Figure 7
Revised: August 26, 2005
By Richard G. Baldwin
File: FwlProj0zz.htm
This laboratory project was prepared specifically for the benefit of my students who are enrolled in ITNW 1351, Fundamentals of Wireless LANs.
The project was designed under the assumption that students enrolled in the course have successfully completed the prerequisite course, ITNW 1325, Fundamentals of Networking Technologies.
The project design also assumes that the students are actively studying the material in the prescribed textbook for this course, which explains such complex topics as the IEEE 802.11g wireless specification.
Another browser window
I recommend that you open another copy of this document in a separate browser window so that you can easily view the discussion and the figures at the same time.
The purpose of this project is fairly limited in scope. The purpose is to show you how to capture log files containing information that can be used for troubleshooting wireless network problems.
However, the project does not show you how to interpret the contents of the log files to actually perform troubleshooting activities.
The following equipment is required to complete this laboratory project:
Getting help from Microsoft
This project is partially based on the Microsoft TechNet article entitled How to gather information to troubleshoot a wireless connectivity problem in Windows XP.
The text of the article begins as follows:
"This article describes how to collect information to troubleshoot a wireless connectivity problem on your Microsoft Windows XP-based computer. This information is required when you contact Microsoft Product Support Services (PSS) for help troubleshooting a wireless connectivity problem."
Required log files
The article describes a great deal of information that you will need to have available when you contact Microsoft for assistance. Included in that information is the following set of log files:
Creating the log files
Those log files describe network activity. This project will show you how to create those log files.
Interpreting the log files
These are plain text files, but their format is far from simple. However, with some extra effort and research on your part, you could probably learn how to interpret the log files yourself and use them in your network troubleshooting efforts.
Using Netsh
According to the Windows XP help system,
"Netsh is a command-line scripting utility that allows you to, either locally or remotely, display or modify the network configuration of a computer that is currently running."
The XP help system goes on further to say,
"To run a netsh command, you must start netsh from the Cmd.exe prompt and change to the context that contains the command you want to use. The contexts that are available to you depend on which networking components you have installed."
The RAS context and the set tracing command
In this case, we are interested in the remote access servers (RAS) context. This context supports about two dozen commands, one of which is set tracing. A description of the set tracing command, taken from the XP help system, is provided in Figure 1.
set tracing
Enables or disables tracing for the specified
component.
Syntax
set tracing Component {enabled | disabled}
Parameters
Component
Required. Specifies the component for which you
want to enable or disable tracing. Use * to
specify all components.
{enabled | disabled}
Required. Specifies whether to enable or
disable tracing for the specified component.
Remarks
To see a list of all installed components, use
the show tracing command without parameters.
Examples
To set tracing for the PPP component, type:
set tracing ppp enabled
Figure 1
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Components in the RAS context
Figure 2 shows a list of all installed components on my machine obtained by executing the command shown in the first line of Figure 2.
C:\jnk>netsh ras show tracing XMLProvI disabled WZCTrace disabled WZCDLG disabled Wlpolicy disabled wavemsp disabled termmgr disabled tapisrv disabled tapi32 disabled tapi3 disabled RASTLS disabled RASTAPI disabled RASSPAP disabled RASPAP disabled RASMAN disabled RASIPHLP disabled RASIPCP disabled RASEAP disabled RASDLG disabled RASCHAP disabled RASCCP disabled RASBACP disabled RASAUTO disabled RASAPI32 disabled PPP disabled NETSHELL disabled NETMAN disabled NDPTSP disabled KMDDSP disabled IPNATHLP disabled IASRECST disabled h323msp disabled FWCFG disabled EAPOL disabled conftsp disabled confmsp disabled BAP disabled Figure 2 |
The components highlighted in boldface in Figure 2 match the seven log files identified in the earlier list from Microsoft.
How to enable logging
There are two different ways to enable logging on those seven components. One way is to execute the command shown in Figure 3 at a command prompt.
C:\jnk>netsh ras set tracing * enabled Figure 3 |
Execution of this command will enable logging on all of the components listed in Figure 2, most of which are not needed for network troubleshooting.
A more selective approach
The second way is to execute the seven individual commands shown in Figure 4 at the command prompt.
C:\jnk>netsh ras set tracing wzctrace enabled C:\jnk>netsh ras set tracing eapol enabled C:\jnk>netsh ras set tracing rastls enabled C:\jnk>netsh ras set tracing wzcdlg enabled C:\jnk>netsh ras set tracing xmlprovi enabled C:\jnk>netsh ras set tracing netman enabled C:\jnk>netsh ras set tracing netshell enabled Figure 4 |
Execution of those seven commands will enable logging on those seven components only.
Don't forget to disable logging and delete the log files
The log files that are created can become quite large and can consume quite a lot of disk space. Therefore, you should always remember to disable logging when it is no longer necessary.
Regardless of which approach you use to enable logging, the easiest way to disable logging is to execute the command shown in Figure 5 at the command prompt. This will disable logging on all components in the RAS context for which logging is currently enabled.
C:\jnk>netsh ras set tracing * disabled Figure 5 |
Also, once you are finished with the log files, as far as I can tell, there is no harm in deleting them.
Where are the log files?
Microsoft describes the location of the log files as the %windir%\Tracing folder. On my machine, that turns out to be the C:\WINDOWS\tracing folder.
What you will do
In this project, you will configure and start two Linksys routers running on different channels with different SSIDs.
Then you will enable logging on the wzctrace and wzcdlg components.
A series of network operations
After that, you will go through a series of operations that involve removing and applying power to the routers as well as switching your wireles connection back and forth between the two routers to generate network activity.
Disable logging, examine log files, and delete them
Then you will disable logging and examine the contents of the two log files to get a feel for the types of information that they contain.
Finally, you will delete the two log files.
Configure two access points
Using what you learned in the project entitled Automatic Switching Among Access Points, set up a wireless network router with the following configuration:
Then, also using what you learned in the project entitled Automatic Switching Among Access Points, set up a second wireless network router with the following configuration:
Enable logging on two components
Obtain a command line window and execute the two commands shown in Figure 6.
C:\jnk>netsh ras set tracing wzctrace enabled C:\jnk>netsh ras set tracing wzcdlg enabled Figure 6 |
(Note, the commands in Figure 6 assume that your current directory is c:\jnk.)
Check on the log files
Go to the folder at C:\WINDOWS\tracing and confirm that the following two files have been created there:
Create network activity
Now plug and unplug the power to the routers a few times to create some network activity.
Using the Wireless Network Connection dialog, manually switch your connection back and forth between the two routers a few times to create a different kind of network activity.
Disable logging
Execute the command shown in Figure 5 at the command prompt to disable logging.
Examine the log files
Double click on each of the log files. That will cause the log files to be opened in Notepad. For example, Figure 7 shows a partial screen shot of the text contained in one of the log files.
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Does it make any sense?
See if you can identify anything in either of the log files that correlates with the network activity caused by applying and removing power and by switching the connection back and forth between the two networks. For example, it might be useful to search for SSID in the Notepad display.
Delete the log files
Delete the two log files to prevent them from wasting space on your hard drive.
Learn how to interpret the log files
Search the web in an attempt to find articles that explain how to interpret the information contained in the log files.
Copyright 2005, Richard G. Baldwin. Reproduction in whole or in part in any form or medium without express written permission from Richard Baldwin is prohibited.
Richard has participated in numerous consulting projects and he frequently provides onsite training at the high-tech companies located in and around Austin, Texas. He is the author of Baldwin's Programming Tutorials, which have gained a worldwide following among experienced and aspiring programmers. He has also published articles in JavaPro magazine.
In addition to his programming expertise, Richard has many years of practical experience in Digital Signal Processing (DSP). His first job after he earned his Bachelor's degree was doing DSP in the Seismic Research Department of Texas Instruments. (TI is still a world leader in DSP.) In the following years, he applied his programming and DSP expertise to other interesting areas including sonar and underwater acoustics.
Richard holds an MSEE degree from Southern Methodist University and has many years of experience in the application of computer technology to real-world problems.
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