Sniff Wi-Fi

WildPackets OmniPeek has long been my favorite WiFi sniffing software, but lately this blog has been short on posts about it.  That needs to change.  So today I start a multi-part series (number of parts to be determined) on how I use OmniPeek to help me plan for and troubleshoot mobile devices. Mobility (defined here as seamless roaming between WiFi access points [APs]) is a longstanding enterprise WLAN issue that has kind of taken a back seat to supporting personal devices (a.k.a. BYOD).  For many enterprises, mobility remains important.  Car dealerships with push-to-talk handsets, warehouses with barcode/RFID scanners and retail locations with point-of-sale terminals are all examples of locations that require user devices to move around a large area without dropping connections, losing speed or experiencing choppy service. The solution to supporting mobility is to make sure that APs have adequate overlapping coverage without interfering.  It sounds simpl...

Oh, those darned iPhones. Can't live with 'em, can't keep your job without 'em. The vagaries of iPhones and other station devices are the most difficult part of managing a WiFi network, but there are some things that can be done on the infrastructure to try to make your stations work better. One of those things is lowering your AP transmit power to a level that more closely matches your client station's transmit power.  My main man G.T. Hill (of Ruckus Wireless ) recently wrote a blog post discussing why this post is bullshit. Now I'm going to tell you why his blog post is bullshit. (sorry, G.T.) G.T.'s primary point is that is is borderline mentally handicapped (politically correct term) to turn your AP's power down. His theory is that even if your client stations transmit at low power levels, having a high AP power level at least allows the from-AP data rates to stay as high as possible. (G.T. goes on to add that most traffic is downstream, th...

You say you like WiFi Sniffing? And having fun? And not succumbing to a painful demise due to liver sclerosis? Well, then there's only one product pronounced eye-pee-ay for you: Metageek's new visual protocol analyzer, Eye P.A. Amid all of our divisions over race, gender, religion and whether the Champions Bowl is going to be better than the Rose Bowl, we can agree one one thing: products named after alcohol are great . So you can imagine my excitement when I was made aware that Metageek -- hero to Windows users , villain to Mac users  and tease to iPad users  -- had introduced a WiFi sniffer. Metageek is known 'round these parts ("round these parts" being, "in my opinion" ) as being a proprietor of low cost, attractive WLAN analysis tools. InSSIDer is the best active site surveying utility I've seen for Windows. The WiSpy/Chanalyzer combination is my spectrum analyzer of choice. (And I'll just choose to ignore the iPad tease that has been...

You're never gonna sniff again Faulty packets got no meaning Though it's easy to pretend I know I'm not a fool Oh, how I want to sing those lyrics . To whom, you ask? Why, to Cisco Clean Air access points. Also, AirMagnet Enterprise sensors, Aruba Air Monitors and anything else that offers me a careless whisper worthless capture. Unlike WHAM! , distributed WLAN analysis is in. It seems that nowadays I can't swing a dead cat without hitting someone who is proud as punch of their system of distributed sensors that does something (spectrum analysis, intrusion detection, frame capture) cool. Distributed sniffing (meaning frame capture) or spectrum analysis does have its uses. If you need to find a rogue AP, identify a denial of service attack or get a general overview of your RF environment, systems like Cisco CleanAir, Fluke AirMagnet Enterprise and Aruba AirWave RAPIDS can all be useful. The problem is that these products are often used for more than that. An...

Blogger's stats are telling me that yesterday was the most-trafficked day in the history of this blog, and as much as I want to credit Titanic's 100 year anniversary, I have to think it is because of my most recent blog post. That post showed how I used WildPackets OmniPeek to analyze the damage that unassociated smartphones can do to a WLAN. This follow-up is just a quick tutorial on how I set OmniPeek up to do that analysis. In order to follow the same steps I did to analyze smartphone activity on a WiFi channel, you'll need a licensed version of WildPackets OmniPeek (Basic, Professional or Enterprise will do) and an 802.11a/b/g/n WiFi adapter that is compatible with OmniPeek. I used OmniPeek Enterprise with a Cisco-Linksys WUSB600Nv1 adapter. To start, insert the WiFi adapter (if necessary) and open OmniPeek. Click the  New Capture  button to bring up the Capture Options window. Next, click the 802.11  link on the left hand side of the screen and select the Scan ...

Enough is enough! I have had it with these motherf*cking smartphones on this motherf*cking WLAN!   - Neville Flynn, played by Samuel L. Jackson in Snakes on a Plane   (paraphrased)  Oh, if only our wireless networks could be saved from smartphones by a foul-mouthed constable. Instead, we have to deal with them. I've done a bit of sniffing recently in an attempt to figure out how much damage a roving smartphone actually does and it led me to a radical conclusion. At halftime of a Los Angeles Clippers game a few months ago, I had the occasion to speak with someone who works with the Staples Center WiFi network. He was unable to share too many details for security reasons, but one thing he did share were the problems Staples Center has with smartphones.  When people attend a sporting event, thousands of WiFi-enabled smartphones are brought into a large open space. The Staples Center WiFi guy told me that the WLAN infrastructure shows that thousand...

There is an old joke in the IT world that software is like sex: you'll need support after you buy it.  Actually, the punchline to that joke is usually, "it's better when it's free." The problem is that the latter punchline fits poorly in the world of WiFi sniffing. The stuff you pay for really is a lot better. That said, a lot of people like to use free software whenever possible, and for Mac OS X and Linux users, there are some decent free WiFi analysis tools out there. For Windows users, however, the search goes on (and on, and on, and on...). Long time readers of this blog may be aware that I prefer commercial WiFi sniffing software when doing real work. But free WiFi sniffers do have a place . If you are trying to learn about the technology, troubleshoot your own personal WiFi device or study for a CWNA / CWSP / CWAP certification exam, then you'll probably want some protocol analysis software but you probably won't want to pay a lot of money fo...