echo message-based multi-hop detection implementation method

Info

Publication number: CN104639433A
Application number: CN201510005766.3A
Authority: CN
Inventors: 李明明
Original assignee: Fiberhome Telecommunication Technologies Co Ltd
Current assignee: Fiberhome Telecommunication Technologies Co Ltd
Priority date: 2015-01-07
Filing date: 2015-01-07
Publication date: 2015-05-20
Anticipated expiration: 2035-01-07
Also published as: CN104639433B

Abstract

The invention discloses an Echo message-based multi-hop detection implementation method, and relates to the field of BFD (Bidirectional Forwarding Detection) protocol multi-hop detection. Routability is configured between two routers; an Echo message is established by a local router and transmitted to a target router; the packaging format of the Echo message is destination Mac+source Mac+0800+IP (Internet Protocol) layer payload+UDP (User Datagram Protocol) layer payload+BFD payload, wherein a destination IP included in the IP layer payload is a destination router interface IP and a source IP is a local router interface IP; after the Echo message is received by the destination router, the destination IP in the IP layer payload is changed into the local router interface IP, and the source IP is changed into the destination router interface IP to form a reply message to be transmitted to the local router; after the reply message is received by the local router, detection is performed according to the BFD protocol regulations. Multi-hop detection is realized through the Echo message, reply establishment of destination equipment is avoided and a state machine thereof is maintained, and the detection process is simplified.

Description

A kind of multi-hop based on Echo message detects implementation method

Technical field

The present invention relates to BFD agreement multi-hop detection field, be specifically related to a kind of multi-hop based on Echo message and detect implementation method.

Background technology

BFD (Bidirectional Forwarding Detection, two-way converting detects) can detect as early as possible and communication failure between neighbouring device, can take measures in time, require the network equipment can fast detecting be out of order and by flow switch to backup link to accelerate network convergence speed, thus ensure that business proceeds, reduce equipment fault or link failure to the impact of business, the availability improving network, BFD is widely used in communication equipment.

The working method of BFD session is divided into two kinds:

Control message mode: both link ends session is by controlling message interaction monitoring Link State.

Echo message mode: link one end is forwarded by the other end by sending Echo message, realizes the bidirectional test to link.

BFD test mode is divided into two kinds:

Single-hop detects: the detection of BFD single-hop refers to carries out IP connectivity detection to two direct-connected systems, and " single-hop " mentioned here is a jumping of IP.

Multi-hop detects: BFD can detect the free routing between two systems, and a lot of jumping may be crossed in these paths, also may overlap in some part.

Define the single-hop form and multi-hop form that control message in current communication protocol, its UDP (User Datagram Protocol, User Datagram Protocol) port numbers is respectively 3784 and 4784; Define the single-hop form of Echo message, its UDP port number is 3785 simultaneously.Therefore, for the free routing in network between two systems, if want BFD technology to detect, because Echo message does not have multi-hop form, the multi-hop inspection needing BFD to control message realizes, the path starting point so needing detected path to carry and object equipment support transmitting-receiving BFD message simultaneously, and create BFD session and safeguard its state machine, testing process is more loaded down with trivial details.

Summary of the invention

For the defect existed in prior art, the object of the present invention is to provide a kind of multi-hop based on Echo message to detect implementation method, realize multi-hop by Echo message and detect, avoid object equipment to create and reply and safeguard its state machine, simplify testing process.

For reaching above object, the technical scheme that the present invention takes is: a kind of multi-hop based on Echo message detects implementation method, configure route between two routers can reach, local router creates Echo message and sends to object router, the encapsulation format of Echo message is: object Mac+ source Mac+0800+IP layer payload+UDP layer payload+BFD payload, for the purpose of the object IP that IP layer payload comprises, router interface IP, source IP are local router interface IP; After object router receives Echo message, the object IP in IP layer payload is become local router interface IP, source IP becomes object router interface IP, forms reply message and issues local router; After local router receives and replys message, detect according to BFD agreement regulation.

On the basis of technique scheme, in described Echo message 0800 is ethernet ip Protocol Type value.

On the basis of technique scheme, UDP floor payload comprises destination interface number, and destination slogan is 4785.

On the basis of technique scheme, BFD payload comprises minimum transmission frequency field and expects Required Min Rx Interval field, is all the parameters for controlling to detect setting, and is 0 value.

On the basis of technique scheme, described local router and object router belong to two systems respectively, and can be reached by routing configuration multi-hop therebetween.

On the basis of technique scheme, after object router receives Echo message, termination message repeating, after identifying the destination slogan 4785 of UDP layer payload, carry out decapsulation, and it is constant to remain potted form, changes encapsulated content Echo message.

On the basis of technique scheme, after local router receives and replys message, the local Echo message multi-hop session status created becomes UP from down, enters detected state, and the change of detected state is carried out according to BFD agreement regulation.

Beneficial effect of the present invention is: E-Packet because Echo message carries out three layers, Echo message is expanded, multi-hop detects to make it support, make the detection range of Echo message from direct-connected system extension to two systems, the path that can detect expands IP multi-hop to from IP mono-jumping, compared with control message multi-hop, same section of multihop routing is detected, initial plant is only needed to create session maintain sessions state machine, object equipment only does message repeating process, simplify testing process, effectively improve the utilance of object equipment B FD session.

Accompanying drawing explanation

Fig. 1 is that the multi-hop that the present invention is based on Echo message detects implementation method schematic diagram;

Fig. 2 is the encapsulation format schematic diagram of Echo message of the present invention;

Fig. 3 is the encapsulation format schematic diagram of IP layer payload;

Fig. 4 is the encapsulation format schematic diagram of UDP layer payload;

Fig. 5 is the encapsulation format schematic diagram of BFD payload.

Embodiment

Below in conjunction with drawings and Examples, the present invention is described in further detail.

The multi-hop that the present invention is based on Echo message detects implementation method, and concrete steps are as follows:

S1. as shown in Figure 1, configure two routers, be divided into local router and object router, local router and object router belong to two systems respectively, and local router interface IP (IP1) and object router interface IP (IP2) can be reached by routing configuration multi-hop therebetween, with the Routing Protocol such as static routing or ospf, i.e. ping IP2 on router-A, can lead to by ping; Ping IP1 on router B, can lead to by ping.

S2. the Echo message multi-hop of local router configuration BFD, and create the session of Echo message multi-hop.The object IP of Echo message multi-hop session is IP2, and source IP is IP1.Echo message, by intermediate equipment coupling routing forwarding message, is sent to object router by local router.As shown in Figure 2, Echo message encapsulation format according to BFD protocol definition is: object Mac (DMac)+source Mac (SMac)+0800+IP layer payload (IP PDU)+UDP layer payload (UDP PDU)+BFD payload (BFD PDU).Wherein, 0800 is ethernet ip Protocol Type value, IP PDU, UDP PDU, BFD PDU are respectively as shown in Fig. 3, Fig. 4, Fig. 5, and the object IP (Destination ip) that IP PDU comprises is IP2, and source IP (Source ip) is IP1; It is 4785 that BFD PDU comprises destination slogan (Destination port); BFD PDU comprises minimum transmission frequency field (Desired Min TX Interval) and expects Required Min Rx Interval field (Required Min RX Interval), all the parameters for controlling to detect setting, for meaningless Echo message, all fill out 0 value, Echo expects that Required Min Rx Interval (Required Min Echo RX Interval) is packet check frequency.

S3. after object router receives Echo message, the object IP comprised due to IP PDU is IP2, termination message repeating, and identifying that BFD PDU comprises destination slogan is after 4785, carries out encapsulated content change to Echo message.Be specially, encapsulation format is constant, and in IP PDU, object IP becomes the IP1 of this Echo message, and source IP becomes the IP2 of this Echo message, is formed and replys message (Echo Reply), by intermediate equipment coupling routing forwarding to local router.

S4. after local router receives described reply message, the local Echo message multi-hop session status created becomes UP from down, enters detected state, detects according to BFD agreement regulation.

The present invention defines BFD PDU, and to comprise destination slogan be 4785, for multi-hop Echo message identification application type, Echo message is encapsulated as local router interface IP (IP1) and object router interface IP (IP2), intermediate equipment walks three layers of forwarding, send on after Echo message arrives object router, object router identification port numbers is after 4785, carries out processing and returning, make Echo message support multi-hop inspection, Echo packet check scope can be expanded.

The present invention is not limited to above-mentioned execution mode, and for those skilled in the art, under the premise without departing from the principles of the invention, can also make some improvements and modifications, these improvements and modifications are also considered as within protection scope of the present invention.The content be not described in detail in this specification belongs to the known prior art of professional and technical personnel in the field.

Claims

1. the multi-hop based on Echo message detects implementation method, it is characterized in that, configure route between two routers can reach, local router creates Echo message and sends to object router, the encapsulation format of Echo message is: object Mac+ source Mac+0800+IP layer payload+UDP layer payload+BFD payload, for the purpose of the object IP that IP layer payload comprises, router interface IP, source IP are local router interface IP; After object router receives Echo message, the object IP in IP layer payload is become local router interface IP, source IP becomes object router interface IP, forms reply message and issues local router; After local router receives and replys message, detect according to BFD agreement regulation.

2. detect implementation method based on the multi-hop of Echo message as claimed in claim 1, it is characterized in that: in described Echo message 0800 is ethernet ip Protocol Type value.

3. detect implementation method based on the multi-hop of Echo message as claimed in claim 1, it is characterized in that: UDP floor payload comprises destination interface number, destination slogan is 4785.

4. detect implementation method based on the multi-hop of Echo message as claimed in claim 1, it is characterized in that: BFD payload comprises minimum transmission frequency field and expects Required Min Rx Interval field, are all the parameters for controlling to detect setting, and are 0 value.

5. detect implementation method based on the multi-hop of Echo message as claimed in claim 1, it is characterized in that: described local router and object router belong to two systems respectively, and can be reached by routing configuration multi-hop therebetween.

6. detect implementation method based on the multi-hop of Echo message as claimed in claim 1, it is characterized in that: after object router receives Echo message, termination message repeating, after identifying the destination slogan 4785 of UDP layer payload, decapsulation is carried out to Echo message, and it is constant to remain potted form, encapsulated content is changed.

7. detect implementation method based on the multi-hop of Echo message as claimed in claim 1, it is characterized in that: after local router receives and replys message, the local Echo message multi-hop session status created becomes UP from down, enters detected state, and the change of detected state is carried out according to BFD agreement regulation.