Q: Lion WiFi Connection Problem

I though that were my words, are the same points, the same trouble, I don't know what Apple is waiting to make a recall, I'm from Brazil,  and the problem is the same in all world. I'm very disappointed  and sad. Do you pay a lot of money for a product that don't work, and the seller doesn't care. What happened with the media about this problem? I haven't seen a report about that.

Although the warning from William Kucharski, I performed the downgrade and from that moment i think my connection is stable. If the problem returns i will report it again.

Finally fixed the problem for me. Started a dicussion thread about this issue and was immediately attacked by Mac kool-aid drinkers trying to tell me it was my fault, and to go away. After only one day, they deleted my posts.

How did I fix it?

My MacBook Pro Lion laptop does not like '

We'll see

Using a non apple router (Speedport) I have this problem of lost WiFi connections since Snow Leopard, upgrade to Lion made no change.

At last I changed in System Preferences/Network/WiFi/Options the value of MTU to minimal value of 1280. Since then my WiFi connections are stable again.

I can confirm with wwdto that changing the MTU to 1280 makes the connection stable. For my connection I've found 1450 is the sweetspot.

Thanks!!

Hi, since I'm still having the same problem, I would like to chech this parameter, but under System Preferences/Network/ I can't see any "WiFi" button, only "advanced". where is it?

where is it?

 Look at:

- System Preferences/Network

- select "Wi-Fi"

- klick button "Advanced"

- choose "Hardware"

- change "Configure" to "manually"

- change "MTU" from "Standard" to "custom"

- Try values from 1280 to<1500

For me it is still stable.

Thank you! Immediate "relief" from the problem that was making me (and Time Warner) insane.

done. thanks and I hope this will be better. Today before setting this MTU my connection was dropping every 30 seconds. And it's the same even connecting through a cable. I'll let you know. thanks

So did you change the MTU setting up or down? Mine is set at 1500 by default. Should I lower it?

POSSIBLE FIX:

I'm a certified Apple Consultant and this fix worked for me on a client's home network. I present it without any warranty/guarantee/promises, etc. Use at your own risk. Don't try this if you don't know what you're doing. Please infer any of the other usual legal ramblings.

Client had a Linksys E3000 with Cisco software. She had an Apple Store Genius upgrade her MacBook Pro from 10.6.8 to 10.7.3. Upgrade was uneventful.

When the client returned home, she noted that every time she put the computer to sleep, logged out or rebooted, one of two things could happen:

1) Her network could not be found and it did not automatically reconnect. She could only find it through looking for networks manually in the Network Preferences pane.

2) Network scanner located the network, but asked manually to join an already-known home network and requested the password every time.

She did not have the same problem on other networks. Only at home. Consequently the Genius Bar could not recreate the problem to help, and several calls to AppleCare failed to resolve the issue. Then, I got the call.

I imagine if you're reading this, you've also frustrated yourself with all the usual potential fixes: deleting System Confguration files, rebuilding the WiFi config, clearing PRAM, reparing permissions, changing the WiFi channel, etc.

I'm here to suggest the problem can only be addressed on the router side. Yes, I firmly believe this is a Lion issue, but nothing you do in Lion -- including reinstalling the OS -- will fix this problem if it happens to you.  So here's what I finally did:

1) Upgraded the router's firmware to the latest version.

This did NOT solve the problem.

2) Completely reset the modem to factory settings and reconfigured it.

This still did NOT solve the problem.

3) Completely reset the modem to factory settings, reconfigured it AND changed the WPA2 password.

THIS FIXED THE PROBLEM. I waited 5 days to post this to ensure that it was still functioning properly for the client. It is.

Here's the vague theory behind it: Something about the upgrade to Lion also corrupted her Keychain. I can't go into details, because it would take forever and I'm only partially sure I understand it myself, but suffice it to say that there were other Keychain-related issues. No matter how many times I rebuilt that WiFi configuration or messed with system files, it came back. Even deleting the Keychain items related to this network didn't take care of it (and honestly, one of the items reappeared immediately after quitting and relaunching Keychain Access. I saw it with my own weary eyes.)

Once the WPA2 password was changed on the router, it forced that router's profile to be re-saved to Keychain, and I think that made the difference.

I'd like to add that I feel strongly that it was a combination of things that finally fixed it. So I believe following the instructions below will solve the problem for many of you. Please report back here if it does work!  As you can see, many people are having this problem.

1) Delete the WiFi profile in Network Preferences.

2) For good measure, you may also want to delete the file /Library/Preferences/SystemConfiguration/com.apple.airport.preferences but I don't know if this going to be necessary.

3) Update the router's firmware to the latest version.

4) After it has been updated and restarted, Completely reset the router to factory settings and start the setup from scratch. DO NOT USE THE SAME WIRELESS PASSWORD AS BEFORE. This is the crucial part, I believe.

5) Recreate the WiFi profile on the computer, inputting the new password.

That's it.

Sorry for the long-winded note, but hopefully this helps a lot of people.

Lowering it to 1280 seems to work for me too. Yahoo!!!

http://support.apple.com/kb/DL1501 iMac fix gives us this popup:

Alert

This software is not supported on your system.

Mac OS X

Version 10.7.4

Processor 2.66 GHz Intel Core 2 Duo

Memory 4 GB 1067 MHz DDR3

BTW, our problem only started happening when we got a Clearwire receiver/router, and it is intermittent. Ours was happening w/ the MacBook Pro, but that has since stopped.

The intermittent problem continues to happen w/ the iMac when we start or when the machine goes to sleep and wakes up.

Another differentiator: this happens with wireless and hardwired connections alike (the iMac and receiver/router are colocated).

Thanks!

(1) Deleting a system preferences file called com.apple.aif.plist, then restarting the machine to rebuild it. This is inside Macintosh HD > Library > Preferences, which is now harder to find in Lion’s Finder because Apple has hidden your hard drive by default in the Sidebar’s list of Devices. You can use Finder’s Preferences to add Hard Drives back to the Sidebar, but based on our experiences, deleting this file doesn’t work to fix the problem.

(2) Reset your Mac’s PRAM and NVAM. This was suggested by an Apple Discussions user, and is explained in this Apple Knowledgebase document. Most reports do not suggest that this works.

(3) Reset your Mac’s System Management Controller Another suggestion from an Apple Discussions user, explained here. Again, most reports do not suggest that this works.

Based on past experiences in trying to fix major issues such as this one, we know that it’s rare that one solution works for everyone, and that readers often come up with great ideas for how to get things working again. We’re going to keep hunting for answers to this, and will update this article when we have one that works for us—did one of these ideas, or something else, work for you? Post in the comments section below.

Finally

- I reinstalled OSX Lion, problem still exists

- In my TimeMachine I switched on the 5-GHz WiFi and connect to that network.

Now my WiFi connection is stable. Strange because before this solution I was also not able to see other WiFi networks anymore.

It seems(?) that MY problem with the WiFi was on my iMac and i solved by changing something on the TimeMachine.

Weird but i'am happy