Wifi Connectivity issues - looking for insight

Question

Hi everyone,
Given the breadth and variety of wifi-related issues on this forum, I was hoping to find a topic that resembled the issues I am currently experiencing. Alas, I was unable to find a solution.
Recently (I noticed on Friday, Dec 18), I have been unable to connect to the internet wirelessly through AirPort. For months now, I've been connecting without problems to my work wireless network (WPA2 Enterprise), and home wireless network (WPA2 Personal) but only recently have both suddenly stopped working. My initial diagnosis was that it was related to a recent software update that I allow OS X to deal with weekly, but if I recall correctly it was a *Java-related update*.
The symptoms, if they might be of use, are as follows:
➔ Airport can see any available wireless networks, secured and unsecured
➔ Preferred networks it can connect to automatically, it will say it's done so (ie. Airport's connectivity icon at the top-right of the screen *shows 4/4 bars for connectivity*, clicking on the wifi icon shows a check mark next to my work network, which is secured)
➔ When I open Network preferences, the Status (using Work network as an example) reads "Authenicated", with subtext "Authenicated via PEAP (Inner Protocol: MSCHAPv2) with a connect time that appears to function normally (ie. it isn't resetting unless I turn off airport and turn it on again)
➔ While the status reads "Authenicated", the Airport icon at the left side of the Network panel reads "Not connected" with an unpleasant red globe clearly signaling that despite the right side of the panel's deceptive text, I have sweet nothing
➔ *Other forms of network connection do not seem to be affected*. Currently, my iPhone is connected to my MBP via USB and is allowing me to write this post via Tethering. I have not tried an Ethernet connect but I would assume that it works at this point.
➔ my computer hardware should be displayed with the post's meta-information
I would prefer a solution that isn't "just update to Snow Leopard," but I'm open to and grateful for any advice offered. I have tried solutions such as this one (http://jkontherun.com/2009/12/13/macbook-firmware-update-kills-my-bluetooth-wi-f i/), but with no success. Simply turning off AirPort and turning it on again has also not been successful.
Thanks in advance. If I can answer any more questions that might assist with the problem, please don't hesitate to ask.
Message was edited by: Tibbsy649

Answer 1

That has to be one of the best written posts describing the problem. Nicely done.
The first thing I would try is to go into System Preferences->Network (under Internet and Wireless) and then select Airport on the left pane. Once there, select the Advanced button on the lower right side.
There, you should see a listing of all the wireless networks your computer has remembered. Delete them all. This will clear out all the stored network settings for each network you've joined.
Once you've done that, rejoin your home network. Then go back to the advanced tab and make sure that the TCP/IP settings are correct and you've been assigned an IP address. Then check the Proxies section. If you do not use proxies, make sure nothing in there is checked (you probably don't use them at home).
I would also try a wired ethernet connection. If that behaves in the same manner, then the issue is somewhere else. If not, then the problem is isolated to the Airport card and may require a trip to the Apple store for further help.
Message was edited by: Jeff Breitner (pizza fingers and other grammatical problems)