No wifi connection after installing Mountain Lion HELP!!

I was contacted by Apple Tech help and gave them router model #s, diagnostic report and some screen shots. They came back to me to advise there was updated software available for the Cisco router that I had been using. After upgrading the software, my problems did go away. My Netgear router also works.

The WiFi connectivity issues after upgrading to Mountain Lion seem to be router related!

I so appreciate Apple contacting me!

BleebfrOK wrote:

The WiFi connectivity issues after upgrading to Mountain Lion seem to be router related!

I so appreciate Apple contacting me!

It is NOT router related. It is Apple changing something that other manufacturers have to make changes to there products to work with the Apple changes. If every other piece of equipment connect to a router and a MBP doesn't then it is the MBP that has the problem.

Absolutely correct! Come on, folks, look at the facts:
1) All other devices work fine

2) My MacBook works fine under 10.6.8

3) I upgrade to ML 10.8

4) 5Ghz becomes problematic

5) All other devices work fine

6) Rebooting to my 10.6.8 partition makes the problem go away

7) Reboot to 10.8 again and problems return

8) NO OTHER DEVICES HAVE PROBLEMS!

How can someone possibly blame this on the router? Sure a firmware update might "fix" it in that whatever Apple has done now becomes no longer a problem. But clearly Apple has done something. And I hope they fix it in 10.8.1.

I am disappointed in the rudeness and tone of some of the responses. Many of us are simply trying to share what has worked for us. If you are upset with Apple, voice your unpleasantness to them and not to other users.

My displeasure is really with you. For thinking it was a router problem. This has been an ongoing problem with one fix working for some but not others then another fix works for other but not all, and so on over and over.

Sure Apple got you to update you router, which you should of done anyway. But that does not fix other peoples problem with Mac computer and dropped WiFi.

Hey guys I found this posted on other blog, and it does WORK!! Good luck!!Thanks to the original author!

"I've been having this same issue and have found a temporary fix. Click your airport/wi-fi icon so you get the drop down menu, then click on Open Network Preferences. The menu bar on the left side of this box has your various connections, Ethernet and Wi-Fi, for example. When you try to toggle your wi-fi on/off, nothing happens, so what you have to do is select your Wi-Fi network, then click the ( - ) button on the bottom of that menu bar. This deletes the wi-fi connection (don't worry you can add it back later). Click Apply and restart your computer. Once you restart, go back to your Network Preferences and now click the ( + ) button. Add a new Wi-Fi network and turn it on. This should get you reconnected.

Now, I had to do this once before I updated to Mountain Lion. After I updated, this has been a pretty persistant issue and while removing, restarting, and re-adding the Wi-Fi connection works, it's awfully annoying and inconvenient, so if anyone has a permanent solution it would be much appreciated."

Hope this helps in the mean time!

I drove myself nuts with this problem. All other machines worked but the new one with ML would not connect to internet unless I went through diagnostics and re-entered password everytime! I finally went to router settings and just changed the name of the network and it connected right away! You might also make sure that your router security is set for "WPA2 personal" as the WEP will not work with Lion. Good luck

For those having problems with WIFI using Verizon MIFI4620L JetPack and Mountain Lion.

Go to this page on Verizon's website:

http://support.verizonwireless.com/pdf/system_update/mifi4620l_instructions.pdf

There are two downloads: drivers to install on your Mac and one to upgrade the software on the JetPack.

We have two computers with Mountain Lion. We were frustrated because the computer would not use the JetPack for WIFI access. The computers recognized the JetPack but we kept getting messages that it timed out or could not connect.

After installing the drivers on our computers and updating our JetPack software everything is working.

There may be other instructions on Verizon's website for other models of the MIFI devices.

Hope this helps some of you who are having this issue.