Using Network Discovery

Now that you understand the ZENworks for Servers 3 network discovery process, you are ready to begin using it to build a topology database from which you can manage and configure your network.

Configuring and using discovery correctly can improve network bandwidth and make administration much easier. This section covers how to start and stop the network discovery, how to monitor its progress, and how to configure it to correctly discover your network.

Starting and Stopping Network Discovery

The first thing you should know about setting up network discovery is how to start it manually, as well as how to stop it. During the installation, you are prompted whether to start the autodiscovery and back-end services. If you select yes to those prompts, Network Discovery automatically launches.

To start the network discovery process and load the back-end services on a server, follow these steps:

1. Start the ZENworks for Servers 3 database by entering the mgmtdbs command at the ZENworks management server console. This command runs the mgmtdbs.ncf file to load the Sybase database engine and the database.

2. Start the rest of the needed ZENworks for Servers processes by entering the mwserver command at the server console.

3. Start the autodiscovery process by entering the netxplor command at the ZENworks management server console. This command runs the netxplor.ncf file, which loads all the discovery modules.

4. Finally, start the basic services on the ZENworks management server by entering the sloader command at the console. This command runs the sloader.ncf file.

The discovery process runs 24 hours a day while it is loaded. The time required to run the initial discovery and build a complete database of your network varies depending on the size of your network and the load placed on your ZENworks for Servers 3 management server.

NOTE

The ZENworks for Servers 3 network discovery process occurs in the background on your server. If your server is being heavily used, it takes considerably longer for the network discovery to finish. We suggest that you schedule your network discovery to occur during nonpeak hours over a weekend, for example.

After the management server is up and running, you can start and stop the discovery process by using the following two commands and the ZENworks for Servers 3 management server console:

• unxp. An NCF file that unloads the discovery files and halts the discovery process.

• netxplor. An NCF file that reloads the discovery files, creates a new version of NETXPLOR.DAT, begins the initial discovery process, and processes the discovery data.

Checking the Status of the Initial Discovery

After the network discovery process is running, an initial discovery is started. This can take a long time, depending on the size of your network. When the initial discovery is completed, your topology maps in the management console reflect the discovered devices while discovery progresses. You must, however, wait for the initial discovery to complete before the topology maps are updated.

The easiest way to determine whether the initial discovery is complete is to use the NXPCON utility on the management server to look at the status of each NetExplorer module. Each module must complete at least one full cycle to complete the initial discovery and draw a complete network map. The following is a list of modules that can be configured to run during discovery:

• NXPIP

• NXPIPX

• NXPLANZ

To view the discovery status, look at the following information displayed on the NetExplorer Console screen, shown in Figure 9.1:

• NetExplorer Up Time. Shows the time since the network discovery started running (in the figure, this is just shown as Up Time).

• NetExplorer System Status. Shows the overall status of network discovery. If the initial discovery process is still running on at least one module, the value is Initial Cycle in Progress. If the initial discovery process is complete on all modules, the value is Initial Cycle Complete. (In the figure, the value for this item is 1 Cycle Completed.)

• Module Status. Shows the status of each module and the number of cycles each module has completed. In the figure, note the status listed for NXPIP, NCPIPX, and NCPLANZ.

Figure 9.1. Network discovery status on the NetExplorer Console screen.

The following is a list of the different statuses that each module can show and what they mean:

• Not Loaded. The module is not loaded. This usually means that this service is not configured for discovery.

• Waiting to Start. Module is loaded, but it is waiting for another module to complete a cycle before it starts.

• Running. Module is currently running and collecting network data.

• Suspended. Module is suspended because it reached the end of the schedule in which it was running.

• Completed. Module completed at least one discovery cycle.

• Unknown. NetExplorer cannot obtain the module status. This is either because the module is not loaded, but is configured to run, or because of an internal error inside the module.

Changing the Default Configuration

The ZENworks for Servers 3 network discovery software is installed with configuration defaults that are designed to work in most network environments. You may, however, want to modify the default configuration to discover more or fewer devices in your network.

To change the default network discovery configuration, you need to use the NXPCON utility on the ZENworks for Servers 3 management server. The NXPCON utility is automatically loaded when the NetExplorer software is loaded, or you can load it manually by using the following command at the ZENworks for Servers 3 management server console prompt:

 load nxpcon 

The following sections describe how you can use the NXPCON utility to choose which discovery modules are loaded, how to change SNMP names, and how to modify the discovery scope to help you optimize the discovery process for your network, and how to ensure workstation discovery.

Choosing Which Modules to Load

After the NXPCON utility is loaded, you can modify which modules are being loaded. If you choose to not load a module, the network discovery is limited to the remaining modules being loaded.

Use the following steps in the NXPCON utility to modify which modules are loaded for network discovery:

1. Select Configuration Options Discovery Modules.

2. Select the module you want to modify from the Discovery Modules menu, shown in Figure 9.2, and then press the Enter key.

   Figure 9.2. Network discovery module setting in the NetExplorer Console screen.

   

3. Select No to unload the module or Yes to load the module, and then press Enter.

4. Press the Esc key to exit the NetExplorer Modules dialog box.

5. Select Yes.

6. Unload the NetExplorer software by entering unxp at the ZENworks for Servers 3 management server's console prompt.

7. Reload the NetExplorer software by entering netxplor and the changes to network discovery are made.

Changing SNMP Community Names

After selecting which modules to load, you may want to change some of the SNMP community names. ZENworks for Servers 3 automatically uses the community name of Public by default. If your network uses SNMP names other than Public, you should reconfigure the SNMP names in NXPCON to ensure your network maintains the proper security.

To view, add, modify, or delete SNMP configuration information from within the NXPCON utility, follow these steps:

1. Select Configuration Options SNMP.

2. Select Edit Community Name List in the SNMP dialog box, shown in Figure 9.3.

   Figure 9.3. Network discovery SNMP options dialog box in the NetExplorer Console screen.

   

3. Select Insert to add a community name, Delete to delete the highlighted community name, or just press the Enter key to modify the highlighted community name.

4. Press the Esc key to exit from the SNMP dialog box.

5. Select Configuration Options Activate Changes to update the ZENworks for Servers database.

Changing the Discovery Scope

After you modify your SNMP community names appropriately, you can change the scope of the network discovery. NXPCON is set to discover all IPX and IP networks by default. But if your network is extremely large, you may want to limit the scope of discovery for the following reasons:

• Reduce network traffic. Limiting the scope of discovery limits the number of discovery and management packets being sent on your network.

• Speed up discovery. Limiting the scope of discovery also speeds up the discovery process by skipping addresses that are not wanted.

• Simplify manageability. Limiting the scope of discovery limits the number of objects discovered and thereby reduces the number of objects that appear in the Atlas view. This can make it much easier to navigate the atlas.

The following two sections discuss how to use the NXPCON utility to modify the network discovery scope.

Changing the IP Discovery Scope

The NXPCON utility enables you to limit the IP discovery scope by address and subnet mask filters. Using these filters enables you to discover only certain segments or addresses.

If you wanted to restrict the discovery scope to your local IP network, for example, you could set a limit to the IP address of your local network and a subnet mask that you want to use. The mask indicates which part of the addresses needs to match for discovery to proceed on a network segment. The number 0 indicates that no match is required. If your local network IP address were 1.1.x.x, you would use the IP address of 1.1.0.0 and a mask of 255.255.0.0 to capture everything on your local network, but nothing else.

Use the following steps in NXPCON utility to limit the scope of IP discovery:

1. Select Configuration Options Discovery Scope.

2. Select IP Discovery Scope.

3. Press the Insert key to add a new IP discovery scope entry, press the Enter key to modify the highlighted scope entry, or press the Delete key to delete the highlighted scope entry.

4. Enter the address and mask for your discovery, as shown in Figure 9.4.

   Figure 9.4. Network discovery IP mask dialog box in the NetExplorer Console screen.

   

5. Press the Esc key and select Yes to save the changes to the configuration file.

6. Press the Esc key to exit the Discovery Scope dialog box.

7. Unload the NetExplorer software by typing unxp at the console prompt.

8. Reload the NetExplorer software by typing netxplor at the console prompt, and the changes will take effect.

Changing the IPX Discovery Scope

The NXPCON utility enables you to limit the IPX discovery scope by network number and mask filters. Using these filters enables you to discover only certain segments or addresses. A zero in the filter indicates that no match is required.

For example, if you use a specific IPX address on your servers of 1111xxxx, you could limit the scope of your IPX discovery to include only your IPX servers by using the network number of 11110000 and a mask of FFFF0000. Discovery would then pick up only IPX devices whose network number started with 1111.

Use the following steps in the NXPCON utility to limit the scope of IPX discovery:

1. Select Configuration Options Discovery Scope.

2. Select IPX Discovery Scope.

3. Press the Insert key to add a new IPX discovery scope entry, press the Enter key to modify the highlighted scope entry, or press the Delete key to delete the highlighted scope entry.

4. Enter the network number and mask for your discovery, as shown in Figure 9.5.

   Figure 9.5. Network discovery IPX mask dialog box in the NetExplorer Console screen.

   

5. Press the Esc key and select Yes to save the changes to the configuration file.

6. Press the Esc key to exit the Discovery Scope dialog box.

7. Unload the NetExplorer software by typing unxp at the console prompt.

8. Reload the NetExplorer software by typing netxplor at the console prompt and the changes will take effect.

Ensuring Workstation Discovery

After you verify your IPX scopes in the NXPCON utility, you may want to ensure that your IPX workstations will be discovered properly. IPX workstations are discovered with a username if the user is logged in to or attached to a NetWare server that is running the management agent software. To ensure that your workstations are properly discovered, ensure that the management agent is installed on all NetWare servers that have users attached.

Checking the Results of a Network Discovery

You can check the results of the network discovery after the initial discovery is completed and after the ZENworks for Servers 3 database has been updated. You should always check your network atlas to determine whether your network topology was accurately discovered.

Your network atlas should have discovered all the servers, desktops, switches, and routers on your network for which you configured it. For each object that is discovered, the following characteristics are captured:

• IP type. IP router, IP host, IP service (HTTP, Telnet, SMTP, DNS, FTP, and DHCP)

• IPX type. IPX workstation, IPX router, IPX service (file, print, any SAP service)

• Subnet mask. Subnet mask used on each segment

• NetWare services. Services such as SAP, NCP, and so on

• eDirectory names and tree. Full distinguished name of nodes on the network, including the tree

If a node is not on your network atlas, you should check the following things about the device:

• Is the device a type that NetExplorer can discover?

• Is the node in the incorrect segment? If NetExplorer cannot get enough information about a node, it may simply have been placed in the wrong segment.

• Is NetExplorer configured to capture this type of device?