Patent Publication Number: US-2017357612-A1

Title: Information processing apparatus and maintenance system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuing application, filed under 35 U.S.C. section 111(a), of International Application PCT/JP2015/056686, filed on Mar. 6, 2015, the entire contents of which are incorporated herein by reference. 
    
    
     FIELD 
     This invention relates to a technique for maintenance of an information processing apparatus. 
     BACKGROUND 
     There is a case where a server is connected to a network for management (hereinafter, referred to as a management network) in addition to a network used by a user OS (Operating System) (hereinafter, referred to as a work network) operating on the server. The management network is a dedicated network for accessing a management controller in the server. Since the work network and the management network are physically separated, user data on the OS cannot be accessed from the management network. 
     When a maintenance worker carries out a maintenance work on such a server, the maintenance worker refers to logs or the like stored in the server in order to check operation of the server. However, if the server cannot be directly controlled due to a security problem, a maintenance terminal is connected to the server via the management network to access the logs stored in the server. 
     According to TCP/IPv4 (Transmission Control Protocol/Internet Protocol version 4), when a maintenance terminal is connected to a server via a management network, the server and the terminal have to belong to the same network. In order to make both belong to the same network, as shown in  FIG. 1 , for example, network settings of the terminal may be changed according to network settings of the server. In the example of  FIG. 1 , an IP address of the terminal is changed from “128.10.20.30” to “192.168.1.11”, and a subnet mask of the terminal is changed from “255.255.0.0” to “255.255.255.0”. Moreover, as shown in  FIG. 2 , for example, the network settings of the server may be changed according to the network settings of the terminal. In the example of  FIG. 2 , an IP address of the server is changed from “192.168.1.10” to “128.10.20.31”, and a subnet mask of the server is changed from “255.255.255.0” to “255.255.0.0”. 
     However, there is a case where the maintenance worker is not able to obtain the network settings of the server (for example, the user does not want to disclose the network settings). In this case, since the maintenance worker is not able to match the network settings, the maintenance worker cannot enable the terminal to access the logs in the server, and the maintenance worker cannot carry out the maintenance work. In a prior art relating to a connection between a server and a terminal, such a problem has not been noticed. In other words, there is no technique for changing network settings of a server into network settings for a terminal when the terminal is connected to a server. 
     Patent Document 1: Japanese Laid-open Patent Publication No. 8-110879 
     SUMMARY 
     An information processing apparatus related to this invention includes a memory and a processor coupled to the memory. And the processor is configured to: detect that a first apparatus is connected to a first network port; change network settings of the information processing apparatus into first network settings for the first network port, upon detecting that the first apparatus is connected to the first network port; and switch transmission paths in the information processing apparatus to enable the first apparatus to communicate using the first network port, upon detecting that the first apparatus is connected to the first network port. 
     In one aspect, it becomes possible to change network settings of a server into network settings for a terminal when the terminal is connected to a server. 
     The object and advantages of the embodiment will be realized and attained by means of the elements and combinations particularly pointed out in the claims. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the embodiment, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram for explaining change of network settings; 
         FIG. 2  is a diagram for explaining change of the network settings; 
         FIG. 3  is a diagram depicting a system outline of a first embodiment; 
         FIG. 4  is a diagram depicting an example of data that is stored in a data storage unit; 
         FIG. 5  is a functional block diagram of a maintenance terminal; 
         FIG. 6  is a diagram for explaining an outline of the first embodiment; 
         FIG. 7  is a diagram depicting a processing flow of processing that is executed by a server in the first embodiment; 
         FIG. 8  is a diagram depicting a processing flow of save processing; 
         FIG. 9  is a diagram depicting a processing flow of settings switch processing in the first embodiment; 
         FIG. 10  is a diagram depicting the processing flow of processing executed by the server in the first embodiment; 
         FIG. 11  is a diagram depicting the processing flow of processing executed by the server in the first embodiment; 
         FIG. 12  is a diagram depicting a system outline of a second embodiment; 
         FIG. 13  is a diagram depicting a processing flow of processing executed by a server in the second embodiment; 
         FIG. 14  is a diagram depicting the processing flow of processing executed by the server in the second embodiment; 
         FIG. 15  is a diagram depicting the processing flow of processing executed by the server in the second embodiment; 
         FIG. 16  is a diagram depicting a processing flow of processing executed by the server in a third embodiment; 
         FIG. 17  is a diagram depicting a processing flow of processing executed by a maintenance terminal in the third embodiment; 
         FIG. 18  is a diagram depicting a system outline of a fourth embodiment; 
         FIG. 19  is a diagram depicting a processing flow of processing executed by a server in the fourth embodiment; 
         FIG. 20  is a diagram depicting the processing flow of processing executed by the server in the fourth embodiment; 
         FIG. 21  is a diagram for explaining an outline of a fifth embodiment; 
         FIG. 22  is a diagram depicting a processing flow of processing executed by a server in the fifth embodiment; 
         FIG. 23  is a diagram depicting a processing flow of settings switch processing in the fifth embodiment; 
         FIG. 24  is a diagram depicting the processing flow of processing executed by the server in the fifth embodiment; and 
         FIG. 25  is a functional block diagram of a computer. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiment 1 
       FIG. 3  illustrates a system outline in this embodiment. Server  1  has a work network port  151  which is a network port connected to a work network, a management LAN port  152  which is a network port connected to a management LAN (Local Area Network), and a maintenance network port  153  which is a network port enables a maintenance terminal  3  to connect the server  1 . The maintenance terminal  3  is connected to the maintenance network port  153  via a LAN cable or the like. 
     The server  1  has a switch controller  10  which is, for example, an NIC (Network Interface Card), a management controller  11 , and a user resource  12  which is a resource for a user of the server  1 . 
     The switch controller  10  has a controller  101 , a detection unit  102 , a first switch unit  103 , a second switch unit  104 , an I/F unit  105 , and a data storage unit  106 . 
     The controller  101  executes processing such as controlling the first switch unit  103  and the second switch unit  104  or the like. The detection unit  102  executes processing for detecting that the maintenance terminal  3  is connected to the maintenance network port  153  or the like. 
     The first switch unit  103  is a switch that switches transmission paths. Specifically, the first switch unit  103  switches transmission paths among a transmission path that connects the management LAN port  152  and the management controller  11  (hereinafter, referred to as a first transmission path), a transmission path that connects the maintenance network port  153  and the management controller  11  (hereinafter, referred to as a second transmission path) and a state in which both transmission paths are broken. In the case of generating the first transmission path, the first switch unit  103  connects the connection point  103   a  and the connection point  103   b . In the case of generating the second transmission path, the first switch unit  103  connects the connection point  103   a  and the connection point  103   c.  When breaking both transmission paths, the first switch unit  103  does not connect the connection point  103   a  to any of the connection points  103   b  and  103   c.    
     The second switch unit  104  is a switch that generates and breaks a transmission path between the controller  101  and the I/F unit  105 . Specifically, the second switch unit  104  connects the connection point  104   a  and the connection point  104   c  when connecting the controller  101  and the I/F unit  105  with a transmission path. When the controller  101  and the I/F unit  105  are not connected with a transmission path, the second switch unit  104  connects the connection point  104   a  and the connection point  104   b.  The I/F unit  105  is an interface for connecting to the management controller  11 . 
       FIG. 4  illustrates an example of data stored in the data storage unit  106 . The data storage unit  106  includes an identification data storage area, a management LAN settings storage area, and a maintenance settings storage area. In the identification data storage area, identification data is stored in advance. The management LAN settings storage area is an area for saving management LAN settings. In the maintenance settings storage area, maintenance settings are stored in advance. The identification data is data used when the maintenance terminal  3  accesses the server  1 . The management LAN settings are the original network settings of the server  1 , and in this embodiment, the network settings include an IP address and a subnet mask. The maintenance settings are network settings used when the maintenance terminal  3  is connected to the server  1 . As well as the management LAN settings, the maintenance settings include the IP address and the subnet mask. In this way, by preparing the maintenance settings in advance, even if acquisition of the original network settings of the server  1  is restricted, the maintenance terminal  3  becomes accessible to the data in the server  1 . 
     Returning to the explanation of  FIG. 3 , the management controller  11  has a management LAN controller  111  having a log management unit  1110 , a log storage unit  112 , an I/F unit  113 , and a network settings storage unit  114 . 
     The log management unit  1110  executes processing for managing a log stored in the log storage unit  112 . In the log storage unit  112 , logs (for example, operation log) regarding the server  1  are stored. The I/F unit  113  is an interface for connecting with the switch controller  10 . The network settings storage unit  114  stores network settings of the server  1 . 
     The user resource  12  includes a CPU  121 , a memory  122 , a bus controller  123 , a LAN controller  124 , an I/O controller  125 , and a storage device  126 . The OS program and the application program of the server  1  are stored in the storage device  126 , loaded in the memory  122 , and executed by the CPU  121 . Since the user resource  12  is the same as the resource used for a normal computer, a detailed explanation will be omitted here. 
       FIG. 5  shows a functional block diagram of maintenance terminal  3 . The maintenance terminal  3  has a communication unit  301 , a network settings storage unit  302 , an identification data storage unit  303 , and a port  31 . The communication unit  301  executes processing for transmitting data to the server  1  and processing for receiving data from the server  1 . In the network settings storage unit  302 , maintenance settings (IP address and subnet mask in the present embodiment) are stored in advance. A network represented by the network settings stored in the network settings storage unit  302  of the maintenance terminal  3  is the same as a network represented by the network settings stored in the maintenance settings storage area. In the identification data storage unit  303 , identification data to be used when the maintenance terminal  3  accesses the server  1  is stored in advance. 
     Next, an outline of this embodiment will be explained with reference to  FIG. 6 . 
     First, the maintenance terminal  3  connected to the maintenance network port  153  of the server  1  transmits network identification data (00-00-5E-00-01-01) and network settings (192.168.1.10/255.255.255.0) to the server  1 . When the network identification data included in the packet is the same as network identification data (00-00-5E-00-01-01) registered in advance in the switch controller  10 , the switch controller  10  in the server  1  connects the maintenance network port  153  and the management controller  11  with a transmission path. 
     However, before access of the maintenance terminal  3  is started, the switch controller  10  saves network settings (192.168.2.10/255.255.255.0) stored in the network settings storage unit  114  of the management controller  11  to an area to which the maintenance terminal  3  is not accessible. Further, the switch controller  10  changes network settings stored in the network settings storage unit  114  of the management controller  11  from the management LAN settings (192.168.2.10/255.255.255.0) to the maintenance settings (192.168.1.10/255.255.255.0). 
     Then, the network settings (192.168.1.10/255.255.255.0) stored in the network settings storage unit  114  of the management controller  11  coincide with the network settings (192.168.1.10/255.255.255.0) included in the packet transmitted by the maintenance terminal  3 . As a result, the maintenance terminal  3  is able to obtain logs stored in the log storage unit  112  from the management controller  11 . Further, when the connection of the maintenance terminal  3  is terminated, normal operation is restarted by storing the saved network settings again in the network settings storage unit  114  of the management controller  11 . 
     Next, with reference to  FIGS. 7 to 11 , this embodiment will be explained in more detail. First, the processing when the maintenance terminal  3  is connected to the server  1  will be explained. 
     First, the detection unit  102  checks status of the maintenance network port  153  ( FIG. 7 : step S 1 ), and determines whether a LAN cable is connected to the maintenance network port  153  (in other words, linked up) (step S 3 ). 
     When the LAN cable is not connected to the maintenance network port  153  (step S 3 : No route), the detection unit  102  waits for a predetermined time and the processing returns to step S 1 . On the other hand, when the LAN cable is connected to the maintenance network port  153  (step S 3 : Yes route), the detection unit  102  extracts network identification data from the packet received via the LAN cable (step S 5 ). In this embodiment, the network identification data is a virtual MAC (Media Access Control) address and is stored in a field of the source MAC address in the packet. 
     The detection unit  102  outputs to the controller  101  a first obtaining request to obtain network identification data. In response to this, the controller  101  reads out network identification data from the identification data storage area in the data storage unit  106  (step S 7 ), and notifies the detection unit  102 . 
     The detection unit  102  determines whether the network identification data extracted from the packet in step S 5  matches the network identification data read out from the identification data storage area in step S 7  (step S 9 ). 
     When the network identification data extracted from the packet in step S 5  does not match the network identification data read out from the identification data storage area in step S 7  (step S 9 : No route), the received packet is discarded. And the processing returns to step S 1 . 
     On the other hand, when the network identification data extracted from the packet in step S 5  coincides with the network identification data read out from the identification data storage area in step S 7  (step S 9 : Yes route), the detection unit  102  notifies the controller  101  that the network identification data matched. 
     The controller  101  outputs a first switching instruction to the first switch unit  103  and the second switch unit  104 . In response to this, the first switch unit  103  breaks the transmission path connecting the management LAN controller  111  and the management LAN port  152 , and switches to a state in which each of the transmission paths is broken. Further, the second switch unit  104  connects the connection point  104   a  and the connection point  104   c  to connect the management LAN controller  111  and the controller  101  with a transmission path (step S 11 ). 
     The controller  101  executes save processing (step S 13 ). The save processing will be explained with reference to  FIG. 8 . 
     First, the controller  101  in the switch controller  10  transmits a second obtaining request to obtain the management LAN settings to the management LAN controller  111  in the management controller  11  ( FIG. 8 : step S 31 ). Here, the second obtaining request is transmitted via the transmission path that connects the controller  101  and the management LAN controller  111 . 
     The management LAN controller  111  in the management controller  11  receives the second obtaining request from the controller  101  (step S 33 ). Then, the management LAN controller  111  reads out the management LAN settings from the network settings storage unit  114  (step S 35 ), and transmits a response including the read out management LAN settings to the controller  101  (step S 37 ). Here, the response is transmitted via a transmission path that connects the controller  101  and the management LAN controller  111 . 
     The controller  101  receives a response from the management LAN controller  111  (step S 39 ), and stores the management LAN settings included in the response in the management LAN settings storage area of the data storage unit  106  (step S 41 ). Then, the processing returns to the calling-source processing. 
     By executing the aforementioned processing, it becomes possible to prevent the management LAN settings from being lost by changing the network settings. Moreover, since the data storage unit  106  is in a location to which the maintenance terminal  3  is not accessible, even if access to the management controller  11  is allowed, the management LAN settings will not be leaked. 
     Returning to the explanation of  FIG. 7 , the controller  101  executes settings switch processing in the first embodiment (step S 15 ). The settings switch processing will be explained with reference to  FIG. 9 . 
     First, the controller  101  in the switch controller  10  reads out the maintenance settings stored in the maintenance settings storage area of the data storage unit  106  ( FIG. 9 : step S 51 ). Then, the controller  101  transmits the maintenance settings read out in step S 51  to the management LAN controller  111  (step S 53 ). Here, the maintenance settings are transmitted via a transmission path that connects the controller  101  and the management LAN controller  111 . 
     The management LAN controller  111  in the management controller  11  receives the maintenance settings from the controller  101  (step S 55 ). Then, the management LAN controller  111  changes the network settings (in this case, the management LAN settings) stored in the network settings storage unit  114  to the maintenance settings received in step S 55  (step S 57 ). Then, the processing returns to the calling-source processing, and the processing shifts to step S 17  of  FIG. 10  via terminal A. 
     By executing the aforementioned processing, the maintenance terminal  3  is permitted to access the management controller  11 . 
     Shifting to the explanation of  FIG. 10 , the controller  101  outputs a second switching instruction to the first switch unit  103  and the second switch unit  104 . In response to this, the second switch unit  104  breaks the transmission path that connects the management LAN controller  111  and the controller  101 , by connecting the connection point  104   a  and the connection point  104   b.  In addition, the first switch unit  103  connects the management LAN controller  111  and the maintenance network port  153  with a transmission path, by connecting the connection point  103   a  and the connection point  103   c  (step S 17 ). 
     Here, the maintenance terminal  3  accesses the management controller  11  and obtains logs from the log storage unit  112  via the log management unit  1110 . The processing here will be explained later. 
     The detection unit  102  checks status of the maintenance network port  153  (step S 19 ), and determines whether a LAN cable is connected to the maintenance network port  153  (step S 21 ). 
     When the LAN cable is connected to the maintenance network port  153  (step S 21 : Yes route), the processing returns to step S 19 . On the other hand, when the LAN cable is not connected to the maintenance network port  153  (step S 21 : No route), the detection unit  102  notifies the controller  101  that the LAN cable is not connected to the maintenance network port  153 . 
     The controller  101  outputs a third switching instruction to the first switch unit  103  and the second switch unit  104 . In response to this, the first switch unit  103  breaks the transmission path that connects the management LAN controller  111  and the maintenance network port  153 , and switches to a state in which each of the transmission paths is broken. Further, the second switch unit  104  connects the connection point  104   a  and the connection point  104   c  to connect the management LAN controller  111  and the controller  101  with a transmission path (step S 23 ). 
     The controller  101  changes the network settings stored in the network settings storage unit  114  (in this case, settings for maintenance) into the management LAN settings saved in the management LAN settings storage area of the data storage unit  106  (step S 25 ). Specifically, the controller  101  transmits the management LAN settings saved in the management LAN settings storage area of the data storage unit  106  to the management controller  11 . The management LAN controller  111  in the management controller  11  changes the network settings stored in the network settings storage unit  114  into the received management LAN settings. In step S 25 , the management LAN settings are transmitted via the transmission path that connects the controller  101  and the management LAN controller  111 . 
     The controller  101  outputs a fourth switching instruction to the first switch unit  103  and the second switch unit  104 . In response to this, the second switch unit  104  breaks the transmission path that connects the management LAN controller  111  and the controller  101 , by connecting the connection point  104   a  and the connection point  104   b . In addition, the first switch unit  103  connects the management LAN controller  111  and the management LAN port  152  with a transmission path, by connecting the connection point  103   a  and the connection point  103   b  (step S 27 ). Then, the processing ends. 
     By executing the aforementioned processing, even if the maintenance staff is not able to obtain the original network settings (in this case, the management LAN settings) in advance, it becomes possible to view the logs of the server  1  and carry out the maintenance work. Moreover, since the change of the network settings is automatically performed, the maintenance worker is able to start maintenance work without particular self-consciousness. Moreover, since the network settings are automatically restored to the original after the maintenance work is finished, it is possible to prevent a maintenance worker from returning to the incorrect network settings. 
     Next, with reference to  FIG. 11 , processing executed by the management controller  11  that has received a packet from the maintenance terminal  3  will be explained. 
     First, the detection unit  102  in the switch controller  10  receives a packet ( FIG. 11 : step S 61 ). The detection unit  102  outputs the received packet to the management controller  11  via the transmission path generated in step S 17 . 
     The management controller  11  determines whether the network settings included in the received packet match the network settings stored in the network settings storage unit  114  (step S 63 ). 
     When the network settings included in the received packet match the network settings stored in the network settings storage unit  114  (step S 63 : Yes route), the management LAN controller  111  executes processing according to data included in the received packet (Step S 65 ). Then, the processing ends. For example, when the packet is a log request packet requesting log acquisition, the log management unit  1110  reads the corresponding log from the log storage unit  112  and transmits it to the maintenance terminal  3  as a response. 
     On the other hand, if the network settings included in the received packet do not match the network settings stored in the network settings storage unit  114  (step S 63 : No route), the management LAN controller  111  discards the received packet (Step S 67 ). Then, the processing ends. 
     By executing the aforementioned processing, it becomes possible to eliminate access from the maintenance terminal  3  which is not entitled to access the management controller  11 . 
     Embodiment 2 
     In a second embodiment, a method for enhancing security by using authentication based on a hardware key will be explained. 
       FIG. 12  illustrates a system outline of the second embodiment. The server  1  has hardware key reading device  13 . Since the part other than the hardware key reading device  13  in the server  1  is the same as in the first embodiment, parts other than those used for the explanation will be omitted. 
     The hardware key reading device  13  obtains information from a hardware key  5  (e.g., a card carrying an IC (Integrated Circuit) chip) which became close to the hardware key reading device  13 , and compares the information from the hardware key  5  with information registered in advance in the hardware key reading device  13  to perform authentication. When the authentication is successful, the hardware key reading device  13  notifies the controller  101  in the switch controller  10  that the authentication is successful. 
     Next, with reference to  FIGS. 13 to 15 , processing executed by the server  1  in the second embodiment will be explained. First, an example will be explained in which processing after terminal B is executed when authentication by the hardware key  5  is successful and network identification data matches. 
     First, the detection unit  102  determines whether the authentication by the hardware key  5  is successful ( FIG. 13 : step S 71 ). Whether or not the authentication by the hardware key  5  is successful is determined from whether or not success of the authentication is notified from the controller  101  notified that the authentication is successful from the hardware key reading device  13 . 
     When the authentication by the hardware key  5  is not successful (step S 71 : No route), the detection unit  102  waits for a predetermined time, and the processing returns to step S 71 . On the other hand, when the authentication by the hardware key  5  is successful (step S 71 : Yes route), the detection unit  102  checks status of the maintenance network port  153  (step S 73 ), and determines whether the LAN cable is connected to the maintenance network port  153  (That is, linked up) (step S 75 ). 
     When the LAN cable is not connected to the maintenance network port  153  (step S 75 : No route), the processing returns to step S 71 . On the other hand, when the LAN cable is connected to the maintenance network port  153  (step S 75 : Yes route), the detection unit  102  extracts network identification data from the packet received via the LAN cable (step S 77 ). In this embodiment, the network identification data is a virtual MAC address and is stored in a field of the source MAC address in the packet. 
     The detection unit  102  outputs to the controller  101  a first obtaining request to obtain network identification data. In response to this, the controller  101  reads out network identification data from the identification data storage area in the data storage unit  106  (step S 79 ), and notifies the detection unit  102 . 
     The detection unit  102  determines whether the network identification data extracted from the packet in step S 77  matches the network identification data readout from the identification data storage area in step S 79  (step S 81 ). 
     When the network identification data extracted from the packet in step S 77  does not match the network identification data read out from the identification data storage area in step S 79  (step S 81 : No route), the received packet is discarded. And the processing returns to step S 71 . 
     On the other hand, when the network identification data extracted from the packet in step S 77  matches the network identification data read out from the identification data storage area in step S 79  (step S 81 : Yes route), the processing shifts to step S 11  of  FIG. 7  via terminal B. 
     Execution of the aforementioned processing makes it possible to enable a double protection method, security becomes enhanced. 
     Next, with reference to  FIG. 14 , an example will be explained in which processing after terminal B is executed when authentication by hardware key  5  is successful or network identification data matches. 
     First, the detection unit  102  determines whether the authentication by the hardware key  5  is successful ( FIG. 14 : step S 91 ). Whether or not the authentication by the hardware key  5  is successful is determined from whether or not success of the authentication is notified from the controller  101  notified that the authentication is successful from the hardware key reading device  13 . 
     When the authentication by the hardware key  5  is successful (step S 91 : Yes route), the processing shifts to step S 11  of  FIG. 7  via terminal B. On the other hand, when the authentication by the hardware key  5  is not successful (step S 91 : No route), the detection unit  102  checks status of the maintenance network port  153  (step S 93 ), and determines the LAN cable is connected to the maintenance network port  153  (that is, linked up) (step S 95 ). 
     If the LAN cable is not connected to the maintenance network port  153  (step S 95 : No route), the processing returns to step S 91 . On the other hand, when the LAN cable is connected to the maintenance network port  153  (step S 95 : Yes route), the detection unit  102  extracts network identification data from the packet received via the LAN cable (step S 97 ). 
     The detection unit  102  outputs to the controller  101  a first obtaining request to obtain network identification data. In response to this, the controller  101  reads out network identification data from the identification data storage area in the data storage unit  106  (step S 99 ), and notifies the detection unit  102 . 
     The detection unit  102  determines whether the network identification data extracted from the packet in step S 97  matches the network identification data readout from the identification data storage area in step S 99  (step S 101 ). 
     When the network identification data extracted from the packet in step S 97  does not match the network identification data read out from the identification data storage area in step S 99  (step S 101 : No route), the extracted packet is discarded. And the processing returns to step S 91 . 
     On the other hand, when the network identification data extracted from the packet in step S 97  matches the network identification data read out from the identification data storage area in step S 99  (step S 101 : Yes route), the processing shifts to step S 11  of  FIG. 7  via terminal B. 
     By executing the aforementioned processing, success of the authentication by the hardware key  5  or match of network identification data enhance convenience for a maintenance worker. 
     Next, with reference to  FIG. 15 , an example will be explained in which once authentication by the hardware key  5  succeeds, processing after terminal B is executed after that if only network identification data matches. 
     First, the detection unit  102  determines whether or not the authentication by the hardware key  5  has already been performed and has been successful ( FIG. 15 : step S 111 ). 
     When the authentication by the hardware key  5  has not been successful (step S 111 : No route), the detection unit  102  executes the following processing. Specifically, the detection unit  102  waits until the authentication by the hardware key  5  succeeds. Then, when the authentication by the hardware key  5  succeeds, the detection unit  102  extracts the source MAC address of the received packet and stores it in the identification data storage area of the data storage unit  106  as network identification data (step S 113 ). The processing shifts to step S 11  of  FIG. 7  via terminal B. 
     On the other hand, if the authentication by the hardware key  5  has been successful (step S 111 : Yes route), the detection unit  102  checks status of the maintenance network port  153  (step S 115 ), and determines whether a LAN cable is connected to the maintenance network port  153  (That is, linked up) (step S 117 ). 
     If the LAN cable is not connected to the maintenance network port  153  (step S 117 : No route), the processing returns to step S 111 . On the other hand, when the LAN cable is connected to the maintenance network port  153  (step S 117 : Yes route), the detection unit  102  extracts network identification data from the packet received via the LAN cable (step S 119 ). In this embodiment, the network identification data is a virtual MAC address and is stored in a field of the source MAC address in the packet. 
     The detection unit  102  outputs to the controller  101  a first obtaining request to obtain network identification data. In response to this, the controller  101  reads out network identification data from the identification data storage area in the data storage unit  106  (step S 121 ), and notifies the detection unit  102 . 
     The detection unit  102  determines whether the network identification data extracted from the packet in step S 119  matches the network identification data read out from the identification data storage area in step S 121  (step S 123 ). 
     When the network identification data extracted from the packet in step S 119  and the network identification data read out from the identification data storage area in step S 121  do not match (step S 123 : No route), the received packet is discarded. And the processing returns to step S 111 . 
     On the other hand, when the network identification data extracted from the packet in step S 119  matches the network identification data read out from the identification data storage area in step S 121  (step S 123 : Yes route), the processing shifts to step S 11  of  FIG. 7  via terminal B. 
     By executing the aforementioned processing, it becomes possible to enhance security and improve convenience for a maintenance worker. 
     Embodiment 3 
     In a third embodiment, a method for enhancing security by not continuing to use the same network identification data will be explained. 
     With reference to  FIG. 16 , processing executed by the server  1  in the third embodiment will be explained. First, the detection unit  102  checks status of the maintenance network port  153  ( FIG. 16 : step S 131 ), and determines whether a LAN cable is connected to the maintenance network port  153  (that is, linked up) (step S 133 ). 
     When the LAN cable is not connected to the maintenance network port  153  (step S 133 : No route), the processing returns to step S 131 . On the other hand, when the LAN cable is connected to the maintenance network port  153  (step S 133 : Yes route), the detection unit  102  extracts network identification data from the packet received via the LAN cable (step S 135 ). In this embodiment, the network identification data is a virtual MAC address and is stored in a field of the source MAC address in the packet. 
     The detection unit  102  outputs to the controller  101  a first obtaining request to obtain network identification data. In response to this, the controller  101  reads out network identification data from the identification data storage area in the data storage unit  106  (step S 137 ), and notifies the detection unit  102 . 
     The detection unit  102  determines whether the network identification data extracted from the packet in step S 135  matches the network identification data read out from the identification data storage area in step S 137  (step S 139 ). 
     If the network identification data extracted from the packet in step S 135  does not match the network identification data read out from the identification data storage area in step S 137  (step S 139 : No route), the received packet is discarded. And the processing returns to step S 131 . 
     On the other hand, when the network identification data extracted from the packet in step S 135  matches the network identification data read out from the identification data storage area in step S 137  (step S 139 : Yes route), the detection unit  102  executes the following processing. Specifically, the detection unit  102  determines whether a packet including new network identification data different from the network identification data extracted in step S 135  has been received from the maintenance terminal  3  (step S 141 ). 
     When the packet including the new network identification data is not received from the maintenance terminal  3  (step S 141 : No route), the detection unit  102  waits for a predetermined time and returns to the processing of step S 141 . On the other hand, when the packet including the new network identification data is received from the maintenance terminal  3  (step S 141 : Yes route), the detection unit  102  outputs the new network identification data to the controller  101 . In response to this, the controller  101  changes network identification data stored in the identification data storage area of the data storage unit  106  into the new network identification data (step S 143 ). The controller  101  notifies the detection unit  102  that change of network identification data is completed. 
     The detection unit  102  transmits, to the maintenance terminal  3 , a completion notification indicating that network identification data has been changed (step S 145 ). Then the processing shifts to step S 11  of  FIG. 7  via terminal B. 
     By executing the aforementioned processing, since network identification data is changed each time the LAN cable is connected, it becomes possible to prevent continuation of using the same network identification data and to improve security. 
     With reference to  FIG. 17 , processing performed by the maintenance terminal  3  in the third embodiment will be explained. This processing is executed after a packet including network identification data is transmitted for the first time. First, the communication unit  301  of the maintenance terminal  3  determines whether connection with the server  1  has been established by initial transmission of a packet including network identification data ( FIG. 17 : step S 151 ). 
     When the connection with the server  1  has not been established (step S 151 : No route), the communication unit  301  waits for a predetermined time and the processing returns to step S 151 . On the other hand, when the connection with the server  1  is established (step S 151 : Yes route), the communication unit  301  randomly generates network identification data (step S 153 ). 
     The communication unit  301  changes network identification data stored in the identification data storage unit  303  into the network identification data generated in step S 153  (step S 155 ). Then, the communication unit  301  transmits, to the server  1 , a packet including the network identification data generated in step S 153  and network settings stored in the network settings storage unit  302  (step S 157 ). 
     The communication unit  301  determines whether a completion notification has been received from the server  1  (step S 159 ). When the completion notification has not been received (step S 159 : No route), the communication unit  301  waits for a predetermined time and the processing returns to step S 159 . On the other hand, when the completion notification is received (step S 159 : Yes route), the processing ends. 
     In this way, since it is possible to generate new network identification data which is difficult to identify each time connection via the LAN cable is made, it becomes possible to enhance security. When the maintenance terminal  3  is changed for some reason, it becomes possible to continue to carry out a maintenance work by taking over network identification data of the new maintenance terminal  3  or restore network identification data registered in the server  1  to initial network identification data. 
     Embodiment 4 
     In a fourth embodiment, an example in which the switch controller  10  and the management controller  11  are provided in separate devices will be explained. 
     With reference to  FIG. 18 , a system outline of this embodiment will be explained. The server  1  in the fourth embodiment has the management controller  11  as in the first embodiment, but does not have the switch controller  10 . The switch controller  10  is provided in the switch device  7 . The switch device  7  has the switch controller  10 , the maintenance network port  153 , and management LAN ports  155  and  157 . 
     The switch controller  10  can switch transmission paths as in the first embodiment. Specifically, by connecting the connection point  103   a  and the connection point  103   c,  the maintenance network port  153  and the management LAN controller  111  are connected by a transmission path. Further, by connecting the connection point  103   a  and the connection point  103   b,  the management LAN port  155  and the management LAN controller  111  are connected by a transmission path. As in the first embodiment, a second switch unit  104  is provided between the controller  101  in the switch controller  10  and the management LAN controller  111 , and the second switch unit  104  generates and breaks transmission paths between the controller  101  and the management LAN controller  111 . However, it is omitted in  FIG. 18  in order to make the figure easy to be seen. 
     It is to be noted that parts other than aforementioned parts of the server  1 , the maintenance terminal  3  and the switch controller  10  are the same as those of the first embodiment, and the description is omitted here. 
     Next, with reference to  FIG. 19  and  FIG. 20 , processing executed by the switch device  7  in the fourth embodiment will be explained. 
     First, the detection unit  102  checks status of the maintenance network port  153  ( FIG. 19 : step S 161 ), and determines whether a LAN cable is connected to the maintenance network port  153  (that is, linked up) (step S 163 ). 
     When the LAN cable is not connected to the maintenance network port  153  (step S 163 : NO route), the detection unit  102  waits for a predetermined time and the processing returns to step S 161 . On the other hand, when the LAN cable is connected to the maintenance network port  153  (step S 163 : Yes route), the detection unit  102  extracts network identification data from the packet received via the LAN cable (step S 165 ). In this embodiment, the network identification data is a virtual MAC address and is stored in a field of the source MAC address in the packet. 
     The detection unit  102  outputs to the controller  101  a first obtaining request to obtain network identification data. In response to this, the controller  101  reads out network identification data from the identification data storage area of the data storage unit  106  (step S 167 ), and notifies the detection unit  102 . 
     In step S 169 , the detection unit  102  determines whether the network identification data extracted from the packet in step S 165  matches the network identification data read out from the identification data storage area in step S 167 . 
     When the network identification data extracted from the packet in step S 165  does not match the network identification data read out from the identification data storage area in step S 167  (step S 169 : No route), the received packet is discarded. And the processing returns to S 161 . 
     On the other hand, when the network identification data extracted from the packet in step S 165  matches the network identification data read out from the identification data storage area in step S 167  (step S 169 : Yes route), the detection unit  102  notifies the controller  101  that the network identification data matched. 
     The controller  101  outputs a first switching instruction to the first switch unit  103  and the second switch unit  104 . In response to this, the first switch unit  103  breaks the transmission path connecting the management LAN controller  111  and the management LAN port  155 , and switches to a state in which each of the transmission paths is broken. Further, the second switch unit  104  connects the connection point  104   a  and the connection point  104   c  to connect the management LAN controller  111  and the controller  101  with a transmission path (step S 171 ). 
     The controller  101  establishes a connection with the management LAN controller  111  of the server  1  based on the management LAN settings stored in the management LAN settings storage area in the data storage unit  106  (step S 173 ). It is assumed that the management LAN settings have been obtained from the server  1  in advance. 
     The controller  101  transmits the maintenance settings stored in the maintenance settings storage area of the data storage unit  106  to the server  1  (step S 175 ). The processing shifts to step S 177  of  FIG. 20  via terminal C. In response to the processing of step S 175 , the management LAN controller  111  in the server  1  changes the network settings (management LAN settings in this case) stored in the network settings storage unit  114  into the maintenance settings. 
     Shifting to explanations for  FIG. 20 , the controller  101  outputs a second switching instruction to the first switch unit  103  and the second switch unit  104 . In response to this, the second switch unit  104  breaks the transmission path connecting the management LAN controller  111  and the controller  101  by connecting the connection point  104   a  and the connection point  104   b.  In addition, the first switch unit  103  connects the management LAN controller  111  and the maintenance network port  153  with a transmission path by connecting the connection point  103   a  and the connection point  103   c  (step S 177 ). 
     Here, the maintenance terminal  3  accesses the management controller  11  and obtains logs from the log storage unit  112  by way of the log management unit  1110 . 
     The detection unit  102  checks status of the maintenance network port  153  (step S 179 ), and determines whether a LAN cable is connected to the maintenance network port  153  (step S 181 ). 
     When the LAN cable is connected to the maintenance network port  153  (step S 181 : Yes route), the processing returns to step S 179 . On the other hand, when the LAN cable is not connected to the maintenance network port  153  (step S 181 : No route), the detection unit  102  notifies the controller  101  that the LAN cable is not connected to the maintenance network port  153 . 
     The controller  101  outputs a third switching instruction to the first switch unit  103  and the second switch unit  104 . In response to this, the first switch unit  103  breaks the transmission path connecting the management LAN controller  111  and the maintenance network port  153 , and switches to a state in which each of the transmission paths is broken. Further, the second switch unit  104  connects the connection point  104   a  and the connection point  104   c  to connect the management LAN controller  111  and the controller  101  with a transmission path (step S 183 ). 
     The controller  101  establishes a connection with the management LAN controller  111  of the server  1  based on the maintenance settings stored in the maintenance settings storage area of the data storage unit  106  (step S 185 ). 
     The controller  101  transmits the management LAN settings stored in the management LAN settings storage area of the data storage unit  106  to the server  1  (step S 187 ). In response to the processing of step S 187 , the management LAN controller  111  in the server  1  changes the network settings (the maintenance settings in this case) stored in the network settings storage unit  114  into the management LAN settings. 
     The controller  101  outputs a fourth switching instruction to the first switch unit  103  and the second switch unit  104 . In response to this, the second switch unit  104  breaks the transmission path connecting the management LAN controller  111  and the controller  101  by connecting the connection point  104   a  and the connection point  104   b . In addition, the first switch unit  103  connects the management LAN controller  111  and the management LAN port  155  with a transmission path by connecting the connection point  103   a  and the connection point  103   b  (step S 189 ). Then, the processing ends. 
     As described above, it becomes possible to flexibly constructing a system suitable for actual conditions such as server placement situation and processing performance, by enabling to realize a system configuration in which the switch controller  10  and the management controller  11  are provided in separate apparatuses. 
     Embodiment 5 
     In the fifth embodiment, an example in which not only an IP address and a subnet mask but also a MAC address is included in the network settings to be saved will be explained. 
     An outline of the fifth embodiment will be explained with reference to  FIG. 21 . 
     First, the maintenance terminal  3  connected to the maintenance network port  153  of the server  1  transmits a packet including network identification data (00-00-5E-00-01-01) and network settings (192.168.1.10/255.255.255.0) to the server  1 . In this embodiment, ARP (Address Resolution Protocol) packets are transmitted (broadcast in this case) for the first time, and network identification data and network settings are included in the ARP packets. 
     When the network identification data included in the ARP packet coincides with network identification data (00-00-5E-00-01-01) registered in advance in the switch controller  10 , the switch controller  10  in the server  1  connects the maintenance network port  153  and the management controller  11  with a transmission path. 
     However, before access of the maintenance terminal  3  is started, the switch controller  10  saves the network settings (192.168.2.10/255.255.255.0/00-00-5E-00-01-02) stored in the network settings storage unit  114  of the management controller  11  to an area where the maintenance terminal  3  is not accessible. Further, the switch controller  10  changes the network settings stored in the network settings storage unit  114  of the management controller  11  from the management LAN settings (192.168.2.10/255.255.255.0/00-00-5E-00-01-02) to the maintenance settings (192.168.1.10/255.255.255.0/11-22-33-44-55-66). The maintenance settings include an IP address, a subnet mask and a MAC address randomly generated by the switch controller  10 . 
     Then, the server  1  transmits an ARP response including the MAC address for which the ARP request was generated to maintenance terminal  3 . In response to this, the maintenance terminal  3  sets the MAC address included in the ARP response as the destination MAC address, and transmits the packet. Then, the network settings (192.168.1.10/255.255.255.0/11-22-33-44-55-66) stored in the network settings storage unit  114  of the management controller  11  coincide with the network settings (192.168.1.10/255.255.255.0/11-22-33-44-55-66) included in the packet transmitted by the maintenance terminal  3 . As a result, the maintenance terminal  3  can obtain logs stored in the log storage unit  112  from the management controller  11 . Further, when a connection of the maintenance terminal  3  is terminated, normal operation may be restarted by storing the saved network settings again in the network settings storage unit  114  of the management controller  11 . 
     Next, with reference to  FIGS. 22 to 24 , processing executed by the server  1  in the fifth embodiment will be explained. 
     First, the detection unit  102  checks status of the maintenance network port  153  ( FIG. 22 : step S 191 ), and determines whether a LAN cable is connected to the maintenance network port  153  (that is, linked up) (step S 193 ). 
     When the LAN cable is not connected to the maintenance network port  153  (step S 193 : No route), the detection unit  102  waits for a predetermined time and the processing returns to step S 191 . On the other hand, when the LAN cable is connected to the maintenance network port  153  (step S 193 : Yes route), the detection unit  102  extracts network identification data from the ARP packet received via the LAN cable (step S 195 ). In this embodiment, the network identification data is a virtual MAC address and is stored in a field of the source MAC address in the ARP packet. 
     The detection unit  102  outputs to the controller  101  a first obtaining request to obtain network identification data. In response to this, the controller  101  reads out network identification data from the identification data storage area in the data storage unit  106  (step S 197 ), and notifies the detection unit  102 . 
     The detection unit  102  determines whether the network identification data extracted from the ARP packet in step S 195  matches the network identification data read out from the identification data storage area in step S 197  (step S 199 ). 
     When the network identification data extracted from the ARP packet in step S 195  does not match the network identification data read out from the identification data storage area in step S 197  (step S 199 : No route), the received ARP packet is discarded. And the processing returns to step S 191 . 
     On the other hand, when the network identification data extracted from the ARP packet in step S 195  matches the network identification data read out from the identification data storage area in step S 197  (step S 199 : Yes route), the detection unit  102  determines that the network identification data matched. 
     The controller  101  outputs a first switching instruction to the first switch unit  103  and the second switch unit  104 . In response to this, the first switch unit  103  cuts off the transmission path connecting the management LAN controller  111  and the management LAN port  152 , and switches to a state in which each of the transmission paths is broken. Further, the second switch unit  104  connects the connection point  104   a  and the connection point  104   c  to connect the management LAN controller  111  and the controller  101  with a transmission path (step S 201 ). 
     The controller  101  executes save processing (step S 203 ). The save processing is the same as explained with reference to  FIG. 8 , and explanation is omitted here. However, in the fifth embodiment, the management LAN settings read out in step S 35  include a MAC address. Therefore, the management LAN settings stored in step S 41  also include the MAC address. 
     The controller  101  executes settings switch processing in the fifth embodiment (step S 205 ). The settings switch processing will be explained with reference to  FIG. 23 . 
     First, the controller  101  in the switch controller  10  randomly generates a MAC address and stores it in the maintenance settings storage area of the data storage unit  106  ( FIG. 23 : step S 231 ). When the MAC address is already stored in the maintenance settings storage area, the controller  101  overwrites the already-stored MAC address. 
     The controller  101  reads out the maintenance settings stored in the maintenance settings storage area of the data storage unit  106  (step S 233 ). The maintenance settings that are read out include an IP address, a subnet mask, and the MAC address generated in step S 231 . 
     Then, the controller  101  transmits the maintenance settings read out in step S 233  to the management LAN controller  111  (step S 235 ). Here, the maintenance settings are transmitted via a transmission path connecting the controller  101  and the management LAN controller  111 . 
     The management LAN controller  111  in the management controller  11  receives the maintenance settings from the controller  101  (step S 237 ). Then, the management LAN controller  111  changes the network settings (the management LAN settings in this case) stored in the network settings storage unit  114  to the maintenance settings received in step S 237  (step S 239 ). Then, the processing returns to the calling-source processing, and the processing shifts to step S 207  of  FIG. 24  via terminal D. 
     By executing the aforementioned processing, the maintenance terminal  3  becomes permitted to access the management controller  11 . 
     Shifting to the explanation of  FIG. 24 , the controller  101  outputs a second switching instruction to the first switch unit  103  and the second switch unit  104 . In response to this, the second switch unit  104  breaks the transmission path connecting the management LAN controller  111  and the controller  101  by connecting the connection point  104   a  and the connection point  104   b.  In addition, the first switch unit  103  connects the management LAN controller  111  and the maintenance network port  153  with a transmission path by connecting the connection point  103   a  and the connection point  103   c  (step S 207 ). 
     The controller  101  transmits an ARP request to the management LAN controller  111  (step S 209 ). In response to this, the management LAN controller  111  transmits an ARP response including the MAC address stored in the network settings storage unit  114  to the controller  101 . Then, the controller  101  transmits the ARP response received from the management LAN controller  111  to the maintenance terminal  3  (step S 211 ). 
     In response to this, the maintenance terminal  3  uses the MAC address included in the ARP response as the destination address of packets to be transmitted to the server  1 . 
     Then, the maintenance terminal  3  accesses the management controller  11  and obtains logs from the log storage unit  112  by way of the log management unit  1110 . 
     The detection unit  102  checks status of the maintenance network port  153  (step S 213 ), and determines whether a LAN cable is connected to the maintenance network port  153  (step S 215 ). 
     When the LAN cable is connected to the maintenance network port  153  (step S 215 : Yes route), the processing returns to step S 213 . On the other hand, when the LAN cable is not connected to the maintenance network port  153  (step S 215 : No route), the detection unit  102  notifies the controller  101  that the LAN cable is not connected to the maintenance network port  153 . 
     The controller  101  outputs a third switching instruction to the first switch unit  103  and the second switch unit  104 . In response to this, the first switch unit  103  breaks the transmission path connecting the management LAN controller  111  and the maintenance network port  153 , and switches to a state in which each of the transmission paths is broken. Further, the second switch unit  104  connects the connection point  104   a  and the connection point  104   c  to connect the management LAN controller  111  and the controller  101  with a transmission path (step S 217 ). 
     The controller  101  changes the network settings (the maintenance settings in this case) stored in the network settings storage unit  114  into the management LAN settings saved in the management LAN settings storage area in the data storage unit  106  (step S 219 ). Specifically, the controller  101  transmits the management LAN settings saved in the management LAN settings storage area of the data storage unit  106  to the management controller  11 . The management LAN controller  111  in the management controller  11  changes the network settings stored in the network settings storage unit  114  into the received management LAN settings. In step S 219 , the management LAN settings are transmitted via the transmission path connecting the controller  101  and the management LAN controller  111 . 
     The controller  101  outputs a fourth switching instruction to the first switch unit  103  and the second switch unit  104 . In response to this, the second switch unit  104  breaks the transmission path connecting the management LAN controller  111  and the controller  101  by connecting the connection point  104   a  and the connection point  104   b . In addition, the first switch unit  103  connects the management LAN controller  111  and the management LAN port  152  with a transmission path by connecting the connection point  103   a  and the connection point  103   b  (step S 221 ). Then, the processing ends. 
     By executing the aforementioned processing, not only the IP address and the subnet mask but also the MAC address is saved, and the security may be further enhanced. 
     Embodiment 6 
     In the first to fifth embodiments, TCP/IP protocol is used, but Fibre Channel or InfiniBand may be used. In this case, instead of an IP address, a subnet mask, and a MAC address, a dynamic port address, a GUID (Globally Unique IDentifier) and a WWN (World Wide Name) may be used. 
     Although the embodiments of this invention were explained above, this invention is not limited to those. For example, the functional block configuration of the server  1  and the maintenance terminal  3 , which are explained above, does not always correspond to actual program module configuration. 
     Moreover, the aforementioned data configuration is a mere example, and maybe changed. Furthermore, as for the processing flow, as long as the processing results do not change, the turns of the steps may be exchanged or the steps may be executed in parallel. 
     In addition, the aforementioned maintenance terminal  3  is a computer apparatus as illustrated in  FIG. 25 . That is, a memory  2501 , a CPU  2503  (central processing unit), a HDD (hard disk drive)  2505 , a display controller  2507  connected to a display device  2509 , a drive device  2513  for a removable disk  2511 , an input unit  2515 , and a communication controller  2517  for connection with a network are connected through a bus  2519  as illustrated in  FIG. 25 . An operating system (OS) and an application program for carrying out the foregoing processing in the embodiment, are stored in the HDD  2505 , and when executed by the CPU  2503 , they are read out from the HDD  2505  to the memory  2501 . As the need arises, the CPU  2503  controls the display controller  2507 , the communication controller  2517 , and the drive device  2513 , and causes them to perform predetermined operations. Moreover, intermediate processing data is stored in the memory  2501 , and if necessary, it is stored in the HDD  2505 . In these embodiments of this invention, the application program to realize the aforementioned processing is stored in the computer-readable, non-transitory removable disk  2511  and distributed, and then it is installed into the HDD  2505  from the drive device  2513 . It may be installed into the HDD  2505  via the network such as the Internet and the communication controller  2517 . In the computer apparatus as stated above, the hardware such as the CPU  2503  and the memory  2501 , the OS and the application programs systematically cooperate with each other, so that various functions as described above in details are realized. 
     The aforementioned embodiments of this invention may be summarized as follows. 
     An information processing apparatus related to a first aspect of these embodiments includes: a memory and a processor coupled to the memory. And the processor is configured to: (A) detect that a first apparatus is connected to a first network port; (B) change network settings of the information processing apparatus into first network settings for the first network port, upon detecting that the first apparatus is connected to the first network port; and (C) switch transmission paths in the information processing apparatus to enable the first apparatus to communicate using the first network port, upon detecting that the first apparatus is connected to the first network port. 
     In this way, communication with the first apparatus may be performed using the first network settings for the first network port, it enables a worker to carry out a maintenance work even if obtaining former network settings is limited. 
     Moreover, the changing may include (b1) saving the network settings before the changing to a storage area to which the first apparatus is not accessible. In this way, it becomes possible to enhance confidentiality of the network settings before the changing. 
     Moreover, the detecting may include (a1) detecting that the first apparatus is not connected to the first network port, the changing may include (b2) changing the network settings from the first network settings to second network settings that is former network settings upon detecting that the first apparatus is not connected to the first network port, and the switching may include (c1) switching the transmission paths in the information processing apparatus to enable to communicate using a second network port that is a former network port upon detecting that the first apparatus is not connected to the first network port. In this way, it becomes possible to return to a former state when a maintenance work is completed. 
     Moreover, the detecting may include (a2) detecting that the first apparatus is connected to the first network port when first identification data stored in a data storage unit matches second identification data received from the first apparatus. In this way, it becomes possible to prevent an apparatus that is not entitled to connect to the information processing apparatus from being connected to the information processing apparatus. 
     Moreover, the detecting may include (a3) updating the first identification data with third identification data that is different from the second identification data, when receiving the third identification data after the first apparatus is connected to the first network port. In this way, it becomes possible to improve security since using the same identification data continually is prevented. 
     Moreover, the processor may further be configured to (D) perform authentication based on information obtained from external hardware, the changing may include (b3) changing the network settings into the first network settings upon detecting that the first apparatus is connected to the first network port and a result of the authentication satisfies a predetermined condition, and the switching may include (c2) switching the transmission paths to enable the first apparatus to communicate using the first network port upon detecting that the first apparatus is connected to the first network port and the result of the authentication satisfies the predetermined condition. In this way, it becomes possible to improve security. 
     Moreover, the network settings may include at least one of an IP (Internet Protocol) address, a subnet mask and a MAC (Media Access Control) address. 
     Moreover, the network settings may include at least one of a WWN (World Wide Name), an address of a dynamic port and a GUID (Globally Unique IDentifier). 
     A maintenance system related to a second aspect of these embodiments includes: (E) an information processing apparatus; and (F) a first apparatus. And the first information processing apparatus includes: a memory and a processor coupled to use the memory. And the processor is configured to: detect that the first apparatus is connected to a first network port; change network settings of the information processing apparatus into first network settings for the first network port, upon detecting that the first apparatus is connected to the first network port; and switch transmission paths in the information processing apparatus to enable the first apparatus to communicate using the first network port, upon detecting that the first apparatus is connected to the first network port. 
     All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present inventions have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.