Q: OSX Yosemite Wifi issues

Just posting my comment to make this clear to Apple that there is a problem. Having WiFi connectivity issue & constant drops on my mid-2012 (10,1) MacBookPro Retina. Reading the posts, this seems to be (at least one of) the affected configurations. Oddly, putting the Wireless Diagnostics in Monitor mode seems to keep the connection from dropping; ok, but can't send diagnostics.

Ditto. 2012 Macbook Pro wifi kept dropping after installing Yosemite. I tried many of the 'fixes' in this and other conversations but nothing improved. So, I went back to 10.9. Apple needs to fix this pronto. It's remarkable that they'd release Yosemite with a problem like this. Not very professional, and it's eaten up quite a bit of my time.

Same same here. MID 2012 Mac pro 13, I5. First off had to restart in safe mode and turn off wifi to complete install. Next rebooted no joy again had to reboot in safe mode and turn off wifi. WiFI works once i start but if I shut down with wifi on or restart with wifi on will not reboot gets stuck on apple logo with bar 1/2 full. APPLE you are ******* me off.

Thanks, this worked for me.

tried new location in Network Prefs, no joy.  Add me to the list of unhappy Yosemite users.  FIX THIS APPLE!!

restarted a 2nd time just to double check and let sleep...seems to work thus far.

The good folks at the Apple Helpline:

Open Finder > Choose Go From the menu at the top of the screen > Click on Computer > Double Click on Macintosh HD > Double Click on Library > Double Click on Preferences > Click once on the file called "SystemConfirguration" > CMD+DEL the file > Enter your password > restart.  https://discussions.apple.com/message/26907035

I'm having the same problems as everyone else. Have tried AC and N networks in the 5GHz and 2.4 GHz ranges. The really interesting thing is that the computer DOES get a wifi connection and can access anything on the local network fine. In fact, I'm typing this from my Late 2013 iMac, but have used Windows Remote Desktop to my Windows 7 server that has the ability to get to the internet. I can access a webserver on my network fine, my router fine, my fileserver fine.

I thought this had something to do with DNS resolution issues that ONLY come into play when trying to get out of the local network, so I tried adding Google's DNS servers to the Mac manually. That didn't fix anything. It is just strange that I can access the local network just fine, but nothing externally will resolve...

I've been trying to get this resolved for days. I finally found something that has worked. It's been at least 5 hours and I have not have any issues at all.

I found the solution on on Reddit post. Repairing the kext file permissions has absolutely fixed the issue. It's worth a try if nothing else has worked and it did for me.

http://tinyurl.com/o2oezmz

Here was the fix for me:  Click on open network preferences, click Advanced, click on TCP/IP, Next to Configure IPv6 change it to Link-local only.  It works beautifully now.

Joining in the list of unhappy upgraders. I have a 2010 Mac mini that sits right next to my mid-2012 MBP most of the time, the mini is rock solid and never drops, the MBP has to be reset all the time, ridiculous. Come on Apple, Steve wouldn't accept this kind of stuff!

Apple really ruined my life this time.. using only apple products for almost the past 10yrs, first my iphone ipad WIFI got killed after iOS 8, now my macs too.

baby is due soon, thanks apple for screwing up my life at this time, my biggest upgrade regret ever. SIGH.

Adding my name to the list - If this doesn't get resolved soon I'll roll back to Mavericks. This is my work machine and I can't afford to be spending every evening trying to fix and re-fix the wifi network that worked FINE on Mavericks.

So far, I've tried (briefly)

1) Nuking SystemConfiguration and rebooting

2) Zapping PRAM

3) Deleting my Wifi connections completely

4) Deleting the Wifi setup completely, reboot, rebuild under a new name "Wifi2"

        This option worked yesterday - but when I came home tonight I was back at square one

        This is not a viable long term solution - but maybe will point someone at Apple in the right direction

5) Turned off bluetooth, rebooted - no difference

6) Changed the access values for the wifi network in KeyChain Access - no dice

7) Changed my TCP-IP / Configure iPv6 to Link-local only - no luck

I'm out of ideas - and getting mad as **** about this.

The 2012 retina MBP works fine all-day at work connected to our Cisco wireless network. But, the minute I come home and connect to my Apple Airport Extreme, I'm toast.

I'm certainly not bothering with Yosemite on any of my home machines while this is happening.

Fix it Apple!!!

We must face it guys

Apple is slowly sinking...

The rush for cash is killing everything..

i have rMBP 15" late 2013.

Wifi is ok but tx rate is bad. I have around 130/150 mbps; my wifi is 802.11n (netgear 4000) @450mpbs.

Yosemite on macbook air 11 late 2011 is ok and wifi is @ 300 mbps (max for MBA).

With Mavericks my wifi was always @ 450 mbps (I'm very near to router). Restarting machine with usb and mavericks i have again 450mbps.

I think is a wifi's driver ...please FIX IT !!!

Well I just returned from a trip and had installed Yosemite since I had a fast internet connection. Upon returning home, all my other devices, iphone, ipad connect to the 2.4 Ghz wifi that was unchanged from before but my Macbook Pro with Yosemite refuses to accept the password which I know is correct since I reset it and the other devices work fine. However my router has both 2.4 Ghz and 5 Ghz and the 5 Ghz connects fine with the same password. Obviously some bug with Yosemite. Very disappointed with Apple. First the IOS 8 bugs and now this! Not a show stopper since I can use my 5 Ghz on the same network but it shouldn't be that way. I've tried many of the suggestions in here but none of them seem to work. I've reset the router and computer both but it will not connect to the 2.4 Ghz anymore.