Mac OS Lion: Massive wi-fi-problems?

I have a late 2009 iMac and since upgrading to Lion in August I have been having the infuriating issue of frequent disconnections, incredibly slow internet (speedtest.net was showing a 0.23mbps connection on a 20mbps fibre optic service).

I've tried installing the Atheros 3.2 firmware (replacing Lions 4.0) and numerous other PRAM and SMC cleans to no avail.

After reading previous discussion boards I read that WEP security settings on wireless routers cause major issues in both Lion and Windows 7, which both Applecare and Microsoft have advised "Modern operating systems do not communicate well with WEP settings as they are not secure". I changed my settings from WEP to WPA to no avail. Tried several configurations through Network preference and same issue.

Today I gave up and turned my security settings off completely.

My iMac now runs speeds of 12mbps (i'm at the other other end of the house from the router so my speeds always been slower).

Apple need to sort this out as they cannot expect people to drop all security settings in order to maintain wifi connection let alone use the internet.

Hope this helps everyone.

Chris

Had same problem with wifi cutoff as well as download problems. I talked to an Apple store genius and he had same issues.

Easy Solution! Buy a new wireless router (11n) Mine is a cisco E2500 $69. It worked like a miracle!!!

NO Problems any more.

Good Luck

BTW, I had issues with imac (mid-2010 & macbook pro 13") & HP PC.

I have had no issues at all until this week. I installed a Cisco anyconnect and remote desktop software to VPN for work. It worked fine as long as I used the anyconnect. I unistalled both of them and it still won't work on my wifi on my home network. It says it's connected, and when I bring up the airport utility, it shows a green dot next to internet, but says it can't find an airport. Everything else is connected and working fine. I'm new to the mac world, and I know on windows, I could play around with my proxy settings in these cases and get it to work. But I don't know what my proxy settings should be. I'm running OS X 10.7.3. I may not have the latest airport software, but how do I upgrade it if I can't get online? I've renewed my DHCP lease with no success. I can't even use my desktop sharing software on my ipad that has been working fine. Any suggestions would be great. I've been scouring the internet in search of anything that will help. Unfortunately, I'm not located at a place where I can hook it up to an ethernet cable. Incidentally, I did have it in a different location on eithernet with no issues and just changed that about a month ago. So, maybe the VPN stuff was just a coincidence?

Thanks in advance,

Keifer

Ok, so I ended up restoring to a date that I knew it was working. That did the trick. When I did, it asked me to update my airport software and that reminded me that I update the software earlier inthe week. That is when I started having issues. So I didn't update and it's working just fine.

I too am having the same problem. I stumbled upon the following solution from a blog. It worked for me:

Just UNCHECK that "Re-open windows when logging back in" button when you log out or shut down and then restart.

http://macnerd-presents.blogspot.com/2011/08/os-x-lion-wifi-no-hardware-installe d.html

Now sorted got new Wi-Fi installed by Apple shop.

I had the same issue.

I have found the source of the error. Prior to the Wifi dropping issue, i changed the WIFI security from mixed WPA/WPA2 to WPA2 AES keeping the same BSSID name for my WIFI network.

So, i just changed the name of my WIFI network in my router configuration so that it was a brand new profile. My macbook pro prompted me for the password and that's it. With a brand new WIFI profile, the WIFI doesn't disconnect anymore.

After battling this out at home, i realised my home Wifi was the only instance that showed BSSID Changed errors. After upgrading firmware on router + modem, updating to Yosemite, deleting network interfaces and removing all keychain entires for the SSID at home - I did the followin with Yosemite in terminal

- sudo discoveryutil mdnsflushcache

Flush the DNS cache locally and you might get somewhere