iMac 2011 - no wifi connection after sleep under Lion

Some problem here. It's really annoying. It's been going on for months. Either someone at Apple made a huge mistake they can't fix, or Apple makes so much money that it doesn't care about its customers because they are stuck in an Apple-ecosystem and they don't feel like they need to fix bugs. Sound like a Redmond-based company in 2001?

I have a very similar problem. I have a mid 2010 MacBook, (MacBook 7,1) and I'm yet to upgrade it to Lion, my sister has a MacBook Pro with Lion and i dont like the look of it. Anway, if i close my laptop and open it, it shows up with the connecting sign in the taskbar, and doesnt connect. I have to turn airport on and off and wait a while before using the internet otherwise it stops working again. I thought it was something to do with the settings because my settings randomly reset, but it wasnt. I think both these things have something to do with when my charger kept working on and off so i had to swap it with my sisters (it worked on hers).

I'm having the same sort of problems, only showed up after upgrading to Lion on my iMac 27" i7, not my older 17" MBP (both running 10.7.2). Any time I restart I have to manually reconnect to wifi. Very irritating, and apparently fairly common, looking at the length of this thread.

Well it appears that Lion 10.7.3 is at the beta stage so should be released soon. If it doesn't fix this wi-fi problem then my mac is going back for good.

Happy new year everyone 🙂

This problem recently started for me. While I have exprerience intermittent outtages before due to dropped Wi-Fi (while using it), lately it has gotten worse, and I've made no changes to my system or network (in fact I haven't used my iMac for a few weeks until now). Now it's having the wake-up issues with not being able to find my network.

I've used 3 different routers (two old ones and my new one) to see if they were the problems, they were not. They were a Linksys, Bufallo and now a D-Link. Wireless a/b/g/n. Every wireless device I have worked fine with them and never expericed a drop. So that leads me to believe it's either my iMac (mid-2011) or OSX Lion (I got the free upgrade).

Every time I put the iMac to sleep, I'll wake it up and it asks me to manually join a network, and it takes while to even find mine, even though the router is like 6 feet away from it -- and it's something I can replicate. Funny how it will always find networks outside my apartment first before it finds the one right next to it. Likely some programing errors on Apple's end for OSX.

I tried all of the fixes found here and around the web, nothing worked. I hope Apple is taking this seriously.

Resetting the SMC worked for me! I also had a 2011 MacBook Pro that was having some VERY frustrating wifi problems. After waking from sleep, it would autoconnect to the right network, I had full signal strength, but I would open my browser and it would tell me I was not connected. I even ran the network diagnostics which showed all green dots. The most frustrating part was this happened spontaneously, not immediately after downloading lion or any software updates, so I still don't know what caused it, but I just woke my computer from sleep and got online straight away!

Head to google to figure out how to restart the SMC, it's the only thing that worked for me, and I tried most of the fixes on this thread

I tried what John G suggested above (System Preferences > Network > WiFi > Advanced > TCP/IP tab: Configure IPv6 "Link-local only".) on my Mid-2011 21.5" iMac and this seems to have fixed the problem! Thanks!

If it starts up again, I'll let you guys know. I've been lurking this thread since I got my iMac (a few days after Lion was released) because of the issues. Thanks John and everyone for your suggestions!

tried both of those, no change. It still won't automatically look for networks, and when I prompt it to by clicking on the menubar icon, it finds my network but doesn't try to link to it. So I have to click on the icon to get it to search, wait for a bit so it can find my network, then click on the icon again and manually select the network. From there it works fine (remembers the password, etc), but it's still not a 'it just works' kind of situation.

I have also set the 'Configure IPv6 "Link-local only"' thing. No effect.

I, too, have tried most, if not all, of the fixes suggested to date in this forum with absolutely no success.

UPDATE: after letting my mid-2011 iMac go to sleep properly over night, I woke it up like I always do and it is still working. I have not lost Wi-Fi once since doing what is suggested below by John. I tried everything and that's the only solution that has worked. Sorry it's not working for some, but it did work for me (though I only have one network saved as this is an iMac, not MB).

Try this:

System Preferences > Network > WiFi > Advanced > TCP/IP tab: Configure IPv6 "Link-local only".

Hope you guys find a solution! I will be lurking to see.

I've been having the same problem since upgrading to Lion.

Found this on another forum thread and it worked (link-local, changing proxy settings, etc didn't)

Go to Network -> Advanced -> Wifi

Remove all preferred networks (hit the minus)

Reboot

Good luck!

I have a new imac that logs into my network but sends a card wifi not available and shows my neighbors networks after waking from sleep.

I went to: System Preferences>Network, and unchecked "Ask to Join New Net Works". Problem solved, this should work if you have your machine setup to login to your network. This was not really a problem, but merely a nuisance.

dale

this is the solution!

open finder and go to the folder, one by one (shift+cmd+G)

/Library/Preferences/SystemConfiguration and delete com.apple.airport.preferences.plist

/Library/Preferences/SystemConfiguration and delete preferences.plist

/Library/Preferences/SystemConfiguration and delete com.apple.nat.plist

/Library/Preferences/SystemConfiguration and delete NetworkInterfaces.plist

/Library/Preferences/SystemConfiguration/CaptiveNetworkSupport and delete Settings.plist

my iMac was reborn...

have a nice day

this is the solution!

open finder and go to the folder, one by one (shift+cmd+G)

/Library/Preferences/SystemConfiguration and deletecom.apple.airport.preferences.plist

/Library/Preferences/SystemConfiguration and delete preferences.plist

/Library/Preferences/SystemConfiguration and delete com.apple.nat.plist

/Library/Preferences/SystemConfiguration and delete NetworkInterfaces.plist

/Library/Preferences/SystemConfiguration/CaptiveNetworkSupport and deleteSettings.plist

my iMac was reborn...

have a nice day

You made my day!!!!! Is there a way I can kiss your butt?

Thanks a lot!!!!