Abstract:
A network management system for managing a computer network in which media switching type infrastructures and media sharing type infrastructures are combined coexistently includes a database destined for network management in which correspondences established among information concerning physical interconnections of individual equipment on the network, information concerning logical network configuration such as that of virtual network, and information concerning the users who make use of the network are stored, identifying devices for identification of the individual equipment on the network and physical addresses intrinsic to network ports, respectively, and retrieval engines for searching information of the physical addresses of the network ports with queries for the logical addresses.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is related to application Ser. No. 09/062,648, filed Feb. 12, 1997, Ser. No. 08/971,621, filed Nov. 17, 1998, and Ser. No. 08/799,759, filed Feb. 12, 1997, now U.S. Pat. No. 5,764,911. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a network management technique suited advantageously for employment in a network in which media sharing type infrastructures and media switch type infrastructures coexist mixedly. 
     Heretofore, a router apparatus and a bridge apparatus have been widely used as the means for controlling communication traffics by dividing a network into a plurality of segments. Further, a high-speed/wide-band switch apparatus of ATM type (Asynchronous Transfer Mode) has also been developed and used for practical applications. As is stated in a draft of “IEEE 802.1q Standards” published by the Institute of Electrical and Electronics Engineers (IEEE) and disclosed in Japanese Unexamined Patent Application Publication No. 130421/1997 (JP-A-9-130421) as well, it is known to implement virtual networks, i.e., logical network segments for every network port under the control of the switch apparatus. However, there exist a plurality of standards for such virtual network systems or schemes which differ from one to another enterprise or from one to another industrial colleague. 
     On the other hand, as a scheme or system for managing machines or equipment on a network, SNMP (Simple Network Management Protocol) prescribed in “Request for Comment 1907 (RFC 1907) published by the Internet Engineering Task Force (IETF) is adopted. With this protocol, setup statuses of the individual machines or equipment can be surveyed and/or altered on an equipment-by-equipment basis. 
     Furthermore, as a method of managing information of the users who are making use of network and computers connected to the network by using a database, the directory services stipulated by “X.500” is adopted as the international standards. 
     The conventional systems or schemes mentioned above, however, suffer problems such as enumerated below. 
     1) In the conventional systems known heretofore, it is certainly possible to implement the logical network segments as the virtual networks by setting previously the network for relaying or repeating packets at the switch apparatus to thereby set up the physical interconnection status of machines or equipment and the logical interconnection status implemented by the virtual networks independent of each other. In that case, however, much difficulty is encountered in referencing or surveying the network configuration as a whole over a wide range and altering or modifying the same. 
     More particularly, because no consideration is paid to the structure of a database destined for consolidative management for the setup status and supervision of the whole virtual network realized by a plurality of equipment, it is extremely difficult in referencing or supervising and altering or modifying the setup status of the virtual network configuration and the network address structure over a plurality of machines or equipment. 
     2) Furthermore, with regard to the packaging of the virtual network, there have been proposed a plurality of different schemes. By way of example, for the asynchronous transfer mode or ATM, LAN emulation (hereinafter also referred to as the LANE) standardized by the standardization association “ATM Forum” is packaged, i.e., adopted actually. Furthermore, concerning the Ethernet switch apparatus, there exist various packaging schemes such as “VLAN Scheme” (IEEE802.1q) currently under discussion for the standardization by the International Standardization Association “IEEE” in addition to those which have been expanded or extended individually by diverse vendors. 
     Now, let&#39;s suppose a network environment in which a plurality of virtual networks of different package types such as mentioned above are combined coexistently. In such environment, it is certainly possible to connect mutually the virtual networks through the medium of the router apparatus. However, the method of referencing or supervising and altering the setup status of the virtual networks differs from one to another virtual network in dependence on the package types as adopted, involving necessity of performing the setup and other operations separately for each of the virtual networks. More specifically, when there arises the necessity of altering or changing the member equipment of the virtual network segments, it is required to alter the setup statuses thereof at the server apparatuses which are in charge of managing the associated virtual network segments, respectively, or the switch apparatuses or both of them. 
     In other words, when a plurality of virtual networks of different types are combined coexistently, an extreme difficulty will be encountered in managing the network as a whole while referencing or altering the setup statuses of the virtual networks in a consolidated manner at one location or station. 
     3) Besides, when configuration of the logical network segment implemented by the virtual network and that of the physical network are grasped in terms of a logical network configuration as viewed from the standpoint a higher-rank protocol, then the management of the virtual network configuration has to be performed separately from the management of the logical network layers with the internet protocol or IP. In such network system, it is impossible to grasp intuitively the physical equipment interconnections as well as relations with and among the logical network configurations. Consequently, when occurrence of obstacle or failure in the network system is detected, extreme difficulty will be involved in determining discriminatively the location where the failure or disturbance is taking place. 
     As will now be appreciated from the foregoing, with the conventional techniques, it is very difficult to realize a means which allows a person in charge of managing or supervising the network system to grasp intuitively the configuration or structure of the network system as a whole by establishing or grasping simultaneously correspondences among the logical network segment structures implemented as the virtual networks, the physical network configuration realized by physically wiring the equipment, and the logical network configuration as viewed from the standpoint of higher-rank protocols of variety. 
     SUMMARY OF THE INVENTION 
     In the light of the state of the art described above, it is an object of the present invention to provide a network management technique which is capable of managing easily a network system which includes a plurality of virtual networks realized in accordance with different schemes. 
     Another object of the present invention is to provide a network management system implemented by adopting the network management technique mentioned above. 
     Yet another object of the present invention is to provide individual apparatuses required for constituting the above-mentioned system. 
     Furthermore, it is an object of the present invention to provide programs for realizing the individual apparatuses. 
     In view of the above and other objects which will become apparent as the description proceeds, the present invention is directed to a network management system for managing a computer network in which a media switching type infrastructure and a media sharing type infrastructure are combined coexistently. 
     In the network management system mentioned above, it is taught according to a general aspect of the present invention that a database for network management is provided, in which correspondences are established among information concerning physical connections of equipment on the network, information concerning logical network configuration such as that of virtual network and information concerning users who make use of the network. 
     With the arrangement of the network management system mentioned above, management of the network including a plurality of virtual networks realized in accordance with respective schemes can be facilitated because the setup status of the virtual networks can be referenced, surveyed or altered easily in a consolidated manner owing to the provision of the service-destined database which is capable of storing the information concerning the physical interconnections of network equipment, the information concerning the logical virtual network configuration and the user information. 
     In a preferred mode for realizing the network management system according to the general aspect of the present invention described above, there may be provided a display unit which is capable of displaying the information concerning the physical network, the information concerning the logical network and the user information in the form of tree-structure type directory data. 
     In another mode for realizing the network management system according to the general aspect of the invention, it is preferred to provide a display means which is capable of disposing the physical network information, the logical network information and the user information on different planes, respectively, for displaying the information on all the planes three-dimensionally within a single frame. 
     In a further mode for realizing the network management system according to the general aspect of the invention, it is preferred to provide an identification means for identifying discriminatively the entities of individual equipment on the network as well as interconnection relations thereof by using physical addresses allocated inherently to network ports, respectively. 
     By virtue of the arrangements described above, it is possible to search (or retrieve) and alter the information concerning the interconnection relations among the physical network equipment, the information concerning the logical virtual network configuration and the user information in a consolidated manner by using as keys the physical addresses allocated to the physical network equipment, respectively. 
     In conjunction with the preferred mode for carrying out the invention described just above, it is preferred to provide a search or retrieve means which is capable of searching or retrieving the information of the physical addresses inherent to the network ports, respectively, in response to queries about the logical addresses. 
     The above and other objects, features and attendant advantages of the present invention will more easily be understood by reading the following description of the preferred embodiments thereof taken, only by way of example, in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the course of the description which follows, reference is made to the drawings, in which: 
     FIG. 1 is a view for illustrating in general an arrangement of a network management system according to an embodiment of the present invention; 
     FIG. 2 is a block diagram showing schematically and generally a structure of a computer serving as a management console which can be employed in the network management system according to the invention; 
     FIG. 3 is a block diagram showing schematically and generally a structure of a computer serving as a supervising manager which can be employed in the network management system according to the invention; 
     FIG. 4 is a block diagram showing schematically and generally a structure of a computer serving as a management platform which can be employed in the network management system according to the invention; 
     FIG. 5 is a view for illustrating communication channels formed or established among individual program modules in the network management system according to the invention; 
     FIG. 6 is a block diagram illustrating a structure of a management console program which can be employed in the management console computer according to the invention; 
     FIG. 7 is a block diagram illustrating a structure of a supervising manager program which can be employed in the supervising manager computer according to the invention; 
     FIG. 8 is a block diagram illustrating a structure of a management platform program which can be employed in the management platform computer according to the invention; 
     FIG. 9 is a flow chart for illustrating a flow of processings involved in collecting information concerning network equipment up to display thereof in the network management system according to the invention; 
     FIG. 10 is a conceptual view for illustrating storing or packaging of network setup information in an object-oriented database in the network management system according to the invention; 
     FIG. 11 is a view for illustrating a data structure adopted for handling object data on a plurality of network structure views which are handled by the network management system according to the invention; 
     FIG. 12 is a view for illustrating a structure of an address management table employed in an environment for carrying out dynamic address allocation in the network management system according to the invention; 
     FIG. 13 is a view for illustrating a method or procedure for handling in a consolidated manner the network setup information in the network management system according to the invention; 
     FIG. 14 is a view for illustrating an example of display generated on a screen of a display device of the management console computer in the system according to the invention; 
     FIG. 15 is a view showing a plurality of network configuration or structure views displayed stereoscopically and hierarchically and illustrating mutual relations among the directory structure views; 
     FIG. 16 is a flow chart for illustrating processings involved in setting the information concerning the network equipment in response to a command for altering the network configuration or structure up to the display of updated network structure information in the network management system according to the invention; 
     FIG. 17 is a flow chart for illustrating a flow of processings for retrieving MAC addresses inherent to network cards mounted on individual equipment by making use of dynamic structure alteration susceptibility of the virtual network in the network management system according to the invention; and 
     FIG. 18 is a view for illustrating an example of a table for management of objects on the network, which table is employed in the network management system according to the invention. 
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The present invention will be described in detail in conjunction with what is presently considered as preferred or typical embodiments thereof by reference to the drawings. 
     Now, a network management system according to an exemplary embodiment of the present invention will be described by reference to FIGS. 1 to  18 . 
     At first, referring to FIG. 1, description will be directed to a system configuration in general of the network management system according to the instant embodiment of the invention. 
     Connected to a network  20  are a computer  21  serving as a management console (hereinafter referred to as the management console computer), a computer  22  serving as a supervising manager (hereinafter referred to as the supervising manager computer), a server computer  23  serving as a management platform (hereinafter referred to as the management platform computer) for providing equipment managing environment such as typified by SNMP (Simple Network Management Protocol), a computer  24  for directory services (hereinafter referred to as the directory server computer) and management-subjected equipment  25  which is subject to management. 
     As management console programs  210  which run on the management console computer  21 , there can be mentioned such program modules as a display processing module  211 , an input/output control module  212 , a web browser module  213  and a communication control processing module  214 . The display processing module  211  serves for realizing the function of displaying network implementation statuses to a network manager. The input/output control module  212  serves for realizing the function of allowing the network manager to input commands. The web browser module  213  serves for providing a standard environment for the management console. The communication control processing module  214  serves for the function for enabling dynamic information exchange between the management console computer  21  and the supervising manager computer  22 . Incidentally, security function such as encrypted communication facility may be incorporated in the communication control processing module  214 . Concerning the hardware structure of the management console computer  21 , description will be made later on by reference to FIG.  2 . 
     The display processing module  211 , the input/output control module  212  and the communication control processing module  214  running on the management console computer  21  can be down-loaded from the supervising manager computer  22  as the program modules designed to run on the web browser module  213  of the management console computer  21  by making use of the function of the web browser module  213 . In that case, the module required to be loaded in the management console computer  21  at the least may be only the web browser module  213 . 
     At this juncture, it should be mentioned that by preparing the functions of the display processing module  211 , etc., destined to run on the management console computer  21  by using a language which is not specific to any particular platform (i.e., language common to or universal to the platforms) such as worldwide standard language VRML (Virtual Reality Modeling Language), Java and the like, the display processing module  211  and others can be so implemented as to run on the web browser module  213  of given type through combination with HTML (Hyper Text Markup Language) or the like. Thus, the display processing module  211  and others can be so prepared as to run on the computers of large variety so long as the WWW (WorldWide Web) can be utilized. Furthermore, as the communication control processing module  214  capable of running on the management console computer  21 , module conforming to other publicly known standards such as FTP (File Transfer Protocol) can be loaded or packaged. 
     As the supervising manager program  220  destined to run on the supervising manager computer  22 , there can be mentioned such program modules as a communication control processing module  222 , a web server module  223 , a database control module  224 , a directory service control module  225 , an equipment control procedure generating module  226 , an equipment control communication processing module  227  and an equipment discriminating or identifying function module  228 . Further provided is an equipment setup information database (DB)  221  which is managed by the supervising manager computer  22 . 
     The communication control processing module  222  is so designed as to allow dynamic information exchange with the management console computer  21 . The web server module  223  serves for presenting static information display service to the management console computer in cooperation with the web browser module  213 . The database control module  224  is designed for storing equipment setup data required for management in the equipment setup information database (DB)  221 . The directory service control module  225  is so designed as to realize retrieval or search function for equipment management data, network user information, etc., by taking into account the structure of equipment and/or hierarchical structure of enterprise organization. The equipment control procedure generating module  226  serves for developing a setup altering procedure for the network equipment to an equipment setting sequence by making use of the equipment setup information database  221 . The equipment control communication processing module  227  serves to send the equipment setting sequence information to the management platform computer  23 . The equipment identifying function module  228  is designed to identify discriminatively network equipment. Incidentally, concerning the hardware structure of the supervising manager computer  22 , description will be made later on by referring to FIG.  3 . 
     As the management platform programs  230  which are destined to run on the management platform computer  23 , there are provided an equipment control procedure execution module  231  and an SNMP (Simple Network Management Protocol) manager module  232 . The equipment control procedure execution module  231  is so programmed as to control the execution of the equipment setting sequence sent from the supervising manager computer  22 . On the other hand, the SNMP manager module  232  sends the information for management to the equipment to be set up (hereinafter referred to as the setup-destined equipment) in accordance with the SNM protocol. 
     In this conjunction, it should be mentioned that in the case where other equipment setup protocol than the SNMP is required, a corresponding manager designed for sending equipment setup information by using a relevant protocol may be disposed similarly to the SNMP manager module  232  to thereby support the relevant protocol. Incidentally, hardware structure of the management platform computer  23  will be described later on by reference to FIG.  4 . 
     As the directory service programs  240  which run on the directory server computer  24 , there can be mentioned such server program modules as typified by a directory server module  242  and a communication control module  243 . A directory database (DB)  241  is managed by the directory server computer  24 . The directory server module  242  is in charge of controlling the directory database  241 . The communication control module  243  is designed to control the communication with the supervising manager computer  22 . 
     Furthermore, as a management-subjected equipment control program  250  designed to run on the management-subjected equipment  25 , there can be mentioned equipment control program modules such as an equipment control module  251 , a management information base  252  and an SNMP (Simple Network Management Protocol) agent module  253 . 
     The equipment control module  251  is programmed to realize the functions of the equipment itself. The management information base  252  is standardized for realizing the network management function through the medium of SNMP or the like. The SNMP agent module  253  performs send/receive processings involved in transferring information stored in the management information base  252  with the SNMP manager module  232 . 
     Next, referring to FIG. 2, description will turn to the structure of the management console computer  21 . 
     The management console computer  21  is realized in a structure similar to that of the conventional computer and is comprised of a main unit  31 , a portable-type disk drive  32  such as a floppy disk drive or the like, a stationary disk storage  33 , an input device  35  such as a keyboard and/or a mouse, and an output device  36  such as a display device. The main unit  31  in turn is comprised of a disk controller  311 , a main storage  312 , a central processing unit (or central arithmetic unit)  313 , a communication input/output interface controller  314 , a keyboard/mouse controller  315  and a video board controller  316 . 
     The management console computer  21  responds to the input/output from/to the network  20  to thereby fetch the management console program  210  including the program modules  211 ,  212 ,  213  and  214  for the management console to store them in the main storage  312 . When the stationary disk drive  33  is provided, it is utilized for the input/output of temporarily saved information  331  such as cache data, etc. In this conjunction, it should be mentioned that the management console program  210 , the program modules  211 ,  212  and  214  except for the web browser module  213  can be delivered from the network  20 , and thus the stationary disk storage  33  illustrated as being provided for the management console computer  21  is not always the indispensable component for the network management system according to the present invention. 
     Next, referring to FIG. 3, description will be made of the structure or configuration of the supervising manager computer  22 . 
     The supervising manager computer  22  is also realized in a structure similar to that of the conventional computer and comprised of a main unit  41 , a portable-type disk drive  42  such as a floppy disk drive, a fixed or stationary disk drive  43 , an input device  45  such as a keyboard and/or a mouse, and an output device  46  such as a display device. The stationary disk drive  43  stores therein the equipment setup information database  221 , a temporarily saved information  431  such as cached data and a program file  432 . The main unit  41  in turn is comprised of a disk controller  411 , a main storage  412 , a central processing unit (central arithmetic unit)  413 , a communication input/output interface controller  414 , a keyboard/mouse controller  415  and a video-board controller  416 . 
     In the supervising manager computer  22 , a group of the program modules for the supervising manager computer and a group of the program modules for the management console computer are held in the stationary disk drive  43  in the form of program files  432 . The group of the program modules for the supervising manager computer  22  are executed on the main storage  412  of the supervising manager computer  22 . In response to an activation request issued from the management console computer  21 , the supervising manager computer  22  sends a group of the program modules  21  for the management console computer to the latter through the medium of the communication input/output interface controller  414 . Further, send/receive requests issued on a real time basis are processed in response to user&#39;s operation or manipulation for the supervising manager computer  22 . 
     Further, the supervising manager computer  22  performs communication with the management platform computer  23  for acquisition and supply of the network equipment setup information. This communication is also performed through the medium of the communication input/output interface controller  414  by way of the network  20  similarly to the communication with the management console computer  21 . Incidentally, the supervising manager computer  22  and the management platform computer  23  need not always be provided independently. The functions of these computers  22  and  23  may be realized by using one and the same computer hardware. In that case, the data transfer mentioned above can be realized through a data bus provided internally of the computer mentioned just above without need for intervention of the network. 
     Next, referring to FIG. 4, description will be made of the structure of the management platform computer  23 . 
     The management platform computer  23  is also realized in a structure of the conventional computer and comprised of a main unit  51 , a portable-type disk drive  52  such as a floppy disk drive, a fixed or stationary disk drive  53 , an input device  55  such as a keyboard and/or a mouse, and an output device  56  such as a display device. The stationary disk drive  53  stores therein a temporarily saved information  531  such as cached data and a program file  532 . On the other hand, the main unit  51  is comprised of a disk controller  511 , a main storage  512 , a central processing unit  513 , a communication input/output interface controller  514 , a keyboard/mouse controller  515  and a video-board controller  516 . 
     Now, referring to FIG. 5, description will be made of communication channels formed for the communications performed among the individual program modules of the management console program  210 , the supervising manager program  220 , the management platform program  230 , the directory service program  240  and the management-subjected equipment control program  250  illustrated in FIG.  1 . 
     The communication channel established or secured between the management console program  210  and the supervising manager program  220  includes a communication channel secured between the web server module  223  and the web browser module  213  for transmission of programs, and a communication channel established between the communication control processing modules  214  and  222  in response to a data send/receive request issued on a real time basis upon activation of the program. As the protocol for these communications, a conventional communication protocol such as “HTTP (Hyper Text Transfer Protocol)” or “Socket” can be used. 
     Further secured or established between the supervising manager program  220  and the directory service program  240 , more specifically, between the directory service control module  225  and the communication control module  243  is a communication channel for enabling search and update processing for the directory database  241 . In that case, as the communication protocol to this end, there may be employed a standard protocol such as DAP (Directory Access Protocol) or LDAP (Lightweight Directory Access Protocol). 
     Furthermore, for allowing the supervising manager program  220  to acquire information from the network equipment and execute setup operation, another communication channel is established between the supervising manager program  220  and the management platform program  230 , more specifically, between the equipment control procedure generating module  226  and the equipment control procedure execution module  231 . As the communication protocol to this end, there can be employed a transfer protocol such as “ftb” and a data exchange protocol such as a data stream processing communication protocol. Besides, in the case where the management platform program  230  and the supervising manager program  220  are designed to run on the same computer hardware, an inter-process communication mechanism such as a pipe can be employed alternatively as the communication channel. 
     Additionally, communication channels are secured between the SNMP manager module  232  of the management platform program  230  and individual SNMP agents  253  of management-subjected equipment control programs  250   a ,  250   b , . . . , and  250   n , respectively. 
     Next, referring to FIG. 6, description will be made in detail of a structure of the management console program  210 . Parenthetically, in this figure, reference numerals same or components as those used in FIG. 1 designate, respectively, like parts as those shown in FIG.  1 . 
     The management console program  210  is constituted by the display processing module  211 , the input/output control module  212 , the web browser module  213  and the communication control processing module  214 , as shown in FIG.  1 . The management console program  210  can be functionally classified globally into three types of application modules in dependence on the contents to be displayed on the output device  36  (FIG. 2) which serves as a user interface for the management console computer  21 . They are a menu module  2101 , a two-dimensional tree view module  2102  and a three-dimensional tree view module  2103 . 
     As the component modules for realizing the display processing module  211 , there can be mentioned a menu control processing module  2111  which is implemented with a web-destined script language such as HTML (Hyper Text Markup Language), Java Script or the like, a two-dimensional tree control processing module  2112  implemented with a web-destined program language and a three-dimensional view control processing module  2113  implemented with a script language for the three-dimensional display such as VRML (Virtual Reality Modeling Language) or the like. 
     As the component modules for realizing the input/output control module  212 , there can be mentioned an input control module  2121  for controlling inputs from the menu as displayed, a two-dimensional database control module  2122  for requesting the supervising manager for input/output of data for the two-dimensional display, a two-dimensional/three-dimensional communication processing module  2123  for performing communication control for interlocking operations of the two-dimensional display and the three-dimensional display, a three-dimensional database control module  2124  for requesting the supervisory manager for input/output of data for the three-dimensional display, and an action library module  2125  for altering contents of the three-dimensional display in accordance with the commands inputted by the user. 
     As the constituent modules required for the web browser module  213 , there can be mentioned a virtual machine module  2131  for executing a web-destined program on the web browser and a VRML (Virtual Reality Modeling Language) plug-in module  2132  designed for executing actual display processing by processing the script language for the three-dimensional display. 
     Furthermore, as the constituent modules for realizing the communication control processing module  214 , there can be mentioned an equipment setting module  2141  for enabling to manipulate directly the function of the management platform from the menu, a two-dimensional database (DB) access module  2142  for actually transferring to the supervisory manager a request issued by the two-dimensional database control module  2122  to thereby acquire the result thereof, and a three-dimensional database access module  2143  for actually transferring to the supervisory manager a request issued by the three-dimensional database control module  2124  to thereby acquire the result thereof. 
     Next, referring to FIG. 7, description will be made in detail of a structure of the supervising manager program  220 . In the figure, like reference numerals as those used in FIG. 1 denote components like as or equivalent to those shown in FIG.  1 . 
     The supervising manager program  220  is constituted by such program modules as the communication control processing module  222 , the web server module  223 , the database control module  224 , the directory service control module  225 , the equipment control procedure generating module  226 , the equipment control communication processing module  227  and the equipment identifying function module  228 , as described hereinbefore by reference to FIG.  1 . The equipment control procedure generating module  226  in turn is comprised of an equipment control module  226   a  and an equipment setting module  226   b  for relaying or repeating to the management platform the information which is required for directly manipulating the management platform computer  23  from the management console computer  21 . 
     As the constituent or component modules for implementing the equipment communication control processing module  222 , there are provided for performing communication processing with the display processing module  211  of the management console computer  21  a two-dimensional database interface module  2221  for receiving commands inputted from the two-dimensional database access module  2142  shown in FIG. 6, a three-dimensional database interface module  2222  for receiving commands inputted from the three-dimensional database access module  2143 , a data conversion module  2223  for converting various types of information supplied from the equipment setup information database  221  and the directory service program  240  into a format suited for data interfacing with the management console program  210 , and a database access control module  2224  for performing a processing of distributing the various database access requests to the pertinent database control modules for the equipment setup information database  221 , the directory database  241  and the like. 
     As the component module for implementing the equipment setup information database  221 , there is required a database function such as an SQL (Structured Query Language) server  2211  or the like. 
     Similarly, for realizing the database control module  224 , there are required a database function such as a view information control module  2241  stored as the data common to the two-dimensional display and the three-dimensional display, an attribute information control module  2242  for controlling the detail attribute information of the management-subjected equipment, and an SQL (Structured Query Language) server  2243  designed for database control. 
     As the component modules for implementing the directory service control module  225 , there are required a directory service control interface module  2251  such as LDAP (Lightweight Directory Access Protocol), API (Application Program Interface) or the like for issuing a request for data search/update or the like to the directory service. 
     Further, as another component module for implementing the equipment control procedure generating module  226 , there is required an SNMP command sequence generating module  2261  for generating an equipment control sequence in the form of a string of commands conforming to SNMP (Simple Network Management Protocol) representative of the equipment control protocol, to thereby supply the control sequence to the management platform computer  23 . Besides, there may be prepared a similar command sequence generating module for realizing or packaging the function for collecting information from the equipment having no SNMP interface and/or for the setup thereof. 
     As the equipment control communication processing module  227 , there may be mentioned a gateway function  2271  to the management platform. 
     Next, referring to FIG. 8, description will be made in detail of a structure of the management platform program  230 . In the figure, like reference numerals as those used in FIG. 1 denote components like as or equivalent to those shown in FIG.  1 . 
     The management platform program  230  includes the equipment control procedure execution module  231  and the SNMP manager module  232 , as can be seen in FIG.  1 . 
     As the component modules for realizing the equipment control procedure execution module  231 , there are provided a socket  2311  for receiving communication from the supervising manager computer  22 , a database application program interface  2312  for manipulating a local database of the management platform computer  23 , and an SNMP application program interface  2313  for enabling manipulation of the SNMP manager  232 . 
     The SNMP manager  232  has be to equipped with an application program interface function for using an application program interface  2321  when the manager function is employed. Additionally, as other components of the SNMP manager module  232 , there are provided a network equipment managing engine  2322 , a device managing engine  2323 , a local database  2324  for networks object and an SNMP demon  2325  for generating SNMP packets. 
     The management-subjected equipment control programs  250   a ,  250   b , . . . and  250   n  are constituted by the equipment control modules  251   a ,  251   b , . . . and  251   n , the management information bases  252   a ,  252   b , . . . and  252   n , and the SNMP agents  253   a ,  253   b , . . . and  253   n , respectively. 
     Next, by referring to FIG. 9, description will be directed to a flow of processings involved in starting or activating of the network management system according to the instant embodiment of the invention, collecting the information concerning the individual network equipment and displaying the network configuration information in the management console computer. In the figure, like reference numerals as those used in FIG. 1 denote components like as or equivalent to those shown in FIG.  1 . 
     Referring to FIG. 9, in the network management system according to the present invention, the web browser module  213  of the management console program  210  is activated in a step S 61 . 
     In succession, the network management system is activated in a step S 62 . 
     In response to the activate processing of the web browser module  213  in the step S 61  and the activate processing of the network management system in the step S 62 , the activation processings mentioned below are executed. 
     In a step S 631 , the management console program  210  executes download processing of the menu page, while the supervising manager program  220  executes upload processing in a step S 641 . Then, the menu page is called through communication between the web server  223  of the supervising manager program  220  and the web browser  213  of the management console program  210 . 
     Subsequently, in a step S 642 , the supervising manager program  220  executes a processing for searching or retrieving the setup information of the individual network equipment from the equipment setup information database  221 . 
     At that time, the supervising manager program  220  decides in a step S 643  whether or not the setup information of all the equipment has been acquired while confirming the existence of the equipment on the network. When it is decided that the setup information of all the equipment on the network has been acquired, the processing proceeds to a step S 647 . 
     By contrast, when it is decided that the setup information of all the equipment has not been acquired yet, the supervising manager program  220  generates a sequence for acquiring the equipment setup information (MIB values (Management Information Base values)) in a step S 644 . 
     In succession, the supervising manager program  220  requests the management platform program  230  to execute the setup information acquisition processing in a step S 645 . 
     The management platform program  230  issues the SNMP command to the management-subjected equipment control programs  250 , respectively, in response to the request for the setup information acquisition processing issued by the supervising manager program  220  in a step S 651 . 
     Each of the management-subjected equipment control programs  250  executes the equipment setup information (MIB value) acquisition processing in response to the SNMP command from the management platform program  230  in a step S 661 . The equipment setup information (MIB value) as acquired is then sent through the medium of the management platform program  230  to the supervising manager program  220 , which receives the information through the processing in the step S 645 . 
     Next, in a step S 646 , the supervising manager program  220  executes a processing for updating the equipment setup information database on the basis of the equipment setup information as received. The updated equipment setup information is sent back to the web server module  223  to be received by the management console program  210  through the upload processing in the step S 641  and the download processing in the step S 631 . 
     Furthermore, in a step S 647 , the supervising manager program  220  executes a processing for generating three-dimensional display data. 
     Hereat, referring to FIG. 10, description will be made of the concept of storing or packaging to network setup information in the object-oriented database in the network management system according to the instant embodiment of the invention. 
     Individual objects appearing in a directory tree structure view  81  representing an organization are packaged or stored in the directory database  241 , while individual objects in a tree structure view  82  representing a structure or configuration of the virtual network are packaged in the equipment setup information database  221 , wherein correlations are established to individual equipment setup information  83  ( 831   a , . . . , and  831   k ), respectively, which correspond to the individual equipment and the functions thereof determined through the equipment control procedure execution module  231  of the management platform computer  23 . 
     In the case of the example illustrated in FIG. 10, two objects “Department # 1 ” and “Department # 2 ” bear correspondences to two virtual segments of LAN emulations “ELAN # 1 ” and “ELAN # 2 ”, respectively, while two sections “Section # 1 ” and “Section # 2 ” correspond to two virtual segments “VLAN # 1 ” and “VLAN # 2 ”, respectively. At this juncture, it should be mentioned that in the case where the correspondence relations lack consistency, it is possible to indicate the correspondence relations by arrows. 
     Furthermore, relations between the users and the individual LEC objects are defined. When the user occupies exclusively one LEC, the correspondence relation with the object is indicated by one-to-one correspondence relation. On the other hand, when a plurality of users use one LEC, the correspondence relation is indicated by a “plural-to-one” correspondence relation. Similarly, in the case where one user is using a plurality of LECs, the relation can be given by “one-to-plural” correspondence relation. 
     The objects  831   a , . . . and  831   k  represent object data of the equipment displayed on the physical network, respectively, and are related to the individual objects on the virtual network. 
     Thus, when the setup status of an object on the virtual network is to be altered, the relevant equipment for which manipulation should be performed can easily be identified. Besides, when the department to which a user belongs is to be changed, it can be easily determined how to alter or change the configuration of the virtual network or for which of the equipment the alteration of the network configuration is to be performed. 
     Next, referring to FIG. 11, description will be directed to an exemplary or typical data structure for handling the object data on a plurality of network structure views handled by the network management system according to the instant embodiment of the invention. 
     Object items  85  and object attributes  86  are stored as parts of the main storage  412  of the supervising manager computer  22 , wherein the object items  85  represents the data of one object displayed on a given one of the network layers. 
     An object identifier  851   a  is composed of an ID (identifier) of the network layer to which the relevant object belongs and an ID of the object on that network layer. 
     Individual information such as object information  851   b  of the physical network layer, link information  851   c  for the physical network layers, object information  851   d  of the virtual network layer, link information  851   e  for the virtual network layers, object information  851   f  of the logical network layer, link information  851   g  for the logical network layers, object information  851   h  of the directory layer, link information  851   i  for the directory layers, object information  851   j  of added layer and link information  851   k  for the added layer are stored as pointers at respective relevant areas of the main storage  412  storing actually the data of the object attribute database  86  to be used as the association information (relation establishing information) for the other objects in the same network or objects on the other network layers. 
     By way of example, in order to know in what fashion a given object is shown on the physical network layer, then the physical network layer object information  851   b  may be referenced to make access to the area where the attribute information of that object is stored. Thus, the information of concern can be obtained. 
     Furthermore, in order to know what kind of relation or association the above-mentioned object bears to other object on the physical network, then the physical network layer link information  851   c  may be referenced to make access to the area where the object attribute information is stored, to thereby acquire the information of concern. 
     By adding the object association information such as mentioned above, information concerning services or the like on the other networks can also be added easily although not described concretely herein. 
     Next, referring to FIG. 12, description will be made of a structure of an address management table employed in the environment in which address allocation is performed dynamically in the network management system according to the instant embodiment of the invention. 
     The address management table  50  for managing the IP address allocation status contains a list of addresses  501  of the IPs which are to be managed with this table as the subjects for the address allocation, information concerning active/reserved/unoccupied statuses of the IP addresses, as designated by reference numeral  502 , and information concerning MAC addresses allocated to network ports of the machines or equipment to which the IP addresses have been allocated, as designated by reference numeral  503 . The address management table  50  is stored in the main storage  412  incorporated in the supervising manager computer  22 . 
     The active/reserved/unoccupied statuses  502  of the IP addresses can be indicated by the respective records  541   a    541   b , . . . and  541   z . By way of example, the IP address “192.168.11.0” of the record  541   a  is allocated with the MAC address “00:00:00:22:11:42” at the port, indicating that the corresponding IP address is currently in the reserved state, which in turn means that the relevant IP address is not currently being used. The IP address “192.168.11.2” is allocated with the MAC address “00:00:00:23:11:55” and is in the active state, i.e., “used or occupied states”. Needless to say, similar management can be performed on the other logical addresses than the IP addresses. 
     In this manner, with the dynamic logical address allocation facility described above, it is possible to manage the address allocation status on a real-time basis. 
     Now, turning back to FIG. 9, processings executed by the management console program  210  in succession to the step S 632  will be described. 
     In a step S 632  in FIG. 9, the management console program  210  executes the directory information acquisition processing for the supervising manager program  220 . 
     In a step S 648 , the supervising manager program  220  responds to a directory information acquisition request issued by the management console program  210  to thereby issue a request for search of the directory database  241 . 
     In a step S 671 , the directory service program  240  makes access to the directory server module  242  in response to the above-mentioned search request to thereby acquire the directory information which is then transferred to the supervising manager program  220 . 
     On the other hand, the supervising manager program  220  transfers the received directory information to the management console program  210  through the processing in a step S 648 . 
     Thus, the management console program  210  acquires the directory information through the processing in the step S 632 . 
     At this juncture, referring to FIG. 13, description will be made of a registration method which allows the network setup information packaged in the object-oriented database shown in FIG. 10 to be handled on the directory database  241  in a consolidated manner. 
     As described hereinbefore by reference to FIG. 10, the data  91 ,  92  and  93  hierarchized on a group basis are registered in the directory database  241 , respectively, at locations determined with reference to other object of a same level in each of the groups. More specifically, of the data  91 , the user related information “User Info.”, and the logical network structure information of the virtual network “Virtual Network Info.” and the physical connection information of the equipment and the network “physical Equipment” are registered in a same hierarchical layer. 
     The directory “User Info.”, for the user-related information has a tree structure in which “Organization” is located at hierarchically lower layer with “Department # 1 ” and “Department # 2 ” being located hierarchically at lower layer than “User Info.”. As to the logical network structure information “Virtual Network Info.”, data  92  of tree structure is registered in “Virtual Network Info.” of the data  91 , whereby such a tree structure is realized in which “LECS” is disposed at a hierarchically lower layer of “Virtual Network Info.” of the data  91  with “ELAN # 1 ” and “ELAN # 2 ” being located at hierarchically lower layer than “LECS”. Similarly, in the physical connection information “Physical Equipment”, data  93  is registered in data  91  “Physical Equipment”, wherein information “ATM”, “LECS”, “LES”, etc., are located at hierarchically lower level than the data  91  “Physical Equipment”. 
     By virtue of the registration such as described above, the setup information of the individual equipment, the information of the virtual network structure or configuration and the user management information can be handled as the same type directory service data, and at the same time the relations or associations between the users and the equipment can easily be packaged in association with the individual object data on the directory service. 
     Furthermore, owing to the availability of the inter-object access control list and the authentication function, manipulation as well as method for allowing the user to make access to the individual equipment can easily be defined. In this conjunction, it should also be mentioned that by defining the authentication functions for the equipment and the virtual networks similarly to the authentication of the users, the network management system of significantly high reliability can be realized while assuring very high security. 
     Now, referring to FIG. 14, description will be made of an example of display generated on a screen of a display device of the management console computer  21  according to the invention. 
     The screen of the display device which serves as the output device  36  of the management console computer  21  may be composed of display areas  1901 ,  1904  and  1905 , a control area or field  1903  and others. In the display area  1901  located at a left-hand side of the display screen, the data acquired or read out from the directory database  241  are displayed in a tree structure. In the case of the illustrated example, the user-related information “User Info.” contained in the data  91  described hereinbefore by reference to FIG. 14 is displayed in the area  1901 . Incidentally, by displaying the menu by clicking a button  1901 A, it is possible to display equally the logical network configuration information “Virtual Network Info.” or the physical connection information “Physical Equipment” in place of the user-related information “User Info.”. 
     In the display area  1904 , a three-dimensional display is generated. The three-dimensional display is composed of a user&#39;s display plane  1040  for displaying the user-related information, a virtual network display plane  1020  for displaying the logical network configuration information and a physical network display plane  1010  for displaying the physical connection information, details of which will be described later on by reference to FIG.  16 . By generating the three-dimensional display in this manner, the information of the users as well as the network information can be displayed very effectively. In this conjunction, it should however be added that although the three-dimensional image is displayed in the case of the example illustrated in FIG. 14, the two-dimensional image generated through the processing in the step S 633  shown in FIG. 9 can equally be displayed by changing the display method correspondingly. 
     The control field  1903  is provided for allowing the sight line for the display area  1904  displayed three-dimensionally. The display area  1905  serves as a status display area for displaying the menu of items for manipulation and the current statuses. 
     Now referring to FIG. 15, description will be directed to a typical method of handling inter-layer relations in the case where a plurality of network structure views and a directory structure view are displayed stereoscopically in hierarchical layers in the network management system according to the instant embodiment of the invention. Parenthetically, FIG. 15 shows the contents displayed in the three-dimensional display area  1904  described above by reference to FIG.  14 . 
     In the physical network display plane  1010  for displaying the physical interconnection information, there is displayed an example of the physical network structure view showing three-dimensionally the physical interconnection relation of the networks handled by the network management system according to the instant embodiment of the invention. 
     More specifically, there are arrayed in the form of stereoscopic object icons on the three-dimensionally displayed plane  1010 , an ATM (Asynchronous Transfer Mode) switch  1012 , a router  1013  connected to the ATM switch  1012 , a personal computer  1011  on which LECS is running, personal computers  1014   a  and  1014   b  on which LES is running, personal computers  1015   a , . . . ,  1015   f  on which LEC are running, a switch  1016  and connection  1019  to other network, respectively. Further, in order to indicate mutual connections among the machines or equipment, lines indicating the equipment interconnection relations are displayed among the individual object icons. 
     Displayed on the virtual network display plane  1020  for displaying the logical network configuration information is a typical virtual network structure view showing three-dimensionally implementation statuses of virtual network segments of the network, as handled by the network management system according to the invention. 
     More specifically, shown on the virtual network display plane  1020  as the virtual network segments are emulated LANs  1027   a  and  1027   b  as well as VLANs  1028   a  and  1028   b  in the form of closed areas, respectively, wherein servers and clients constituting the virtual network are shown as stereoscopical object icons, respectively. In more concrete, the LECS  1021  and the LESs  1024   a  and  1024   b  are shown as server objects of the LAN emulation as connected to the ATM while the LESs  1025   a , . . . ,  1025   f  and the Ethernet switch apparatus  1022  are shown as the client objects, respectively. It can further be seen that lines are displayed for indicating server-client relations between the server objects and the client objects, respectively. 
     The user display  1040  is generated in dependence on the users and the departments or sections of an organization to which the users belongs. In the case of the example illustrated in FIG. 10, the directory data are displayed three-dimensionally in the form of a directory data structure  81 . Two departments “Department # 1 ” and “Department # 2 ” mentioned previously by reference to FIG. 10 are shown as the closed areas, respectively. On the other hand, sections “Section # 1 ” and “Section # 2 ” are shown in the form of closed areas  1048   a  and  1048   b , respectively. The ranking relation among the individual areas and the affiliations of the users are indicated by subsumptive relations among the closed areas, respectively. Thus, the individual users  1045   a , . . . ,  1045   f  are disposed within the closed areas indicating the departments or sections to which the users belong, respectively. 
     Arrows  1401   a ;  1401   b  and  1402   a ;  1402   b  represent relations or associations among the objects shown as the stereoscopical object icons in a plurality of network structure views. By way of example, the arrow  1401   b  indicates that in the virtual network, the user  1045   a  is a same entity as the LEC computer  1025   a  which belongs to the virtual segment  1027   a . Further, the arrow  1401   c  indicates that in the physical network, the LEC computer  1025   a  is a same entity as the computer  1015   a . Similarly, correspondence relations among the user  1045   c , the computer  1025   c  on the virtual network and the computer  1015   a  on the physical network are indicated by the arrows  1402   b  and  1402   c , respectively. 
     Next, referring to FIG. 16, description will be made of a flow of processings involved in setting the information concerning the individual network equipment up to the generation of display of the information concerning an altered or updated network structure or configuration in response to a user&#39;s command demanding alteration or change of the network configuration in the network management system according to the invention. 
     In a step S 71 , when user inputs a command for alteration or change or modification of the network configuration, processings according to the instant embodiment of the invention is started. 
     In a step S 731 , the management console program  210  decides whether or not the user&#39;s command indicates alteration of the network configuration. Unless the ommand indicates the alteration, i.e., when the decision tep S 731  results in negation “NO”, the processing proceeds to a step S 733 . 
     When the network configuration being set up is to be altered, the management console program  210  messages or informs the supervising manager program  220  of the contents of the alteration. 
     Upon reception of the message informing the alteration, the supervising manager program  220  acquires the contents of alteration in a step S 741 . 
     In succession, the supervising manager program  220  searches the equipment setup information database  221  in a step S 742 . 
     In a step S 743 , the supervising manager program  220  lists up the machines or equipment for which the setup status is to be altered. 
     Subsequently, the supervising manager program  220  checks validity of the contents of the alteration as well as the validity of the setup status updating processing in a step S 744 . 
     In a step S 745 , the supervising manager program  220  generates a sequence of the equipment setup information (MIB (Management Information Base) values). 
     In succession, in a step S 746 , the supervising manager computer  22  activates the setup processing while informing the management platform program  230  of the setup processing. 
     In a step S 751 , the management platform program  230  issues the SNMP command to the individual management-subjected equipment control programs  250 , respectively, in accordance with the setup processing information issued by the supervising manager program  220 . 
     In a step S 761 , the management-subjected equipment control program  250  executes the setup processing in accordance with the equipment setup information (MIB values) in response to the SNMP command issued by the management platform program  230 . Upon completion of the setup processing, information concerning completion of the setup processing is sent to the supervising manager program  220  through the medium of the management platform program  230  and received by the former through the processing in a step S 746 . 
     In succession, in a step S 747 , the supervising manager computer  22  updates the contents of the equipment setup information database  221 . 
     Additionally, in a step S 748 , the supervising manager program  220  issues a request to the directory service program  240  for updating the contents of the directory database  241 . 
     Upon reception of the content updating request mentioned above, the directory service program  240  makes access to the directory server module  242  to update the contents of the directory database  241  in a step S 771 . 
     On the other hand, the supervising manager program  220  terminates the alteration or updating processing in a step S 749 . 
     Upon reception of the information of completion of the alteration processing, the management console program decides whether or not the contents of display is to be updated in a step S 733 . When the display is not to be updated, the processing proceeds to a step S 736 . 
     By contrast, when the content of display is to be updated, the management console program  210  executes the two-dimensional display program for altering or modifying the content of display, to thereby generate two-dimensional display data on the screen of the output device  36  such as the display device of the management console computer  21  in a step S 734 . 
     In a step S 735 , the management console program  210  executes the three-dimensional display program to alter the content of display, for thereby generating the three-dimensional display data on the screen of the output device  36  such as the display screen of the management console computer  21 . 
     Furthermore, in a step S 736 , the management console program  210  executes the directory display data generating processing for generating the directory display data on the screen of the output device  36  such as the display screen of the management console computer  21 . 
     Thereafter, the processing of the management console program  210  makes transition to a step S 737  where the user&#39;s input is waited for. 
     Next, referring to FIG. 17, description will be made of a flow of processings for identifying the network equipment and searching or retrieving the MAC (Media Access Control) addresses intrinsic to network cards each mounted on the equipment by making use of the dynamic virtual network altering facility, for thereby acquiring topology information which represents the physical-interconnection relations of the network equipment in the network management system according to the invention. 
     Referring to FIG. 17, in a step S 910 , the supervising manager program  220  responds to activation of the VLAN topology search by activating a topology search system in a step S 911 . 
     In succession, the supervising manager program  220  executes a processing for retrieving the setup information of the individual network equipment. 
     At that time, the supervising manager program  220  decides in a step S 913  whether or not the setup information of all the LANs have been acquired while confirming the interconnection relations of the equipment on all the LANS. When it is decided that the setup information of the equipment on all the LANs have already been acquired, the processing proceeds to a step S 919 . 
     By contrast, when it is decided that the setup information of the equipment on all the LANs have not been acquired yet, i.e., when the interconnection relations among the equipment have not defined yet is found, the supervising manager program  220  activates existing VLAN setup information acquisition processing for saving temporarily the information concerning the current virtual network configuration, whereon request for the acquisition processing of the setup information is issued to the management platform program  230  in a step S 914 . 
     The management platform program  230  issues the SNMP command to the management-subjected equipment control programs  250 , respectively, in response to the request for the setup information acquisition processing issued by the supervising manager program  220  in a step S 931 . 
     Each of the management-subjected equipment control programs  250  executes the equipment setup information (MIB value) acquisition processing in response to the SNMP command from the management platform program  230  in a step S 941 . The equipment setup information (MIB value) as acquired is then sent through the medium of the management platform program  230  to the supervising manager program  220 , which receives the information through the processing in the step S 914 . 
     Next, in a step S 915 , the supervising manager program  220  activates the setup processing for the searching or retrieving VLAN and issues a message of the processing for setting the setup information for the management platform program  230 . 
     In a step S 931 , the management platform program  230  issues the SNMP command to the individual management-subjected equipment control programs  250 , respectively, in accordance with the setup processing information issued by the supervising manager program  220 . In that case, the management platform program  230  alters dynamically the virtual networks managed by the equipment by performing the control for retrieving the individual network ports. 
     In a step S 942 , the management-subjected equipment control program  250  executes the setup processing in accordance with the equipment setup information (MIB values) in response to the SNMP command issued by the management platform program  230 . Upon completion of the setup processing, information concerning completion of the setup processing is sent to the supervising manager program  220  through the medium of the management platform program  230 . 
     In that case, the supervising manager program  220  executes the MAC address information query processing in a step S 916 . In other words, the supervising manager program  220  can grasp the inter-equipment connection relations by retrieving the MAC addresses of the equipment connected to the ports, respectively. 
     Next, in a step S 917 , the supervising manager program  220  executes a processing for restoring the original virtual network configuration after completion of a series of the processings described above. 
     Furthermore, in a step S 918 , the supervising manager computer  22  updates the contents of the equipment setup information database  221 . 
     Now, description will be made of an exemplary object management table indicating the interconnection status of the network which results from the updating step S 918  and which is stored in the equipment setup information database  221 . 
     The object management table  60  contains a list of MAC addresses  61  employed for identification of the objects, a list of computer names  62  used as the names representing the objects, respectively, a list of logical address allocation statuses  63  indicating the addresses allocated to the individual objects and a list of given statuses  64 . Each of the objects is identified by the intrinsic MAC address allocated to the port of the equipment and can be managed independent of the allocation status of the logical network addresses. The object management table  60  is generated by the supervising manager program  220  and stored in the equipment setup information database  221  of the supervising manager computer  22 . 
     Now, turning back to FIG. 17, the supervising manager program  220  makes decision as to whether or not the search has been completed for all the ports. Unless the search has been completed, the steps S 914  et seq. are executed repeatedly. When the search has been completed, the VLAN topology search processing comes to an end. 
     As will now be appreciated from the foregoing description, according to the teachings of the present invention incarnated in the illustrated embodiment, the interconnection relation of the physical network equipment, logical structure information of the virtual networks and the user information can be stored in the directory service data. By virtue of such arrangement, the setup of the virtual network can be referenced or supervised or altered easily at one location or place in a consolidated manner. 
     By using the management console computer capable of generating the two-dimensional or three-dimensional display, the configuration of the logical network segments based on the virtual network and the physical network configuration implemented through physical wiring of the equipment can be managed will very high reliability and accuracy while establishing concurrently the correspondences, respectively, to the logical network configurations as viewed from various upper-rank protocols. 
     Additionally, the information concerning the physical interconnection relations among the network equipment, the information concerning the logical virtual network configuration and the user information can be searched and altered in a consolidated manner by using as the key the MAC addresses allocated to the physical network equipment even when the information mentioned above can not be acquired directly by resorting to the SNMP or like means. 
     Besides, by making use of the database, the logical network segment configuration based on the virtual network, the physical network configuration as viewed from various upper-rank protocols can be managed while establishing concurrently correspondences thereamong by using as the keys the MAC addresses allocated to the physical network configuration, respectively. 
     Thus, according to the teachings of the present invention management of the network including the virtual networks implemented in conformance with plural schemes or standards can be carried out easily.