What I am about to write about is nothing new. Some of my wifi peers have written about Chanalyzer and Cisco CleanAir or various aspects of each or both before. I am going to take you through my journey to get a lightweight Cisco 3502i converted back to autonomous code and connected to MetaGeek’s Chanalyzer.
I suppose I should fill you on what my intent is with this project so you don’t have to wonder why I am going about it the way that I am. I currently use MetaGeek’s Wi-Spy DBx with Chanalyzer on a regular basis and it does everything I need it to do. When I found out I could get an even higher resolution layer 1 view with a Cisco AP that supports CleanAir, I had to give it a try. This was done with no other reason than “just because.”
You might say that the DBx is my “go to” tool when I first arrive onsite to check out an issue. I love MetaGeek because their products are excellent and their staff are top notch. Whether you are working with inSSIDer, EyePA, or Chanalyzer, you are always dealing with quality. If you ever need help with any of them my buddy Joel Crane is ALWAYS there to help.
The first part of the project began with talking to Sam Clements. He is my go to guy when it comes to Cisco wifi. He gave me some pointers and even hooked me up with ANOTHER 3502i for this project. Sam had previously hooked me up with two other 3502i APs because he felt bad for me and my single 1131 connected to my Cisco WLC 2504. When the 3502i arrived I put Sam’s advice into action. I connected the lightweight 3502i to my WLC 2504 to get it’s code upgraded to 220.127.116.11. Upon completion I took my nice fresh copy of autonomous AP code (ap3g1-k9w7-tar.153-3) and loaded it to the 3502i. I SSH’ed into the WLC and issued the following command:
The process took a few minutes and the AP rebooted a couple of times. Everything is straight forward at this point and you can watch the progress of the “downgrade” via your console output if you have consoled into the AP. Once the process is complete you will recognize that the AP has good ol’ IOS running on it.
At this point most of the heavy lifting has been done. At the advice of Sam, I configured the BVI with an IP address and created a DHCP pool. This was done to allow for easy connection to the AP via Ethernet cable and POE injector directly from my laptop.
For my particular application I chose to use a POE injector to power my AP. I do not have a survey rig battery and I needed something a little more portable. If you do have a survey rig battery you should check out this blog post from Nolan Herring: https://nolanwifi.com/2016/04/22/spectrum-box/. He has built something called a Spectrum Box, also with the help of Sam (that Sam guy is all over the place).
Now that you have connectivity between your laptop and AP you have to tell the radios in the 3502i that they need to be evaluating the spectrum and not serving up wifi. This mode is also known as SE-Connect mode.
The AP is now fully configured for use with Chanalyzer. At this point I was super excited but I was soon met with disappointment. I had failed to realize previously that connecting to a CleanAir AP with Chanalyzer was an additional feature that would require a purchase. I quickly got in touch with Joel at MetaGeek and let him know of my predicament. He graciously provided me with a key enabling the CleanAir feature so that I could continue my project. A big thank you goes out to Joel and MetaGeek for providing me with this feature so that my project did not come to a screeching halt.
We are now at the point where we can open our trusty ol’ Chanalyzer. This is where everything that us DBx folk are used to, will change. Once you have Chanalyzer open you will notice there is a menu named CleanAir (as long as you have purchased this feature). When you click on CleanAir it will prompt you with some options. If this is your first time connecting to a CleanAir AP you should select “Connect to a CleanAir AP.” You will then be prompted with a box that looks like this:
Enter the AP’s IP address (in my case it is the default gateway given to me by the DHCP services on the AP), enter the NSI key, and enter a friendly name. You might be asking yourself what an NSI key is, much like I was. It is a unique code that is used like a password so that Chanalyzer can connect to a CleanAir AP. You can get the NSI key from the AP by issuing the following command from the CLI:
You’re In!!! At this point you are ready to check out the detail that the Cognio chipset has to offer inside of a Cisco CleanAir AP!
As you can see the resolution of the Cisco CleanAir AP with the Cognio chipset is very clear. Each mode definitely serves it’s purpose though. The DBx will still be my go to tool in the field but the clarity of the CleanAir AP is hard to beat. If you already have CleanAir APs in service this could be a much more practical remote monitoring solution for you. It should be noted that there are several other use cases\situations that this could be deployed for.
If you don’t have the CleanAir capability with Chanalyzer and you currently have Cisco CleanAir APs, do yourself a favor and visit MetaGeek’s website and purchase the accessory. You definitely won’t be disappointed!
Here is a few blog posts that I read through while completing the project:
Nolan Herring – https://nolanwifi.com/2016/04/22/spectrum-box/
Joel Crane via MetaGeek – https://support.metageek.com/hc/en-us/articles/201872824-Chanalyzer-Wi-Spy-User-Guide