KR102207936B1 - Method and system for information synchronization between the switch - Google Patents

Abstract

The present invention discloses a method and system for synchronizing information between switches. Information between switches in a system including at least one physical switch according to an aspect of the present invention, a configuration controller for managing the physical switch, at least one logical switch allocated to the physical switch, and a switch controller for managing the logical switch The method of synchronizing, the physical switch, receiving an information change request from the configuration controller, and confirming the logical switch affected by the information change; Transmitting, by the physical switch, change request information to the identified logical switch and receiving a message indicating whether the change is successful or not from the identified logical switch; And transmitting, by the physical switch, a notification message regarding a change result to the configuration controller.

Description

Information synchronization method and system between switches {METHOD AND SYSTEM FOR INFORMATION SYNCHRONIZATION BETWEEN THE SWITCH}

The present invention relates to a method and system for synchronizing information between switches, and more particularly, to a method and system for synchronizing information between switches for synchronizing information between a logical switch and a physical switch based on a switch and a controller.

In order to introduce a new service in the current network infrastructure, there are difficulties such as having to individually replace or upgrade different hardware and then undergo a compatibility test, which has made network innovation difficult. In addition, it was very difficult for network users or researchers to develop and apply new network protocols because each equipment manufacturer has a different way of operating equipment or user interface. Therefore, in order to overcome this problem, a switch or router technology having an open interface has been studied. However, network technologies providing such an open interface are difficult to commercialize because they are expensive compared to performance. Therefore, open flow technology has emerged to provide an open standard interface to users or developers while overcoming the high cost problem.

OpenFlow technology separates the packet forwarding function and control function of a network switch (or router) and provides a protocol for communication between these two functions.

In recent years, standardization of technologies for efficiently operating communication systems by separating the traffic forwarding function and control function of the switch has been established as ONF (Open Networking Foundation), IETF (Internet Engineering Task Force), ETSI ISG Network Function Virtualization (NFV) and It is progressing around ITU-T.

SDN (Software Defined Network) refers to a user-oriented network in which a user has control rights regardless of basic network equipment such as switches or routers, and a separate software controller controls traffic flow.

Among standardization organizations promoting the standardization of open flow technology, which is one of the SDN technologies, the Open Networking Foundation (ONF) is defining an interface connecting a switch (hardware) and a controller (Network OS). This is a protocol for interacting with the data transmission function by separating the function for controlling how data packets are transmitted through the network from the physical network.

Currently, ONF recommends the use of OFP_ECHO_REQUEST and OFP_ECHO_REPLY for the purpose of checking the connection status between the controller and the switch in the open flow standard.

However, when a state change occurs in a specific switch, if another switch fails to apply the change, packet forwarding is impossible, and a failure occurs accordingly.

Korean Patent Publication No. 2014-0050460 (published on April 29, 2014)

The present invention has been proposed in order to solve the above problems, and information between switches that synchronizes information between a physical switch managed by a configuration controller and a logical switch managed by a switch controller to eliminate control errors due to inconsistency of the information. Its purpose is to provide a synchronization method and system.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by an embodiment of the present invention. In addition, it will be easily understood that the objects and advantages of the present invention can be realized by the means shown in the claims and combinations thereof.

At least one physical switch according to an aspect of the present invention for achieving the above object, a configuration controller for managing the physical switch, at least one or more logical switches allocated to the physical switch, and a switch controller for managing the logical switch A method of synchronizing information between switches in a system including the steps of: receiving, by the physical switch, an information change request from the configuration controller and checking a logical switch affected by the information change; Transmitting, by the physical switch, change request information to the identified logical switch and receiving a message indicating whether the change is successful or not from the identified logical switch; And transmitting, by the physical switch, a notification message regarding a change result to the configuration controller.

The physical switch checks a plurality of logical switches in the verifying step,

The receiving may include, by the physical switch, receiving a message regarding a change failure from some of the plurality of logical switches, and receiving a message regarding a change success from the remaining logical switches, and transmitting the message. Prior to the step, the physical switch, transmitting a restoration request to the remaining logical switch; may further include.

The change request information may be port/queue information of a switch.

At least one physical switch according to another aspect of the present invention for achieving the above object, a configuration controller for managing the physical switch, at least one logical switch allocated to the physical switch, and a switch controller for managing the logical switch A method of synchronizing information between switches in a system including, by the switch controller, receiving change information from a logical switch whose information has been changed, and comparing the received change information with change information received from the configuration controller; Transmitting, by the switch controller, a normal control message to the logical switch when the change information matches; And if the change information does not match, transmitting, by the switch controller, a change request corresponding to the change information received from the configuration controller to the logical switch.

Prior to the comparing step, the configuration controller, receiving change information from the physical switch whose information has been changed, and transmitting the received change information to the switch controller; may further include.

The comparing may include: confirming, by the switch controller, that change information has not been received from the configuration controller; And requesting and receiving, by the switch controller, change information of a physical switch from the configuration controller.

A system according to another aspect of the present invention for achieving the above object includes at least one physical switch; A configuration controller that manages the physical switch; At least one logical switch assigned to the physical switch by the configuration controller; And a switch controller for managing the logical switch, wherein the physical switch identifies a logical switch affected by information change upon receiving an information change request from the configuration controller, and transmits change information to the corresponding logical switch. In response to this, a message regarding whether the change is successful may be received, and a notification message regarding the change result may be transmitted to the configuration controller.

The physical switch checks a plurality of logical switches affected by the information change, and when receiving a message about change failure from some of the plurality of logical switches, makes a restoration request to the logical switch that responds to the change success. Can be transmitted.

A system according to another aspect of the present invention for achieving the above object includes at least one physical switch; A configuration controller that manages the physical switch; At least one logical switch assigned to the physical switch by the configuration controller; And a switch controller for managing the logical switch, wherein the switch controller receives change information from the logical switch whose information has been changed, and compares the received change information with the change information received from the configuration controller, and the comparison result The corresponding message can be transmitted to the logical switch.

The switch controller may transmit a normal control message to the logical switch when the change information matches, and transmit a change request corresponding to the change information received from the configuration controller to the logical switch when the change information does not match. .

When the switch controller receives change information from a logical switch whose information has been changed, if there is no change information received from the configuration controller, the switch controller requests change information of a physical switch to the configuration controller, and the configuration controller, the change information Upon receiving the request of, the change information may be checked with a corresponding physical switch, and the confirmation result may be transmitted to the switch controller.

The configuration controller may receive change information from a physical switch whose information has been changed and transmit the received change information to the switch controller.

According to an aspect of the present invention, by synchronizing information between a physical switch managed by a configuration controller and a logical switch managed by a switch controller, there is an effect of preventing the occurrence of traffic loss by removing a control error due to inconsistency of the information. have.

The following drawings appended to the present specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of the present invention along with specific details for carrying out the invention, so the present invention is not limited to such drawings. It should not be interpreted as being limited to the information described.
1 is a diagram showing the configuration of a system for performing a method of synchronizing information between switches according to an embodiment of the present invention;
2 is a diagram illustrating a method of synchronizing information between switches according to an embodiment of the present invention;
3 is a diagram showing a method of synchronizing information between switches when a plurality of logical switches exist;
4 is a diagram illustrating a method of synchronizing information between switches according to another embodiment of the present invention;
5 is a diagram illustrating a method of synchronizing information between switches when changes in physical switches are not transmitted
6 is a diagram illustrating a method of synchronizing information between switches when a change of a logical switch is not transmitted.

The above-described objects, features, and advantages will become more apparent through the following detailed description in connection with the accompanying drawings, whereby those of ordinary skill in the technical field to which the present invention pertains can easily implement the technical idea of the present invention. There will be. In addition, in describing the present invention, if it is determined that a detailed description of a known technology related to the present invention may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Throughout the specification, when a certain part "includes" a certain component, it means that other components may be further included rather than excluding other components unless otherwise stated. In addition, “… A term such as “sub” means a unit that processes at least one function or operation, which may be implemented by hardware or software, or a combination of hardware and software.

1 is a diagram showing the configuration of a system for performing a method of synchronizing information between switches according to an embodiment of the present invention.

Referring to FIG. 1, a system for performing the method of synchronizing information between switches according to the present embodiment may include a controller 100 and a switch 200. In this case, the information may be port/queue information of the switch.

The controller 100 may be a software component for controlling the flow of traffic, and may include a configuration controller 110 and a switch controller 130. In this case, the controller 100 may control switches and routers, and is not limited to a physical implementation form or location. In addition, the controller 100 may include a flow table to store port/queue information of a switch.

The configuration controller 110 may control the function of the physical switch 210 through a configuration protocol. The configuration controller 110 may control a plurality of physical switches 210 and may allocate several logical switches 230 within the physical switch 210. In addition, the configuration controller 110 may configure a port/queue of the physical switch 210 and perform a function of changing a state. In addition, the configuration controller 110 may have various functions, such as performing authentication for communication between the switch controller 130 and the logic switch 230.

In addition, the configuration controller 110 may store port/queue information of the connected physical switch 210 in the form of a flow table.

The switch controller 130 may manage the logical switch 230 in the physical switch 210 through a switch protocol. In this case, there may be a plurality of physical switches 210 and logic switches 230.

In addition, the switch controller 130 may store port/queue information of the connected logical switch 230 in the form of a flow table.

The switch 200 may be a hardware component having a function of substantially forwarding, switching, or routing traffic (or packets). In this case, the switch 200 may mean a switch, a router, etc. defined by ONF, IETF, ETSI and/or ITU-T. The switch 200 according to the present embodiment includes a physical switch 210 for forwarding traffic through control of the configuration controller 110 and a logical switch 230 for forwarding traffic through control of the switch controller 130. I can.

As shown in FIG. 1, the configuration controller 110 and the switch controller 130 control and manage the same queue/port, but operate independently of each other, so between the controllers, more specifically, between the switches included in the controller. Synchronization is required. A more detailed description of the synchronization will be described later with reference to FIGS. 2 to 6.

2 is a diagram illustrating a method of synchronizing information between switches according to an embodiment of the present invention.

Referring to FIG. 2, the synchronization according to the present embodiment is a method of performing synchronization through message exchange between switches controlled by the controller, rather than through a message exchange between controllers.

A synchronization procedure through message exchange between switches according to the present embodiment will be described below.

1. The configuration controller 110 calls the physical switch 210 to request a new creation or state change of a port/queue, that is, information change of a port/queue (S210).

2. The physical switch 210 applies the change of information requested by the configuration controller 110, that is, the information of the port/queue, and checks the logical switch 230 affected by the information of the applied port/queue ( S220).

3. The physical switch 210 transmits the port/queue information to the internal logical switch 230 (S230).

4. The logical switch 230 receives the information of the port/queue, applies the changed information, and transmits the information of the port/queue to the switch controller 130 (S240).

5. The switch controller 130 receives and changes the information of the port/queue, and transmits a response message to the logical switch 230 when the change of the information is successful (S250).

6. The logical switch 230 transmits a result notification message to the physical switch 210 after receiving a message notifying that the change of information is successful from the switch controller 130. In this case, the result notification message may be a message indicating that the logical switch 230 and the switch controller 130 have recognized and shared all of the changed information (S260).

7. The physical switch 210 applies the changed information of the port/queue requested from the configuration controller 110 (S270).

8. The physical switch 210 transmits a result notification message to the configuration controller 110 when the port/queue is newly created or the state change, that is, the port/queue information change is applied. In this case, the result notification message may be a message indicating that the physical switch 210, the logical switch 230, and the switch controller 130 have recognized and shared all of the changed information (S280).

According to the above, by synchronizing and matching information between switches, that is, port/queue information through message exchange between the physical switch 210 and the logical switch 230, control errors due to information inconsistency are removed and traffic is lost. It can be prevented from occurring.

3 is a diagram illustrating a method of synchronizing information between switches when a plurality of logical switches 230 are present.

Referring to FIG. 3, the synchronization according to the present embodiment is a method of synchronizing through message exchange between switches when a plurality of logical switches 230 exist in the physical switch 210. In this embodiment, it will be described that there are three logical switches 230 inside the physical switch 210.

When there are multiple logical switches 230, a synchronization procedure through message exchange between switches will be described below.

1. The configuration controller 110 calls the physical switch 210 to request a new creation or state change of a port/queue, that is, change information of a port/queue (S310).

2. The physical switch 210 applies the change of information requested by the configuration controller 110, that is, the information of the port/queue, and checks the logical switch 230 affected by the information of the applied port/queue ( S321).

3. The physical switch 210 transmits the port/queue information to the internal logical switches 230 (S323).

4. The logical switch 230 receives the port/queue information and applies the changed information. At this time, only switches 2 and 3 of the logical switches 230 that have received the port/queue information are successfully applied as the transmitted port/queue information, and the remaining logical switch 230 is Application fails with port/queue information (S325).

5. The logical switch 230 that has failed to apply with the transmitted port/queue information, that is, the first logical switch 230 transmits a message informing that the change has failed to the physical switch 210 (S327).

6. The logical switch 230 that has successfully applied the received port/queue information, that is, the 2nd and 3rd logical switches 230, transmits the changed contents of the port/queue to the switch controller 130 (S329). ).

7. The switch controller 130 changes the flow table by receiving information of the changed port/queue of the 2nd and 3rd logic switches 230, and sends a response message to the logic switch 230 (2nd and 3rd and 3rd). It is transmitted to the logical switch 230 (S331).

8. The second and third logical switches 230 transmit result notification messages to the physical switch 210. In this case, the result notification message may be a message indicating that application of the changed information has been completed (S333).

9. The physical switch 210 checks the logical switches 230 that are affected by the change information requested from the configuration controller 110. For example, the first logical switch 230 fails to apply the requested change information, and the second and third logical switches 230 confirm that the application of the requested change information has been successful. At this time, the physical switch 210 confirms that application of the requested change information from the configuration controller 110 is impossible due to the failure to apply the requested change information of the first logical switch 230 (S335).

10. The physical switch 210, which has confirmed that the change requested from the configuration controller 110 is not applicable, informs the second and third logical switches 230 to which the change is applied, that is, information of the port/queue. Request to restore the original state (S337).

11. The second and third logical switches 230 restore the information of the port/queue to the original state, and notify the result to the switch controller 130 (S339).

12. The physical switch 210 transmits a port/queue information change impossible message according to a failure to apply the change information of the first logical switch 230 to the configuration controller 110 (S341).

After the procedure is completed, the configuration controller 110, which has received changed information, that is, that it is impossible to change to the port/queue information, goes through the above process again after a certain period of time, and the physical switch 210 and the logical switch 230 The information of the changed port/queue can be synchronized through the exchange of messages between them.

4 is a diagram illustrating a method of synchronizing information between switches according to another embodiment of the present invention.

Referring to FIG. 4, the synchronization according to the present embodiment is a method of performing synchronization through message exchange between controllers controlling the switch, rather than through message exchange between switches.

A synchronization procedure through message exchange between controllers according to the present embodiment will be described below.

1. When the information of the port/queue is changed, the physical switch 210 transmits the change to the configuration controller 110 (S410).

2. The configuration controller 110 checks the change content, that is, the switch controller 130 affected by the information of the changed port/queue. At this time, the configuration controller 110 may request information of the flow table from the switch controller 130 to check the switch controller 130 affected by the changed port/queue information (S420).

3. The configuration controller 110 changes the flow table with the received port/queue information, and transmits the changed content to the switch controller 130 (S430).

4. The switch controller 130 receives port/queue change information from the logical switch 230. At this time, the switch controller 130 must receive the change information from the logic switch 230 within a predetermined time. However, if the change information is not received, the switch controller 130 may request the current information, that is, port/queue information, and receive a response from the logical switch 230 (S440).

5. The switch controller 130 compares the port/queue change information transmitted from the configuration controller 110 with the port/queue change information transmitted from the logical switch 230 (S450).

6. If the port/queue change information in the comparison is the same, the switch controller 130 transmits a message indicating that normal control is possible to the logical switch 230 because normal traffic control is possible (S460).

7. However, if the change information of the port/queue is not the same in the comparison, the switch controller 130 cannot control normal traffic, and thus the port/queue transmitted from the configuration controller 110 to the logical switch 230 By transmitting the change information, a request is made to change the port/queue information in the same manner as the information of the physical switch 210 (S470).

8. The logic switch 230 changes the port/queue information received from the switch controller 130, and when the change is completed, transmits a response message thereto to the switch controller 130 (S480).

According to the above, by synchronizing and matching information between switches, that is, information of ports/queues through message exchange between the configuration controller 110 and the switch controller 130, control errors due to information inconsistency are eliminated and traffic is lost. It can be prevented from occurring.

5 is a diagram illustrating a method of synchronizing information between switches when changes in the physical switch 210 are not transmitted.

Referring to FIG. 5, in the synchronization according to the present embodiment, changes in the physical switch 210 include missing change information in the physical switch 210 or a network error between the configuration controller 110 and the switch controller 130. If it cannot be delivered to the controller for a reason, it is a synchronization process through message exchange between controllers.

A synchronization procedure through message exchange between controllers according to the present embodiment will be described below.

1. Information, that is, port/queue information is changed in the physical switch 210. The physical switch 210 transmits the changed port/queue change information to the configuration controller 110, but the changed port/queue information cannot be transmitted to the configuration controller 110 due to a network error or the like. Therefore, the configuration controller 110 does not check the switch controller 130 affected by the changed port/queue information, and does not transmit the changed port/queue information of the physical switch 210 to the switch controller 130. Can not (S510) (S511).

2. At this time, the logical switch 230 transmits a message notifying that the information of its port/queue has been changed to the switch controller 130 (S513).

3. The switch controller 130 checks the port/queue change information of the physical switch 210 received from the configuration controller 110 in order to apply the port/queue change information of the received logical switch 230 (S515).

4. However, the switch controller 130 confirms that there is no port/queue change information received from the configuration controller 110, and requests the changed information of the physical switch 210 to the configuration controller 110 (S517). ).

5. The configuration controller 110 requests port/queue information to the physical switch 210 (S519).

6. The physical switch 210 transmits the port/queue information to the configuration controller 110 (S521).

7. The configuration controller 110 transmits the port/queue information of the physical switch 210 requested by the switch controller 130 to the switch controller 130 (S523).

8. The switch controller 130 stores the port/queue information of the physical switch 210 received from the configuration controller 110 and the changed port/queue information of the logical switch 230 received from the logical switch 230. It compares and checks whether it is changed (S525).

9. The switch controller 130 informs that normal traffic control is possible with the logical switch 230 when the information of the port/queue between the logical switch 230 and the physical switch 210 is the same as a result of the comparison. The message is delivered (S527).

10. However, if the change information of the port/queue is not the same in the comparison, the switch controller 130 cannot control normal traffic, and thus the port/queue transmitted from the configuration controller 110 to the logical switch 230 By transmitting the change information, it is requested to change the port/queue information in the same manner as the information of the physical switch 210 (S529).

11. The logic switch 230 changes the port/queue information received from the switch controller 130, and when the change is completed, transmits a response message thereto to the switch controller 130 (S531).

6 is a diagram illustrating a method of synchronizing information between switches when changes in the logical switch 230 are not transmitted.

Referring to FIG. 6, the synchronization according to the present embodiment is a method of synchronizing through message exchange between controllers when changes in the logical switch 230 are not transmitted to the switch controller 130 due to a network error or the like.

1. When a port/queue information change occurs, the physical switch 210 transmits the change to the configuration controller 110 (S610).

2. The configuration controller 110 checks the change content, that is, the switch controller 130 affected by the information of the changed port/queue. At this time, the configuration controller 110 may request the information of the flow table from the switch controller 130 to check the switch controller 130 affected by the changed port/queue information (S620).

3. The configuration controller 110 changes the flow table with the received port/queue information, and transmits the changed content to the switch controller 130 (S630).

4. The switch controller 130 receiving the change information checks the changed port/queue information from the logical switch 230 within a predetermined time period (S640).

5. The switch controller 130 transmits the port/queue change information received from the configuration controller 110 to the logical switch 230, and changes the port/queue information in the same manner as the information of the physical switch 210. Request (S650).

6. The logic switch 230 changes the information of the port/queue received from the switch controller 130, and when the change is completed, transmits a response message thereto to the switch controller 130 (S660).

While this specification includes many features, such features should not be construed as limiting the scope or claims of the invention. In addition, features described in individual embodiments of the present specification may be combined and implemented in a single embodiment. Conversely, various features described in a single embodiment of the present specification may be individually implemented in various embodiments, or may be properly combined and implemented.

Although the operations have been described in a specific order in the drawings, it should not be understood that such operations are performed in a specific order as shown, or as a series of consecutive sequences, or that all described operations are performed to obtain a desired result. Multitasking and parallel processing can be advantageous in certain environments. In addition, it should be understood that classification of various system components in the above-described embodiments does not require such classification in all embodiments. The above-described app components and systems may generally be implemented as a package in a single software product or multiple software products.

The method of the present invention as described above may be implemented as an app and stored in a recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.) in a computer-readable form. This process can be easily carried out by a person of ordinary skill in the art to which the present invention pertains, and thus will not be described in detail.

The present invention described above, for those of ordinary skill in the art to which the present invention belongs, various substitutions, modifications, and changes are possible within the scope of the technical spirit of the present invention. It is not limited by the drawings.

100: controller
110: configuration controller
130: switch controller
200: switch
210: physical switch
230: logic switch

Claims (12)

Information between the physical switch and the logical switch in a system including at least one physical switch, a configuration controller managing the physical switch, at least one logical switch allocated to the physical switch, and a switch controller managing the logical switch As a way to synchronize,
Receiving, by the physical switch, an information change request from the configuration controller and confirming a logical switch affected by the information change;
Transmitting, by the physical switch, change request information to the identified logical switch and receiving a message indicating whether the change is successful or not from the identified logical switch; And
And transmitting, by the physical switch, a notification message regarding a change result to the configuration controller. The method of claim 1,
The physical switch checks a plurality of logical switches in the verifying step,
The receiving step,
And receiving, by the physical switch, a message regarding a change failure from some of the plurality of logical switches, and a message regarding a change success from the remaining logical switches; and
Before the transmitting step,
And transmitting, by the physical switch, a restoration request to the remaining logical switches. The method according to claim 1 or 2,
The information synchronization method between switches, characterized in that the change-requested information is port/queue information of a switch. Information between the physical switch and the logical switch in a system including at least one physical switch, a configuration controller managing the physical switch, at least one logical switch allocated to the physical switch, and a switch controller managing the logical switch As a way to synchronize,
Receiving, by the switch controller, change information from a logical switch whose information has been changed, and comparing the received change information with change information received from the configuration controller;
Transmitting, by the switch controller, a normal control message to the logical switch when the change information matches; And
And when the change information does not match, transmitting, by the switch controller, a change request corresponding to the change information received from the configuration controller to the logical switch. The method of claim 4,
Prior to the comparing step,
Receiving, by the configuration controller, change information from a physical switch whose information has been changed, and transmitting the received change information to the switch controller. The method of claim 4,
The comparing step,
Confirming, by the switch controller, not receiving change information from the configuration controller; And
And requesting and receiving, by the switch controller, change information of a physical switch from the configuration controller. At least one physical switch;
A configuration controller that manages the physical switch;
At least one logical switch assigned to the physical switch by the configuration controller; And
Includes; a switch controller for managing the logic switch,
The physical switch,
Upon receiving an information change request from the configuration controller, the logic switch affected by the information change is identified, the change information is transmitted to the corresponding logical switch, and a message regarding whether the change is successful is received in response to the change information, and the configuration controller Information synchronization system between switches, characterized in that transmitting a notification message about the change result. The method of claim 7,
The physical switch checks a plurality of logical switches affected by the information change, and when receiving a message about change failure from some of the plurality of logical switches, makes a restoration request to the logical switch that responds to the change success. Information synchronization system between switches, characterized in that the transmission. At least one physical switch;
A configuration controller that manages the physical switch;
At least one logical switch assigned to the physical switch by the configuration controller; And
Includes; a switch controller for managing the logic switch,
The switch controller,
A system for synchronizing information between switches, comprising receiving change information from a logical switch whose information has been changed, comparing the received change information with the change information received from the configuration controller, and transmitting a message according to the comparison result to the logical switch. The method of claim 9,
The switch controller,
When the change information matches, a normal control message is transmitted to the logical switch, and when the change information does not match, a change request corresponding to the change information received from the configuration controller is transmitted to the logical switch. Information synchronization system. The method of claim 9,
The switch controller,
When receiving change information from a logical switch whose information has been changed, if there is no change information received from the configuration controller, requesting change information of a physical switch to the configuration controller,
The configuration controller,
Upon receiving the request for the change information, the change information is checked by a corresponding physical switch and the confirmation result is transmitted to the switch controller. The method of claim 9,
The configuration controller,
Information synchronization system between switches, comprising receiving change information from a physical switch whose information has been changed and transmitting the received change information to the switch controller.

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