JP2019165326A - Network device, network system, and network switching method - Google Patents

Abstract

To provide a network device capable of confirming whether a route has been changed as expected.SOLUTION: A network device 30 having at least three or more network interfaces 205 includes: switching request acquisition means 33 that acquires a network switching request from one of the network interfaces; connection means 31 that connects a first network interface and a second network interface, in accordance with the network switching request acquired by the switching request acquisition means; and test communication means 32 that, when the first network interface and the second network interface are connected by the connection means, causes a first device connected to the first network interface to execute a test communication with a second device connected to the second network interface.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a network device, a network system, and a network switching method.

  Two or more physically separated networks are appropriately used for the purpose of ensuring security, limiting functions, and the like. When one user terminal uses the functions of two or more networks properly, an administrator or the like needs to change the network configuration so that the user terminal can communicate with the target network.

  For example, in an educational institution such as a university, there is an operation example in which communication from a user terminal to the Internet is restricted only during a test and the user terminal is temporarily connected to a network of another system in which a test server is placed. Conventionally, such network switching is performed by an administrator replacing a physical cable of a network device such as a switch or a router.

  However, when the network device to which the physical cable is connected is located remotely, the network switching by inserting / removing the physical cable requires the administrator to go to that location and perform the replacement work. Alternatively, it is necessary to ask a worker who is used to network work to replace the physical cable, and both of them are troublesome. In addition, there is a possibility of erroneous connection, and unintended communication may be performed.

  A technique for switching networks without inserting or removing a physical cable is known (see, for example, Patent Document 1). In Patent Document 1, in order to change the route A from the communication device 4 to the communication device 1, the monitoring control device causes the communication device 3 to change the routing table for changing the route. A communication system for changing to route B to 5 is disclosed.

  However, in the conventional technique, since it has not been confirmed whether or not the route change has been normally performed, there is a problem that the route change may not be performed as expected. For example, when switching networks using the routing table, the routing table may not be set correctly, or the routing table may be correct, but the network configuration may not be appropriate. There is.

  An object of this invention is to provide the network device which can confirm whether the route change as expected was performed in view of the said subject.

  In view of the above problems, the present invention is a network device having at least three or more network interfaces, the switching request acquisition unit acquiring a network switching request from one of the network interfaces, and the switching request acquisition unit In response to the network switching request, the connection means for connecting the first network interface and the second network interface, and when the first network interface and the second network interface are connected by the connection means, Test communication means for causing the first device connected to one network interface to execute test communication with the second device connected to the second network interface.

  It is possible to provide a network device capable of confirming whether a route change as expected has been performed.

It is an example of the figure explaining schematic operation | movement of a network switching control apparatus. It is an example of the schematic hardware block diagram of a network switching control apparatus. It is an example of the functional block diagram which shows the function of the HTTP server which a network system has, a network switching control apparatus, and an administrator terminal in a block form. It is an example of the figure explaining the structure at the time of the network switching in a network switching control apparatus. It is an example of the sequence diagram explaining operation | movement of the network system at the time of network switching. It is a figure which shows an example of the network switching screen displayed on LCD of an administrator terminal. It is an example of the sequence diagram explaining operation | movement of the network system which performs test communication after network switching and detects switching failure. It is a figure which shows an example of the switching determination result screen which an administrator terminal displays on LCD. It is an example of the functional block diagram which shows the function of the HTTP servers A and B which a network system has, the network switching control apparatus, and an administrator terminal in the block form (Example 2). FIG. 10 is an example of a sequence diagram for explaining an operation of a network system that detects test failure by performing test communication after network switching (second embodiment); It is an example of the functional block diagram which shows the function of the HTTP servers A and B which a network system has, a network switching control apparatus, and an administrator terminal in the block form (Example 3). FIG. 10 is an example of a sequence diagram illustrating an operation of a network system that detects test failure by performing test communication after network switching (third embodiment).

  Hereinafter, as an example of an embodiment for carrying out the present invention, a network system and a network switching method performed by the network system will be described with reference to the drawings.

<Outline of this example>
FIG. 1 is an example of a diagram illustrating a schematic operation of the network switching control device 30 according to the present embodiment. A network A, a network B, and a network C are connected to the network switching control device 30. An HTTP server 50 is connected to each of the networks A and B. Of the HTTP servers 50, the HTTP server 50 connected to the network A is called an HTTP server A, and the HTTP server 50 connected to the network B is called an HTTP server B. .
(1) The administrator 9 operates the administrator terminal 10 to communicate with the network switching control device 30 and switches the connection destination of the network C from the network A to the network B (or from the network B to the network A).
(2) The network switching control device 30 connects the network B and the network C as instructed by the administrator terminal 10. In this embodiment, the network C communicates with either the network A or B at the same time, but disconnects if necessary (if the network A and the network C remain connected).
(3) The network switching control device 30 instructs the administrator terminal 10 to perform test communication with the HTTP server A existing in the network A and the HTTP server B existing in the network B.
(4) The administrator terminal 10 performs test communication with the HTTP server A existing in the network A, and similarly performs test communication with the HTTP server B present in the network B. If the switching is performed as expected, there is no response from the HTTP server A, and there should be a response from the HTTP server B.
(5) Since the administrator terminal 10 transmits the test result to the network switching control device 30, the network switching control device 30 can perform switching determination based on the test result.

  As described above, the network switching control device 30 according to the present embodiment can detect a switching failure when the administrator terminal 10 cannot normally switch for some reason when issuing the network switching instruction. When a failure is detected, the network connection state can be switched normally by the administrator 9 performing appropriate work.

<Terminology>
The administrator terminal 10 is an example of a first device, and the HTTP servers A and B and the terminal devices A and B are examples of a second device or a third device.

  A network interface is an interface to which a network is connected. In the present embodiment, the term “network card” is used, but it may also be called an Ethernet card (registered trademark), a LAN interface, or the like.

<Configuration example>
A system configuration of the network system 100 will be described with reference to FIG. Three networks A to C are connected to the network switching control device 30. Three is an example, and four or more networks may be connected. In this embodiment, the networks A and B are disconnected physically or electrically. Therefore, communication from network A to B or vice versa is not possible. In contrast, the networks A and C or the networks B and C can be physically or electrically connected. In this embodiment, the networks A and C and the networks B and C are not connected at the same time.

  Further, when the networks A and C are connected as the same network by a bridge or a hub, the networks A and C are the same network having the same network address. However, in the present embodiment, they will be described as separate networks for convenience of explanation. . Further, when the networks A and C are connected by a router, for example, they are different networks. Different networks refer to different network addresses, for example. In addition, there are cases in which segments having different network addresses have different segments.

  The networks A and B are preferably networks that are not physically or electrically connected, but may be networks that have different network addresses and are treated as different networks by a router or the like.

  The network switching control device 30 changes from the state where the networks A and C are connected to the state where the networks B and C are connected, or from the state where the networks B and C are connected to the state where the networks A and C are connected. This is an information processing apparatus that switches an internal connection state. Such a device may be called a LAN switching device. Alternatively, an OpenFlow switch corresponding to OpenFlow may be used. In OpenFlow, an OpenFlow switch sets a rule (Flow Entry) including a “condition” and an “action” of a packet to be processed that the OpenFlow controller “acts (processes) in this way for a packet of this condition”. By writing in, it is possible to switch software.

  The administrator terminal 10 is an information processing apparatus operated by the administrator 9. The administrator 9 is a person who manages the network system 100, and in this embodiment, refers to a person who has the authority to switch the network to which the network C is connected to the network A or B. The administrator terminal 10 may be any device having a function of communicating with the network switching control device 30, the HTTP server A, and the HTTP server B. For example, an apparatus on which browser software operates is assumed. Specific examples include, but are not limited to, a PC (Personal Computer), a tablet terminal, a smartphone, and a wearable PC. Further, it may be an office device such as a multifunction machine, an electronic blackboard, a video conference terminal, or a projector on which browser software operates.

  Further, the software operating on the administrator terminal 10 may be application software dedicated to the network switching control device 30. In this application software, the IP address and the like of the network switching control device 30 are set, and the current network connection state is monitored or the network connection state is switched by communicating with the network switching control device 30. Can do.

  Further, the administrator terminal 10 does not always need to be connected to the network C, and may be connected to the network C when the network is switched.

  The HTTP servers A and B are information processing apparatuses that return an HTTP response to an HTTP request transmitted from the administrator terminal 10 for test communication. Any device can be used as long as it can confirm the communication, and it is not required to support HTTP like a device called a server. However, when the communication with the HTTP servers A and B is confirmed, the browser software only needs to operate on the administrator terminal 10, so that special application software is not necessary.

  The HTTP communication protocol is a function of the fifth to seventh layers of the OSI basic reference model, but the HTTP servers A and B are the routers or L3 switches corresponding to the TCP / IP of the third and fourth layers, or the third It may be a network device corresponding to the layer ICMP, an L2 switch corresponding to the second layer Ethernet (registered trademark), or the like. A case where the HTTP servers A and B are not servers will be described in a second embodiment.

<About hardware configuration>
FIG. 2 is an example of a schematic hardware configuration diagram of the network switching control device 30. The network switching control device 30 includes a CPU 201 and a memory 202 that enables high-speed access of data used by the CPU 201. The CPU 201 and the memory 202 are connected to other hardware elements such as a graphics driver 204 and a network card (NIC) 205 via the system bus 203.

  The graphics driver 204 is connected to an LCD (Liquid Crystal Display) 206 via a bus and monitors a processing result by the CPU 201. The LCD 206 is an example of a display device. The network card 205 connects the network switching control device 30 to the network at the transport layer level and the physical layer level, and establishes a session with various devices in the networks A to C (network I / O). F). The network switching control device 30 has at least three or more network cards 205.

  An I / O bus bridge 207 is further connected to the system bus 203. On the downstream side of the I / O bus bridge 207, a storage device such as an HDD (hard disk drive) 209 is provided by IDE, ATA, ATAPI, serial ATA, SCSI, USB, etc. via an I / O bus 208 such as PCI. Is connected. The HDD 209 stores a program 209p for controlling the entire network switching control device 30. The HDD 209 may be an SSD (Solid State Drive).

  An input device 210 such as a keyboard and a mouse (referred to as a pointing device) is connected to the I / O bus 208 via a bus such as a USB, and receives input and commands from an operator such as a system administrator. Yes.

  The hardware configuration of the administrator terminal 10 and the HTTP servers A and B is the same as that of the network switching control device 30, or even if there is a difference, there is no problem in the description of this embodiment. To do.

  Further, the HTTP servers A and B may correspond to cloud computing. In this case, the hardware configuration shown in the figure does not need to be housed in a single housing or provided as a group of devices, and is preferably a hardware element that the HTTP servers A and B have. Show.

<About functions>
FIG. 3 is an example of a functional block diagram illustrating the functions of the HTTP server 50, the network switching control device 30, and the administrator terminal 10 included in the network system 100 in a block form.

<< Network switching control device >>
The network switching control device 30 includes a network switching unit 31, a network switching failure detection unit 32, an HTTP server unit 33, and an authentication unit 34. Each of these functions of the network switching control device 30 is a function or means realized by the CPU 201 executing the program 209p expanded from the HDD 209 to the memory 202 shown in FIG. Note that the program 209p may be distributed from a program distribution server, or may be distributed in a state of being stored in a portable storage medium such as a USB memory or an optical storage medium.

  Further, the network switching control device 30 includes a login information storage unit 35 and an IP address storage unit 36 which are constructed in at least one of the HDD 209 or the memory 202 shown in FIG. The login information storage unit 35 will be described with reference to Table 1.

表１は、ログイン情報記憶部３５に記憶されている情報を模式的に示す。ログイン情報記憶部３５には、ネットワーク切替制御装置３０が管理者９を認証するためのログイン情報を記憶している。このログイン情報を認証情報又はアカウント情報と称してもよい。ログイン情報記憶部３５には、個人ＩＤに対応付けてパスワードと権限の各項目が登録されている。個人ＩＤは管理者９のようにネットワーク切替制御装置３０を操作する者を特定又は識別するための識別情報の一例である。管理者ＩＤ又はユーザＩＤなどと称してもよい。なお、ＩＤはIdentificationの略であり識別子や識別情報という意味である。ＩＤは複数の対象から、ある特定の対象を一意的に区別するために用いられる名称、符号、文字列、数値又はこれらのうち１つ以上の組み合わせをいう。他のＩＤについても同様である。パスワードは管理者９がネットワーク切替制御装置３０から認証を受けるために秘密にしておく情報である。権限は、管理者９等がネットワーク切替制御装置３０に対し行うことが許可された操作内容である。

Table 1 schematically shows information stored in the login information storage unit 35. The login information storage unit 35 stores login information for the network switching control device 30 to authenticate the administrator 9. This login information may be referred to as authentication information or account information. In the login information storage unit 35, password and authority items are registered in association with the personal ID. The personal ID is an example of identification information for specifying or identifying a person who operates the network switching control device 30 such as the administrator 9. It may be referred to as an administrator ID or a user ID. Note that ID is an abbreviation of Identification and means an identifier or identification information. ID refers to a name, a code, a character string, a numerical value, or a combination of one or more of these used to uniquely distinguish a specific target from a plurality of targets. The same applies to other IDs. The password is information kept secret for the administrator 9 to receive authentication from the network switching control device 30. The authority is an operation content that the administrator 9 or the like is permitted to perform on the network switching control device 30.

表２は、ＩＰアドレス記憶部３６に記憶されている情報を模式的に示す。ＩＰアドレス記憶部３６には、ネットワークの切り替え後にネットワーク切替失敗検知部３２が管理者端末１０にテスト通信させるため、ＨＴＴＰサーバＡ、ＢのＩＰアドレスが記憶されている。ＩＰアドレスはアドレス情報の一態様であり、ＩＰアドレス記憶部３６はアドレス情報記憶手段の一態様である。ＩＰアドレスはTCP/IPネットワーク上で、通信相手(ホスト)を識別する識別情報である。ＩＰアドレス記憶部３６にはサーバ名、ネットワーク名、及び、ＩＰアドレスの各項目が登録されている。サーバ名はサーバの名称であり、例えばドメイン名である。ネットワーク名はＨＴＴＰサーバＡ、Ｂが接続されているネットワークの名称である。サーバ名とネットワーク名は主に管理者が判読するために使用される。ＩＰアドレスの項目はＨＴＴＰサーバＡ、ＢのＩＰアドレスを示す。ＩＰアドレス記憶部３６の情報は、管理者９等が予め設定している。

Table 2 schematically shows information stored in the IP address storage unit 36. The IP address storage unit 36 stores the IP addresses of the HTTP servers A and B so that the network switching failure detection unit 32 causes the administrator terminal 10 to perform test communication after network switching. The IP address is an aspect of address information, and the IP address storage unit 36 is an aspect of address information storage means. The IP address is identification information for identifying a communication partner (host) on the TCP / IP network. In the IP address storage unit 36, items of a server name, a network name, and an IP address are registered. The server name is the name of the server, for example, a domain name. The network name is the name of the network to which the HTTP servers A and B are connected. The server name and network name are mainly used for the administrator to read. The IP address item indicates the IP addresses of the HTTP servers A and B. Information in the IP address storage unit 36 is set in advance by the administrator 9 or the like.

  Returning to FIG. The authentication unit 34 authenticates the administrator 9 with reference to the login information storage unit 35. The authentication unit 34 determines that the authentication is established when the personal ID and password transmitted from the administrator terminal 10 match those of the login information storage unit 35, and determines that the authentication is not established when they do not match. When the authentication is established, the authentication unit 34 permits the administrator 9 to log in, and permits the operation content authorized by the authority. Note that IC card information or biometric authentication information may be used as login information.

  The HTTP server unit 33 communicates with the administrator terminal 10 in accordance with a protocol called HTTP, and operates as a server that provides screen information serving as a user interface to the administrator terminal 10. The screen information is described by, for example, HTML, JavaScript (registered trademark), and CSS (Cascade Style Sheet).

  The network switching unit 31 exclusively connects the network C and the network A or connects the network C and the network B. As a result, the network connection state can be switched. Details will be described later.

  The network switching failure detection unit 32 causes the administrator terminal 10 to perform test communication after network switching, and notifies the administrator terminal 10 whether the network switching has succeeded or failed.

<< HTTP Server A, B >>
The HTTP servers A and B have a server unit 51 and a communication unit 52. These functions of the HTTP servers A and B are functions or means realized by the CPU 201 executing the program 209p loaded from the HDD 209 and the memory 202 shown in FIG.

  The communication unit 52 of the HTTP server A communicates with the administrator terminal 10 via the network A. As will be described later, when the network A and the network C are bridge-connected, since the networks A and C are the same LAN, the network switching control device 30 is viewed from the administrator terminal 10 as the data link layer of the OSI basic reference model It is only one device connected to (Layer 2). That is, the administrator terminal 10 can communicate with the HTTP server A by designating the IP address of the HTTP server A, and can communicate with the network switching control device 30 by designating the IP address of the network switching control device 30.

  The server unit 51 of the HTTP server A provides an HTTP server function. Therefore, a method such as GET or POST included in the HTTP request is analyzed, and a response or registration of a specified resource is performed. In addition, error processing determined by HTTP is also performed.

  The function of the HTTP server B is the same as the function of the HTTP server A.

<< Administrator terminal >>
The administrator terminal 10 includes a communication unit 11, an analysis unit 12, a display control unit 13, and an operation reception unit 14. These functions of the administrator terminal 10 are functions or means realized by the CPU 201 executing the program 209p expanded from the HDD 209 shown in FIG. In the present embodiment, the browser software 19 is assumed as an example of the program 209p that runs on the administrator terminal 10.

  The communication unit 11 communicates with the network switching control device 30 via the network C, communicates with the HTTP server A via the networks A and C, and further communicates with the HTTP server B via the networks B and C. The IP address and port number of the network switching control device 30 are known to the administrator. The IP addresses of the HTTP servers A and B are stored in the IP address storage unit 36, and the port number is normally 80. As described above, the administrator only needs to store the IP address of the network switching control device 30, and does not need to store or manage the IP addresses of the HTTP servers A and B.

  The analysis unit 12 analyzes the screen information transmitted from the HTTP server unit 33 of the network switching control device 30 or the server unit 51 of the HTTP servers A and B, and outputs HTML, JavaScript (registered trademark), and CSS. Take out and execute in order from the top. In addition, an event corresponding to the operation of the administrator 9 is detected and processing described in HTML or JavaScript (registered trademark) is executed.

  The display control unit 13 displays a screen serving as a user interface on the LCD 206 based on the screen information analyzed by the analysis unit 12. Further, the screen is changed according to the operation received by the operation receiving unit 14.

  The operation reception unit 14 receives various operations on the administrator terminal 10. For example, it accepts pressing of a button displayed on the screen, screen scrolling, input of information, and the like.

  Note that the user terminal 60 is a terminal used by a general user and has the same function as the administrator terminal 10. The user terminal 60 can communicate with various servers of the network A switched by the administrator 9 or various servers of the network B. For example, when the network switching control device 30 is used in an educational institution such as a university, it is connected to the network A connected to the Internet during the lesson, and connected to the network B on which an examination server is placed during the examination. .

<Network switching method>
Next, a network switching method will be described with reference to FIG. FIG. 4 is a diagram illustrating a configuration at the time of network switching in the network switching control device 30.

  In FIG. 4, the network switching control device 30 has three network cards 205 (referred to as network cards A to C in FIG. 4), the network A is connected to the network card A, and the network B is connected to the network card B. The network C is connected to the network card C. Further, the network switching control device 30 has a bridge 40, and the network card C is always connected to the bridge 40, and one of the networks A and B is exclusively connected. That is, the network cards A and B are not connected to the bridge 40 at the same time. It may be in a state where it is not connected to either network A or B. The network card C is an example of a first network interface, and the network cards A and B are examples of a second network interface or a third network interface (in no particular order).

  The bridge 40 is a data relay device in the data link layer of the OSI basic reference model. Therefore, the networks A and C and the networks B and C are each one LAN. The bridge 40 learns the MAC address of the device connected to the ports PA to PC, determines which port the device having the destination MAC address of the frame flowing through the LAN is connected to, and transfers the frame only to the port where the device is located. To do. In the example of FIG. 4, the MAC address of the HTTP server A is learned in association with the port PA of the bridge 40, and the MAC address of the HTTP server B is learned in association with the port PB of the bridge 40.

  The bridge 40 may also be an L2 switch that can connect networks in the data link layer.

  The bridge 40 may be a hub. The hub is a data relay device in the physical layer of the OSI basic reference model. Unlike the bridge 40, the same frame is transmitted from all the remaining ports other than the port that received the frame. In this embodiment, since the bridge 40 and the network cards A and B are not connected at the same time, a hub may be used.

  The network switching unit 31 switches the network card A connected to the bridge 40 to the network card B, or the network card B connected to the bridge 40 to the network card A. For example, a relay device is known as such a switching circuit. A relay device, also called a relay, has an electromagnet and a contact mechanism, and is a device that changes the connection state (open / close) of the contact mechanism by using electromagnetism generated when a current is passed through the electromagnet. In the relay device, an exclusive connection is mechanically realized.

  As shown in FIG. 4, the network switching seen from the user terminal 60 can be realized by switching the connection between the bridge 40 and the network cards A and B.

<Operation procedure>
<< Network switching >>
FIG. 5 is an example of a sequence diagram illustrating the operation of the network system 100 at the time of network switching.

  S1: The administrator 9 operates the administrator terminal 10 to request the HTTP server unit 33 of the network switching control device 30 to switch the network. The administrator designates the IP address of the network switching control device 30 (or HTTP server unit 33) or obtains it from a DNS server or the like. The operation receiving unit 14 of the administrator terminal 10 receives the operation of the administrator 9, and the communication unit 11 transmits a network switching request to the network switching control device 30 using an HTTP request. The network switching request includes at least the connection destination network (network A or B in this embodiment). An example of the network switching screen 501 displayed on the administrator terminal 10 is shown in FIG.

  S2: The HTTP server unit 33 of the network switching control device 30 receives the HTTP request. When the HTTP server unit 33 analyzes the HTTP request and determines that the request is a network switching request, the HTTP server unit 33 sends a network switching instruction to the network switching unit 31. The network switching instruction includes at least the network (network A or B) to which the bridge 40 is connected after switching.

  S2-1: As described with reference to FIG. 4, the network switching unit 31 performs network switching so that the network terminal A or B requested by the administrator 9 can communicate with the user terminal 60. The HTTP server unit 33 is notified that the network switching has been completed.

  S3: After the network switching is completed, the HTTP server unit 33 detects whether the network switching has been successful or has failed by the network switching failure detection unit 32 in order to check whether the network switching process has succeeded or failed. Request communication.

  In response to this, the network switching failure detection unit 32 performs test communication described with reference to FIG. 7 and returns a switching determination result to the HTTP server unit 33. The switching determination result is also returned to the administrator terminal 10 through the HTTP server unit 33.

  FIG. 6 is a diagram illustrating an example of the network switching screen 501 displayed on the LCD 206 of the administrator terminal 10. The network switching screen 501 includes a message 502 “Select a network switching destination”, a line 503 connecting the network C and the network A or B, a radio button 504 in front of “Network A”, and in front of “Network B”. Radio button 505 and execute button 506.

  The administrator 9 can switch networks by a visual operation of clicking (or tapping) radio buttons 504 and 505 in front of the network A or the network B. In addition, since it is a radio button, the networks A and B are not simultaneously selected, and erroneous input can be suppressed.

  When the administrator 9 selects the radio button 504 of the network A, the line 503 connects the network C and the radio button 504 of the network A, and when the administrator 9 selects the radio button 505 of the network B, the line 503 is connected to the network C and the network A. B radio button 505 is connected. In this way, the contents of switching can be confirmed visually (visually).

<< Test communication instructions >>
Next, a procedure for detecting a network switching failure will be described with reference to FIG. FIG. 7 is an example of a sequence diagram for explaining the operation of the network system 100 that detects test failure by performing test communication after network switching. The process of FIG. 7 is started by step S3 of FIG.

  S11: First, the network switching failure detection unit 32 transmits an HTTP request transmission instruction to the administrator terminal 10. More specifically, an HTTP request transmission instruction is transmitted via the HTTP server unit 33 of the network switching control device 30, but is omitted in FIG. The network switching failure detection unit 32 causes the administrator terminal 10 to communicate with the HTTP server A, the HTTP server B, and the HTTP. An example of a method in which the administrator terminal 10 performs HTTP communication with the HTTP server A and the HTTP server B without screen transition is XMLHttpRequest. XMLHttpRequest is an API (Application Interface) for HTTP communication with a server on a browser. In particular, it is used in AJAX (asynchronous communication). The network switching failure detection unit 32 reads the IP addresses of the HTTP server A and the HTTP server B from the IP address storage unit 36 and instructs the administrator terminal 10 to transmit an XMLHttpRequest with these addresses as destinations. The transmission instruction may be performed by transmitting JavaScript (registered trademark), for example.

  Alternatively, when screen transition may be performed, a mechanism called redirection may be used. There are several methods for realizing it, for example, a method using JavaScript (registered trademark) or HTML. In the case of JavaScript (registered trademark), the IP addresses of HTTP server A and HTTP server B are set in the URL of “location.href =“ URL ”;”. In the case of HTML, “meta http-equiv =“ refresh ”content =“ URL = http: // URL ”” is described in the head tag of HTML (URL is the IP address of HTTP server A and HTTP server B). In addition, a direct method such as 301 redirect may be used.

  S12: The communication unit 11 of the administrator terminal 10 transmits an HTTP request to the HTTP server A in accordance with an HTTP request transmission instruction. An HTTP response is returned from the HTTP server A.

  S13: The communication unit 11 of the administrator terminal 10 transmits an HTTP request to the HTTP server B in accordance with an HTTP request transmission instruction. An HTTP response is returned from the HTTP server B. Note that the test communication may be performed only for a network switched as a connection destination of the network C or a network disconnected from the connection destination of the network C. For example, if test communication is performed only with the network switched as the connection destination of the network C, the test communication ends early. If test communication is performed only to the network disconnected from the connection destination of the network C, it can be confirmed that the connection is disconnected in a situation where security is lowered if the Internet or the like is connected.

  Here, the HTTP response includes an HTTP response status code. The HTTP response status code indicates whether the HTTP request has been normally completed, and there are five types of information response, success response, redirect, client error, and server error.

  For example, a test communication when switching from the network A where the HTTP server A is installed to the network B where the HTTP server B is installed will be described as an example. When the switching can be executed normally, an HTTP response from the HTTP server A is returned with an error code of 404 (Not Found). Also, 200 (OK) or the like should be returned from the HTTP server B. On the other hand, when 200 (OK) is returned from the HTTP server A or when an error such as 404 (Not Found) is returned from the HTTP server B, the network switching has failed.

  Therefore, the administrator terminal 10 can also detect the determination result of the network switching at the time of steps S12 and S13.

  S14: The communication unit 11 of the administrator terminal 10 transmits the HTTP response status code received from the HTTP server A and the HTTP server B as a test result to the network switching failure detection unit 32 of the network switching control device 30. Such transmission is described in, for example, JavaScript (registered trademark) acquired from the network switching failure detection unit 32.

  S15: The network switching failure detection unit 32 determines whether the switching is successful based on the HTTP response status codes from the HTTP server A and the HTTP server B. As described with reference to FIG. 5, since the switching determination result is transmitted to the administrator terminal 10, the administrator 9 can determine whether or not the network switching has succeeded.

  FIG. 8 shows an example of the switching determination result screen 511 displayed on the LCD 206 by the administrator terminal 10. The HTTP server unit 33 of the network switching control device 30 creates a switching determination result screen 511 based on the switching determination result of success or failure, and transmits it to the administrator terminal 10. FIG. 8A shows an example of success, and a message 512 “Switching from network A to network B was successful” is displayed.

  FIG. 8B shows an example of failure, and a message 513 “Switching from network A to network B has failed” is displayed. In the case of failure, the character color may be red or flashed to call attention. By doing so, the administrator 9 can confirm the success or failure of the network switching.

<Summary>
As described above, the network system 100 according to the present embodiment has a function of detecting a failure when the administrator terminal 10 transmits a network switching instruction when the switching fails for some reason. Success / failure can be determined.

  Further, if any network user can switch the network, the communication control may be difficult. Therefore, only the administrator 9 can switch the network by the authentication function.

  In this embodiment, the administrator 9 can select the network to be switched on the network switching screen 501 as shown in FIG.

  Conventionally, the administrator 9 needs to connect to the LAN device from the network that is the switching source. However, in this embodiment, the administrator makes a switching request using the browser software 19, so the network switching control device 30 The location is not limited as long as it can be accessed.

  In the first embodiment, the HTTP server A is connected to the network A and the HTTP server B is connected to the network B. However, there may be cases where no HTTP server exists in the networks A and B. Without the HTTP servers A and B, test communication is difficult with the browser software 19 of the administrator terminal 10.

  Therefore, in this embodiment, a description will be given of a network system 100 in which the administrator terminal 10 monitors the life and death of a terminal device that does not have a server function.

  In the present embodiment, the components denoted by the same reference numerals in FIGS. 1 and 2 perform the same function, and therefore, only the main components of the present embodiment may be mainly described.

<About functions>
FIG. 9 is an example of a functional block diagram showing the functions of the HTTP servers A and B, the network switching control device 30, and the administrator terminal 10 included in the network system 100 in a block form. In the description of FIG. 9, differences from FIG. 3 are mainly described.

  In this embodiment, a terminal device 70 that can communicate from the administrator terminal 10 and has an IP address is installed in the network A and the network B. The terminal device 70 connected to the network A is called a terminal device A, and the terminal device 70 connected to the network B is called a terminal device B.

  The terminal device 70 does not need to be an HTTP server. The terminal device 70 may be any device that can communicate with the administrator terminal 10 and has an IP address. Examples of the terminal device 70 include a multifunction peripheral, an electronic blackboard, a projector, and a video conference terminal. In addition, a PC, digital signage, a television receiver, or the like may be used.

  In this embodiment, the IP address storage unit 36 stores the IP addresses of the terminal devices A and B instead of the IP addresses of the HTTP servers A and B.

  Further, the administrator terminal 10 has a management tool 21 that is application software, and the management tool 21 has a function as an HTTP client of the network switching control device 30 and a life / death monitoring function of the terminal device 70 in the network. Unlike the browser, the application software can communicate without being limited to the HTML description format.

<Operation procedure>
Since the process at the time of network switching may be the same as that in FIG. 5, the switching failure detection will be described.

  FIG. 10 is an example of a sequence diagram for explaining the operation of the network system 100 that detects test failure by performing test communication after network switching. The process of FIG. 10 is started by step S3 of FIG.

  S11: First, the network switching failure detection unit 32 transmits an alive monitoring instruction to the administrator terminal 10. That is, the administrator terminal 10 is made to communicate with the terminal device A and the terminal device B using an appropriate communication protocol. In this embodiment, it is only necessary to notify the management tool 21 of the IP addresses of the terminal devices A and B and instruct the life and death monitoring. The management tool 21 and the HTTP server unit 33 of the network switching control device 30 may communicate with each other using HTTP.

  S12: The communication unit 11 of the manager terminal 10 performs life / death monitoring on the terminal device A according to the life / death monitoring instruction. The communication protocol at this time may be any communication protocol as long as the terminal device A and the terminal device B are compatible. For example, a Ping command (ICMP protocol) is transmitted. A Ping response is returned from the terminal device A.

  S13: The communication unit 11 of the manager terminal 10 performs life / death monitoring on the terminal device B according to the life / death monitoring instruction. For example, a Ping command is transmitted. A Ping response is returned from the terminal device B.

  Here, the Ping response includes a response time when the terminal devices A and B respond normally, and a message “timed out” when the terminal devices A and B do not respond.

  For example, a test communication when switching from the network A in which the terminal device A is installed to the network B in which the terminal device B is installed will be described as an example. When the switching can be executed normally, the message “Timed out” is returned as the Ping response from the terminal device A. The terminal device B should return “approximate time 5 milliseconds” or the like. On the other hand, when “approximate time 5 milliseconds” or the like is returned from the terminal device A or when a message “timed out” is returned from the terminal device B, the network switching has failed.

  S14: The communication unit 11 of the administrator terminal 10 transmits the life / death monitoring result received from the terminal device A and the terminal device B to the network switching failure detection unit 32 of the network switching control device 30 as a test result. Such transmission is set in the management tool.

  S15: The network switching failure detection unit 32 determines whether the switching has succeeded based on the alive monitoring result (Ping response from the terminal devices A and B). As described with reference to FIG. 5, since the switching determination result is transmitted to the administrator terminal 10, the administrator 9 can determine whether or not the network switching has succeeded.

<Summary>
As described above, the network system 100 according to the present embodiment can determine success or failure of network switching even if the devices of the networks A and B are not HTTP servers. Therefore, the administrator 9 does not have to prepare the HTTP servers A and B on the networks A and B.

  In this embodiment, alive monitoring is performed using the Ping command, but the communication protocol may be a predetermined, arbitrary, or predetermined communication protocol. For example, ARP (Address Resolution Protocol), SNMP (Simple Network Management Protocol), FTP (File Transfer Protocol), TELNET (Teletype network), NTP (Network Time Protocol), IPsec (Security Architecture for Internet Protocol), etc. may be used. Good. In a network where one of the protocols is restricted for security, failure detection can be performed by using another protocol that is not restricted.

  In this embodiment, a network system 100 in which the network switching control device 30 has a reverse proxy will be described.

  In the first embodiment, the administrator terminal 10 that has communicated with the HTTP server unit 33 of the network switching control device 30 communicates with the HTTP server A and the HTTP server B. However, it is sometimes prohibited by the SOP (Same Origin Policy) that the administrator terminal 10 performs HTTP communication to different servers (different domains). SOP means that a restriction is imposed so that a request cannot be transmitted to a site of another domain. That is, when the SOP works, the administrator terminal 10 may not be able to communicate with the HTTP server A and the HTTP server B.

  Therefore, in this embodiment, a reverse proxy is installed in the network switching control device 30. The administrator terminal 10 communicates with the HTTP server unit 33, the HTTP server A, and the HTTP server B in the network switching control device 30 via the reverse proxy of the network switching control device 30. Since the communication destination of the administrator terminal 10 remains the reverse proxy, the restriction due to SOP can be avoided.

<About functions>
FIG. 11 is an example of a functional block diagram illustrating the functions of the HTTP servers A and B, the network switching control device 30, and the administrator terminal 10 included in the network system 100 in a block form.

  FIG. 11 shows the main functions of the network switching control device 30 according to the present embodiment. In addition to the functions shown in FIG. 11, the network switching control device 30 shown in FIG. The same applies to the administrator terminal 10 and the HTTP servers A and B.

  The network switching control device 30 in FIG. 11 has a reverse proxy 37. The reverse proxy 37 is an alternate (proxy) server that accepts access from a client instead of an arbitrary Web server. The reverse proxy 37 is placed in front of the Web server, receives a request to the Web server, and passes it to the HTTP server behind.

  The administrator terminal 10 connects to the HTTP server unit 33, the HTTP server A, and the HTTP server B of the network switching control device 30 via the reverse proxy 37 of the network switching control device 30. As a result, the communication destination of the administrator terminal 10 is only the reverse proxy 37, and thus is within the constraints of the SOP.

More specifically, the URLs of the HTTP server unit 33 and the HTTP servers A and B of the network switching control device 30 are as follows. The right side of “:” is a TCP port number.
HTTP server unit 33
→ http: // localhost: 4567
HTTP server A
→ http: // (serverA IP addr): 80 or http: // (serverA domain): 80
HTTP server B
http: // (serverB IP addr): 80 or http: // (serverB domain): 80
The administrator terminal 10 communicates with the reverse proxy 37 by designating the IP address of the reverse proxy 37 (note that the port number is 443, which is a general port number of HTTPs). The administrator terminal 10 need only communicate with the network switching control device 30.

  In the present embodiment, since the reverse proxy 37 communicates with the HTTP server unit 33, the HTTP server A, and the HTTP server B, the reverse proxy 37 refers to the proxy path. For this reason, the network switching control device 30 has a proxy path storage unit 38.

表３は、プロキシパス記憶部３８に記憶されているプロキシパスの一例を示す。プロキシパス記憶部３８はプロキシ記憶手段の一例である。プロキシパスは、例えば、「ProxyPass 公開パス 転送先URL」のようなフォーマットで設定される。ProxyPassはプロキシパスの設定であることを示し、公開パスは転送先のＵＲＬの代わりに管理者端末１０が指定するネットワーク切替制御装置３０のパス（フォルダ）である。したがって公開パスはＨＴＴＰサーバＡ、Ｂにアクセスするためのアクセス情報又は転送先の識別情報となる。転送先ＵＲＬは管理者端末１０からリバースプロキシ３７への通信が転送されるＵＲＬである。本実施例ではネットワーク切替制御装置３０のＨＴＴＰサーバ部３３、ＨＴＴＰサーバＡ、及び、ＨＴＴＰサーバＢのＩＰアドレス又はドメインが登録されている。

Table 3 shows an example of proxy paths stored in the proxy path storage unit 38. The proxy path storage unit 38 is an example of a proxy storage unit. The proxy path is set in a format such as “ProxyPass public path transfer destination URL”, for example. ProxyPass indicates a proxy path setting, and the public path is a path (folder) of the network switching control device 30 specified by the administrator terminal 10 instead of the transfer destination URL. Accordingly, the public path becomes access information for accessing the HTTP servers A and B or transfer destination identification information. The transfer destination URL is a URL to which communication from the administrator terminal 10 to the reverse proxy 37 is transferred. In the present embodiment, the IP addresses or domains of the HTTP server unit 33, HTTP server A, and HTTP server B of the network switching control device 30 are registered.

With such a proxy path, the reverse proxy 37 can transfer (distribute) access to the reverse proxy 37 to the HTTP server unit 33, the HTTP server A, and the HTTP server B.
http://www.riverseproxy.co.jp/server → http: // localhost: 4567
http://www.riverseproxy.co.jp/serverA → http: // (HTTP server A IP address): 80
http://www.riverseproxy.co.jp/serverB → http: // (HTTP server B IP address): 80
<Operation procedure>
FIG. 12 is an example of a sequence diagram for explaining the operation of the network system 100 that detects test failure by performing test communication after network switching. The process of FIG. 7 is started by step S3 of FIG.

  S31: First, the network switching failure detection unit 32 transmits an HTTP request transmission instruction to the administrator terminal 10. More specifically, an HTTP request transmission instruction is transmitted through the HTTP server unit 33 and the reverse proxy 37 of the network switching control device 30, but is omitted in FIG. The network switching failure detection unit 32 makes the public path of the reverse proxy 37 corresponding to the HTTP server A and the HTTP server B from the proxy path storage unit 38 to allow the administrator terminal 10 to communicate with the HTTP server A and the HTTP server B using HTTP. read out. Then, “http://www.riverseproxy.co.jp/serverA” and “http://www.riverseproxy.co.jp/serverB” are instructed to the administrator terminal 10 as the destination of the HTTP request.

  S32: The communication unit 11 of the administrator terminal 10 transmits an HTTP request with the public path of the reverse proxy 37 corresponding to the HTTP server A and the HTTP server B as a destination according to the HTTP request transmission instruction. Therefore, the HTTP request is transmitted not to the HTTP server A and the HTTP server B but to the reverse proxy 37.

  S33: The reverse proxy 37 acquires the IP address of the HTTP server A stored in the proxy path storage unit 38 from the access to “http://www.riverseproxy.co.jp/serverA” and makes an HTTP request to the HTTP server A. Send. An HTTP response is returned from the HTTP server A.

  S34: Similarly, the reverse proxy 37 acquires the IP address of the HTTP server B stored in the proxy path storage unit 38 from the access to “http://www.riverseproxy.co.jp/serverB”, and obtains the HTTP server B. An HTTP request is sent to. An HTTP response is returned from the HTTP server B.

  S35: The communication unit 11 of the administrator terminal 10 transmits the HTTP response status code received from the HTTP server A and the HTTP server B to the network switching failure detection unit 32 of the network switching control device 30. Such transmission is described by, for example, JavaScript (registered trademark) acquired from the network switching failure detection unit 32.

  S36: The network switching failure detection unit 32 determines whether switching has succeeded based on the HTTP response status codes from the HTTP server A and the HTTP server B. As described with reference to FIG. 5, since the switching determination result is transmitted to the administrator terminal 10, the administrator 9 can determine whether or not the network switching has succeeded.

<Summary>
As described above, the network system 100 according to the present embodiment enables the administrator terminal 10 to perform test communication with the HTTP servers A and B while using the reverse proxy 37 while avoiding the restrictions on the SOP.

<Other application examples>
The best mode for carrying out the present invention has been described above with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the scope of the present invention. And substitutions can be added.

  For example, in the present embodiment, the networks A to C may be wired communication networks or wireless communication networks. Since wired or wireless is a communication path employed in the physical layer of the OSI basic reference model, it does not affect higher-level communication.

  In addition, the communication performed by HTTP in the present embodiment can be replaced by communication equivalent to HTTP, such as HTTPs and HTTP / 2.

  In the present embodiment, whether the test result is success or failure is determined based on the HTTP response status code, but may be determined based on a response such as ack (success) or nack (failure). That is, the criteria for success or failure of the test result may vary depending on how the communication protocol notifies that it can or cannot communicate.

  In the present embodiment, the network C is fixed to the bridge. However, the network switching may be performed by connecting any two specified by the administrator from three or more networks.

  Moreover, the HTTP server of this embodiment means the server which mainly communicates by HTTP, and may be called a Web server or a WWW server.

  The HTTP server unit 33 is an example of a switching request acquisition unit, the network switching unit 31 is an example of a connection unit, the network switching failure detection unit 32 is an example of a test communication unit, and the operation reception unit 14 is an operation reception unit. The communication unit 11 is an example of a transmission unit.

DESCRIPTION OF SYMBOLS 9 Administrator 10 Administrator terminal 19 Browser software 21 Management tool 30 Network switching control device 37 Reverse proxy 40 Bridge 50 HTTP server 60 User terminal 70 Terminal device 100 Network system

JP 2012-165172 A

Claims (10)

A network device having at least three or more network interfaces,
A switching request acquisition means for acquiring a network switching request from one of the network interfaces;
A connection means for connecting the first network interface and the second network interface in response to the network switching request acquired by the switching request acquisition means;
When the first network interface and the second network interface are connected by the connection means, the second device connected to the second network interface is connected to the first device connected to the first network interface. Test communication means for executing test communication with the apparatus of
Network equipment. In addition to the test communication between the first device and the second device, the test communication means,
When the first network interface and the third network interface are disconnected by the connection means, the third device connected to the third network interface is connected to the first device connected to the first network interface. The network device according to claim 1, wherein test communication with the device is executed. The second device and the third device are servers capable of HTTP communication from the first device,
The test communication unit causes the browser software operating on the first device to execute the test communication by transmitting an HTTP request to the second device and the third device. The network device according to claim 2. The second device and the third device are terminal devices having no server function,
The test communication unit causes the application software operating on the first device to execute the test communication by performing alive monitoring of the second device and the third device using a predetermined communication protocol. The network device according to claim 2, wherein: Address information storage means for storing address information of the second device and the third device,
The test communication means designates the address information of the second device and the third device stored in the address information storage means, and the second device and the first device are designated to the first device. The network device according to claim 3, wherein the network device communicates with the third device. A reverse proxy function for accepting access on behalf of the second device and the third device;
Proxy storage means for associating the access information for the reverse proxy with the address information of the second device and the third device,
When the reverse proxy specifies the access information from the first device and accepts the test communication, the address information of the second device and the third device acquired by referring to the proxy storage unit The network device according to claim 3, wherein the test communication is performed with the address as a destination. The switching request acquisition means transmits screen information for visually accepting network switching to a device connected to one of the network interfaces,
The network device according to any one of claims 1 to 6, wherein a switching request for designating at least a connection destination network selected by a user is received.   The network device according to claim 1, wherein the test communication unit transmits a result of the test communication performed by the test communication unit in order to display the result on the first device. A network system having a network device having at least three or more network interfaces, and a first device connected to one of the first network interfaces,
The first device is:
Operation accepting means for accepting a network switching request;
Transmitting means for transmitting a network switching request to the network device,
The network device is:
Switching request acquisition means for acquiring a network switching request from the first device;
A connection means for connecting the first network interface and the second network interface in response to the network switching request acquired by the switching request acquisition means;
When the first network interface and the second network interface are connected by the connecting means, the test communication with the second device connected to the second network interface is performed with respect to the first device. A test communication means for
A network system. A network switching method performed by a network device having at least three network interfaces,
A switching request acquisition unit acquiring a network switching request from one of the network interfaces;
A connection unit connecting the first network interface and the second network interface in response to the network switching request acquired by the switching request acquisition unit;
When the test communication means connects the first network interface and the second network interface by the connection means, the test communication means sets the second network interface to the first device connected to the first network interface. Performing a test communication with a connected second device;
A network switching method.

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