Mountain Lion no Wifi after wake from sleep

I had this problem - but I also had an app called Printopia installed. I removed Printopia and that fixed the problem for me.

Post your system.log file contents around the time you see the drop and I can take a look to help you out.

Not sure how to post a file in here... unless you really want to see the whole raw text...

I have to say that I am losing hope that Apple will ever fix this issue - I have a 2010 Macbook Air which has suffered from this problem since the day I bought it.

Both Lion and now Mountain Lion have suffered from exactly the same issue - specifically when waking up from sleep, the wifi does not re-connect. I have to turn the WIFI on/of twice before it will finally re-connect - it is so frustrating and ruins an otherwise fantastic computing experience.

Apple are well aware of this problem because I have had a tech support call with an Apple expert in Germany who knew about it but could not fix the issue. I then had another Apple guy from the US collect a load of logs and info saying that he was tasked with contacting people experiencing this issue and collecting debug information for the developers - but this was well over a year ago now.

How can it take two years to fix such a fundamental problem like this - this is really beyond me? The whole point of the MacBook Air is that you should be able to open the lid and it wakes from sleep immediately and off you go surfing. This is being miss-sold because I have to wait several minutes whilst I manipulate my WIFI on/off several times to connect.

This seems to me to be something to do with the system not waking from sleep properly and hence the WIFI does not connect. I am in a flat so there are about 10 WIFI networks around me, but this should not be a problem - it certainly isn't for my other Apple devices and Windows devices. Another observation is that my router broadcasts A,B,G & N wireless Networks and I see the B/G network immediated in the WIFI list but it takes several refreshes of the list of networks before the N WiFi network appears - maybe this is why it does not connect immediately?

Please, please, please, if there is someone from Apple who can do something about this well known and common problem - please do something about it. This is completely ruinuing an otherwise fantastic MacBook Air user experience.

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I can only chime in and report that I am having the same problem that most posters here report. My Mac Mini upon waking from sleep periodically goes into the endless loop of searching for WIFI and the only way I can get my computer back to normal ops is to do a forced shutdown. I have tried everything recommended here to no avail and now have resorted to turning the WIFI off and using ethernet for internet which is clearly not satisfactory because I now cannot connect to my wireless printer, Apple TV, etc. I have multiple apple computers and iOS devices in my house but only this late model MAC Mini is having the problem. My macbook air, wife's mac mini and all of our iPads, iPhones etc can connect and operate flawlessly using WIFI. I have a third generation Apple Airport Extreme broadcasting. I went to the Genius and they expressed surprise that I was having the problem..don't these people get any briefing or information from Apple...does Apple not read these threads? There are over 350 posts just here!!! The genius guy ran some hardware routines but his only answer was to reinstall the sys software like I had not already tried that! This is frustrating. Wake Up Apple and fix this problem.

I'm still signed up to this thread, having posted previously. My situation started with downloading and installing ML. I also went through all the recommended possible "fixes" to little avail. In frustration, though many have stated that this is not a hardware issue, I replaced my older AEBS (bought at the beginning of 2006) with a new one. That was it for me; all my connectivity problems disappeared and I have had no problems since (more than several months now).

Please see my response to ken123....for what it's worth.

I have considered upgrading my Airport Extreme to the current (fifth) generation unit and will if I can't solve this annoying problem. It seems on the face of things that it is unlikely that my current 3rd generation extreme router is the problem because all the other devices in my house work fine.

Just curious, but is your macbook air and your wife's mac mini all running the same OS (ML, I presume?)?

Yes, all running latest Mountain Lion OS 10.8.2

That does defy explanation, doesn't it? In my case, my older AEBS was also responsible for dropping the connection on my son's Macbook Pro and even my wife's Toshiba pc running Windows XP. Was your Mac Mini, by any chance, furthest from your AEBS or in any other circumstance that could affect the strength of the signal? The other benefit for me of upgrading my AEBS was a much stronger signal at the outer perimeters of my house (back bedrooms, etc.).

Yes, it is furthest from AEBS plus it has a cordless phone close. i changed channels on the router to see if that would help. I use my MBAir in the same room as the mini so distance may not be a factor. Baffling....

Ok, so could there be a difference in the wifi/bluetooth board between that of your Mac Mini and your MB Air?

Ok I think I have finally solved this most frustrating of issues.

Basically a nearby router that my macbook can see is incorrectly configured with the wrong country code (or someone has imported a foreign router).

When the macbook wakes it looks for any wireless signal to understand what country it is in and then only listens on the wireless channels for the country detected.

I have about 10 wireless networks around me and one of them is set for Country "TW" - I am in Country Code "GB"

Most of the times the first network I see is the GB one and my laptop looks for my wireless network on the GB wireless channels and connects OK.

Sometimes, my laptop detects this rogue TW router first and only listens on wireless channels that are correct for TW - it hence can't see my wireless network as it is configured on channel 48 which is not part of the TW approved set of channels:

Here is a snippet from my syslog:

Nov 9 18:18:11 GarysMacBook kernel[0] <Debug>: en0: 802.11d country code set to 'TW'.

Nov 9 18:18:11 GarysMacBook kernel[0] <Debug>: en0: Supported channels 1 2 3 4 5 6 7 8 9 10 11 56 60 64 100 104 108 112 116 120 124 128 132 136 140 149 153 157 161 165

Hence, the options are find the neighbour with the rogue router and get it fixed/binned, or choose a channel that can be seen by both the rogue router country and your own country.

The GB channels are:

Nov 4 14:01:23 GarysMacBook kernel[0] <Debug>: en0: 802.11d country code set to 'GB'.

Nov 4 14:01:23 GarysMacBook kernel[0] <Debug>: en0: Supported channels 1 2 3 4 5 6 7 8 9 10 11 12 13 36 40 44 48 52 56 60 64 100 104 108 112 116 120 124 128 132 136 140

Unfortunately for me, my Netgear WNDR3700v2 (N600) router only allows me to chose channels 36, 40, 44 or 48 - None of which are visible if my laptop detects the country as TW !!!!

I need to find the neighbour with the rogue router, I guess...

Oh well, at least I know what causes the problem...

BTW - I could do with the forum thankyou points, so please be generous...

Rgds

Gary