Sniff Wi-Fi

You'd think a great company like Apple would care about my privacy BUT NO. Behold, my iPhone: You see what's going on here?  That's my iPhone there.  Apple_57:8d:89.  (Filtered using wlan.sa == f4:f1:5a:57:8d:89 if you're curious.)  And look what it's doing.  IT'S PROBING.  The iPhone of a respected security do-gooder like myself is out there for any hooligan to see. Do I look like the type of person who wants the world to know that I used my phone at the MGM Signature in Las Vegas?  (Well, maybe.  I could've prevented the phone from probing by just tapping on the SSID instead of typing it in.  But typing in SSIDs on iPhones/iPads is a neat trick for keeping stinky captive portal splash pages from coming up over and over again on guest WLANs.)  Or on the VerizonWiFi network at Staples Center?  (Which added a captive portal and lost A TON of guest connections, thus harming overall channel performance for all WiFi users in t...

802.11ac: A Survival Guide  is a recently published handbook about 802.11ac.  The author is Matthew Gast, a very knowledgeable WiFi guy who follows the  IEEE 802.11 Working Group closely.  I recommend the book if you work in WiFi.  It is informative.  There is great attention to detail.  All areas of the subject are covered.  But  I was left uninspired.  And my uninspiration (is that a word?) was the result of the book being short on something that I always hope to find in any technical writing: the Why. In some ways yours truly is the target audience for the book and in some ways I'm not.  I need to know the intricate details of how WiFi works.  (Point)  I already knew most of the tweaks that 802.11ac is making to 802.11n.  (Counterpoint) The physical layer is the most important part of 802.11ac, and that is where this book wins.  For example, before I ...

In my last (real) post, I detailed how I used WildPackets OmniPeek to solve an iPhone 5 QoS problem.  But what about AirMagnet WiFi Analyzer?  I am a fan of both of those fine WiFi sniffers, so I figure it's a good idea to show you how QoS can be analyzed with Fluke Networks' signature WiFi protocol analyzer. WildPackets OmniPeek is more of a hardcore protocol analyzer than AirMagnet WiFi Analyzer is.  If you're going to be doing the type of sniffing I detailed in the last blog post , you will have an easier go of it with WildPackets' product.  But AirMagnet is popular and both tools are expensive.  So if you happen to be a gal (or guy) who needs to troubleshoot WiFi voice or video and you have AirMagnet, this brief tutorial should help. To begin analyzing QoS, one must first capture on the VoFi devices channel.  In my case I associated my iPhone 5 to a network with the SSID of "R&T".  Then I looked at the Start screen in AirMagnet: The "...

My love for WildPackets OmniPeek may be one of the few things in technology that exceeds my love for the iPhone... Now that I've run off 20% of my audience, let's talk about how the former can be used to figure out if the latter is causing a problem. I have a lot of enemies in life, and I'm proud of that.  In my opinion, part of being an adult is recognizing who your enemies are.  UCLA football players are my enemy when they play college football.  Drivers who text while stopped at green lights are my enemy when I am running late.  (No comments from the peanut gallery on that one, GT Hill .)  And deductive reasoning is often my enemy when troubleshooting. Deductive reasoning is oh so tantalizing.  It's simple math; A + B = C.  The WLAN works (C) when VoFi handsets (B) connect to my APs (A).  If I switch out the VoFi handsets for SIP-based iPhones (thus changing the value of B) and the WLAN ...

I am working on an online video project, so I want to test out some videos.  Here's a two minute video on capturing WiFi in Mac OS X.

I am going to try a Reddit AMA. http://www.reddit.com/r/IAmA/comments/1oguh2/im_a_wifi_expert_ask_me_anything/

It's Columbus Day!  A holiday that many of us heard of, a few of us object to and some of us don't get the day off for.  Let's call it a half-holiday. Yours truly is going to celebrate the day by celebrating one of my favorite sniffers, Fluke AirMagnet WiFi Analyzer.  Due to it being half-holiday, this will be a half-efforted blog post.  So no links and no graphics.  Just a little talk about my favorite part of that fine sniffer. AirMagnet WiFi Analyzer from Fluke Networks has been around for a long, long time (at least in WiFi years) and it continues to be one of the top WiFi sniffing options available.  I probably like WildPackets OmniPeek a little bit more because of its ease in manipulating frame traces, but AirMagnet (as I'll call Fluke AirMagnet WiFi Analyzer from here on out) has long been the best option for solving the vast majority of in-the-field WiFi problems. Last week I got to introduce AirMagnet to a few folks and it struck me that eve...