CN103401726A

CN103401726A - Network path detecting method, device and system

Info

Publication number: CN103401726A
Application number: CN2013103069324A
Authority: CN
Inventors: 张春宇; 魏波
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2013-07-19
Filing date: 2013-07-19
Publication date: 2013-11-20
Anticipated expiration: 2033-07-19
Also published as: CN103401726B

Abstract

The invention discloses a network path detecting method, a network path detecting device and a network path detecting system. When an exchanger receives a detecting message, if the exchanger is an initial exchanger or an intermediate exchanger in a path to be detected, the exchanger determines that a universal matching head of the detecting message is matched with matching item information in a detecting flow table of the exchanger and the exchanger determines that check flow table data in the detecting message is matched with matching item information in a forwarding flow table of the exchanger according to a command in the detecting flow table of the exchanger, the detecting message is sent to a next exchanger of the exchanger according to a command in the forwarding flow table of the exchanger and a detection response message is sent to a controller, so that if not receiving a detection response message sent by the next exchanger of the exchanger in preset time, the controller determines that a fault exists in the path between the exchanger and the next exchanger of the exchanger according to the detection response message sent by the exchanger, and thus, the problem that the fault path cannot be specifically determined in the prior art is solved.

Description

Network path detection method and device, system

Technical field

The embodiment of the present invention relates to communication technical field, relates in particular to a kind of network path detection method and device, system.

Background technology

In software defined network (SDN, Software Defined Network) technology, controller is realized the management to all switches of the whole network by the agreement (OpenFlow) of standard, completes switch all of the port information and overall network topology.Controller can be revised by OpenFlow the stream table information of switch, realizes the control to the transmission path of message in the whole network switch.

Due to the transmission of switch bearing message, the connectedness of therefore surveying the path between the whole network switch is very important, is in the prior art by path trace (TraceRoute) technology, to survey the connectedness in the path between switch.For example, source node sends for the first time with life span field (time-to-live, TTL) value is 1 test packet, test packet is through first switch, it is 0 that its value just subtracts 1, test packet is just abandoned by first switch, and first switch sends the overtime error message of TTL to source node, and source node can determine that source node is communicated with to the path of the first switch; Afterwards, it is 2 test packet that source node sends ttl value for the second time, test packet is every subtracts 1 through a switch ttl value, when test packet through second switch, ttl value is 0, test packet is just abandoned by second switch, and second switch sends the overtime error message of TTL to source node, and source node can determine that source node is communicated with to the path of the second switch; Afterwards, it is 3 test packet that source node sends ttl value for the third time, test packet is every subtracts 1 through a switch ttl value, when test packet through the 3rd switch, ttl value is 0, test packet is just abandoned by the 3rd switch, and the 3rd switch sends the overtime error message of TTL to source node, and source node can determine that the path of source node to the three switches is communicated with.Further, suppose that it is not receive error message after 4 test packet that source node the 4th time sends ttl value, there is failure path in the path that can determine source node to the four switches, but because the each path that forwards of test packet is likely different, the test packet that sends for the 4th time does not likely pass through above-mentioned the second switch and the 3rd switch after tested, therefore, can not determine that there is fault in which section path between source node to the four switches, that is to say that there is fault in the path of can not determine between which two switch.

Hence one can see that, in prior art, by TraceRoute detection failure path, can't specifically determine the problem of failure path.

Summary of the invention

The invention provides a kind of network path detection method and device, system, in order to solve in prior art, exist and can't specifically determine the problem of failure path.

First aspect, provide a kind of network path detection method, comprising:

Switch receives probe messages, and described probe messages is that described controller builds according to the path list item in path to be detected;

if described switch is initial exchange machine or intermediary switch in described path to be detected, described switch determines that the occurrence information in the detection flows table of the general match head of described probe messages and described switch is complementary, and described switch determines that according to the instruction in the described detection flows table of described switch the occurrence information in the forwarding flow table of verification stream table data in described probe messages and described switch is complementary, according to the instruction in the described forwarding flow table of described switch, described probe messages is sent to the next switch that is connected with described switch on described path to be detected, and send detection response message to described controller, so that the detection response message that described controller sends according to described switch, if in Preset Time, do not receive the detection response message that the next switch of described switch sends, there is fault in the path between the next switch of definite described switch and described switch.

Based on first aspect, in the possible implementation of the first, described method also comprises:

if described switch is the termination switch in described path to be detected, if the occurrence information in the general match head of the definite described probe messages of described switch and the detection flows table of described switch is complementary, and described switch determines that according to the instruction in the detection flows table of described switch the occurrence information in the forwarding flow table of verification stream table data in described probe messages and described switch is complementary, to described controller, send detection response message, so that the detection response message that described controller sends according to described switch, determine that the path between the upper switch of described switch and described switch is communicated with.

Based on the possible implementation of the first of first aspect, in the possible implementation of the second, if described switch is the initial exchange machine in described path to be detected, described switch reception probe messages comprises: described switch receives the described probe messages that described controller sends;

If described switch is intermediary switch or termination switch in described path to be detected, described switch reception probe messages comprises: described switch is received in the described probe messages of the upper switch transmission that is connected with described switch on described detective path.

Based on the possible implementation of first or the second of first aspect or first aspect, in the third possible implementation, described switch comprises before receiving probe messages:

Described switch receives the described detection flows table that described controller sends, and the described forwarding flow table corresponding with described switch.

The third possible implementation based on first aspect, in the 4th kind of possible implementation, occurrence information in described detection flows table comprises the protocol port information of described probe messages, and the occurrence information in described forwarding flow table comprises source host information and the destination host information in described path to be detected.

Based on the possible implementation of first or the second of first aspect or first aspect, in the 5th kind of possible implementation, when described probe messages was User Datagram Protoco (UDP) UDP message, the general match head of described probe messages comprised the protocol port information of described probe messages; The verification stream table data of described probe messages comprise source host information and the destination host information in described path to be detected.

Second aspect, provide a kind of network path detection method, and described method is applied to controller, comprising:

Receive the detection response message that the switch in path to be detected sends, described detection response message comprises the sign of described switch;

The sign of the described switch that comprises according to described detection response message, if while determining that described switch is initial exchange machine in described path to be detected or intermediary switch, and in Preset Time, do not receive the detection response message of the next switch transmission that is connected with described switch on described path to be detected, determine that there is fault in the path between described switch and described next switch.

Based on second aspect, in the possible implementation of the first, after the detection response message that the switch in described reception path to be detected sends, comprising:

The sign of the described switch that comprises according to described detection response message, if, while determining that described switch is the termination switch in described path to be detected, according to described detection response message, determine that described termination switch and the path between a upper switch that is connected with described termination switch on described path to be detected are communicated with.

Based on the possible implementation of the first of second aspect or second aspect, in the possible implementation of the second, before the detection response message that the switch in receiving path to be detected sends, also comprise:

The detection flows table is sent to each switch in described path to be detected, and forwarding flow table corresponding with each switch in described path to be detected is sent to corresponding switch in described path to be detected;

In described path to be detected, each switch comprises initial exchange machine, intermediary switch and termination switch.

Based on the possible implementation of the second of second aspect, in the third possible implementation, occurrence information in described detection flows table comprises the protocol port information of described probe messages, and the occurrence information in described forwarding flow table comprises source host information and the destination host information in described path to be detected.

Based on the possible implementation of the second of second aspect, in the 4th kind of possible implementation, described the detection flows table is sent to each switch in described path to be detected, and, after forwarding flow table corresponding with each switch in described path to be detected is sent to switch corresponding in described path to be detected, comprising:

According to the path list item in path to be detected, build probe messages, the path list item in described path to be detected comprises the source host information in described path to be detected, destination host information and each exchanger information.

Based on the 4th kind of possible implementation of second aspect, in the 5th kind of possible implementation, described probe messages comprises general match head and verification stream table data;

The general match head of described probe messages mates in order to the occurrence information in the detection flows table corresponding with each switch in described path to be detected, when if described probe messages is User Datagram Protoco (UDP) UDP message, the general match head of described probe messages comprises the protocol port information of described probe messages;

The verification stream table data of described probe messages are mated in order to the occurrence information in the forwarding flow table corresponding with each switch in described path to be detected, and the verification stream table data of described probe messages comprise source host information and the destination host information in described path to be detected.

Based on the 4th or the 5th kind of possible implementation of second aspect, in the 6th kind of possible implementation, described path according to path to be detected list item, after building probe messages, comprising:

described probe messages is sent to the initial exchange machine in described path to be detected, so that if the occurrence information in the detection flows table of the general match head of the definite described probe messages of described initial exchange machine and described initial exchange machine is complementary, and determine that according to the instruction in the detection flows table of described initial exchange machine the occurrence information in the forwarding flow table of verification stream table data in described probe messages and described switch is complementary, according to the instruction in the forwarding flow table of described initial exchange machine, described probe messages is sent to the next switch of described initial exchange machine, and send detection response message to described controller.

The third aspect, provide a kind of network path sniffer, is positioned at exchanger side, comprising:

Receiver module, be used to receiving probe messages, described probe messages is that controller builds according to the path list item in path to be detected;

Determination module, when when described switch, being the initial exchange machine in described path to be detected or intermediary switch, determine that the occurrence information in the detection flows table of the general match head of described probe messages and described switch is complementary, and determine that according to the instruction in the detection flows table of described switch the occurrence information in the forwarding flow table of verification stream table data in described probe messages and described switch is complementary;

Sending module, instruction for the forwarding flow table according to described switch, described probe messages is sent to the next switch of described switch, and send detection response message to described controller, so that the detection response message that described controller sends according to described switch, if in Preset Time, do not receive the detection response message that the next switch of described switch sends, there is fault in the path between the next switch of definite described switch and described switch.

Based on the third aspect, in the possible implementation of the first, if described switch is the termination switch in described path to be detected, at described determination module, determine that the occurrence information in the detection flows table of the general match head of described probe messages and described switch is complementary, and while determining that according to the instruction in the detection flows table of described switch occurrence information in the forwarding flow table of verification stream table data in described probe messages and described switch is complementary;

Described sending module, for sending detection response message to described controller; So that according to the detection response message that described switch sends, determining the path between the upper switch of described switch and described switch, described controller is communicated with.

Based on the possible implementation of the first of the third aspect, in the possible implementation of the second, if described switch is the initial exchange machine in described path to be detected, described receiver module: the described probe messages that specifically sends be used to receiving described controller;

If described switch is the intermediary switch in described path to be detected or stops switch, described receiver module: specifically be used to being received in the described probe messages of the upper switch transmission that is connected with described switch on described detective path.

Based on the possible implementation of first or the second of the third aspect or the third aspect, in the third possible implementation, described receiver module, the described detection flows table that also sends be used to receiving described controller, and the described forwarding flow table corresponding with described switch.

The third possible implementation based on the third aspect, in the 4th kind of possible implementation, occurrence information in described detection flows table comprises the protocol port information of described probe messages, and the occurrence information in described forwarding flow table comprises source host information and the destination host information in described path to be detected.

Based on the possible implementation of first or the second of the third aspect or the third aspect, in the 5th kind of possible implementation, when described probe messages was User Datagram Protoco (UDP) UDP message, the general match head of described probe messages comprised the protocol port information of described probe messages; The verification stream table data of described probe messages comprise source host information and the destination host information in described path to be detected.

Fourth aspect, provide a kind of network path sniffer, is positioned at the controller side, comprising:

Receiver module, for the detection response message that the switch that receives path to be detected sends, described detection response message comprises the sign of described switch;

Determination module, the sign that is used for the described switch that comprises according to described detection response message, if determine that described switch is initial exchange machine or the intermediary switch in described path to be detected, and the detection response message that the next switch that does not receive described switch in Preset Time sends, determine that there is fault in the path between described switch and described next switch.

Based on fourth aspect, in the possible implementation of the first, described determination module, also for the sign of the described switch that comprises according to described detection response message, if, while determining that described switch is the termination switch in described path to be detected, according to described detection response message, determine that described termination switch and the path between a upper switch that is connected with described termination switch on described path to be detected are communicated with.

Based on the possible implementation of the first of fourth aspect or fourth aspect, in the possible implementation of the second, described device also comprises:

Sending module, for the detection flows table being sent to each switch of described path to be detected, and send to corresponding switch in described path to be detected by forwarding flow table corresponding with each switch in described path to be detected;

Based on the possible implementation of the second of fourth aspect, in the third possible implementation, occurrence information in described detection flows table comprises the protocol port information of described probe messages, and the occurrence information in described forwarding flow table comprises source host information and the destination host information in described path to be detected.

Based on the possible implementation of the second of fourth aspect, in the 4th kind of possible implementation, described device, is characterized in that, also comprises:

Build module, for at described sending module, the detection flows table being sent to each switch of described path to be detected, and after forwarding flow table corresponding with each switch in described path to be detected is sent to switch corresponding in described path to be detected, path list item according to path to be detected, build probe messages, the path list item in described path to be detected comprises the source host information in described path to be detected, destination host information and each exchanger information.

Based on the 4th kind of possible implementation of fourth aspect, in the 5th kind of possible implementation, described probe messages comprises general match head and verification stream table data;

the 4th or the 5th kind of possible implementation based on fourth aspect, in the 6th kind of possible implementation, described sending module, also for the probe messages by described structure module construction, send to the initial exchange machine in described path to be detected, so that if the occurrence information in the detection flows table of the general match head of the definite described probe messages of described initial exchange machine and described initial exchange machine is complementary, and determine that according to the instruction in the detection flows table of described initial exchange machine the occurrence information in the forwarding flow table of verification stream table data in described probe messages and described switch is complementary, according to the instruction in the forwarding flow table of described initial exchange machine, described probe messages is sent to the next switch of described initial exchange machine, and send detection response message to described controller.

The 5th aspect, provide a kind of network path detection system, comprising: each switch in controller and path to be detected, and in described path to be detected, each switch comprises the initial exchange machine;

Described controller, build probe messages for the path list item according to described path to be detected, and described probe messages sent to described initial exchange machine;

described initial exchange machine, for after receiving described probe messages, if the occurrence information in the general match head of definite described probe messages and the detection flows table of described initial exchange machine is complementary, and described initial exchange machine determines that according to the instruction in the described detection flows table of described initial exchange machine the occurrence information in the forwarding flow table of verification stream table data in described probe messages and described initial exchange machine is complementary, according to the instruction in the described forwarding flow table of described initial exchange machine, described probe messages is sent to the next switch that is connected with described initial exchange machine on described path to be detected, and send detection response message to described controller,

Described controller, also for the detection response message according to described initial exchange machine transmission, if in Preset Time, do not receive the detection response message that the next switch of described initial exchange machine sends, there is fault in the path between the next switch of definite described initial exchange machine and described initial exchange machine.

Based on the 5th aspect, in the possible implementation of the first, the next switch of described initial exchange machine comprises intermediary switch;

described intermediary switch, if the occurrence information for the detection flows table of the general match head of determining described probe messages and described intermediary switch is complementary, and described intermediary switch determines that according to the instruction in the described detection flows table of described intermediary switch the occurrence information in the forwarding flow table of verification stream table data in described probe messages and described intermediary switch is complementary, according to the instruction in the described forwarding flow table of described intermediary switch, described probe messages is sent to the next switch that is connected with described intermediary switch on described path to be detected, and send detection response message to described controller,

Described controller, also for the detection response message according to described intermediary switch transmission, if in Preset Time, do not receive the detection response message that the next switch of described intermediary switch sends, there is fault in the path between the next switch of definite described intermediary switch and described intermediary switch.

The possible implementation of the first based on the 5th Huo Diwu aspect, aspect, in the possible implementation of the second, the next switch of described initial exchange machine comprises the termination switch, or the next switch of described intermediary switch comprises the termination switch;

Described termination switch, if the occurrence information for the detection flows table of the general match head of determining described probe messages and described termination switch is complementary, and described termination switch determines that according to the instruction in the detection flows table of described termination switch the occurrence information in the forwarding flow table of verification stream table data in described probe messages and described termination switch is complementary, and sends detection response message to described controller;

Described controller, the detection response message for sending according to described termination switch also, determine that the path between the upper switch of described termination switch and described termination switch is communicated with.

The present invention by switch when receiving probe messages, when if described switch is initial exchange machine or intermediary switch, and the occurrence information in the general match head of definite described probe messages and the detection flows table of described switch is complementary, and the occurrence information in the verification stream table data in definite described probe messages and the forwarding flow table of described switch is complementary, according to the instruction in the forwarding flow table of described switch, described probe messages is sent to the next switch of described switch, and send detection response message to described controller; So that the detection response message that described controller sends according to described switch, if in Preset Time, do not receive the detection response message that the next switch of described switch sends, there is fault in the path between the next switch of definite described switch and described switch, can solve in prior art and can not specifically determine the problem of failure path.

The accompanying drawing explanation

In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, below will the accompanying drawing of required use in embodiment or description of the Prior Art be briefly described, apparently, accompanying drawing in the following describes is some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain according to these accompanying drawings other accompanying drawing.

The schematic flow sheet of the network path detection method that Fig. 1 provides for one embodiment of the invention;

The schematic flow sheet of the network path detection method that Fig. 2 provides for another embodiment of the present invention;

The signaling diagram of the network path detection method that Fig. 3 provides for another embodiment of the present invention,

Fig. 4 is the system architecture diagram of described network path detection method application embodiment illustrated in fig. 3;

The structural representation of the network path sniffer that Fig. 5 provides for another embodiment of the present invention;

The structural representation of the network path sniffer that Fig. 6 provides for another embodiment of the present invention;

The structural representation of the network path sniffer that Fig. 7 provides for another embodiment of the present invention;

The structural representation of the network path sniffer that Fig. 8 provides for another embodiment of the present invention;

A kind of structural representation of the network path detection system that Fig. 9 provides for another embodiment of the present invention;

Another structural representation of the network path detection system that Figure 10 provides for another embodiment of the present invention.

Embodiment

For the purpose, technical scheme and the advantage that make the embodiment of the present invention clearer, below in conjunction with the accompanying drawing in the embodiment of the present invention, technical scheme in the embodiment of the present invention is clearly and completely described, obviously, described embodiment is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment in the present invention, those of ordinary skills, not making under the creative work prerequisite the every other embodiment that obtains, belong to the scope of protection of the invention.

The schematic flow sheet of the network path detection method that Fig. 1 provides for one embodiment of the invention, as shown in Figure 1, the network path detection method of the present embodiment can comprise:

101, switch receives probe messages, and described probe messages is that controller builds according to the path list item in path to be detected.

For instance, source host information, destination host information and each exchanger information in the described path to be detected that comprises according to the path list item in path to be detected of controller build probe messages.Probe messages comprises general match head (Common match header) and verification stream table data (Real match data);

Wherein, the general match head of described probe messages mates in order to the occurrence information in the detection flows table corresponding with each switch in described path to be detected, when if described probe messages is User Datagram Protoco (UDP) UDP message, the general match head of described probe messages comprises the protocol port information of described probe messages;

In an optional execution mode of the present invention, described switch comprises before receiving probe messages:

Wherein, the forwarding flow table of described switch is that described controller builds according to the path list item in described path to be detected;

The path list item in described path to be detected for example comprises source host information and the destination host information in described path to be detected, and the information of each switch in described path to be detected, wherein, the information of each switch for example comprises sequence number and sign corresponding to each switch that each switch is corresponding, and the sign that each switch is corresponding comprises the sign of initial exchange machine, sign and the termination switch identification of intermediary switch;

Occurrence information in forwarding flow table corresponding to described switch for example comprises source host information and the destination host information in described path to be detected, can also comprise the information (for example sequence number of described switch and sign) of described switch;

The detection flows table of described switch be described controller and described switch between build after the escape way set up, for and described probe messages mate, when if described probe messages is user datagram protocol message, the occurrence information in described detection flows table for example comprises the protocol port information of described probe messages.

In an optional execution mode of the present invention, identification information according to switch, if described switch is the initial exchange machine in described path to be detected, described switch reception probe messages comprises: described switch receives the described probe messages that described controller sends;

102, when described switch is initial exchange machine or the intermediary switch in described path to be detected, if described switch is determined the occurrence information in the detection flows table of the general match head of described probe messages and described switch and is complementary, and determine that according to the instruction in the detection flows table of described switch the occurrence information in the forwarding flow table of verification stream table data in described probe messages and described switch is complementary, according to the instruction in the forwarding flow table of described switch, described probe messages is sent to the next switch of described switch, and send detection response message to described controller, so that the detection response message that described controller sends according to described switch, if in Preset Time, do not receive the detection response message that the next switch of described switch sends, there is fault in the path between the next switch of definite described switch and described switch.

In an optional execution mode of the present invention, the detection response message that described controller sends according to described switch, if in Preset Time, receive the detection response message that the next switch of described switch sends, the path between the next switch of definite described switch and described switch is UNICOM.

In an optional execution mode of the present invention, if described switch is the termination switch in described path to be detected, described switch comprises after receiving probe messages:

Described switch determines that the occurrence information in the detection flows table of the general match head of described probe messages and described switch is complementary, and determine that according to the instruction in the detection flows table of described switch the occurrence information in the forwarding flow table of verification stream table data in described probe messages and described switch is complementary, and sends detection response message to described controller; So that according to the detection response message that described switch sends, determining the path between the upper switch of described switch and described switch, described controller is communicated with.

the present invention by switch when receiving probe messages, when if described switch is initial exchange machine or intermediary switch, and the occurrence information in the general match head of definite described probe messages and the detection flows table of described switch is complementary, and determine that according to the instruction in the detection flows table of described switch the occurrence information in the forwarding flow table of verification stream table data in described probe messages and described switch is complementary, according to the instruction in the forwarding flow table of described switch, described probe messages is sent to the next switch of described switch, and send detection response message to described controller, so that the detection response message that described controller sends according to described switch, if in Preset Time, do not receive the detection response message that the next switch of described switch sends, there is fault in the path between the next switch of definite described switch and described switch.Can solve in prior art and can not specifically determine the problem of failure path.

The schematic flow sheet of the network path detection method that Fig. 2 provides for another embodiment of the present invention as shown in Figure 2, comprising:

201, controller receives the detection response message that the switch in path to be detected sends, and described detection response message comprises the sign of described switch.

In an optional execution mode of the present invention, described controller comprises before receiving the detection response message of the switch transmission in path to be detected:

Described controller sends to each switch in described path to be detected by the detection flows table, and forwarding flow table corresponding with each switch in described path to be detected is sent to corresponding switch in described path to be detected;

In described path to be detected, each switch comprises initial exchange machine, intermediary switch and termination switch;

Wherein, described detection flows table be described controller and each switch between build after the escape way set up, for and described probe messages mate, when described probe messages was user datagram protocol message, the occurrence information in described detection flows table for example comprised the protocol port information of described probe messages.

Wherein, the forwarding flow table that each switch is corresponding is that described controller builds according to the path list item in described path to be detected;

In an optional execution mode of the present invention, described the detection flows table is sent to each switch in described path to be detected, and, after forwarding flow table corresponding with each switch in described path to be detected is sent to switch corresponding in described path to be detected, comprising:

Described controller, according to the path list item in path to be detected, builds probe messages, and the path list item in described path to be detected comprises the source host information in described path to be detected, destination host information and each exchanger information;

Wherein, described probe messages comprises general match head and verification stream table data;

In an optional execution mode of the present invention, described controller, according to the path list item in path to be detected, after building probe messages, comprising:

described controller sends to the initial exchange machine in described path to be detected by described probe messages, so that determining the occurrence information in the detection flows table of the general match head of described probe messages and described initial exchange machine, described initial exchange machine is complementary, and determine that according to the instruction in the detection flows table of described initial exchange machine the occurrence information in the forwarding flow table of verification stream table data in described probe messages and described switch is complementary, according to the instruction in the forwarding flow table of described initial exchange machine, described probe messages is sent to the next switch of described initial exchange machine, and send detection response message to described controller.

202, the sign of the described switch that comprises according to described detection response message of controller, if determine that described switch is initial exchange machine or the intermediary switch in described path to be detected, and the detection response message that the next switch that does not receive described switch in Preset Time sends, determine that there is fault in the path between described switch and described next switch.

In an optional execution mode of the present invention, the sign of the described switch that controller comprises according to described detection response message, if determine that described switch is initial exchange machine or the intermediary switch in described path to be detected, and the detection response message that the next switch that receives described switch in Preset Time sends, determine that the path between described switch and described next switch is UNICOM.

In an optional execution mode of the present invention, the sign of the described switch that controller comprises according to described detection response message, if while determining that described switch is the termination switch in described path to be detected, described controller determines that the path between the upper switch of described switch and described switch is UNICOM.It should be noted that, in the present embodiment, the detection response message that switch sends to controller comprises the identification information of this switch, and the identification information of described switch is used to indicate the type of exchange, for example stops switch, intermediary switch or initial exchange machine.Therefore, stop switch and to the detection response message of controller transmission, comprise the sign of this termination switch, when the controller stage after detection response message, if determine that detection response message comprises the sign that stops switch, determine that this detection response message is to stop switch to send, determine that the path detection finishes, and the path between a upper switch of definite this termination switch and this termination switch is UNICOM.

the embodiment of the present invention by switch when receiving probe messages, when if described switch is initial exchange machine or intermediary switch, and the occurrence information in the general match head of definite described probe messages and the detection flows table of described switch is complementary, and determine that according to the instruction in the detection flows table of described switch the occurrence information in the forwarding flow table of verification stream table data in described probe messages and described switch is complementary, according to the instruction in the forwarding flow table of described switch, described probe messages is sent to the next switch of described switch, and send detection response message to described controller, so that the detection response message that described controller sends according to described switch, if in Preset Time, do not receive the detection response message that the next switch of described switch sends, there is fault in the path between the next switch of definite described switch and described switch.Can solve in prior art and can not specifically determine the problem of failure path.

The signaling diagram of the network path detection method that Fig. 3 provides for another embodiment of the present invention, Fig. 4 are the system architecture diagram of described network path detection method application embodiment illustrated in fig. 3, and as shown in Figure 3, the described network path detection method of the present embodiment comprises:

301, controller is determined the path list item in path to be detected.

As shown in Figure 4, controller (Controller) and each switch have completed the Path Setup between each switch and controller by the Openflow agreement, controller can manage all switches by the Openflow agreement, realizes all of the port information of each switch and the topology of overall network.when host A needs and host B while communication failure occurring, for the path failure between host A and host B positions, at this moment, controller can be according to media access control (the Medium Access Control of host A, MAC) address and Internet protocol (Internet Protocol, IP) address, and the MAC Address of host B and IP address, and according to the topology information of overall network, determine the path to be detected between host A and host B, determine the path list item in path to be detected between host A and host B, as shown in Figure 2, path list item between host A and host B comprises that switch 1 is to the sequence number of switch 5 correspondences (for example 1, 2, 3, 4, 5), also comprise the sign of switch 1 to switch 5 correspondences, for example, the initial exchange machine that is designated of switch 1, switch 5 be designated the termination switch, switch 2 is to the intermediary switch that is designated of switch 4.Further, in the path list item between host A and host B, also comprise host A (source host) information and host B (destination host) information.

It should be noted that, before step 301, controller has sent to the detection flows table respectively each switch in path to be detected, and the forwarding flow table that in path to be detected, each switch is corresponding is sent to switch corresponding in path to be detected.

As shown in Figure 4, controller when with switch 1, switch 2, switch 3, switch 4 and switch 5 foundation safety, being connected, can send to switch 1, switch 2, switch 3, switch 4 and switch 5 by the detection flows table by the escape way of setting up separately respectively.The protocol port information that for example comprises probe messages in occurrence information in the detection flows table.

As shown in Figure 4, when between host A and host B, needing to communicate by letter, controller, according to the path list item between host A and host B, is determined the forwarding flow table of switch 1 to switch 5 correspondences.It should be noted that, switch 1 to switch 5 each self-corresponding forwarding flow tables comprise occurrence information.Wherein, switch 1 for example comprises source host information and the destination host information in the path between host A and host B to the occurrence information in the forwarding flow table of switch 5 correspondences; Wherein, source host information for example comprises source port information, source host (host A) IP address or MAC Address, and destination host information for example comprises IP address or the MAC Address of destination interface information, destination host (host B).

302, controller, according to the path list item in path to be detected, builds probe messages.

Wherein, the probe messages of controller structure comprises openflow head, general match head and verification stream table data.

Wherein, the openflow head is the openflow protocol header that communicates between controller and switch;

General match head mates in order to the occurrence information in the detection flows table corresponding with each switch in path to be detected, for example, probe messages is User Datagram Protoco (UDP) (User Datagram Protocol, during UDP) message, the port numbers of the udp protocol of this probe messages (such as 55555) can be set to general match head.

User's verification stream table data are mated in order to the occurrence information in the forwarding flow table corresponding with each switch in path to be detected, with sending on corresponding switch that this guarantees that probe messages can be correct.Wherein, verification stream table data comprise source host information and the destination host information in path to be detected; Wherein, source host information for example comprises source port information, source host (host A) IP address or MAC Address, and destination host information for example comprises IP address or the MAC Address of destination interface information, destination host (host B).

303, controller sends to the initial exchange machine by the probe messages of structure.

For example, controller can send to the initial exchange machine by probe messages by openflow agreement between controller and initial exchange machine.

304, the initial exchange machine is determined the occurrence information matches success in the detection flows table of general match head in probe messages and initial exchange machine, and according to the instruction in the detection flows table of initial exchange machine, determine in the forwarding flow table of verification stream table data and initial exchange machine in probe messages the occurrence information matches successfully.

305, the initial exchange machine, according to the instruction in the forwarding flow table of initial exchange machine, sends to probe messages the next switch of initial exchange machine.

As shown in Figure 4, after the probe messages that initial exchange machine (switch 1) sends controller is removed the openflow head, by removing openflow head probe messages afterwards, send to switch 2.

306, the initial exchange machine sends detection response message to controller.

Wherein, in detection response message, can comprise the sign of the probe messages that controller builds and the information of initial exchange machine (such as the sequence number of initial exchange machine, sign etc.), further, the forwarding flow table information that can also comprise the initial exchange machine in detection response message, so that controller is verified the detection response message that the initial exchange machine sends.

If 307, controller does not receive the detection response message of the next switch transmission of initial exchange machine in Preset Time, determine that there is fault in the path between initial exchange machine and next switch.

For instance, as shown in Figure 4, there is fault in the path between switch 1 and switch 2, and switch 2 does not receive the probe messages that switch 1 sends, thereby switch 2 also can not send detection response message to controller.Therefore, controller, after the detection response message that receives switch 1 transmission, does not receive the detection response message that switch 2 sends in Preset Time, determines that there is fault in the path between switch 1 and switch 2.

it should be noted that, if suppose that controller receives the detection response message that switch 2 sends in Preset Time, determine that switch 1 is communicated with the path between switch 2, occurrence information matches in the general match head that switch 2 can be in determining probe messages and the detection flows table of switch 2 successfully, and according to the instruction in the detection flows table of switch 2, determine on the basis of the occurrence information matches success in the forwarding flow table of verification stream table data in probe messages and initial exchange machine, to switch 3, send probe messages, and send detection response message to controller, further, suppose that controller receives the detection response message that switch 3 sends in Preset Time, determine that the path between switch 2 and switch 3 is communicated with, if in Preset Time, do not receive the detection response message that switch 3 sends, determine that there is fault in the path between switch 2 and switch 3, by that analogy, switch 4 can be transmitted to probe messages and stop switch (switch 5), at this moment, after switch 5 receives probe messages, do not need to forward again probe messages, but directly to controller, send detection response message, wherein, the detection response message that switch 5 sends comprises the sign that stops switch, make controller determine stopping the detection of termination path, switch place.Therefore, if controller receives the detection response message that in path to be detected, each switch returns in Preset Time, can determine that path to be detected is communicated with.

It should be noted that, suppose to have path failure between switch 1 and switch 2, controller is again using switch 2 as the initial exchange device, redefine the path list item in path to be detected, and rebuild probe messages according to the path list item in the path to be detected that redefines, the probe messages that will rebuild afterwards sends to the initial exchange machine that redefines, and repeats above-mentioned steps and continues to initiate same fault-finding.

the embodiment of the present invention builds probe messages by controller according to the path list item in path to be detected, and probe messages is sent to the initial exchange machine in path to be detected, make the initial exchange machine in determining probe messages general match head and the occurrence information in the detection flows table of initial exchange machine be complementary, and on the basis that the occurrence information in the verification stream table data in definite probe messages and the forwarding flow table of initial exchange machine is complementary, to controller, return to detection response message, and probe messages is sent to the next switch (first intermediary switch) of initial exchange machine, make first intermediary switch in determining probe messages general match head and the occurrence information in the detection flows table of first intermediary switch be complementary, and on the basis that the occurrence information in the verification stream table data in definite probe messages and the forwarding flow table of first intermediary switch is complementary, this first intermediary switch is returned to detection response message to controller, and probe messages is sent to the second intermediary switch, suppose that the path between each switch in path to be detected is communicated with, controller can receive the detection response message that in path to be detected, each switch returns in Preset Time, thereby can determine that path to be detected is communicated with, suppose to have fault in path to be detected, the information of the controller switch that can comprise according to last detection response message that receives in Preset Time, determine that there are fault in switch that last sends detection response message and the path between next switch.

The probe messages that does not need to send according to the quantity of each switch in path to be detected respective amount due to the controller of the embodiment of the present invention, but only need to send a probe messages to the initial exchange machine in path to be detected, afterwards, if controller respectively receives at Preset Time the detection response message that in path to be detected, each switch returns respectively, determine that this path to be detected is communicated with, therefore, can improve detection efficient; Secondly, suppose to have fault in path to be detected, controller can send according to last the information of the switch that detection response message comprises, determine that there are fault in the switch of last transmission detection response message and the path between next switch, therefore can specifically determine failure path.

The structural representation of the network path sniffer that Fig. 5 provides for another embodiment of the present invention; Be positioned at exchanger side, as shown in Figure 5, comprise:

Receiver module 51, be used to receiving probe messages, described probe messages is that controller builds according to the path list item in path to be detected;

Determination module 52, when when described switch, being the initial exchange machine in described path to be detected or intermediary switch, determine that the occurrence information in the detection flows table of the general match head of described probe messages and described switch is complementary, and determine that according to the instruction in the detection flows table of described switch the occurrence information in the forwarding flow table of verification stream table data in described probe messages and described switch is complementary;

Sending module 53, instruction for the forwarding flow table according to described switch, described probe messages is sent to the next switch of described switch, and send detection response message to described controller, so that the detection response message that described controller sends according to described switch, if in Preset Time, do not receive the detection response message that the next switch of described switch sends, there is fault in the path between the next switch of definite described switch and described switch.

For instance, if described switch is the termination switch in described path to be detected, at described determination module 52, determine that the occurrence information in the detection flows table of the general match head of described probe messages and described switch is complementary, and while determining that according to the instruction in the detection flows table of described switch occurrence information in the forwarding flow table of verification stream table data in described probe messages and described switch is complementary;

Described sending module 53, for sending detection response message to described controller; So that according to the detection response message that described switch sends, determining the path between the upper switch of described switch and described switch, described controller is communicated with.

For instance, if described switch is the initial exchange machine in described path to be detected, described receiver module 51: the described probe messages that specifically sends be used to receiving described controller;

If described switch is the intermediary switch in described path to be detected or stops switch, described receiver module 51: specifically be used to being received in the described probe messages of the upper switch transmission that is connected with described switch on described detective path.

For instance, described receiver module 51, the described detection flows table that also sends be used to receiving described controller, and the described forwarding flow table corresponding with described switch.

For instance, the occurrence information in described detection flows table comprises the protocol port information of described probe messages, and the occurrence information in described forwarding flow table comprises source host information and the destination host information in described path to be detected.

For instance, when described probe messages was User Datagram Protoco (UDP) UDP message, the general match head of described probe messages comprised the protocol port information of described probe messages; The verification stream table data of described probe messages comprise source host information and the destination host information in described path to be detected.

The structural representation of the network path sniffer that Fig. 6 provides for another embodiment of the present invention; Be positioned at the controller side, as shown in Figure 6, comprise:

Receiver module 61, for the detection response message that the switch that receives path to be detected sends, described detection response message comprises the sign of described switch;

Determination module 62, the sign that is used for the described switch that comprises according to described detection response message, if while determining that described switch is initial exchange machine in described path to be detected or intermediary switch, and the detection response message that the next switch that does not receive described switch in Preset Time sends, determine that there is fault in the path between described switch and described next switch.

For instance, determination module 62, also for the sign of the described switch that comprises according to described detection response message, if, while determining that described switch is the termination switch in described path to be detected, according to described detection response message, determine that described termination switch and the path between a upper switch that is connected with described termination switch on described path to be detected are communicated with.

For instance, described device also comprises:

Sending module 63, for the detection flows table being sent to each switch of described path to be detected, and send to corresponding switch in described path to be detected by forwarding flow table corresponding with each switch in described path to be detected;

For instance, described device also comprises:

Build module 64, for at described sending module 63, the detection flows table being sent to each switch of described path to be detected, and after forwarding flow table corresponding with each switch in described path to be detected is sent to switch corresponding in described path to be detected, path list item according to path to be detected, build probe messages, the path list item in described path to be detected comprises the source host information in described path to be detected, destination host information and each exchanger information.

For instance, described probe messages comprises general match head and verification stream table data;

for instance, described sending module 63, also for the probe messages that described structure module 64 is built, send to the initial exchange machine in described path to be detected, so that if the occurrence information in the detection flows table of the general match head of the definite described probe messages of described initial exchange machine and described initial exchange machine is complementary, and determine that according to the instruction in the detection flows table of described initial exchange machine the occurrence information in the forwarding flow table of verification stream table data in described probe messages and described switch is complementary, according to the instruction in the forwarding flow table of described initial exchange machine, described probe messages is sent to the next switch of described initial exchange machine, and send detection response message to described controller.

The structural representation of the network path sniffer that Fig. 7 provides for another embodiment of the present invention.This network path sniffer can be switch.As shown in Figure 7, comprising: processor 71, memory 72 and communication bus 73, processor 71 is connected with memory 72 by communication bus 73, in memory 72, preserves the instruction that realizes the network path detection method; Further, can also comprise communication interface 74, by communication interface and other network element devices (for example controller or other switch) communication connection.

Processor 71 is carried out following steps for the instruction of calling memory 72:

Receive probe messages, described probe messages is that described controller builds according to the path list item in path to be detected;

if determine that described switch is initial exchange machine or the intermediary switch in described path to be detected, and the occurrence information in the general match head of definite described probe messages and the detection flows table of described switch is complementary, and determine that according to the instruction in the described detection flows table of described switch the occurrence information in the forwarding flow table of verification stream table data in described probe messages and described switch is complementary, according to the instruction in the described forwarding flow table of described switch, described probe messages is sent to the next switch that is connected with described switch on described path to be detected, and send detection response message to described controller, so that the detection response message that described controller sends according to described switch, if in Preset Time, do not receive the detection response message that the next switch of described switch sends, there is fault in the path between the next switch of definite described switch and described switch.

for instance, if determine that described switch is the termination switch in described path to be detected, and the occurrence information in the general match head of definite described probe messages and the detection flows table of described switch is complementary, and determine that according to the instruction in the detection flows table of described switch the occurrence information in the forwarding flow table of verification stream table data in described probe messages and described switch is complementary, to described controller, send detection response message, so that the detection response message that described controller sends according to described switch, determine that the path between the upper switch of described switch and described switch is communicated with.

For instance, if determine that described switch is the initial exchange machine in described path to be detected, receive probe messages and specifically comprise: receive the described probe messages that described controller sends;

If determine that described switch is the intermediary switch in described path to be detected or stops switch, receives probe messages and specifically comprises: the described probe messages that is received in the upper switch transmission that is connected with described switch on described detective path.

For instance, before receiving probe messages, comprising:

Receive the described detection flows table that described controller sends, and the described forwarding flow table corresponding with described switch; Wherein, the occurrence information in described detection flows table comprises the protocol port information of described probe messages, and the occurrence information in described forwarding flow table comprises source host information and the destination host information in described path to be detected.

The structural representation of the network path sniffer that Fig. 8 provides for another embodiment of the present invention.This network path sniffer can be controller.As shown in Figure 8, comprising: processor 81, memory 82 and communication bus 83, processor 81 is connected with memory 82 by communication bus 83, in memory 82, preserves the instruction that realizes the network path detection method; Further, can also comprise communication interface 84, by communication interface 84 and other network element devices (for example switch) communication connection.

Processor 81 is carried out following steps for the instruction of calling memory 82:

The sign of the described switch that comprises according to described detection response message, when determining that described switch is initial exchange machine in described path to be detected or intermediary switch, if in Preset Time, do not receive the detection response message of the next switch transmission that is connected with described switch on described path to be detected, determine that there is fault in the path between described switch and described next switch.

For instance, the sign of the described switch that comprises according to described detection response message, when definite described switch is the termination switch in described path to be detected, according to described detection response message, determine that described termination switch and the path between a upper switch that is connected with described termination switch on described path to be detected are communicated with.

For instance, before the detection response message that the switch in receiving path to be detected sends, also comprise:

For instance, described the detection flows table is sent to each switch in described path to be detected, and, after forwarding flow table corresponding with each switch in described path to be detected is sent to switch corresponding in described path to be detected, comprising:

According to the path list item in path to be detected, build probe messages, the path list item in described path to be detected comprises the source host information in described path to be detected, destination host information and each exchanger information;

For instance, the general match head of described probe messages mates in order to the occurrence information in the detection flows table corresponding with each switch in described path to be detected, when if described probe messages is User Datagram Protoco (UDP) UDP message, the general match head of described probe messages comprises the protocol port information of described probe messages;

For instance, described path according to path to be detected list item, after building probe messages, comprising:

A kind of structural representation of the network path detection system that Fig. 9 provides for another embodiment of the present invention, as shown in Figure 9, comprising: each switch in controller 91 and path to be detected; Wherein, each switch in path to be detected comprises initial exchange machine 92;

For instance, controller 91, build probe messages for the path list item according to described path to be detected, and described probe messages sent to described initial exchange machine;

initial exchange machine 92, for after receiving described probe messages, if the occurrence information in the general match head of definite described probe messages and the detection flows table of described initial exchange machine is complementary, and described initial exchange machine determines that according to the instruction in the described detection flows table of described initial exchange machine the occurrence information in the forwarding flow table of verification stream table data in described probe messages and described initial exchange machine is complementary, according to the instruction in the described forwarding flow table of described initial exchange machine, described probe messages is sent to the next switch that is connected with described initial exchange machine on described path to be detected, and send detection response message to described controller,

Controller 91, also for the detection response message according to described initial exchange machine transmission, if in Preset Time, do not receive the detection response message that the next switch of described initial exchange machine sends, there is fault in the path between the next switch of definite described initial exchange machine and described initial exchange machine.

For instance, as shown in Figure 9, the next switch of initial exchange machine comprises intermediary switch 93;

intermediary switch 93, if the occurrence information for the detection flows table of the general match head of determining described probe messages and described intermediary switch is complementary, and described intermediary switch determines that according to the instruction in the described detection flows table of described intermediary switch the occurrence information in the forwarding flow table of verification stream table data in described probe messages and described intermediary switch is complementary, according to the instruction in the described forwarding flow table of described intermediary switch, described probe messages is sent to the next switch that is connected with described intermediary switch on described path to be detected, and send detection response message to described controller,

Controller 91, also for the detection response message according to described intermediary switch transmission, if in Preset Time, do not receive the detection response message that the next switch of described intermediary switch sends, there is fault in the path between the next switch of definite described intermediary switch and described intermediary switch.

For instance, another structural representation of the network path detection system that Figure 10 provides for another embodiment of the present invention, as shown in figure 10, the next switch of described initial exchange machine comprises termination switch 94, perhaps as shown in Figure 9, the next switch of described intermediary switch comprises termination switch 94;

Stop switch 94, if the occurrence information for the detection flows table of the general match head of determining described probe messages and described termination switch is complementary, and described termination switch determines that according to the instruction in the detection flows table of described termination switch the occurrence information in the forwarding flow table of verification stream table data in described probe messages and described termination switch is complementary, and sends detection response message to described controller;

Controller 91, the detection response message for sending according to described termination switch also, determine that the path between the upper switch of described termination switch and described termination switch is communicated with.

In several embodiment that the application provides, should be understood that, disclosed system, apparatus and method, can realize by another way.For example, device embodiment described above is only schematic, for example, the division of described unit, be only that a kind of logic function is divided, during actual the realization, other dividing mode can be arranged, for example a plurality of unit or assembly can in conjunction with or can be integrated into another system, or some features can ignore, or do not carry out.Another point, shown or discussed coupling each other or direct-coupling or communication connection can be by some interfaces, indirect coupling or the communication connection of device or unit can be electrically, machinery or other form.

Described unit as separating component explanation can or can not be also physically to separate, and the parts that show as unit can be or can not be also physical locations, namely can be positioned at a place, or also can be distributed on a plurality of network element.Can select according to the actual needs wherein some or all of unit to realize the purpose of the present embodiment scheme.

In addition, each functional unit in each embodiment of the present invention can be integrated in a processing unit, can be also that the independent physics of unit exists, and also can be integrated in a unit two or more unit.Above-mentioned integrated unit both can adopt the form of hardware to realize, the form that also can adopt hardware to add SFU software functional unit realizes.

The integrated unit that above-mentioned form with SFU software functional unit realizes, can be stored in the form of code in a computer read/write memory medium.Above-mentioned code storage, in a computer-readable recording medium, comprises that some instructions are used so that processor or hardware circuit are carried out the part or all of step of the described method of each embodiment of the present invention.And aforesaid storage medium comprises: the miniature high power capacity mobile storage disc without phisical drive of USB (universal serial bus), portable hard drive, read-only memory (English: Read-Only Memory, abbreviation ROM), the various media that can be program code stored such as random access memory (English: Random Access Memory, abbreviation RAM), magnetic disc or CD.

Finally it should be noted that: above embodiment only, in order to technical scheme of the present invention to be described, is not intended to limit; Although with reference to previous embodiment, the present invention is had been described in detail, those of ordinary skill in the art is to be understood that: it still can be modified to the technical scheme that aforementioned each embodiment puts down in writing, or part technical characterictic wherein is equal to replacement; And these modifications or replacement do not make the essence of appropriate technical solution break away from the protection range of various embodiments of the present invention technical scheme.

Claims

1. a network path detection method, is characterized in that, comprising:

2. method according to claim 1, is characterized in that, also comprises:

3. method according to claim 2, is characterized in that,

If described switch is the initial exchange machine in described path to be detected, described switch reception probe messages comprises: described switch receives the described probe messages that described controller sends;

4. the described method of according to claim 1-3 any one, is characterized in that, described switch comprises before receiving probe messages:

5. method according to claim 4, it is characterized in that, occurrence information in described detection flows table comprises the protocol port information of described probe messages, and the occurrence information in described forwarding flow table comprises source host information and the destination host information in described path to be detected.

6. the described method of according to claim 1-3 any one, is characterized in that, when described probe messages was User Datagram Protoco (UDP) UDP message, the general match head of described probe messages comprised the protocol port information of described probe messages; The verification stream table data of described probe messages comprise source host information and the destination host information in described path to be detected.

7. a network path detection method, is characterized in that, described method is applied to controller, comprising:

8. method according to claim 7, is characterized in that, after the detection response message that the switch in described reception path to be detected sends, comprising:

9. according to claim 7 or 8 described methods, is characterized in that, before the detection response message that the switch in receiving path to be detected sends, also comprises:

10. method according to claim 9, it is characterized in that, occurrence information in described detection flows table comprises the protocol port information of described probe messages, and the occurrence information in described forwarding flow table comprises source host information and the destination host information in described path to be detected.

11. method according to claim 9, it is characterized in that, described the detection flows table is sent to each switch in described path to be detected, and, after forwarding flow table corresponding with each switch in described path to be detected is sent to switch corresponding in described path to be detected, comprising:

12. method according to claim 11, is characterized in that, described probe messages comprises general match head and verification stream table data;

13. according to claim 11 or 12 described methods, is characterized in that, described path according to path to be detected list item, after building probe messages, comprising:

14. a network path sniffer, be positioned at exchanger side, it is characterized in that, comprising:

15. device according to claim 14 is characterized in that:

If described switch is the termination switch in described path to be detected, at described determination module, determine that the occurrence information in the detection flows table of the general match head of described probe messages and described switch is complementary, and while determining that according to the instruction in the detection flows table of described switch occurrence information in the forwarding flow table of verification stream table data in described probe messages and described switch is complementary;

16. device according to claim 15, is characterized in that, if described switch is the initial exchange machine in described path to be detected, described receiver module: the described probe messages that specifically sends be used to receiving described controller;

17. the described device of according to claim 14-16 any one, is characterized in that, described receiver module, the described detection flows table that also sends be used to receiving described controller, and the described forwarding flow table corresponding with described switch.

18. device according to claim 17, it is characterized in that, occurrence information in described detection flows table comprises the protocol port information of described probe messages, and the occurrence information in described forwarding flow table comprises source host information and the destination host information in described path to be detected.

19. the described device of according to claim 14-16 any one, is characterized in that, when described probe messages was User Datagram Protoco (UDP) UDP message, the general match head of described probe messages comprised the protocol port information of described probe messages; The verification stream table data of described probe messages comprise source host information and the destination host information in described path to be detected.

20. a network path sniffer, be positioned at the controller side, it is characterized in that, comprising:

21. device according to claim 20, it is characterized in that, described determination module, also for the sign of the described switch that comprises according to described detection response message, if, while determining that described switch is the termination switch in described path to be detected, according to described detection response message, determine that described termination switch and the path between a upper switch that is connected with described termination switch on described path to be detected are communicated with.

22. according to claim 20 or 21 described devices, is characterized in that, also comprises:

23. device according to claim 22, it is characterized in that, occurrence information in described detection flows table comprises the protocol port information of described probe messages, and the occurrence information in described forwarding flow table comprises source host information and the destination host information in described path to be detected.

24. device according to claim 22, is characterized in that, also comprises:

25. device according to claim 24, is characterized in that, described probe messages comprises general match head and verification stream table data;

26. according to claim 24 or 25 described devices, it is characterized in that, described sending module, also for the probe messages by described structure module construction, send to the initial exchange machine in described path to be detected, so that if the occurrence information in the detection flows table of the general match head of the definite described probe messages of described initial exchange machine and described initial exchange machine is complementary, and determine that according to the instruction in the detection flows table of described initial exchange machine the occurrence information in the forwarding flow table of verification stream table data in described probe messages and described switch is complementary, according to the instruction in the forwarding flow table of described initial exchange machine, described probe messages is sent to the next switch of described initial exchange machine, and send detection response message to described controller.

27. a network path detection system, is characterized in that, comprising: each switch in controller and path to be detected, in described path to be detected, each switch comprises the initial exchange machine;

28. system according to claim 27, is characterized in that, the next switch of described initial exchange machine comprises intermediary switch;

29. according to claim 27 or 28 described systems, is characterized in that, the next switch of described initial exchange machine comprises the termination switch, or the next switch of described intermediary switch comprises the termination switch;