Apple Mac OSX Wi-Fi Diagnostic Tools

Like a colleague of mine, for the last few weeks I’ve had some random issues with my home Wi-Fi network dropping out.  It’ seems pretty random, though happens more in the evening – just when I’m likely to be using it.

It’s an odd problem, especially as its cause is normally invisible interference, the only symptom is the Wi-Fi not working.  I figured that that there must be some tools out there that could help identify the cause, hopefully visualising it in some way so I can see what’s happening. 

I’ve posted before about a Windows tool called inSSIDer that does a good job identifying other wireless networks around you.  Keeping an eye on this few a few days ruled out a competing Wi-Fi network, and to be honest I doubt another wireless work could kill my network as completely as I’ve been seeing – they’re designed to be tolerant of that sort of thing.

I also did quick search for Mac tools, there doesn’t seem to be much out there, but a few sources did point to a native tools included in Lion, Apples own Wi-Fi Diagnostics.  It’s not all that easy to find if you don’t know it’s there, but you’ll find it in the /System/Library/CoreServices/Wi-Fi Diagnostics folder.

In Finder click the Go menu and ‘Go To Folder…’
Enter in /System/Library/CoreServices/Wi-Fi Diagnostics and you’ll find at the bottom

Start it up and you’ll be given four options:

The first, monitor performance give you a simple chart of both signal and noise strength over time – this is really very handy, it showed me that when my network drops out the amount of noise sky rockets way above the signal strength.

The second option shows a log of significant events that happen on your network, such as joining a different network or changing AP.  I didn’t bother with a screen shot as not much really happens in here and it’ll mostly be empty.

The third option allows you to do a full packet capture of the traffic on your network, the traffic to and from your computer or traffic on nearby networks.  These can be saved in the standard .pcap format and opened up in wireshark, but you can’t view them in real-time using the tool itself.

The last option shows a detailed log of what’s happening on the network, I don’t pretend to understand that much about what’s happening but I’d assume it’s useful into on the right hands!

So there you go, if you have a Mac there’s a handy little tool hidden away within it that could help troubleshoot Wi-Fi problems.  Now I just need to figure out what might cause three 30 second bursts of 2.4GHz interference over a three minute period and therefore stops me streaming movies to my Xbox!