Q: Wifi Constantly Dropping in Lion

Hi everyone,

I am currently on a MacBook (Late 2009) and have run into the same issues. I recently discovered our Netgear DGN2000 (with Wi-Fi) was running in G mode, so I switched it up to 270Mbps mode which uses the 20Mhz-40Mhz spectrum. After making this switch, I found the WiFi constantly dropping in Lion.

After fiddling around for a while I have found some interesting things:

• Waking from sleep often does not help
• Unlocking the 'system' keychain in Keychain Access and reconnecting to Wi-Fi helps a little
• If you have an older Wi-Fi device (in my case an iPhone 3GS), your Mac won't like it. I have another Mac connected (Late 2008 MacBook) and it never drops out, nor do the other Windows 7 laptops.
  • The minute I turn on my phone's wifi and connect, guaranteed 2 mins of MacBook (Late 2009) connection and then kaput - it stops working :/
• Bluetooth can cause problems if a device is connected (like a mouse) before you connect to Wifi.

Also, my router uses the 2.4GHz spectrum to acheive Wireless-N via WPA2.

-AllSeeingMac

Just FYI....

Macs and iOS devices do not support HT40 in 2.4GHz. Nor will they ever. HT40 in 2.4GHz, while not a spec violation, can be a real ball buster to bluetooth devices and all of your neighbors who are using 2.4GHz. Remember, 2,4 has a whopping 3, non-overlapping channels. 1 6 and 11 (at least in the FCC zone). If you choose channel 1, 1 (HT 40) that means your router is sucking up channels 1 - 8 (approx). If you use channel 11, -1 (HT40) you are sucking down channels approx 3 to 11!

I do not believe the Mac devices and iOS devices support the HT40 intolerance bit.

If you must use a 2.4GHz router with Macs and iOS, just stick with HT20. If you really want HT40 speeds, then get yourself a nice Dual Band N router and do HT40 in 5GHz. Faster speeds, more channels and less interferance.

Disable HT40 in 2.4 Ghz mode. First play around with some channels when in 11n HT20 mode mode in 2.4 Ghz and see if you get a good connection. As Dr. Venture mentions, HT40 in 2.4 is a really bad idea. From what you describe 11g mode works fine. How old is your router ? Some older routers don't support 11n very well and cause interop. issues. Just a few things to check.

I have the same problem with intermittent wifi.

I can fix it temporarily by going through the "Diagnostics..." option located in the "Network" preference pane via the "Assist me..." button.  As you are stepped through the diagnostics procedure, you will be asked to select your Wi-Fi network. Once you select your diplayed wifi network and press continue, it starts working again in a few seconds. Unfortunately the problem comes back after a while.

I have EXACTLY the same problem and use the same resolution, i.e. "Diagnostics"  But, it's not fixing the isssue.  I've been working with Apple support since I upgraded to Lion and am still waiting.  The tech has captured data from my computer and referred the matter to the "engineers"... 3-4 weeks ago and nothing has come of it yet.  None of the proposed solutions I've seen here look to be promising.  It appears to me that the issue lies in the Atheros firmware for Airport Extreme.  Lion upgraded the firmware from 3.0 to 4.0 thereby creating the issue.  Some have gone thru some fixes to revert the firmware, but that really isn't the fix.  The 4.0 needs to be fixed.

i.e.,

Card Type:          AirPort Extreme  (0x168C, 0x8F)

  Firmware Version:          Atheros 9280: 4.0.58.4-P2P

nanochow and Sandpuppy,

One other thing to try is to see if a 'Renewing the DHCP' Lease fixes your issue. You can get to it from System prefs->Network->WiFi->Advanced->TCP/IP.

Check if that works for you. Have pings running to some address to verify your connection when you drop the connection and then get it working again by renewing the DHCP lease. That should verify if it worked.

eg: ping www.google.com

Same problem here,iMac`27 Mid-2010 with OS X 10.7.2.

The connection drops radomly,some times works without problems for hours,then starts to drop every minute.

To wifiguru:

It seems that the plist files are protected so I can't delete them. Can I change the filemode somehow?

Launch Terminal and enter

cd /Library/Preferences/SystemConfiguration/

Then Enter

sudo rm *.*

to delete all the plist files. Remember this cleans up your entire Preferred Network list and any stored AirPort preferences.

Reboot your machine and join the network again.

This kinda offers a clean start to WiFi on your machine. The only other place that has some remnants of previous network passwords etc. is in your keychain.

This worked great. Now it reconnects to wifi automatically, like it used to before Lion. Thanks!

And also to Thomas_Hinna:

This really isn't a solution.  Mine automatically reconnects after a delay of varing periods, even if I do nothing. But before Lion, it just didn't drop at all.  My iPad, iPhone 4, old Powerbook G4, my wife's older iMac, iPhone 3G and iPad2 never drop.  If it were this simple, I suspect Apple tech would tell us.  I went through deleting plists, etc. and it didn't resolve the issue.

Well, we seem to be e few hundred in this thread, but then again, there are many threads like this. I wonder how long we will have to play around with useless plist deletions before one or two out of the thousands of Apple engineers - whose salaries we kinda pay - take responsability and act.

Got the follwing from R_2 at another posting.  I tried it and it works great so far.  No dropouts now for two consecutive days, whereas before I was losing connection around 5 to 10 times a day.

"update your lion to 10.7.1 and do these:

1)reset smc

2)reset pram

it works well for me.i've never suffer from the wifi problem since then!"

Could one, or some of you who are not tech challenged as I am update the possible solutions to this problem?  I had just switched from PC to Mac in August and had no wi-fi problems--that I noticed--until the iOS 5 update this month. Now am dropping wi-fi like crazy. It will reconnect fairly easily, but is very frequent. Have reported this and several other bugs to Apple, hoping every drop counts...Anyway I have the same symptoms of losing connection on both new Macbook Pro and 27" iMac. I MUST use Verizon mi-fi as my connection at home, no router, just the hot spot unit,  mine is made by Novatel. I had been blaming the drops on Verizon since they upped my rural area to 4G a few weeks before the iPhone 4S came out. Have not looked yet, and will post on a different thread, but is anyone also having problems with frozen screensaver and/or waking from sleep mode?? Please list possible corrections for wi-fi connection drops as at over 54 pages in this thread since August, I am lost as to what should be attempted after the 10.7.2 update was downloaded on both computers and need detailed instruction if possible, reset smc and pram are over my Macnewbie head without further step by step.

Thanks

Since your new, you are covered by Apple Care.  Call and raise ****.  I called the techs back in early September and the issue was then referred to the "engineers"  I also wrote to the tech blog at the Washington Post and David Pogue at the NYT.  I'm still waiting for a resolution.  Many of the suggestions here are over my head and mostly seem to be workarounds to are not really solutions.  This is definitely a problem with Lion even with two upgrades. It's a **** shame that Apple won't pay more attention to those of us experiencing this problem.  I want to say the issue is with the Atheros firmware for Airport Extreme.  But, I'm not a techie either so I can't be sure.