wirelezz blog

waves're in the air everywhere I look around…

Posts Tagged ‘wlan

[Solved] That Atheros AR9285 WLAN Card Problem

with 20 comments

About six months ago, I bought this awesome Samsung laptop at a great price. It’s been working just great, the only problem has been the WLAN card. It’s an Atheros AR9285 802.11a/b/g/n. At the beginning it worked fine, but lately it’s been failing like mad: it randomly loses connectivity from the WiFi network, although Windows stated otherwise.

I quickly thought it should have been a driver issue, so I looked for one that would do the job, and I found it at HP’s support website. Since it’s just a driver, it wouldn’t be a problem, right?

Here is the driver’s link: It’s for an AR9285 WLAN card running under a 64-bit Windows 7 (be sure to read that)

In case you don’t know how to install it, here’s how to:

  1. Extract its contents and then, under network connections, get in the properties of your wlan card
  2. Click on configure
  3. Then click on driver’s tab and then click on update driver
  4. Now click on Browse my computer for driver software.
  5. Click on the “Let me pick from a list…”
  6. Click on “Have a disk” and then click on browse, and search for the netathr.inf file. Then next.
  7. Select AR9285 802.11a/b/g/n from the list, then next. That should install it.

It works great now. It was just a matter of updating the driver, but looking for the right one is a real pain in the neck. Let me know if it works for you too.


Written by Wirelezz

September 17, 2011 at 2:21 pm

Posted in etc

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What is so great about OpenWRT?

with 3 comments

Lately I’ve been experimenting with OpenWRT, a linux distribution for embedded devices. The great thing about OpenWRT is that you can install it to most of the cheapest WLAN devices, ie. routers (check the table of supported hardware).

I know that most Open Source projects may never be as good as proprietary solutions for real implementations. However, in the particular case of OpenWRT, I have identified three major advantages:

It’s a great tool for research
It’s an awesome tool for researching on many fields such as: protocol design, fast handoff schemes research, WIDS, Wireless mesh networking, and so on. Learning and doing Unix socket programming in C for OpenWRT may give a large number of headaches, but it’s the best way to get the full control of the information sent over the air.

It’s a great study tool
There’s indeed a difference between reading about the 802.11 standard and getting hands-on training equipment -of course, reading is extremely important- but some of the most advanced concepts are not available anywhere but in enterprise solutions. If you don’t have the access to such equipment, you may want to install OpenWRT on your (cheap) Linksys WRT54GL and also install some packages that would do the magic.

For instance, how do you see what is actually going on through a WPA2-Enterprise (with a RADIUS server, EAP/MD5 auth) handshake on both the wired and wireless side? You could install FreeRadius to a linux box to use as authentication server. Sniffing the air is possible by using wireshark or tcpdump in the OpenWRT box.

If you want to learn a little more about WLAN Controllers, you may want to take a look at the ChilliSpot project. You need to install it on both a WRT54G and a Linux box to see it in action.

VLAN segmentation by editing configuration files, deploying a VPN server on the router, wireless mesh networking using different routing protocols, installing Asterisk on the box, etc. There’re A LOT of packages that can be installed.

Save money
It’s as simple as this: you get many of the features only found in (expensive) enterprise solutions by installing a free firmware on a $60 router.

As I said (somewhere) above, OpenWRT may not be suitable for large enterprise implementations (should not), but it’s a great tool for studying the 802.11 standard, researching or just having some fun. I do not recommend it for illegal purposes.

Some useful links:
Installing and configuring OpenWRT Kamikaze
OpenWRT forum
Use FreeRADIUS for Wi-Fi Authentication

The idea of writing this post came up after reading a question asked by @jameyk1stner via Twitter which basically stated: is there any way to practice for the CWNA exam with real scenarios by using real APs, Controllers, etc?.

Written by Wirelezz

August 23, 2010 at 10:15 am

Posted in Uncategorized

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TKIP and WEP: Game Over

with one comment

So the other day I read the following in WiFiNews:

TKIP and WEP won’t be allowed in new devices with the Wi-Fi stamp in a staged elimination over three years starting in 2011.

My first reaction was: “Why did it take so long?”. It is well known that WEP is one insecure standard for IEEE 802.11 Networks. I’m no security expert, but there’s something I’ve learned in the past 7 years from different sources of information: “Don’t implement WEP on your wireless network”.

According to the post, “While TKIP hasn’t been broken, it has known vulnerabilities, such as a susceptibility to dictionary-based attacks for short keys, and some very clever ways to insert packets through manipulating a flaw in the packet integrity protocol.”.

However, it looks like it’s going to take some time to be accomplished:

At the start of 2011, access points will no longer be certified with TKIP as an option by itself, commonly revealed as WPA-PSK, WPA-TKIP, or WPA Personal. Mixed modes, in which an AP can accept either TKIP or AES keys, will still be allowed. But also starting in 2011, manufacturers can opt to ship Wi-Fi hardware preset to use WPA2 out of the box.

In 2012, new Wi-Fi adapters (so-called stations in 802.11 parlance) won’t be allowed to support TKIP.

In 2013, WEP is finally disallowed for APs. While that seems incredibly late, its inclusion is there only for certain categories of legacy devices for which no other option is available.

In 2014, the mixed TKIP/AES mode for access points can no longer be included in certified devices, and WEP cannot be available to new client devices.

As you may also know, 802.11n implements 802.11i security and gives TKIP support for those non-AES devices (however, 802.11n with TKIP won’t support data rates higher than 54Mbps).

While I think this should have been done severals years ago and that security standards should walk together with 802.11 innovations (such as 802.11n), I’m also interested in finding out how to meet the point in which new security schemes will not affect 802.11 handoffs as more handshakes and protocols are added in the process.

Source: WiFiNews

Written by Wirelezz

June 27, 2010 at 3:50 pm

Posted in News

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Meraki WiFi Stumbler

with 2 comments

During the time I was working on my thesis, I had to do a quick Site Survey in order to prepare the testbed for my VoWLAN call tests. So I started looking for the software that did the “site survey” magic.

This kind of software (as you might already know) is called Stumbler. What a Stumbler basically does is taking a look at the wireless medium and search for active Access Points, as well as their SSIDs, the signal received, etc.

There are plenty of tools that do the job. For instance, there’s NetStumbler, which is a great piece of software. However, after reading a @meraki tweet, I tried it and I have to say: it’s very cool.

Here’s the link to the Meraki Stumbler site

First of all, you don’t need to install it: it’s web-based, so it saves you the work of looking for the right installer for your OS and, of course, skip the installation requirements.

It has a friendly interface. Clean and easy to use and understand.

It shows you a graph of the channels versus the number of clients that are using each channel. Which is pretty useful to start doing the site survey. Why would I care that much about looking for a level of interference of channel 1 if I can see that there are 10 APs using it and that the channel 11 is clean?

It’s Java-based: I’m sorry, I really love Java. You might not need to install it (it’s not a installing requirement), but there’s a prerequisite: you need the JRE to use the Stumbler.

Here’s a video showing how it works. Pretty simple.

I’m aware that this may not be as complete as Netstumbler is, but I found Meraki Stumbler a very minimalistic yet clean approach for a quick “hey what’s going on around here?” survey.

What’s your favorite site survey software? Leave a comment!

Written by Wirelezz

June 26, 2010 at 12:05 am

Posted in Tools

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