Using Mac OS X Lion’s new Wi-Fi Diagnostics Tool
Just this week, Apple started shipping their latest incarnation of the OS X operating system, named Lion. Included in this operating system is a new Wi-Fi Diagnostics tool. This tool isn’t really designed for casual use by end-users, but as wireless LAN professionals, you should enjoy some of these latest features.
First though, a couple of other tools that helps with Wi-Fi Diagnostics on a Macintosh platform.
You have probably already used the ‘Option-Key’ trick when you click on the Wi-Fi logo to get detailed information about your current connection. (This used to be called the AirPort logo, but in Lion it's been renamed the more accurate Wi-Fi)
Here’s what the standard left-click on the Wi-Fi logo gives you:
Now notice the extra information available when you hold down the ‘Option’ key and click on the same Wi-Fi logo:
I also like to use a tool called iStat Menus from Bjango to have a quick view of my network connections, and what IP addresses each of the network interfaces is using. Plus, you can watch traffic flows without taking up too much screen real estate.
Another tool to leave on screen is a very small app that does only one thing. It posts the current connection rate. It shares the same name as the Spectrum Analyzer from Metageek, but does something completely different, it’s called WiSpy. I can’t tell you how helpful this little app has been in diagnosing Wi-Fi issues.
And finally, you’ll want a quick way to see what SSIDs and APs are in your vicinity. Look no further than Zaib’s Wi-Fi Scanner. It just works. Shows you the surrounding Wi-Fi signals, including SSID, Channel, BSSID, and security mode. It will also give you detailed information about your current connection.
Now on to the Apple’s latest Wi-Fi Diagnostics tool.
This tool is kind of hidden. Not really placed somewhere a casual end-user might find it accidentally. You’ll find it here: /System/Library/CoreServices/Wi-Fi Diagnostics … you might want to do what I did, and make an alias and put it on your desktop.
To find the Wi-Fi Diagnostics application:
1. From Finder – type ‘ Shift Command G’ – or click ‘Go, Go to Folder … ’
2. Type in /System/Library/CoreServices/ Enter
3. Scroll down to the Wi-Fi Diagnostics application
4. Double-Click on the Wi-Fi Diagnostics application to run
To make an Alias:
‘Right-Click’ on the Wi-Fi Diagnostics application and choose ‘Make Alias’. Copy the Wi-Fi Diagnostics Alias to your desktop
The app itself has four possible options:
The first shows a graph monitoring the performance of your current connection.
The second option starts a recording of Wi-Fi events. These are large changes, like moving between APs, or choosing a different SSID.
We will now skip to the final option, a more detailed logging of Wi-Fi events. This is the nitty gritty information on what is going on with your Wi-Fi network interface.
And the last option we’ll talk about, happens to be the third option, is to do a packet capture. You can set the frame capture options to do a variety of captures. From just your own NIC, or promiscuous mode. These each will set different sets of frames on the Wireless LAN.
You cannot view these captured frames coming in live. But you can save the capture as a PCAP file and open in your favorite tool. Here’s a Wi-Fi Diagnostics capture viewed in Wireshark running on the Mac.
With all of the included tools, you have an option of saving the reports locally, to Finder, or email the results. You receive a .tgz compressed file. When uncompressed this folder has the results of your scans. In the case of Packet Capture, you’ll get a .PCAP file.
These files are designed to help Technical Support see the details of your wireless environment. I like how they REALLY don’t want the end users playing with this … note the help file graphic.
Now go and start playing with this new Wi-Fi Diagnostic tool that comes with OS X Lion!