Mountain lion wifi problems

I noticed today that AirPlay didn't work for more than 30 seconds on my 2007 MacBook Pro (trying it for the first time after installing ML). My 2010 Air, iPhone 4S, and iPad3 had no problem with AirPlay. I connected the 2007 MBP to my Airport Extreme with an Ethernet cable, and bingo the problem was immediately solved.

So I thought, oh, I must be part of this problem where a lot of people are having wi-fi connectivity issues with ML.

Called Apple, they had me boot in Safe Mode (hold down Shift while booting), which runs diagnostics and fixes like most of what runnuing Disk Utility would do, and now Airplay is fixed and working perfectly, just as it did before ML was installled.

tl;dr: solved wi-fi problem(s) by rebooting into Safe Mode and then rebooting.

(The next two steps would have been PRAM reset and then SAC reset.)

I changed my MTU to 1300 on the WiFi network and it solved my problem. Please try it and let us know if that solved it for you.

Go to System Preferences -> Network -> Advanced -> Hardware

check to Manually, MTU: 1300

4 hours later and problem returned. I feel burned.

The Apple specialist said, "Whenever there is an upgrade, 90% of user problems are because there was something wrong with their machines—it's not the OS update."

I took him at his words. What a fool I was.

I should have known when he told me he'd been doing his job for Apple for nine years. How many people in tech these days keep the same job at the same company for that long? It's just dumb.

I told him I'd in been in IT for 30 years; he just got more patronizing.

jfsiman, I will try your fix. Then PRAM and SAC reset.

Folks, just between us and the wall, I think it's an ML problem.

jfsim wrote:

>I changed my MTU to 1300 on the WiFi network and it solved my problem. Please try it and let us know if that solved it for you.

Nope, this didn't work. Nor did PRAM reset. Nor SAC reset. Nor making sure NONE of my other devices were set to any AirPlay Airport Express in my Loft.

Houston, we have a problem.

I'm calling Apple back.

Seems to be flash related issue at least in my case. My wlan freezes during flash video f.ex. ping on background or other pages stops working. And I have this problem only with my 2nd access point (TP-link) 😮.

Having same problem - called Apple and no fix worked - heading to the Apple Store with the desktop

this afternoon. Ethernet does not work for connection either. Can't reload and install ML cause can't get on the

net. Frustrating.

Tried getting rid of network and setting up anew, new location, renewing DCHP, and all the online fixes listed

above - nothing even comes close. New hard drive on this computer so know it is not that either. Hope APPLE comes

up with a solution - all the lap tops work just fine.

I am running into problems when my summer 2011 iMac wakes up. Even when it reconnects to the wifi signal, webpages will not load and get a DNS error. If I go through and renew the DNS and then use the connection assistant to reconnect I am able to get on the Internet again, but that is the only way. This problem is directly related to Mountain Lion as it only begain occuring once I applied the update.

I am having the same problem... None of these solutions are working on a vanilla 2010 iMac with ML and an airport express that feeds Internet fine to all other devices. It was working for several days but now (with no changes to computer) it has stopped, exactly as the others have described. Occasionally I can get a connection for 5-10 seconds by renewing dhcp lease but the IP address goes away shortly thereafter... Using my phone to post this. Never should have installed ML and will advise all clients not to. Argh.

Try updating firmware on your router - that was my problem. Needed two updates and then

everything worked on the wireless network, phone, ipad, lap tops, desktops and printer.

Apparently the tech in ML is more than the old router could handle in translation so was kicking me

off after 30 seconds. Did all the other suggestions and even called Apple but it was the router after

all that. Hope this helps.

After so much monitoring I have came to the conlcusion that it's a signal issue. I run a digital agency and have been using mac since 1984, I know them inside out. I am also the guine pig in the agency trying out first new things and have my own tech team working out solutions.

Boils down to:

The problem obvisouly is Mountain Lion and how it react to the signal of the Wi-fi.

Ethernet always works and most of the time I am on ethernet.

Using a USB dongle works well

Sometimes it connectes to wi-fi sometimes it doesn't. If I try to wi-fi first in my lounge (3mt from router) it does't work, then I walk to my bedroom and it connects, then go back to the lounge and it works and stays connected but then sometimes it drops out. There is really no explanation or reason I think it's how ML interprets the signal from the wi-fi.

The trick of renewing the DHCP doesnt always work, sometimes it does. If you delete the whole WI-WFi and re-create it sometimes it fixes it sometimes it doesnt. Again it's a bit of a russian roulette. But from my bedroom (6mt from rotuer + wall) it never drops out and always connects.

I found ways to position my mac so it works, so it's not an issue as much although Apple needs to fix it, so I am checking everyday when 1.8.1 is ready.

So I hope I am being helpful.

Mac is: MacBook Pro, 2.2 i7, 16GB Ram, 1TB Hardrive.

Mountain Lion was an upgrade although I normally would just do a clean install.

PR - Another issue I have with ML is that the Empty trash is Very Very and I mean Very slow. But this is another issue. All in all ML purrs quite well and better than Lion.

Upgraded to ML thus morning. Now, each time I wake my iMac from sleep, it fails to make a WiFi connection. Approaching the WiFi fan in the menu-bar causes the pointer to turn into the spinning beachball. I can open System Preferences, but trying to open the Network panel again causes the cursor to turn into the spinning beachball. The only way out of this, it seems, is to Restart (and this often first involves force quitting applications).

Sam issue - upgrade to Mountain Lion is the only change I made. I show connected to the Wi-fi network from which I am writing this post on my iPad, so clearly working. From my upgraded iMac on ML, anytime I launch a browser it attempts to load, but simply stays frozen during the load. If I go to command line and ping a site (as suggested earlier with ping www.apple.com)' I am successful at getting consistent responses with no packet loss. Therefore I clearly have a working Internet connection on my upgraded computer, but ML is not able to leverage it in my browser or any other web enabled application.

Apple, this is a major issue. Help!!!

UPDATE: I tried a great many of the suggestions listed in the forums to no avail, until I logged into my router (Netgear N750 dual-band) and upgraded the firmware. I then made sure that I was connected to the 5Ghz band, and my connection has now been back to normal for a full day so far, where until now it would freeze several times an hour. Even though the signal showed up strong the whole time, apparently the router's firmware didn't 'like' my ML install, and needed to be upgraded in order for the two to play nice.

Ok, for my particular issue I found a solution unrelated to the operating system. This may not impact everyone, but sharing since I was originally convinced the only issue was the new OS.

Right before upgrading, I moved my iMac to the first floor of my townhome, and the router is still on the 3rd floor. This worked fine for days, and I was still able to work fairly seamlessly on my non-upgraded macbook pro when my iMac stopped working on wireless. However, after doing a lot of troubleshooting I found that the signal strength on my AT&T provided 802.11g router was relatively weak at that distance, and there are A LOT of other routers that are likely 802.11g in close proximity that likely are causing interference. I carried my iMac upstairs again, and it instantly worked like a charm once it was close to the router.

Since I still want the computer downstairs, I purchased an Airport Extreme this morning and setup a dedicated 5ghz 802.11n network, and now I'm typing from my Mountain Lion iMac 2 floors away from my Airport Extreme, and everything is working seamlessly. While I would like to say this is wholly a hardware/interference issue, what I can't explain is why my non-upgraded macbook pro, iPads, and iPhones all work perfectly fine on the old 802.11g 2.4ghz network from the same place. All things being equal, it suggests that Mountain Lion makes browsers/applications more sensitive to poor wi-fi signals, since as I indicated before I did have some connectivity prior to upgrading the router since I was able to ping sites from the command site, but wasn't able to pull them up in a browser or use any web enabled applications. This also corresponds with an earlier post where I believe someone solved their issue by switching channels (maybe from 1 to 6, but not recalling at the moment): They likely had interference problems that weren't an issue under an earlier version of OS X, but was an issue under Mountain Lion.

Hopefully this solves the issue for me for the long term - good to luck to everyone else.