Networking

Product Review: Inspecting and troubleshooting with Fluke Network Inspector 4.0

A review of Fluke Network Inspector 4.0


In this Daily Drill Down, we'll look at the program Fluke Network Inspector 4.0, a tool for network engineers, administrators, and network technicians who have to maintain local area networks (LANs). Fluke lets you monitor and troubleshoot a variety of problems on your network, such as those involving servers, routers, switches, printers, managed hubs, and clients. In addition, it monitors the status of devices and will alert you to errors, warnings, and changes. On a network of about 200 nodes, most network devices will be discovered in 10 minutes or less. You can use the Fluke Network Inspector program with Windows 95, 98, NT, Me, and 2000.

Features
Fluke 4.0 offers many features that will help you visualize your network. You can monitor and display network changes in real time and get advice on fixing common network problems. The Console screen allows you to sort all the devices found using any of the column headings, such as name, IPX name, NetBIOS name, IP address, and MAC address.

You can also create a network map using Microsoft Visio or generate and save network maps in standard file formats, such as HTML, JPEG, GIF, or BMP. Fluke will send alerts to e-mail addresses or pagers for notification of selected errors, warnings, or changes. Fluke also provides switch reports and displays the closest connected switch, devices connected to a switch, and other information.

Installation
The computer on which you install Fluke 4.0 must be at least a 200-MHz Pentium-class processor and have a minimum of 64 MB of RAM and 100 MB of free hard disk space. It can be installed on Windows 9x, Me, or 2000, but Windows NT must have Service Pack 3 or later installed. You must also have a TCP/IP stack and 150 MB of virtual memory. In addition, the computer must be accessing the database of discovered devices locally.

Installing Fluke is not a simple task. You should close all other programs prior to installing the Network Inspector application. When you insert the CD, the setup program will launch and present the welcome screen. Depending on your operating system and its configuration, you may have to install different drivers and reboot several times.

You will have to have a valid serial number to complete the installation. You must also decide whether you want to install the Fluke Network Inspector Agent and Console on the same computer or just one of the components.

In order for a computer running Windows 9x to gather information from your network using Fluke, it must have the Fluke protocol loaded. When you install the Network Inspector application or try to run the Agent, your computer must have the required Microsoft TCP/IP stack installed, or you will receive an error message. If your computer is running Windows 95 and does not have Microsoft Winsock 2.0 installed, you’ll be given the opportunity to install it while you’re installing Fluke.

As shown in Figure A, you can choose not to install the packet driver, but the program will not be operational until it is loaded. The setup program leads you step-by-step through the process by opening your network properties sheet and then displaying the help text next to it.

Figure A
Fluke’s Setup Complete screen tells you that until you load the packet driver, Network Inspector will not be operational.


The directions in the help screen explain how you have to add a new networking protocol. You’ll find the appropriate driver on the installation CD. After you load the driver, it will appear in the protocol section, as shown in Figure B.

Figure B
The Fluke Network Inspector packet driver will appear in the components list box on the Configuration tab of the Network dialog box.


You must reboot to effect the changes. Once you’ve completed installing Fluke, you’ll see these items in your Programs folder: Agent (or Agent Manager, if you installed on an NT computer), Console, Getting Started, Inspector Reports, LANMeter Reports, Option Manager, and Readme.

Agent Manager
The main function of the Fluke Network Inspector Agent is to discover and analyze the devices, IP subnets, IPX networks, and NetBIOS domains on the local subnetwork where the Agent resides. In order for the Agent to discover, it listens to the traffic on the subnetwork, and it sends broadcast and directed queries to devices on the subnetwork. The devices that respond to the broadcast will be sent protocol-specific messages to determine whether each device is local to the Agent's subnetwork.

For each local IP device discovered, the Agent then sends a DNS query to the DNS server to get the device's DNS name and it sends a Simple Network Management Protocol (SNMP) query to each IP device to get its SNMP System Group information. For Windows 95, 98,  and Me, the Agent runs as a taskbar application. In Windows NT, it runs as a service that is set to Manual Start during the installation process.

When the Agent launches, it begins to look for devices on the network. The devices discovered by the Agent are limited to the devices that can be probed on the local side of the network, as bound by the first router(s) discovered. Devices located on the other side of a router cannot be seen by the Agent. You can, however, add them manually using the Fluke Console. When devices are found, they are added to a Microsoft Access ODBC relational database named Netins.mdb on the computer where the Agent is installed.

If you run Network Inspector on a segment with more than 1,200 network devices or more than 50 switches, performance will be degraded, and incomplete data collection can occur. For the discovery of IPX names for IPX devices, the Agent assumes there is a drive mapping to the SYS\PUBLIC directory on the Novell server. It also assumes that the USERLIST.EXE and NLIST.EXE files exist in that directory. If the SYS\PUBLIC directory is not mapped, or if the files do not exist there or in any other path, IPX name discovery will not function.

The Fluke Network Inspector Agent Manager dialog box has several tabs. For example, the Notification tab, shown in Figure C, lets you enable e-mail notification so that you are alerted when errors, warnings, and changes that you specify occur.

Figure C
The Notification tab offers the Enable E-mail Notification option.


The Advanced tab (shown in Figure D) allows you to specify the Discovery method that the Agent will use to find devices on your network.

Figure D
The Advanced tab lets you specify the SNMP Discovery method.


The changes will take effect the next time the Agent is started. It is important that you check the Database/Address tab in the Agent's dialog box and deselect the Overwrite option, as shown in Figure E. Starting the Agent may overwrite your existing database. As long as the Agent is running, it will continue to monitor network devices and update the database with new or changed devices.

Figure E
Make sure you deselect the Overwrite option on the Database/Address tab.


The Fluke Console
The Fluke Console displays the information written to the database during the discovery process. You can also use the Console to run reports and launch Fluke network tools and other PC-based tools. The Console, shown in Figure F, is the main graphical user interface (GUI) for the Network Inspector application, and it is the component you’ll interact with the most.

Figure F
The Fluke Network Inspector Console is the main GUI for Network Inspector.


You can use the Console to display the various problem logs. Error, warnings, and changes are tracked, and you can view them simply by clicking on the desired log. For any error, warning, or change, you can position the cursor over the symbol to get a detailed description, as shown in Figure G.

Figure G
You can view a detailed error message.


The Console can also be used to display specific devices on your network. Whether it is a server, router, switch, hub, or host, Fluke allows you to quickly retrieve information about the device. The Console will also let you view information about your local network by delivering information grouped by subnet, IPX networks, and NetBIOS domains.

If you are running the Network Inspector Agent and Console on the same computer, you must stop the Agent before starting the Protocol Inspector to prevent conflicts. For a Windows NT computer, this means that the service must be stopped. For a Windows 9x computer, you must stop the Agent and close its dialog box. Stopping the Agent will interrupt the collection of any trend data that you might be collecting; stopping the Agent for more than one hour will clear all trend data.
The Protocol Inspector tool is a protocol analyzer for Ethernet or Token Ring that monitors local network segments. You can access the Protocol Inspector tool from the Tools menu. It incorporates comprehensive real-time monitoring capabilities with the troubleshooting capabilities of a protocol analyzer. These capabilities can function simultaneously, enabling a user to maintain the network using a single multipurpose tool.
Using Visio to create diagrams
An impressive feature built into Fluke is its ability to interface with Visio 2000. You must load a version of Visio of 5.0c or greater before using the Network Map feature with Fluke. From the Network Map menu, you can choose to create the following diagrams:
  • Switch (Spanning Tree) Diagram: Draws a diagram of switches and interconnecting hubs on your network.
  • Server Connections In Switched Network: Draws a diagram of servers, switches, and interconnecting hubs on your network.
  • Router Connections In Switched Network: Draws a diagram of routers, switches, and interconnecting hubs on your network.
  • Fluke Tool Connections In Switched Network: Draws a diagram of Fluke tools, switches, and interconnecting hubs on your network.
  • Single Switch Detail: Draws a diagram of the selected switch and all of the servers, routers, switches, and interconnecting hubs that are directly connected to it.

When you choose to create one of the reports, Fluke automatically launches Visio when the generating Network Map progress bar is about 65 percent complete. Visio then draws the map as you watch. These diagrams help you to get an overview of your network and document it with almost no effort. To be sure that no devices are left out of a map, you must run the Network Inspector Agent for at least five minutes (or for 15 minutes for networks with more than 500 nodes).

The Console will automatically select the page size and page orientation for the quantity and types of devices to be diagrammed. Some diagrams can become quite busy if there are several devices to draw. After the map has been created, you can modify it as you wish using Visio.

Conclusion
The cost of Fluke 4.0 or any other network analyzer can be quite high. You can download a fully functional 15-day trial version of Fluke 4.0 Network Inspector Release 4.0 Trial at the Fluke Corporation Web site. It is truly an invaluable tool when it comes to helping you troubleshoot and document a network.
The authors and editors have taken care in preparation of the content contained herein but make no expressed or implied warranty of any kind and assume no responsibility for errors or omissions. No liability is assumed for any damages. Always have a verified backup before making any changes.

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