Fixing OS X Yosemite Wi-Fi issues

“You may have seen or heard the growing disquiet about Yosemite and Wi-Fi. Like me, you may even be affected,” Paul Ducklin reports for Naked Security. “No-one seems to know what’s wrong, and without a scientific explanation it’s hard to know where to lay the blame.”

“Yosemite itself could have introduced a bug; or your hardware might be affected by a reliability problem that simply didn’t show up before; or some third-party software might be revealing a latent flaw,” Ducklin reports. “The symptoms are varied, but the most commonly reported problem is pretty much what I’ve experienced since first rebooting into OS X 10.10 and going online wirelessly. Your network works fine for a while, typically between about 30 seconds and five minutes, and then fairly abruptly begins to suffer almost total traffic loss. The network shows up as active, and low-level packets such as PINGs can be sent and received as normal. But traffic such as UDP and TCP just doesn’t get through. So you can’t use DNS.”

“We’re not going to blame Yosemite yet, but we are turning to the Naked Security community for fixes, workarounds or even bodges,” Ducklin reports. “What’s your bodge?”

Read more in the full article here.

MacDailyNews Take: This is not a new issue. It also happened with OS X Mavericks. We had this problem on one of our Macs running OS X Yosemite and fixed it the way we always have, by resetting the SMC (System Management Controller).

We don’t know precisely why this works, only that it has worked for us in multiple cases of wonky Wi-Fi with iMacs and MacBook Airs running OS X Mavericks and OS X Yosemite.

Resetting the System Management Controller (SMC)

Resetting the SMC on portables with built-in batteries:
1. Shut down the computer.
2. Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.
3. On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
4. Release all the keys and the power button at the same time.
5. Press the power button to turn on the computer.

Resetting the SMC on Mac portables with a battery you can remove:
1. Shut down the computer.
2. Disconnect the MagSafe power adapter from the computer, if it’s connected.
3. Remove the battery.
4. Press and hold the power button for 5 seconds.
5. Release the power button.
6. Reconnect the battery and MagSafe power adapter.
7. Press the power button to turn on the computer.

Resetting the SMC for Mac Pro, Intel-based iMac, Intel-based Mac mini, or Intel-based Xserve:
1. Shut down the computer.
2. Unplug the computer’s power cord.
3. Wait fifteen seconds.
4. Attach the computer’s power cord.
5. Wait five seconds, then press the power button to turn on the computer.

Note: Resetting the SMC does not reset, or otherwise change, the contents of PRAM, which is also known as NVRAM on Intel-based Macs.

[Thanks to MacDailyNews Reader “Ritt Padd” for the heads up.]

25 Comments

    1. Resetting the SMC alone worked for us. No PRAM reset was required.

      Resetting PRAM can change some system settings and preferences. If you reset your PRAM, you’ll have to use System Preferences to restore your settings (designated startup disk, display resolution, speaker volume, etc.).

    1. I wonder what would happen if I tried.

      Maybe all my extensions (in Firefox) would conflict and I’d end up having to turn half of them off, then half of the half and half of that half, until there’s none left and it doesn’t work, anyway.

      Speaking of voodoo, does Apple sell a SCSI-to-lightning adapter?

  1. I’ve been using Yosemite since beta and know for a fact that the OS is not the cause of this issue. Also resetting your locations in the network control panel by adding a new one can also fix weird connectivity issues. Once you have set your new location and tested that it works typically you can then switch back to the previous one which is usually automatic and then that one will reset and typically work for you again.

      1. Same issue with my MBPro 13″ mid 2012, still dropping wifi after the SMC reset. Also tried erasing the wifi in prefered networks and connecting again, it doesn’t work for me.

  2. My problem is Safari just suddenly stops loading any pages with Yosemite. It does come back after a few minutes. I thought it was Verizon FIOS.
    Thanks MDN for the info. I’ll try MDN’s fix. And yes Jim, I also turned Bluetooth on when I installed Yosemite.

  3. I’m having no problems with Yosemite. If anything, WiFi connectivity seems faster and less funky. Little Snitch is showing a lot fewer background packets going back and forth. This may be because I’m not yet back to my usual 50-ish Safari tabs open.

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