Abstract:
According to this invention, it is possible to display the overall configuration of a network and, at the same time, an important part of the network in detail according to the objective of monitoring so as to be able to grasp/monitor the important part of the network in detail, while globally grasping/monitoring the network configuration, for the purpose of an efficient monitoring operation on the network configuration. A network configuration management apparatus  100  for managing the configuration of a network  101  formed by connecting a plurality of network devices comprises a topology information acquiring section  11  for acquiring topology information on each of the network devices and a degree of importance determining section  12  for computationally determining the degree of importance of each of the network devices, using the topology information acquired by the topology information acquiring section  11 . The apparatus  100  displays a network map on the basis of the computationally determined degrees of importance.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     This invention relates to a network configuration management apparatus, network configuration management program and a network configuration management method for managing the configuration of a network that is composed by connecting a plurality of network devices and displaying the configuration on a display screen. A network configuration management apparatus, a network configuration management program and a network configuration management method according to the invention can find applications in the field of maintaining a network and monitoring the services of a network and also failures that can disrupt network communications.  
         [0003]     2. Description of the Related Art  
         [0004]     Network configuration management apparatus for managing the physical and logical connections of the network devices (routers, servers, switches, PCs and so on) that constitute a network are known. Such apparatus are typically adapted to display the configuration and the running condition of the network on the display screen of a display apparatus such as a monitor as network map.  
         [0005]     In the trend of forming large-scale networks in recent years, it is difficult to grasp all the network devices by means of such a network configuration management apparatus if all the network devices are displayed as a single network map on the display screen of a monitor because of the limited display area of the display screen.  
         [0006]     For this reason, techniques for dividing the network and displaying a part of the network have been developed. For example, there are known techniques proposed to improve the operating efficiency of the user interface for displaying a network map by displaying partial information relating to the devices that are objects of management by means of the devices out of the information necessary for managing the configuration of the network (see, inter alia, Patent Document 1: Jpn. Pat Appin. Laid-Open Publication No. 9-237236).  
         [0007]     With such a technique, map information including information on the symbols to be displayed on the network map and identification information on network maps of lower orders corresponding to each symbol is stored in a map information storage means in advance and a map symbol relocation means retrieves the information on the symbol to be displayed on the network map of a lower order to be deleted from the map information storage means according to a relocation command transmitted from a relocation execution control means and relocates the symbol on a network map of a higher order to reconfigure the network map of the higher order, while deleting the network map of the lower order. Then, a network map display processing means executes a process of displaying a network map that reflects the reconfigured network map.  
         [0008]     However, such a technique is based on an idea of dividing a network map and hence does not allow a person to visually recognize the entire network on a single monitor screen. Then, the person cannot grasp/monitor the network configuration globally and efficiently.  
       SUMMARY OF THE INVENTION  
       [0009]     In view of the above-identified problem, it is therefore an object of the present invention to provide a network configuration management apparatus, a network configuration management program and a network configuration management method that can display the overall configuration of a network and, at the same time, an important part of the network in detail according to the objective of monitoring so as to be able to grasp/monitor the important part of the network in detail, while globally grasping/monitoring the network configuration, for the purpose of an efficient monitoring operation on the network configuration.  
         [0010]     In an aspect of the present invention, the above object is achieved by providing a network configuration management apparatus for managing the network configuration formed by connecting a plurality of network devices, the apparatus comprising: a topology information acquiring section that acquires topology information on each of the network devices; and a degree of importance determining section that computationally determines the degree of importance of each of the network devices, using the topology information acquired by the topology information acquiring section.  
         [0011]     A network configuration management apparatus according to the invention may further comprise: a displaying information quantity computing section that computes the quantity of information for displaying a network map on the basis of the degree of importance as computationally determined by the degree of importance determining section. Furthermore, the apparatus according to the invention may comprise: an importance ratio defining section that defines the importance ratio corresponding to each piece of topology information in a plurality of pieces of topology information, and the displaying information quantity computing section computing the quantity of information to be displayed, using the importance ratio set by the importance ratio defining section.  
         [0012]     A network configuration management apparatus according to the invention may further comprise: a degree of importance parameter defining section that emphasizes the correlation of the quantity of information to be displayed as computed by the displaying information quantity computing section for each of the network devices relative to the degree of importance computationally determined by the degree of importance determining section, and the degree of importance determining section computationally determining the degree of importance, using the degree of importance parameter defined by the degree of importance parameter defining section.  
         [0013]     A network configuration management apparatus according to the invention may further comprise: a displaying largest area defining section that defines the largest area for displaying a network map on a display section for display the network map, and the displaying information quantity computing section computing the quantity of information to be displayed on the basis of the largest area set by the displaying largest area defining section as well as on the degree of importance computationally determined by the degree of importance determining section.  
         [0014]     Further, as the topology information, the types of network devices, the number of connections and the traffic rate can be used. Alternatively, as the topology information, the types of services, the number of services and the number of accesses can be used.  
         [0015]     In another aspect of the present invention, there is provided a network configuration management apparatus for managing the network configuration formed by connecting a plurality of network devices, the apparatus comprising: a selecting section that selects two of the network devices; a route acquiring section that acquires the communication route between the two network devices selected by the selecting section; a shortest distance computing section that computes the distances from each of the network devices to each of the network devices on the communication route and acquires the smallest value thereof; a route relation degree determining section that computationally determines the degree of route relation on the basis of the shortest distance computed by the shortest distance computing section; and a degree of importance determining section that computationally determines the degree of importance of each of the network devices computationally determined by the route relation degree determining section.  
         [0016]     In still another aspect of the invention, there is provided a medium that has recorded therein, readably by a computer, a network configuration management program for causing a computer to operate for managing the network configuration formed by connecting a plurality of network devices, the program comprising: a topology information acquiring step that acquires topology information on each of the network devices; and a degree of importance determining step that computationally determines the degree of importance of each of the network devices, using the topology information acquired by the topology information acquiring section.  
         [0017]     In still another aspect of the invention, there is provided a medium that has recorded therein, readably by a computer, a network configuration management program for causing a computer to operate for managing the network configuration formed by connecting a plurality of network devices, the program comprising: a selecting step that selects two of the network devices; a route acquiring step that acquires the communication route between the two network devices selected in the selecting step; a shortest distance computing step that computes the distances from each of the network devices to each of the network devices on the communication route acquired in the route acquiring step and acquires the smallest value thereof; a route relation degree determining step that computationally determines the degree of route relation on the basis of the shortest distance computed in the shortest distance computing step; and a degree of importance determining step that computationally determines the degree of importance of each of the network devices computationally determined in the route relation degree determining step.  
         [0018]     In still another aspect of the present invention, there is provided a network configuration management method of causing a network configuration management apparatus to operate for managing the network configuration formed by connecting a plurality of network devices, the method comprising: a topology information acquiring step that acquires topology information on each of the network devices; and a degree of importance determining step that computationally determines the degree of importance of each of the network devices, using the topology information acquired in the topology information acquiring step.  
         [0019]     In a further aspect of the present invention, there is provided a network configuration management method of causing a network configuration management apparatus to operate for managing the network configuration formed by connecting a plurality of network devices, the method comprising: a selecting step that selects two of the network devices; a route acquiring step that acquires the communication route between the two network devices selected in the selecting step; a shortest distance computing step that computes the distances from each of the network devices to each of the network devices on the communication route acquired in the route acquiring step and acquires the smallest value thereof; a route relation degree determining step that computationally determines the degree of route relation on the basis of the shortest distance computed in the shortest distance computing step; and a degree of importance determining step that computationally determines the degree of importance of each of the network devices computationally determined in the route relation degree determining step.  
         [0020]     Thus, according to the invention, it is possible to display the overall configuration of a network and, at the same time, an important part of the network in detail according to the objective of monitoring so as to be able to grasp/monitor the important part of the network in detail, while globally grasping/monitoring the network configuration, for the purpose of an efficient monitoring operation on the network configuration. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]      FIG. 1  is a schematic block diagram of a first embodiment according to the present invention, illustrating the configuration and the operation thereof;  
         [0022]      FIG. 2  is a table showing the topology information stored in the topology information database;  
         [0023]      FIG. 3  is an image displayed on the monitor screen, showing a standardized view of the network synthesis;  
         [0024]      FIG. 4  is a table showing the computationally determined values of the degrees importance in terms of the type of device;  
         [0025]      FIG. 5  is a table showing the computationally determined values of the degrees of importance in terms of the number of connections of device;  
         [0026]      FIG. 6  is a table showing the computationally determined values of the degrees of importance in terms of the traffic rate of device;  
         [0027]      FIG. 7  is a table illustrating the outcome of computations on the sizes of nodes for a network maintenance view;  
         [0028]      FIG. 8  is an image displayed on the monitor screen, showing a network maintenance view;  
         [0029]      FIG. 9  is a table showing the computationally determined values of the degrees of importance in terms of the type of service;  
         [0030]      FIG. 10  is a table showing the computationally determined values of the degrees of importance in terms of the number of services;  
         [0031]      FIG. 11  is a table showing the computationally determined values of the degrees of importance in terms of the number of accesses;  
         [0032]      FIG. 12  is a table showing the outcome of computations on the sizes of the nodes in a network service monitoring view;  
         [0033]      FIG. 13  is an image displayed on the monitor screen, showing a network service monitoring view;  
         [0034]      FIG. 14  is a schematic block diagram of a third embodiment according to the present invention, showing the configuration and the operation thereof;  
         [0035]      FIG. 15  is a table showing the computationally determined values of the degrees of importance of the third embodiment; and  
         [0036]      FIG. 16  is an image displayed on the monitor screen, showing a communication disabling fault view. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0037]     Now, the present invention will be described by referring to the accompanying drawings that illustrate preferred embodiments of the invention.  
       First Embodiment  
       [0038]      FIG. 1  is a schematic block diagram of a first embodiment according to the present invention, illustrating the configuration and the operation thereof.  
         [0039]     The network configuration management apparatus  100  of the first embodiment comprises a topology information acquiring section  11  for acquiring topology information on the configuration of the network  101  and a degree of importance determining section  12  for computationally determining the degree of importance of each of the network devices on the basis of the topology information acquired by the topology information acquiring section  11 , a displaying information quantity computing section  13  for computing the quantity of information to be displayed on the basis of the degrees of importance computationally determined by the degree of importance determining section  12 , a display data generating/outputting section  14  for generating displaying data for displaying a network map on the basis of the quantity of information to be displayed as computed by the displaying information quantity computing section  13  and a display section (monitor)  15  for displaying the displaying data generated by the display data generating/outputting section  14 .  
         [0040]     The network configuration management apparatus  100  additionally comprises a degree of importance parameter defining section  16  adapted to define a degree of importance parameter that can be used appropriately when the degree of importance determining section  12  computationally determines the degree of importance, an importance ratio defining section  17  adapted to define an appropriate importance ratio when the displaying information quantity computing section  13  computes the quantity of information to be displayed and a largest display area defining section  18  adapted to define the largest display area of the display section  15 . The network configuration management apparatus  100  additionally comprises a topology information database (DB)  19  adapted to store the topology information acquired by the topology information acquiring section  11  that can be referred to appropriately.  
         [0041]     Now, the operation of the first embodiment will be described below.  
         [0042]     The topology information acquiring section  11  is adapted to be connected to the network  101  and acquires topology information from each of the network devices that form the network  101 . The acquired topology information is temporarily stored in the topology information database  19 .  FIG. 2  is a table illustrating the topology information stored in the topology information database  19 .  FIG. 3  is an image displayed on the monitor screen of the display section  15 , showing a standardized view. It shows the network configuration contained in the topology information in  FIG. 2 .  
         [0043]     In this embodiment of network configuration in which a plurality of network devices are connected, a firewall  2  and a switch  3  are connected to a router  1  and a server  4  and another server  5  are connected to the firewall  2 , while a PC  6  is connected to the switch  3 . The symbols indicating the respective network devices (nodes) are used as node IDs in the following description.  
         [0044]     The image (standard view) being displayed on the monitor screen of the display section  15  as shown in  FIG. 3  may be switched to a network maintenance view, a service monitoring view or a communication disabling fault view. Any of these views can be selected by depressing the corresponding one of the view selection buttons  7  through  9  and the setting button  10  in  FIG. 3 . In the following description of the first embodiment, it is assumed that the network maintenance view button  7  is depressed/selected so as to use the network configuration management apparatus  100  for the purpose of maintenance of the network. In the following steps described below are those of the operation of the network configuration management apparatus of this invention. (Sn) (n=1, 2, . . . ) in  FIG. 1  indicate the sections that are principally responsible for the operations of the respective steps.  
         [0000]     (Step S1: Acquisition of Topology Information)  
         [0045]     To compose a network maintenance view of this embodiment, the network configuration management apparatus  100  computationally determines the degree of importance of each of the network devices, using the type of the network device  21 , the number of connections of the device  22  and the traffic rate  23  as topology information. In other words, the topology information acquiring section  11  acquires the above values from the topology information database  19  and delivers them to the degree of importance determining section  12  (the topology information acquiring section  11  may be so adapted as to acquire the values directly from each of the devices by way of the network  101  without using the topology information database  19 ).  
         [0000]     (Step S2: Computationally Determining the Degree of Importance)  
         [0000]     (Step S2-1: Computation of the Degree of Importance of Each Type of Device)  
         [0046]     Firstly, the network configuration management apparatus  100  acquires the predetermined value of each type of device from the topology information table (Step S2-1-1). Alternatively, the network configuration management apparatus  100  may acquire the value by referring to the conversion table shown below at each computing operation on the basis of the type of device.  
         [0047]     firewall: 5  
         [0048]     router: 4  
         [0049]     switch: 3  
         [0050]     server: 2  
         [0051]     PC: 1  
         [0052]     Note that the above conversion table is simply an example prepared on a policy that firewalls and routers have a high degree of importance and switches and servers have a medium degree of importance, whereas PC have only a low degree of importance and the present invention is by no means limited thereto.  
         [0053]     Then, the network configuration management apparatus  100  computes the average μ and the standard deviation σ of all the nodes (devices) (Step S2-1-2).  
         [0054]     When the six nodes shown on the table of  FIG. 2  are used for the computation, μ=2.83 and σ=1.34.  
         [0055]     The degree of importance of the type of device is expressed by imp_x, where x represents the type (a numerical value) of a device (node) and the degree of importance imp_x of each type of device is defined by the formula below. The network configuration management apparatus  100  determines the degree of importance imp_x by computation (Step S2-1-3). 
 
 imp   —   x= exp{ k ( x− μ)/σ}
 
         [0056]     k in the above formula represents an degree of importance parameter. Assume k=1 here for computations.  FIG. 4  shows the values obtained by the computations. More specifically,  FIG. 4  shows the node (device) IDs, the host names, the types of devices, the values corresponding to the respective types of devices and the degrees of importance of the types of devices.  
         [0000]     (Step S2-2: Computation of the Degree of Importance of the Number of Connections)  
         [0057]     Then, the degree of importance of the number of connections is computed by using a similar formula (imp_y).  
         [0058]     In the above formula, y represents the number of connections.  FIG. 5  is a table showing the computationally determined values of degree of importance in terms of the number of connections of device. Note that connections as used herein include not only physical connections but also logical connections.  
         [0000]     (Step S2-3: Computation of the Degree of Importance of the Traffic Rate)  
         [0059]     Then, the degree of importance of the traffic rate is computed by using a similar formula (imp_z).  
         [0060]     In the above formula, z represents the traffic rate.  FIG. 6  is a table showing the computationally determined values of the degree of importance in terms of the traffic rate.  
         [0000]     (Step S3: Computation of the Quantity of Information to be Displayed for Each Node)  
         [0061]     If the size of a node is s, the quantity of information to be displayed for each node is expressed by the formula below. 
 
 s= (( imp   —   x ˆα)×( imp   —   y ˆβ)×( imp   —   z ˆγ))ˆ(⅓) 
 
         [0062]     In the above formula, α, β and γ are ratios defined by the user. However, as for the size (the display area), the largest area (s_max) is defined by the user and the requirement of 
 
Σ s≦s _max 
 
 has to be met. If the above requirement is not met, each s is recomputed in a manner as defined below. 
 
 s←s×s _max/Σ s  
 
         [0063]     After computing each node, sizes for display of the network devices (nodes) are obtained as numerical values shown in  FIG. 7 .  
         [0000]     (Step S4: Displaying a Network Map)  
         [0064]     Thehe network map display data generating/outputting section  14  creates the data to be used for display by using the values obtained by the computation for the quantity of information to be displayed for each node in Step S3. For example, the network map display data generating/outputting section  14  prepares data so as to make the display area of each device (node) equal to a multiple of the listed value and outputs it to the monitor. Then, as a result, it is possible to display the network and the devices, each of which is emphasized as a function of the degree of importance in the network configuration as shown in  FIG. 8 .  
         [0065]     As shown in  FIG. 8 , the firewall  2 , the router  1 , the switch  3 , the server  4 , the server  5  and the PC  6  have respective display areas that reflect their degrees of importance that are computationally determined. The firewall  2  that shows the highest degree of importance has the largest display area and is followed by the router  1 . The display areas decrease in the above listed order. With this arrangement, the user can grasp the overall network configuration by means of a single image on the monitor screen and monitor the network by referring to the degrees of importance of the devices that are reflected to the display areas in the image.  
         [0066]     While the display areas of the network devices are made to reflect the respective degrees of importance of the devices in this embodiment, they may alternatively be made to reflect the degrees of detailedness of pieces of information on the devices respectively, such as the lengths of connection, the diametrical sizes of connection, the IP addresses or the like, in relation to the degree of importance.  
         [0000]     (Step of Defining Various Set Values)  
         [0067]     Additionally, if necessary, the steps of defining various set values including the above-described ones (the largest display area (s_max), the importance ratio (α, β, γ), degree of importance parameter (k)) to be used for the computations of determining the degrees of importance and the quantities of information to be displayed are conducted appropriately. Each of the set values may be defined collectively in advance or each value necessary for the computations may be defined whenever necessary.  
         [0068]     The above described largest display area (s_max) is defined in terms of the ratio of the area to be used for displaying all the nodes (devices) relative to the entire display area of the monitor screen when displaying the network configuration on the monitor screen (Step S0-1). This computation is carried out by the largest display area defining section  18  according to the corresponding user operation. Thus, the ratio (%) of the display area to be used for displaying the nodes relative to the largest display area (s_max) is defined in this step.  
         [0069]     The importance ratio (α, β, γ) is defined for each type of device, the number of connections thereof and each of a plurality of pieces of topology information (Step S0-2). The importance ratio is defined by the importance ratio defining section  17  according to the corresponding user operation so as to meet the following conditional formula. The importance ratio represents the ratio to which the type of device, the number of connections and the traffic rate is regarded as important. 
 
α+β+γ=3, 
 
 where 
    α: ratio of the type of device,     β; ratio of the number of connections and     γ; ratio of the traffic rate.    
 
         [0073]     Note that α=1, β=1 and γ=1 are defined as default values.  
         [0074]     Additionally, the degree of importance parameter (k) is defined to emphasize the correlation of the display area relative to the degree of importance (Step S0-3). The degree of importance parameter (k) is defined by the degree of importance parameter defining section  16  according to the corresponding user operation. When the degree of importance parameter is made to show a large value, the size difference among the nodes is emphasized.  
       Second Embodiment  
       [0075]     The first embodiment is described above in terms of displaying a network maintenance view. Now, a second embodiment will be described below in terms of displaying a network service monitoring view. More specifically, in the following description of the second embodiment, it is assumed that a service monitoring view button  8  in  FIG. 3  is depressed/selected so as to use the network configuration management apparatus  100  for the purpose of monitoring services.  
         [0076]     In the second embodiment, the types of service  31 , the number of services  32  and the number of accesses  33  of each of the network devices are used as topology information.  FIGS. 9 through 11  show the computationally determined values of the degrees of importance in terms of the above items. The configuration of the management apparatus of the second embodiment is identical with the one illustrated in  FIG. 1 .  
         [0077]     For the types of service, the following conversion table is used.  
         [0078]     HTTP, SMTP, POP, DNS: 3  
         [0079]     DB, business application: 2  
         [0080]     SSH, Ftp, telnet 1  
         [0081]     Note that the above conversion table is simply an example prepared on a policy that the types of service of HTTP, SMTP, POP and DNS show a high degree of importance and those of DB and business application show a medium degree of importance, whereas those of SSH, FTP and telnet have a small degree of importance and the present invention is by no means limited thereto. As for the number of services, a device that is not providing any service takes a value of 0, while a device that is providing two or more than two services takes a high value.  
         [0082]     For the operation of the second embodiment, formulas similar to those of the first embodiment are used. Values that correspond to respective types of service are acquired as variable x as described above for the first embodiment. The numbers of services are used as variable y as described above for the first embodiment, while the numbers of accesses are used as variable z also as described above for the first embodiment.  
         [0083]      FIG. 12  is a table showing the outcome of computations on the sizes of the network devices (nodes).  FIG. 13  shows a network service monitoring view obtained as a result of the computations.  
         [0084]     While the size of each network device being displayed may be altered according to the degree of importance thereof in the second embodiment, it may alternatively be so arranged that information on the network device may be displayed with an altered degree of detailedness along with the alteration of the size of the device when the degree of importance of the device is altered.  
       Third Embodiment  
       [0085]     Now, a third embodiment according to the present invention will be described below in terms of displaying a communication disabling fault view.  
         [0086]     More specifically, in the following description of the third embodiment, it is assumed that a communication disabling fault view button  9  in  FIG. 3  is depressed/selected so as to use the network configuration management apparatus for the purpose of monitoring communication faults.  
         [0087]      FIG. 14  is a schematic block diagram of the third embodiment, showing the configuration and the operation thereof.  
         [0088]     A network configuration management apparatus  100 A of the third embodiment comprises, in addition to the components illustrated in  FIG. 1 , a fault information acquiring section  41 , a device (node) selecting section  42 , a communication route acquiring section  43 , a shortest distance computing section  44  and a degree of route relation computing section  45 , the outcome of the operation of the degree of route relation computing section  45  is output to the degree of importance determining section  12 . The apparatus  100 A additionally comprises a fault information database  46  for storing fault information acquired by the fault information acquiring section  41 . The configuration from the topology information acquiring section  11  down to the topology information database  19  of the third embodiment is identical with that of the first embodiment described earlier by referring to  FIG. 1  and hence will not be described here any further. Note that the defining sections  16  through  18  are omitted from  FIG. 14 .  
         [0089]     Now, the operation will be described by referring to  FIG. 14 .  
         [0000]     (Step S11: Acquisition of Fault Information)  
         [0090]     The fault information acquiring section  41  acquires fault information from the network  101  or the fault information database  46  and delivers it to the device selecting section  42 .  
         [0000]     (Step S12: Selection of Devices (Node) Between Two Points)  
         [0091]     The device selecting section  42  selects two devices (nodes) that define the longest distance in which communication is disabled and delivers them to the communication route acquiring section  43 .  
         [0092]     It is assumed in the description of this embodiment that router  1  and svr  5  are selected.  
         [0000]     (Step S13: Acquisition of a Communication Route)  
         [0093]     The communication route acquiring section  43  computationally determines the communication route between the two nodes and acquires it. In the case of this embodiment, it becomes clear that the communication route is defined by the router  1 -fw  2 -the svr  5 . The communication route acquiring section  43  delivers this information to the shortest distance computing section  44 . The topology information acquired by the topology information acquiring section  11  in Step S13′ is used appropriately in the operation of computationally determining the communication route and that of computationally determining the shortest distance.  
         [0000]     (Step S14: Computation of the Shortest Distance)  
         [0094]     The shortest distance computing section  44  computes the distance (the number of links) from each of the nodes on the communication route to each of the nodes and selects the smallest value of the computed distances as m. Then, it delivers the smallest value m to the degree of route relation computing section  45 .  
         [0000]     (Step S15: Computation of the Degree of Route Relation)  
         [0095]     Then, the degree of route relation computing section  45  computes the degree of route relation X, using m acquired from the shortest distance computing section  44  and the formula shown below. Then, it delivers the degree of route relation X to the degree of importance determining section  12 . 
 
 X= 1/(1+ m ) 
 
 (Step S16: Computation of the Degree of Importance) 
 
         [0096]     The degree of importance determining section  12  computationally determines the degree of importance imp, using X and the formula shown below. In the formula below, the values of k, μ and σ are the same as those of the first embodiment. 
 
 imp= exp{ k ( X −μ)/σ}
 
 (Step S17: Computation of the Quantity of Information to be Displayed) 
 
         [0097]     The displaying information quantity computing section  13  computes the quantity of information to be displayed on the basis of the degree of importance obtained by the degree of importance computing section  12 . Note that the size s of a node is typically expressed by a multiple of the degree of importance that is confined within a range that does not exceed the largest display area.  
         [0000]     (Step S18: Display of a Network Map)  
         [0098]     The network map display data generating/outputting section  14  prepares the data to be displayed on the monitor screen, using the values obtained as a result of the computations in Step S17 for determining the quantity of information to be displayed.  
         [0099]      FIG. 15  is a table showing the values obtained as a result of the above-described computations.  FIG. 16  is an image displayed on the monitor screen, showing the result thereof.  
         [0100]     While the size of each network device being displayed may be altered according to the degree of importance thereof in the third embodiment, it may alternatively be so arranged that information on the network device may be displayed with an altered degree of detailedness along with the alteration of the size of the device when the degree of importance of the device is altered as in the first and second embodiments.  
         [0101]     With any of the above-described embodiments of the present invention, it is possible to prepare a network configuration management program according to the invention by means of the program for executing the operations of the steps described above in detail by referring to  FIGS. 1 and 14 . The prepared program is stored in a computer-readable storage medium by a computer so as to become computer-executable. Computer-readable recording mediums that can be used for the purpose of the present invention include portable storage mediums such as CD-ROMS, flexible disks, DVDs, magneto optical disks and IC cards as well as databases adapted to hold computer programs, other computers and their databases and transmission mediums on communication lines.