Lion - Wi-Fi doesn't automatically reconnect when reawakening after sleep

I'll try the ping test when I next have the issue. More to follow....

As far as my recent visit to the Apple store...the short version of the story is after 6 or more sleep/wake cycles we were able to get the MBP to fail once (darn...did it alot more often at home with a Netgear and AirPort Extreme). After a considerable amount of poking around and the Guiness Bar guy researching web sites that "regular" people are not supposed to know about....he confided in me that he was escalating the issue to Apple Engineering for review and comment.

OH...FYI...APple Stores do NOT use Apple made WiFi routers...no...they use CISCO routers.

The guy at the store compared this issue to a problem that the original iPad's had where they were VERY sensitive to certain versions of routers...he said it took them a couple of weeks and they fixed it.

Sorry everybody....

I am hacing thje exact same problem on my Mac Pro. This happened first when I simply updated from Snow Leopard and now from a fresh install of Lion. I am confident there is a bug in Lion. Apple staff will always say they know nothing of it. i am sure when 10.7.1 or 10.7.2 comes out they will fix it.

All this PRAM, SMC etc is a load of crap. I have been using Macs now for 5 years and they have had issues and neither of them were fixed with that rubbish. This may have been a big thing in the day with Power PC maybe but I am yet to see anything like this fix a problem with the Intel Macs. I may be wrong though but that is my opinion.

I had this exact same problem with my 11" Macbook Air.

I was told to do the following, which fixed it for me.

Go to System Preferences

Then Network

Select the "Location" drop down menu

Click "Edit Locations".

Add a New Location. Call it anything you like.

That seemed to do it for me.

Mixed results...tried that...actually deleted all previous entries and added a new one. Did not 100% correct the problem.

Also tried deleting all the network associated PLIST files and the reboot to allow the computer to rebbuild the loibraries...again, mixed result but not 100% corrected.

I have the same problem. However, it only occurs at home. When I use the wifi at work, it wakes and reconnects on its own.

How much do you want to bet that the problem is linked to the performance if some routers? Apple stores use Cisco routers and I'll bet your office does as well. I have a Netgear and Apple Airport Extreme at home and I see the issue several times a day. During a recent visit to my local Apple store a techie indicated that the original iPad had a similar issue. It's more of an annoyance now that I know how to work around it.

well...10.7.1 didn't fix it....still waiting for a fix..........

I had the same problem with a "family" of machines (2 older imacs, a macbook pro, and a macmini); just fixed them all with the process below; guess they were all having the same problem. Can't guarantee it is the same issue that many of you are having.

I went into System Preferences>Network>WiFi>Advanced.

I deleted all of my "Preferred Networks" by highlighting them and clicking on the "-".

Clicked on "Apply" before leaving the Network settings.

Restarted the machine.

Selected my home network.

Now they all work just fine. Go to sleep, wake up, reconnect automatically.

I noticed that prior to deleting my home network, the "Preferred Networks" window listed the network as having no security. Now it shows (accurately) that I am using WPA/WPA2 Personal.

Hope this helps somebody; sure improved my day.

+1 for deleting the preferred networks. Worked for me! Thanks!

I'm gonna try it and I'll advise this thread but I'm honestly not overly optimistic.

Please stand by....LOL

Deleting the prefered networks in System Preferences did it for me. It seems like the reconnecting issue is related to Keychain access. Before deleting the prefered networks i manualy deleted all entries for my Wifi networks in Keychain Access. Did not help at all. When entering my wifi i was asked for password every time. Only when unchecking the Save password option i could connect. The entries was not added to Keychain if I checked the save password option.

Now when I enter a new network and check Save password it creates a new entry in Keychan. As it should be.

Maybe the is no Wifi issue at all, but a Keychain issue instead...

Interesting situation for me...

After waking I do not have the problem every time (after deleting & re-adding the networks). When I do have a problem I found that if I refresh the page...the connection appears to work and I can browse just fine.

The connection is NOT working consistently however as proven by my email not automatically downloading any new mail.

I'm sorry but I expected more from Apple on this one....

carlfromtucson's solution is working for me. Thank you!

One thing I had to do, though, was change my security from WEP to WPA Personal.

I have the problem too but like you said, it does not happen all the time. My impression is, the problem appears if my Mac goes to sleep when the TimeMachine is in the middle of doing a backup. Any other people here have seen this related to TimeMachine ?

Hi there,

so I confirm in my case this is definitely linked to the MobileMe sync. Whenever my Mac doesn't want to reconnect to Wifi, I just kill the FileSyncAgent process and this fixes the problem. I have the bug on both my MB Air and my iMac 27'', same behavior on both machines

Hope this helps