Mountain lion wifi problems

I have the same exact issue. 😟

Please help. I tried everything. I found these but to no avail. still cant connect.

Fix #1: Add a New Network Location & Renew DHCP

This may work best for those who upgraded from a previous version of OS X to Mountain Lion but if you’re having the wifi drop issue go ahead and do it anyway because it is consistently successful with addressing wireless issues:

• Open System Preferences from the  Apple menu and choose “Network”
• Pull down the “Location” menu and choose “Edit Locations…”
• Click the [+] button to add a new location, name it whatever you want then click Done
• Back at the “Network” screen, click the “Network Name” menu and join the wireless network

Your wireless connection may now be active and working fine, but renew the DHCP lease anyway:

• From the Network panel, click on the “Advanced” button in the lower right corner, then click the “TCP/IP” tab
• Make sure “Configure IPv4:” is set to “Using DHCP” and then click the “Renew DHCP Lease” button, click “Apply” when prompted
• The appropriate DHCP settings should be renewed from the connected router, click “OK” and exit out of System Prefs

The network location and DHCP renewal tip resolved similar wifi problems in Lion, and it seems to work in Mountain Lion too for many users.

Fix #2: Change MTU Size to Prevent Dropped Connections

This is a bit geeky but bare with us: MTU stands for Maximum Transmission Unit and controls the largest packet size allowed for transmission over the network. If this setting is greater than network capacity, the computer will experience packet loss and dropped connections. The default setting of 1500 is somewhat aggressive and some networks reject packets of that size, but it turns out that 1453 is just small enough to maintain a consistent connection with most networks but just large enough to not cause any slowdowns, it’s the magic number and an old cisco networking secret.

• Open System Preferences from the  Apple menu and select “Network”
• Click the “Advanced” button in the lower corner, followed by the “Hardware” tab
• Pull down the “Configure” menu and set to “Manually”
• Change “MTU” to “Custom” and set the field to “1453″

• Click “OK” and close out of Network preferences

Be sure you’re joined on a wireless network, close out of System Preferences, and enjoy the internet as usual.

Interesting.

You can connected via Wi-Fi to your router but Safari reports you have no internet connection.

First lets see if your dns entries are good.

Open a terminal and try to ping apple like this:

ping www.apple.com

Let the ping command run a few times then hit control c to stop the pings.

Do the pings go through to www.apple.com or are you getting timeouts? Also, copy and paste the output from the terminal to this thread.

If you are getting pings to go through, can you run this command in terminal:

scutil -r www.apple.com

And then paste the output here of the above command.

Let's start here.

Tried the same things with the same results - none. The fact that everyone else (non-upgraded) on the exact same network I am on is still fine and surfing smoothly while the only thing I did was to upgrade to 10.8 without adjusting anything else puts egg on my face as well as putting me in hot water with my employer as I cannot get things done! Angry and frustrated at Apple right now for releasing something that was NOT ready.

-----------------------------------------------------

17" MBP 2011, 2.4Ghz i7, 8GB Ram

To repeat my most important findings:

• Fresh install of OS X 10.8.2 on an iMac 27", 2011, Intel Core i7 3.4 GHz, 8 GB RAM
• From the very beginning NO WiFi connection at all (even from the "Install OS X" "boot menu")
• Router: FritzBox 7340, personal WPA2, 801.11 n/g, 2.4 GHz, manual channel selection (channel 4)
• When running OS X 10.8.2: Connection to my router fails, self-assigned IP address 169.x.x.x ("invalid address")
• Re-newing DHCP lease, deleting PRAM (when booting), setting MTU to 1453 (other than default 1500), re-starting the router, changing channel to "auto" etc. did not help
• Wi-Fi diagnosis comfirms (not unexpected) that network settings could not have been established (hint: press Option key while clicking on WiFi symbol in menu bar above right)
• Changing my router to use the 5 GHz band (801.11 n/a) DOES WORK! (I did not test the reliability of the connection extensively, though)
• When using 2.4 GHz: the "WiFi info" (Option key + WiFi symbol in menu bar) says: RSSI: -40, Send rate: 0, MCS-Index: 0 whereas
• When using 5 GHz: the "WiFi info" says: RSSI: -40, Send rate: 300, MCS-Index: 15
• Bluetooth is enabled (as to make use of the Apple Bluetooth mouse)
• Running Ubuntu 12.04 from a DVD on the very same machine and the same "non-working" router settings (2.4 GHz) does work, even with Bluetooth enabled (which I read that it might interfere with other devices in the 2.4 GHz band - which does not seem to be the case here) - connection is properly re-established after wakeup from sleep (standby).
• The successful test with Ubuntu on the same machine also shows that a) the hardware is not faulty and b) the router settings do work (in fact: every other device is able to connect - funnily even another MacBook Pro 11" 2010 with OS X 10.8.2 - but the later went through an upgrade from 10.6 to 10.7 to 10.8 - and even on 10.8 connection is shaky, especially when transferring large files in the order of Gigabytes
• During all Wi-Fi tests Ethernet cable was physically disconnected
• Ethernet connection is also very shaky: it completely drops after some usage time (sometimes even after minutes), most observable while transfering large files (in the middle thereof). A reboot then restores the connection, or it seems that after hours (during the night) the connection is also somehow restored - renewing the DHCP lease not not help in these cases, re-connecting the cable does also not help (it might or might not be related to the WiFi issues we're discussing, and I'd like to keep that discussion elsewhere)

The fact that Wi-Fi does work on my MacBook Pro 2010 probably means that the issue is hardware dependent, or it might also be that some "settings", still enabled from Snow Leopard (or Lion) times, make it work.

However I remember right after upgrading to OS X 10.8.0 the connection initially also did not work at all, but at that time I could work around that my "dropping" the connection (removing it from the "remembered connections" list) and re-establishing it (by re-entering the password etc.). I think a renewal of the IP address (as assigned from my provider) inside the router settings did also a trick.

However all this does not help with my current iMac 2011. And I should not be doing all this mess in the first place, since all other devices (most notably my older iMac 27" 2008 running Snow Leopard) adapt to all router setting changes (changing from 2.4 GHz to 5 GHz, changing channels, changing from WPA to WPA2 etc.) without the need of ANY manual intervention (as expected) - they simply see that the WiFi network is gone, they see it again with different settings - and they cope with it (except the iPhone 3GS and 4, off course, which do not support 5 GHz).

So hints like "you have to renew the DHCP lease, delete the PRAM, disable Bluetooth, change the MTU to any value below the standard 1500, drop the connection, restart the router etc. etc." might make OS X 10.8 seem to work (or trigger something which correctly initialises the connection or whatever) - but they are simply crude hacks which should not be necessary in any case!

An yes, I will provide all my findings to Apple, and so should you: http://www.apple.com/feedback/

davidgrantaustin wrote:

Basically, it seems that Mountain Lion (upon coming out of a sleep state) looks at the "service order" list and attempts to connect using the first thing in that list. In this case, the default order is: 1.) Bluetooth DUN, 2.) Firewire, 3.) Ethernet, 4.) WiFi.

To be honest, from a probability standpoint of consumer usage, I would quite confidently say, that list is almost inverse.

The Service Order list is by user choice, you can change it: (see below)

In System Preferences>Network.

If you'll look back at my previous posts in this thread you'll see my setup, and I'm now happy to say, I recently solved the wifi dropping problem, but not with any idea I found on this thread. In the end, I got the IT department at our company to isolate the issue and the only thing that worked was to replace the access point (router) with a different unit from a different manufacturer. Even after running the latest firmware update on the router it still did not function correctly.

I have a brand new MacBook Pro running OS10.8.2 that works fine on my home router (Airport Extreme) and would work on several other routers with no problem, but the one at work would disconnect me anytime I tried to backup a large file to the cloud or download a bigger file. This happened every 10 minutes or sometimes even more.

The airport card in my laptop was checked at the Genius bar...it was operating perfect. They could not figure it out so I tried everything listed here including a clean install....none of it worked! The bottom line was that the router at work would not function dependably with Mountain Lion. The IT guys who handle thousands of computers (PC's & Macs) at the studio said they have not been able to solve it with Mountain Lion except by exchanging the router with a different brand. They have followed this thread, too and tried many ideas listed here!!

This is ridiculous, and Apple's lack of response is what angers me the most, but I'm happy it finally works and its really fast as well. Last thought, even when the old router would work for a few minutes it was never able to reach these speeds which also confirms it was not relating well to Mountain Lion's handling of the connection.

See results attached:

Mountain lion wifi problems = My Solution

All I did was turn all routers wifi off.... After one min turn it on again and rescan wifi on the macbooks Working again...

Did this with the Air and the Pro

Both had issues now all solved

Good luck!

Russ

Tried almost every solution and finally the solution that Bob Allison posted above is the best and seems to work so far without any issues:

Bob Allison SW Suburban Boston Area

The solution to this is usually very simple (or has been for all machines I have dealt with).

Go to Network Preferences then in the lower left click the service 'wheel' icon.

Select set service order and drag your WiFi to the top of the list. Click OK then Apply.

The one thing i did after this is restarted my Mac.

I too am exhausted by this problem, but in addition to posting here, please take the two minutes to send Apple a feedback post!!

EVERYONE NEEDS TO DO THIS NOW TO GET THEIR A** IN GEAR!!!

http://www.apple.com/feedback/macosx.html

It's not only wifi that has the problem, changed to network cable and still have problems. i can connect to the router, every other machine on the home network can connect without any problems but not so the mountain lion crap. I hope everyone has given feedback. Do you know if your are really fed up you can just click the back button and send it again and again and again. How many can you send !

http://www.apple.com/feedback/macosx.html

Hi folks,

I am writing this message on an Ubuntu 12.04 system - on the VERY same iMac 27" 2011 hardware which reliably fails me to even get a valid WiFi connection running under a FRESHLY installed Mountain Lion 10.8.2!

Here are my findings so far:

I got this iMac from a colleague and the harddisk was formatted. The iMac was then booted (from the "rescue partition", I guess) until the option menu "Install new Mountain Lion" (or so, can't remember) appeared.

EVEN AT THAT POINT I could not connect to my WiFi Router, a FritzBox 7340 (not uncommon brand, at least here in Europe), so I went on via Ethernet cable and made a FRESH INSTALL of latest Mountain Lion 10.8.2.

After installing a few applications from Apple Store and also applying the latest updates (yes, there were still some updates pending, such as iTunes 11, RAW compatibility, ... nothing ground-breaking however) I tried the WiFi connection: still did not work! The "connection bar" had an exclamation mark ⚠, but turned into a "full reception bar" later on (in fact, my new 27" is located in the very same room currently as the router, not too close to the router however, about 2.5 metres).

It turns out that the DHCP lease does not work, my machine always (self-)assings an address of 169.x.x.x ("invalid address").

My router settings at this point:

* 801.11 n+g

* Band: 2.4 GHz, manual channel selection (channel 4, with least noise from other networks)

* WPA2 (only, no WPA support), private password key

Off course I also tried "Automatic channel selection" in the router settings, re-started the router, dropped the WiFi connection in Mountain Lion, tried re-newing the DHCP lease, rebooted the iMac several times, to no avail!

BUT THE FOLLOWING WORKED!

* 801.11 n+a (or so, not sure, but the crucial point is...)

* Band: 5 GHz

At those settings the iMac 27" 2011 is perfectly able to connect to my router!

Now since every other device, including a MacBook 11" 2010 running Mountain Lion 10.8.2 as well (1), an older 2008 iMac running Snow Leopard, an iPhone 3GS, 4 and an iPad 3 (all latest iOS) etc. connects perfectly with the 2.4 GHz settings, this must be a software driver issue on Mountain Lion! Especially since when running Ubuntu 12.04 on that VERY SAME HARDWARE the connection with the VERY SAME ROUTER SETTINGS (2.4 GHz, WPA2, ...) DOES work! Go figure!

I even tried putting Ubuntu into "standby" (sleep) mode. And guess what, after waking up a "notification" message was there saying that the WiFi had been disconnected, the WiFi connection bars immediatelly started blinking ("scanning")... and the connection was succesfully RE-ESTABLISHED!

So currently I am running my iMac/Mountain Lion with Ethernet cable, BUT EVEN THERE CONNECTION drops after a few hours of work (I am encoding DVDs currently...). No DHCP renewal seems to work, the connection stays dead, and the network status says either "invalid address" (169.x.x.x) or even "unknown status" (go figure!). A reboot then re-establishes the Ethernet connection. Or maybe when you wait another (couple of) hours - this morning my iMac did have a valid connection again, after it was dropped yesterday evening.

First I thought that Ethernet disconnect was related to "sleep" mode (which I now turned off for the time being), but yesterday the Ethernet connection was interrupted "right before my eyes", while I was updating/downloading another application! Bang!

SO THERE IS DEFINITIVELY SOMETHING VERY FISHY going on with network connections in general in Mountain Lion! It might be that changing the MTU settings or who knows what may make Mountaion Lion work (for a while), but given the FACT that EVERY other device is able to cope with my router settings - INCLUDING the iMac 27" itself running Ubuntu (so no hardware issue either!) - is a clear indication that the FAULT IS (still) WITHIN MOUNTAIN LION 10.8.2!

So I urge everyone to send feedback to Apple here: http://www.apple.com/feedback/

I will also try to re-send some more information ("it does work on Ubuntu", my "5 GHz finding", router settings....) to Apple.

(1) but the MacBook Pro went from 10.6 to 10.7 to 10.8, so there could be those "crucial settings" left which make it work there - or it simply is a different network card and 10.8 works "by chance" there. However connection speed is rather slow, especially when transferring large files connection drops evey 5 seconds to a few KBytes/sec - but different story).

till213,

That's good info. I was starting to suspect the same thing with respect to the frequency band in use. For the record, I have a MacBook Pro that worked fine with Snow Leopard and Lion, but now fails miserably after the Mt. Lion upgrade. I also just bought a *NEW* iMac for my kids for Christmas and it's suffering the exact same problems. When I ordered the iMac, I also got a new Time Capsule for backup and was using the 5 GHz signal for a while and things seemed to work better. I wasn't sure whether that was my imagination or not. Good to have that confirmed. I might try some more tests to see if that works. Unfortunately, my wife's PC laptop is limited to 2.4 GHz, I think (802.11g/n, not a/n).

Note that I don't think this is a hardware issue at all. My MacBook Pro hardware was working great until the upgrade.

kx2, I don't see any issues with wired networking. I'm typing this right now while connected to an Ethernet cable string across my office and I don't see any drops.

And again, if you start a ping command in a terminal window, just pinging your local router's IP, your wireless will continue to work. That's the only workaround I have encountered. Network activity seems to keep it from experiencing the problem.

BTW, based on my experience trying to fix this and the fact that the brand spankin' new iMac has the exact same problem, I don't think this is a configuration or upgrade problem. This has to be a driver problem, as till213 says, which means we need to force Apple to deal with it and get a patch released.

So I urge everyone to send feedback to Apple here: http://www.apple.com/feedback/

@lara: Interesting: so - in some combinations - limiting the WiFi network to 801.11 g also seems to work.

Be aware however that you limit your entire WiFi network - all devices in your household connected to that router - to 54 MBit/sec, whereas with 801.11 n you get up to 450 MBit/sec (when your router has 3 distinct antennas - I think recent iMacs and probably even MacBook (Pros) support 450 MBit/sec).

(The above numers are theoretical numbers, off course, but even the net bandwidth is reduced considerably when refraining to the 'g' standard)!

So what you have is a crude "workaround", which might just do fine in practise for you, but if you have many devices - like me - connected to that WiFi network, then this would be a terrible drawback!

Or in other words: that definitively is a bug somewhere in OS X when your OS X 10.8 device cannot connect (reliably!) with the 'n' standard (or any defined and officially supported standard, for that matter).

For details about all these standards and supported bandwidth https://en.wikipedia.org/wiki/IEEE_802.11#802.11g is a good starting point. Also note that the next standard, 'ac' is already lingering in front of our door (first routers runnning the "draft" of this upcoming standard are already available since several months). That standard supports up to 1300 MBit/sec, closing in to Gigabit Ethernet 🙂 But I am drifting off somewhat...

Still, Lara, so I'd recommend you also send in feedback to Apple, using https://www.apple.com/feedback/, and tell Apple that your machine/OS X 10.8 is not able to connect to an industry standard router, using 801.11 n on the 2.4 GHz. The more data Apple has available - and the more "pressure" - the more likely and quicker it becomes that the may be able to fix it.

I mean, it's not like they never had it running before...(Snow Leopard hooooray!)

Cheers

In reply to my own post 😊

Just been clicking around this site and tried something I hadn't tried already and my one outstanding issue now appears to be fixed!!! who would have thought something so simple??! 😮

By doing the step below my wifi popped back on in the network area of system preferences!! Additionally I can now see 2.4ghz homehub, BTwifi & btwifiw ith FON all available to me on the top right of mac (airport triangle icon) !!!

https://discussions.apple.com/thread/4766477?answerId=21109692022#21109692022

"Your computer is showing it's connected to the Wifi router all right, but perhaps the router isn't connected to the Internet.

If your connecting the Ethernet cable directly to the modem and resetting it, bypassing th erouter and then getting online, fine that's good.

If your connecting to the router directly and getting on the Internet fine, it means the router is connected to the Internet.

If the last one is true then likely what has occured is your DCHP lease is expired because your computer doesn't have the right time and date as the router, it's showing a good signal but your not connecting.

Open System Preference and check the date and time and set it to update to Apple's time server for your location.

Sometimes Apple's time is off, as third party routers get their time elsewhere and sometimes the two don't match and thus DCHP lease is expired."

Okay Eeryone, I am not so sure why this discussion is going on so long.

People in Feb. are redisovering a solution given back in Nov.

It seems new issues/symptoms are being injected into this thread so it is hard to find the solutions.

I am suggestiong new threads get opened for any issues different from the OP.

The solution was verified by a few after it was posted.

The key is put WiFi and Ethernet as # and #2 in the list. Ethernet then WiFi may work too (unverified)

Make sure both bluetooths are low in the list or deleted.

Re: Mountain lion wifi problems