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Showing posts from January, 2015

Free Sniffing in Windows! (Kind Of)

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Nine months ago (bad way to start a blog post, I know) I wrote a blog about the future of WiFi sniffing.  In the comments section (perhaps the only worse thing for a blogger to say), someone mentioned a free, Windows-based application called Acrylic WiFi.   I briefly checked out the app and dismissed it as yet another Discovery utility disguised as a something more. 

Then I actually used Acrylic WiFi and...  it works!  It sniffs WiFi frames (sort of) and it does it for free (outside of the cost of an ordinary 802.11 USB adapter)!  This changes everything (kind of)!

For years, the method for free WiFi sniffing on a Mac has been simple.  Head down to the bottom of this post for a reminder.

Now, we can do similar things in Windows.  It's not quite as simple and it's not totally free, but it works (pretty much).

1. Download and install Acrylic WiFi Free, including Monitor Mode support (and, actually, if you can find an old download of Acrylic v1, then you'll be able to save ca…

How Fast Is My 802.11ac WiFi?

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802.11ac is the latest and greatest WiFi standard, but it's confusing.  So many questions: Is it really that much faster than 802.11n? (It can be.)  Is it worth upgrading?  (Probably not in the enterprise, but at home, absolutely.)  How fast is my device?  (Data rates as low as 6.5 Mbps and a high as 1.3 Gbps.)  

Getting specific answers to 802.11ac performance questions can be a chore sometimes, but there's a simple way to check your APs.  All you need is a wireless sniffer and about five minutes.

Today I wanted to find out what my 802.11ac AP is capable of.  I suppose I could've gone in search of a data sheet, but instead I decided to break out the wireless sniffer.  It was a quick and simple process.

Step 1: Find the channel of your AP

If you're a Mac OS X user, you can use Wireless Diagnostics.  If you use Windows, then Acrylic WiFi is probably your best option.

My channel was 48.

Step 2: Capture on your channel 

Using a professional protocol analyzer like AirMagnet W…

Killing My WiFi (With This Song)

Spec-ing the Layers with WiSpy
(one time, one time)
Channel gone red with this stream
(two times, two times)
Killing my channel with this song
Killing my WiFi
With this song
Taking my WiFi
With this stream
Killing my WiFi
With Bluetooth spe-ee-ee-eeakers...

Wireless streaming (music, video or, in the case of the wonderful song referenced above, a music video) can sure kill a WiFi connection.  It's good to have a spectrum analyzer to identify the problem.  It's even better to remember to use it.

Wireless streaming devices are popular nowadays, but most of them are benign.  An AppleTV, for instance, can wirelessly stream audio and video or it can act as a mirroring device for whatever audio or video is on your smartphone, tablet or laptop.  (And mirroring is tougher on WiFi than basic streaming.  When I mirror my iPhone 5, I'm creating three streams.  One from my wireless router to my phone for the Internet stream, a second from my phone back to the wireless router as part of mirroring…