Why aren't there any passive sniffers for AirPort Extreme
The broadcom 802.11g chips used

Why would I prefer .public networks?
Appending '.public' to the SSID of an access point makes it clear that the network is being intentionally shared. iStumbler can be instructed to prefer these networks when Auto-Selecting and Auto-Joining are enabled.

Why can't iStumbler see my network?
iStumbler scans by sending out probe packets via an Apple interface Access Points MAY respond to these probes but they might also be configured as private networks. Future versions of iStumbler may introduce monitoring for and joining private networks, but not necessarily scanning for them. iStumbler is intended to find publicly available wireless. Making your network private is the equivalent of putting up a "No Trespassing" sign.

Updated: iStumbler can now see any network you have connected to, if it's responding to probes or not. Currently you will need to use the AirPort utilities to connect to hidden networks.

Does iStumbler allow me to access networks protected by WEP?
No. A few have asked for this feature but I don't plan to implement it. If you want KisMac you now know where to find it. iStumbler is intended to be an easy to use tool for finding open, public networks. While the ability to test your security setup is useful in some cases, it's out of scope.

What do the abbreviations mean?

• WEP = (Wired Equivalent Protection) a form of layer-2 encryption
• SSID = (Select System IDentifier) the network name
• IBSS = ad-hoc network
• BSS = managed network
• mac = Media Access Controller) unique hardware address

Does iStumbler support wireless interfaces other than AirPort?
Not yet. I have been in contact with the author of the OpenSource wireless driver for Mac OS X, when a new version is released I will be able to support it. It's been a few months since this time, there's less hope.

Thanks to a hot tip we will be supporting DLink USB adapters soon.

Does iStumbler leak memory?
iStumbler may leak a little memory. In typical use it keeps it's VSIZE below 90M now that it forgets old encounters.

Why did iStumbler forget all the networks it saw!
Every time iStumbler scans for wireless networks it records it's findings in an Encounter object. Each of these takes up some space in memory and if iStumbler remembered all encounters it would eventual use all your RAM. By default encounters more than 10 minutes old are forgotten, you can change this value to 1 hour for an extended site survey or forever if you're up to something else.

Does iStumbler work with my GPS?
If you GPS supports the NMEA protocol over a serial or bluetooth connection to your computer iStumbler should be able to use it. Currently the GPS must be on the first serial port.