NerveCenterTM 3.8: An Overview
-
Contents - NerveCenter Components -
This section introduces the main components that make up NerveCenter. For this discussion, we will analyze NerveCenter as a standalone network management application in its simplest configuration.
NerveCenter Components and Communication illustrates the main NerveCenter components and shows the direction in which data flows.
NerveCenter Components and Communication
The following table describes the components in the diagram:
The following sections expand on the diagram and components just described.
The NerveCenter Client lets you monitor the network as well as create and modify the behavior models managed by the NerveCenter Server. You can access the MIBs, nodes, behavior models, alarm filters, and other NerveCenter objects associated with that Server. The Alarm Summary window displays all current alarms for the connected Server.
Alarm Summary Window shows a sample Alarm Summary window.
The left pane contains a tree that displays the total number of current alarm instances, the number of instances in each severity group (Fault and Traffic), and the number of instances of each severity. If there is no number next to a severity, there are no active alarm instances of that severity.
The right pane provides detailed information about current alarm instances for the folder or severity that is highlighted in the tree view.
NerveCenter also provides a Web-based console that lets you monitor network activity from any machine that has a Microsoft Internet Explorer or Netscape Navigator browser installed. For a description of the NerveCenter Web Client, see Web-based Monitoring.
Though you can manually add nodes to NerveCenter, it is easy to configure NerveCenter to discover nodes. When NerveCenter discovery is enabled, if the database does not already contain a node that sends it an SNMP trap or NerveCenter inform, NerveCenter adds that node to the database.
NerveCenter Configured To Discover Nodes
After installing NerveCenter, you can use the NerveCenter Administrator to define subnet IP filters that limit the sets of nodes NerveCenter can monitor. These filter values are stored with the NerveCenter configuration settings.
When a trap is received from a node, NerveCenter compares the node against those that are already in its database and confirms whether the node falls within the subnet IP filters you defined. Nodes that fall within the subnet range but are not in the database are added to the database.
You can also use NerveCenter's ping sweep utility, IPSweep, to populate your database. See IPSweep for more information about IPSweep.
NerveCenter includes two utilities that facilitate data management.
NerveCenter uses different methods of storing information on UNIX and Windows systems.
The following sections describe data management for each platform:
NerveCenter uses two files for data storage on UNIX:
nervecenter.ncdb -- Contains information about NerveCenter objects, such as polls, masks, and alarms.
nervecenter.node -- Contains information about the nodes that NerveCenter manages.Both files are loaded into NerveCenter during installation. After installation, you can back up, restore, and transfer this data by using SerializeDB.
NerveCenter Data Storage Files on UNIX shows the UNIX database files.
NerveCenter Data Storage Files on UNIX
SerializeDB performs two operations:
You can use the serialized file as a backup. Should you need to restore the backup, convert the file back to your original *.ncdb and *.node files. You can also transfer the serialized file to another NerveCenter machine and convert the file to *.ncdb and *.node files for that NerveCenter. Finally, you can transfer your original database files to a Windows NerveCenter and import the files to its database. For more information about multiple NerveCenters, see Multiple NerveCenters.
On Windows, NerveCenter stores its behavior model objects in a database that is accessed using ODBC.
NerveCenter Database Components on Windows shows the Windows database files along with the other NerveCenter components.
NerveCenter Database Components on Windows
NerveCenter ships with a serialized file that is imported into the database during installation. The file, NCExport.asc, contains the base set of NerveCenter objects, such as polls, masks, and alarms. During installation, DBWizard allows you to enter settings, for example, an ODBC source and a SQL Server host. DBWizard invokes an installation tool called InstallDB to configure the SQL Server or Access database. InstallDB, in turn, invokes SerializeDB to convert NCExport.asc to the proper database format. InstallDB can also be run standalone with SerializeDB to perform unattended database installations.
Afterward, if you upgrade to a new version of NerveCenter, DBWizard can be used to run an upgrade script against your database. Upgrade requirements for each new release are included in the Release Notes that accompany the release.
As with the UNIX environment, you can use SerializeDB to transfer data between your NerveCenter database and a serialized file. This lets you back up, restore, and transfer a database. On Windows, SerializeDB performs the following operations:
For information about working with multiple NerveCenters, see Multiple NerveCenters.
You can also use DBWizard as an interface that runs SerializeDB and InstallDB to import a serialized file that you specify in DBWizard.
NerveCenter enables you to control which types of devices are managed based on their SNMP management information base (MIB) definitions. NerveCenter MIB Files shows the NerveCenter MIB files along with the other NerveCenter components.
The compiled MIB file shipped with NerveCenter, NerveCtr.mib, contains definitions for Internet Standard RFC SNMP Versions 1, 2 and 3 agents as well as many vendor specific MIBs. NerveCtr.mib defines the management information available from an SNMP agent based on the MIBs the agent supports. This support information is contained in the .ASN1 file for each managed device. NerveCenter's MIB file enables you to construct SNMP requests for particular devices and to decode data received in SNMP traps.
NerveCtr.mib is compiled from definitions referenced in a text file, which by default is named MibComp.txt. MibComp.txt, in turn, points to the *.ASN1 files you are using. To add support for new devices, modify MibComp.txt to include the new *.ASN1 files, located within the installation/Mib directory. You must have the proper .ASN1 file for each device that is defined.
After modifying the text file, you recompile the MIB file. NerveCenter's MIB compiler, MibComp, verifies each respective .ASN1 file, compiles the definitions in the text file, and creates a new version of NerveCtr.mib that can then be loaded into the NerveCenter Server.
NerveCenter includes the following utilities that extend its capability and enhance its performance:
The following sections briefly describe each utility.
TrapGen is a standalone utility that allows you to send an SNMP trap or inform to a particular device. From a command line or shell prompt, you can set the generic and specific trap numbers, provide the sender and recipient IP addresses, include an enterprise identifier, and specify the variable bindings.
Generating a trap is useful for testing trap masks and behavior models. When you send an SNMP trap to a NerveCenter Server, any trap mask configured to detect the specified trap values fires its trigger. If your trap mask and alarm are working properly, you see the alarm listed in your console.
The traprcv command displays the SNMP Trap messages received by the NerveCenter Trap service. This utility can be useful when debugging behavior models. When you run the traprcv command from a command line or shell prompt, any trap you receive is shown on the screen.
Traprcv can receive the following traps and informs:
ImportUtil is a utility that does the following from the command line:
NerveCenter Configured to Discover Nodes shows ImportUtil along with the other NerveCenter components.
NerveCenter ImportUtil Utility
ImportUtil imports the data referenced in the editable file ImpUtil.ini, which is located in the installation/Sms directory (Windows) or the installation/userfiles directory (UNIX).
You can edit NerveCenter configuration settings in ImpUtil.ini as well as specify the behavior models and nodes you want to import. You must have the proper *.mod or *.node file for the behavior models or nodes you want to import. When you have made the changes you want to ImpUtil.ini, run ImportUtil to import the specified information or files.
You can use NerveCenter's ping sweep utility, IPSweep, to populate your database. NerveCenter Configured to Discover Nodes shows how IPSweep fits in with the other NerveCenter components.
IPSweep itself does not populate the NerveCenter server database. All it does is send a trap to NerveCenter if it gets a ping response from an IP address. The server can add the "unknown" node to its database once it gets a trap.
NerveCenter Configured to Discover Nodes
Ipsweep extracts information from the NerveCenter configuration settings about the subnet IP filters defined for NerveCenter. IPSweep also obtains node information from the NerveCenter database, identifies nodes that fall within the subnet range but are not in the database, and sends those nodes a ping (ICMP echo request). If the ping returns a response, IPSweep issues an SNMP trap. The trap can be sent either to a host specified as the node source or, if no node source is specified, to the local NerveCenter. In a standalone configuration, the trap is sent to NerveCenter. Once NerveCenter receives the trap, the node is added to the NerveCenter database.
You run IPSweep by enabling the IPSweep behavior model. For more information about NerveCenter's IPSweep behavior model, refer to the Learning How to Create Behavior Models online guide shipped with NerveCenter.
| Behavior Model Operation | Web-based Monitoring |
| 29 July 2003 |