56 posts categorized "Wi-Fi" Feed

Capture packets with a standard Windows tool (by Paul Offord)

Wireshark is a great way to capture network packets, but it's not always practical to use it.  In an enterprise environment, at the very least, we need to get a change approved to install the software.  Often it is just not possible to get approval to install Wireshark onto a desktop or server.  So packet capture isn't possible - or is it?

Windows includes a rarely-used command line tool that has many of the capabilities of Wireshark dumpcap.  It's there ready and waiting, on every Windows machine!  Let's take a look at how we can use it.


Windows 2000 introduced a command line utility called netsh (network shell).  As the name suggests, netsh is a shell environment that provides commands that address network issues.  One of the commands it provides is netsh trace, a simple command line packet capture tool.

 In the following video ..

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Wireless Site Surveys Done Right (by Tony Fortunato)

Just got my first article posted at Network Computing... Yippeee!!  ;)

In this article I discuss the pros and cons of active versus passive site surveys.  I also discuss some of the concerns I have when i see analysts using tools incorrectly and cause you to down the rabbit hole.

When I present or troubleshoot, I always get asked about this very topic.  

There is no fast or hard rule, but hope you'll find my input helpful.


Let me know if this topic interests you and I'll be glad to post more info.


How To Decrypt WPA2 Trace With Wireshark (by Tony Fortunato)

Packet analysis was tricky enough without layering WiFi on top of it.

First you need to know if you have a WiFi card that can capture the WiFi radio header, then you have to figure out if you can capture in promiscuous mode, then you need to understand if the wireless network has client isolation or similar configurations.  Whew…  yeah real straight forward.

That's where having a specifically designed WiFi tool helps. In this example I used a Fluke Networks One Touch to capture some packets.  Capturing them was the easy part.  Now I have to decrypt them.

I chose to use Wireshark and want to share with you how to decrypt a trace file when the client is using WPA2 encryption.

As I said in the video, the key (no pun) here is to start your capture before the client authenticates with the access point.



WiFi Do's and Dont's (by Tony Fortunato)

The other week AirMagnet/Fluke Networks asked me to put together a webcast covering some WiFi tips from my expereince.

When i am asked to do these webcasts for Vendors, I always have that thought in the back of my head that the majority of my information will be transformed into a product sales pitch losing the technical relevance and value for the audience.  I am happy to report that did not happen. I have to give AirMagnet credit for not turning my presentation into a Marketing 'dog and pony show'.

I was shocked when I heard that over 300 people had registered for the event proving to me that analysts were interested in someone's experience with WiFi.

On to the material, I covered various aspects of WiFi design, impementation, support and testing and hope you find the session helpful.

I was very impressed with the audience participation and appreciated the questions posed to me.


WiFi Video Link


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Chat about Wifi Interference (by Tony Fortunato)

This is the last of my 5 part Evidence Based Network series where I start talking about WiFi network interference.

One of the most important points to take away is that timing is everything.  You need to find a methodology that will capture when the interference is occurring.

Unfortunately when interference is misdiagnosed, you may inadvertently increase transmission levels, increasing noise levels.

WiFi interference can be caused by non 802.11 devices, or wireless devices, so having access to a spectrum analyzer is critical. The ability to leave a tool and get an alert when the noise occurs would be a HUGE bonus.




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Live Demo @ LMTV | Visual TruView from Fluke Networks (by Zack Belcher)

Flluke170x200Assessing and managing the VoIP network presents an entirely unique challenge from monitoring traditional data applications. As an example, there is a significant difference between an email taking 15 seconds to be sent and a garbled VoIP phone conversation.

Common challenges include:

  • Managing an infrastructure where VoIP can live with other applications harmoniously, is challenging at best without full visibility into the performance of both with the goal of optimizing the end-user experience.
  • Identifying not just when, but where, VoIP degradations are occurring.
  • Traditional VoIP monitoring tools rely on endpoints to report call quality—limiting troubleshooting effectiveness right from the start.
In this week's episode of LMTV, +Zack Belcher of +Fluke Networks and the other editors of LoveMyTool discussed these challenges and methods to overcome them, including a demonstration of Fluke Networks’ Visual TruView, the easiest to use VoIP quality of experience monitoring in the industry.

ZackZack Belcher is a product manager with Fluke Networks and has worked in network and application performance monitoring for over 8 years, across multiple vendors in the industry. He holds bachelor’s degree in Computer Engineering from Schaefer School of Engineering and Science at Stevens Institute of Technology. Zack resides in Austin, Texas.

For more episodes of LMTV, please visit LoveMyTool.TV.