Project 14: Network Troubleshooting in Packet Tracer--Part 1 (15 pts.)

What You Need

Purpose

This project is just a walk-through of basic troubleshooting steps, using a working network in Packet Tracer.

You won't actually fix any problems now--that comes in the next project.

Basic Troubleshooting Methodology

The essence of troubleshooting is to divide the problem in half repeatedly until you can locate the problem, and then fix or replace the defective component.

Here are general steps, in a common order. This is not a strict order--experienced troubleshooters will often skip steps, but following a systematic series of steps will usually result in a solution within a reasonable time.

  1. Listen to the complaint--some user is reporting a problem. Be very polite to the user--they are often frustrated and angry, and need reassurance that their problem is being taken seriously.
  2. Reproduce the problem from your own workstation if possible, or perhaps from the user's workstation.
  3. Determine the scope--quickly test to see if there is a huge company-wide problem, such as the Web server being down, or total loss of Internet access. If it's not affecting the whole company, is it affecting one building or room, or just one computer? This affects both the repair steps and its priority.
  4. Fix the problem you located
  5. Test the result, showing that the problem you reproduced is now gone
  6. Contact the original complainant again--it is very common for network technicians to regard a problem as fixed when the original complainant still cannot get work done. Make sure to check with that person to see if they really have what they need now.

Troubleshooting Techniques in Packet Tracer

Here are some useful techniques, along with details of performing them in Packet Tracer.

To practice them, open this file in Packet Tracer. To download it, right-click the link and save the file on your desktop.

home-good.pkt

You should see a small network, as shown below.

Wait a few seconds for all the link lights to turn green.

For reference, the address table is also shown.

Address Table

Device Address Subnet Mask Default Gateway
Laptop0192.168.0.101255.255.255.0192.168.0.1
Laptop1192.168.0.102255.255.255.0192.168.0.1
PC1192.168.0.201255.255.255.0192.168.0.1
PC2192.168.0.202255.255.255.0192.168.0.1
Wireless Router0 LAN192.168.0.1255.255.255.0
Wireless Router0 WAN8.8.8.1255.255.255.08.8.8.8
Server08.8.8.8255.255.255.08.8.8.1

IPCONFIG

Click on Laptop0.

On the Desktop tab, click "Commmand Prompt".

In the Command Prompt window, execute this command:

IPCONFIG
You see the addressing information, as shown below. You can compare this to the Address Table to find problems. In this network, everything is correct.

Ping the Default Gateway

The IPCONFIG command showed you the default gateway, which is 192.168.0.1.

In the Command Prompt window, execute this command:

PING 192.168.0.1
You should see replies, as shown below. Sometimes the first few pings time out, because the network is still initializing with ARP and STP packets, but if you repeat the command a second time they should all get replies.

If you don't get replies from the default gateway, that means the problem is either in the PC or in the device it is connected to (usually a router or switch).

Ping a Remote Host

The server at 8.8.8.8 is a Google DNS server, and it answers pings.

Because it's easy to remember, it's a handy way to test networks.

This Packet Tracer simulation is not connected to the real Internet, so the only Internet host you can use for testing is 8.8.8.8.

In the Command Prompt window, execute this command:

PING 8.8.8.8
You should see replies, as shown below.

Saving a Screen Image

Make sure you can see at least one Reply, as shown above.

On your keyboard, press the PrntScrn key.

Click Start, type in PAINT, and open Paint.

Press Ctrl+V to paste in the image of your desktop.

YOU MUST SUBMIT WHOLE-DESKTOP IMAGES TO GET FULL CREDIT.

Save the image with a filename of "Proj 14a from YOUR NAME".

Traceroute

Traceroute is sometimes helpful, especially in complex networks with several routers.

It shows all the hops between a PC and a remote host.

In the Command Prompt window, execute this command:

TRACERT 8.8.8.8
You should see two hops, as shown below; first the router (192.168.0.1) and then Google (8.8.8.8).

Adjusting Network Addresses on a PC

In the top right of the "Command Prompt" window, click the X to close it.

On the Desktop tab, click the "IP Configuration" tile.

The "IP Configuration" window opens, as shown below.

This is a good place to correct any errors.

Adjusting Wireless Configuration on a Laptop

In the top right of the "IP Configuration" window, click the X to close it.

On the Desktop tab, click the "PC Wireless" tile.

A "Linksys" box opens. Click the Connect tab.

After a few seconds, the network name "CCSF Wireless" appears, as shown below.

This is a good place to correct wireless configuration errors.

Saving a Screen Image

Make sure you can see "CCSF Wireless", as shown above.

On your keyboard, press the PrntScrn key.

Click Start, type in PAINT, and open Paint.

Press Ctrl+V to paste in the image of your desktop.

YOU MUST SUBMIT WHOLE-DESKTOP IMAGES TO GET FULL CREDIT.

Save the image with a filename of "Proj 14b from YOUR NAME".

Adjusting Router Configuration

Close the "Laptop0" window.

Click the "Wireless Router0" icon.

Click the GUI tab.

The WAN configuration is at the top of this page, labelled "Internet Setup", and the LAN setup is at the bottom, in the "Network Setup" section, as shown below.

This is the place to correct router configuration errors.

In the Linksys setup page, at the top center, click the Wireless tab.

This is the place to adjust any errors in the wireless configuration.

Saving a Screen Image

Make sure you can see "CCSF Wireless", as shown above.

On your keyboard, press the PrntScrn key.

Click Start, type in PAINT, and open Paint.

Press Ctrl+V to paste in the image of your desktop.

YOU MUST SUBMIT WHOLE-DESKTOP IMAGES TO GET FULL CREDIT.

Save the image with a filename of "Proj 14c from YOUR NAME".

Turning in Your Project

Email the images to: cnit.106sam@gmail.com with a subject line of Proj 14 From Your Name, replacing Your Name with your own first and last name. Send a Cc to yourself.

Last Modified: 10-19-13 11:45 am