Lab 7.6.2 Network Discovery

Estimated time: 20 min.

Objectives:

  • Use Network Inspector (or equivalent) Software to Perform Network Discovery.

Background:

One of the most powerful tools for troubleshooting computer networks is Network Management software. There are many fine programs for performing various network discovery, monitoring, and analysis tasks. In this lab you will explore a basic network management application: Fluke Network Inspector 3.0 (or equivalent). You will use the Network Inspector to perform a process called network discovery. As the number of computers, servers, printers, switches, and routers on a network grows, it can be difficult to keep track of all of the relevant characteristics of the devices. Such information as MAC addresses, IP addresses, and topologies are crucial for troubleshooting a network. You will use Network Inspector to perform a network discovery on an Ethernet 10BASE-T (or 100BASE-TX) network.


Tools / Preparation:

Each PC must be running Windows 95, 98, or NT, Microsoft TCP/IP stack, and Winsock 2.0. Fluke Network Inspector 3.0 (or equivalent) must be installed on each PC. During the installation of the software you must specify which network adapter (NIC, dial-up, etc.) you wish to monitor – specify the NIC which attaches the PC to an Ethernet. The PCs should be on either a 10BASE-T or 100BASE-TX Ethernet network which preferably includes servers, switches, routers, and printers (this will make the network discovery more interesting). The following resources will be required:

  • PC with Windows 95, 98, or NT, Microsoft TCP/IP stack, and Winsock 2.0.
  • Fluke Network Inspector 3.0 Software

Worksheet

  1. If you have not done so already, install Network Inspector software (the "Agent" and the "Console") on your PC. How will you know if this step was done correctly? 


  2. Make sure you are connected to a working Ethernet network. What are some signs that you are on the network? 


  3. Open Fluke Network Inspector Agent. You will be prompted to do something. What are you prompted to do and why do you suppose you must do this? 


  4. Now the Agent will prompt you with a status screen. Click on the tabs and write down the major categories of things you can control about the Agent. Under the database/address tab, click on "overwrite" so that the new data you are controlling will be stored in the database. Click Apply.


  5. Start the Agent. What is the status shown? What does the status change to after a few minutes? What do you suppose is happening? Minimize the Agent. 


  6. Open Fluke Network Inspector Console. What do you see? 


  7. Allow the agent to run for a few minutes. What do you see?


  8. Stop the Agent and Minimize the Agent screen. What significant information about the network have you obtained? Write down a few complete lines of the database. 






  9. In the left hand control panel, click on each of the "Devices" and explain briefly what they are: "Fluke Tools", "Key Devices", "Utilization Sources", " SNMP Agents", "Services", "Routers", "Switches", "Printers",  and "Hosts".






  10. Start another capture to examine the network you are on.

Reflection:

Imagine you have earned your CCNA and are working in a medium-size company. Write in your journal what value you see in using Network Management software.






 

LAB 7.6.2 – NETWORK DISCOVERY - ANSWERS

  1. If you have not done so already, install Network Inspector software (the "Agent" and the "Console") on your PC. How will you know you are done with this step?
    The icons for both programs should appear in your Program Directory Menu.
  2. Make sure you are connected to a working Ethernet network. What are some signs that you are on the network? 
    The link light on your NIC is lit and the other LED is indicating network traffic. You examine your cable run and note that you are connected to a hub or switch. You are able to send and receive email and access the Internet (if your network is connected). You can "ping" other machines IP addresses. Etc.
  3. Open Fluke Network Inspector Agent. You will be prompted to do something. What are you prompted to do and why do you suppose you must do this? Click OK when finished.
    You will be prompted to decide which interface, specifically which Network Interface Adapter, you want to study. Many PCs will have multiple adapters installed (perhaps one for modem, one for Ethernet, and others); you must choose one for the software to study.
  4. Now the Agent will prompt you with a status screen. Click on the tabs and write down what are the major categories of things you can control about the Agent. Under the database/address tab, click on "overwrite" so that the new data you are collecting will be stored in the database. Click Apply. 
    Agent, Database/Address, SNMP, Problems, Advanced, About
  5. Start the Agent. What is the status shown? What does the status change to after a few? What do you suppose is happening? Minimize the Agent.
    The status first changes from "stop" to "to start pending", then "running". The agent is discovering your network.
  6. Open Fluke Network Inspector Console. What do you see? 
    You see the console interface and the database being filled with discovered devices.
  7. Allow the agent to run for a few minutes. What do you see? 
    The database has filled with information.
  8. Stop the Agent and Minimize the Agent screen. What significant information about the network have you obtained? Write down a few complete lines of the database.
    You obtain icons indicating the type of device, device identifier names, IP addresses, IPX addresses (if any), NetBIOS addresses (if any), and MAC addresses. All crucial information for managing your network.
  9. In the left hand control panel, click on each of the "Devices" and explain briefly what they are: "Fluke Tools", "Key Devices", "Utilization Sources", "SNMP Agents", "Servers", "Routers", "Switches", "Printers", and "Hosts"
    Fluke Tools – other Fluke hardware devices which can be attached at other points in the network to help study it; Key Devices – servers, switches, routers; Utilization sources – which devices are causing network traffic; SNMP Agents – devices which use the Simple Network Management Protocol to report network information; Servers – computers which provide services to client computers; Routers – Layer 3 path determination and switching devices; Switches – Layer 2 multiport bridges; Printers – common peripheral devices; hosts – PCs on the network.
  10. Close the Agent and the Console. You have begun using a very powerful piece of software.

Reflection:  

Imagine you have earned your CCNA and are working in a medium-sized company. Write in your journal what value you see in using Network Management software.

As a newly hired CCNA, one of the first tasks you might be given is to study the existing network. No doubt some amount of sneakernet is in order – walk around, talk to people, look in wiring closets. But Network discovery will greatly assist you in documenting and studying the current status of the network.