Q: Lion WiFi Connection Problem

Sorry Lupunus, it is Lion. I will wholly agree it is not the machines involved. When one simply removes Lion and reverts to SL (for those who can, those who get stuck with Lion from the get go are out of luck probably) and the problem is gone there is only one anwser. To claim otherwise is purely ignorant.

I have three machines in my house that connect to WiFi, an iPad, an iMac (2009 i5), and a Dell Laptop from work. Guess which one and only which one has a problem regardless of router, proximitiy to the router, or day of the week, phase of the moon, rain or shine?  The iMac but only when Lion is installed. Worse, this is the best part, bootcamp to 7 and it never loses its connection. Hilarious fun.

Now what I need to do is see if the Parallels instance loses its connection when the OS X does. I haven't tried that but I am going to do so next. Lion has a bug in it, what it is no one seems to know.

FWIW, I recently swapped out to a shiny new Air Port Extreme, guess which machine still has random issues with the network?  The Lion iMac. Lion, should be known as OS X / Vista

hormelmeatcompany wrote:

 

Lupunus,

 

OS X includes drivers for hardware. If Snow Leopard's drivers worked and Lion's did not, the problem is essentially with that version of OS X. Saying it's not the OS but the drivers when in fact, the 2 come together, is really just semantics.

First, your contribution is very interesting and leads to some new conclusions. Thanks for that.

In written communication semantics is essential as a sender of a message did not have the normal communication control mechanism like facial expression, gestures and sound of the voice to proof the receivers understanding.

Also on such a difficult field as computers (which mostly contains physics, math and "trillions" of configuration scripts) semantics is crucial.

Nevertheless, as well as I use in conversation with colleagues the "Lion seems to haven a wireless problem" term too, all participants in such a discussion know the meaning and understand this as "Lions wifi stack seems to have... "

Here at the forum's it's more complicated as it is a mixed audience of "normal" computer users and technician's looking on a issue and "talk" about.

Enough on semantic, back to the issue now.

hormelmeatcompany wrote:

 

If drivers were the root cause,

Unfortunately it's difficult to compare e.g. the firmware version due to the fact that there are different "numbers" on the versions depending on the country of the participants here. Although the firmware functions in general are identical, for instance USA, Europe and Japan have different regulations on wireless; e.g. number of channel's.

To use a bit semantics. (sorry) The firmware in question is the "driver" of the wifi chipset and is also a kernel extension (kext) get load into the operating systems kernel (systems core) on runtime if the wifi get switched ON.

On that (firsthand) it's generally independent of the used OS X version. (see later descr.)

On this your idea of swapping the kext files for testing is a interesting one in the way of troubleshoot. But! What you not swapped where the additional configuration files which controls the actual settings of the "driver" before it get load.

That makes me think about something....

Let's first concentrate on the Broadcom and 2011 MB side of the issue to simplify it a bit.

As the 2011 used Chipset is the same regardless of SL and Lion the "driver" have to be basically the same.

Looking over the rim of the plate let us see, that SL users with 2011 MacBook's are also affected by the WiFi issue. (As I was too)

They blame in their respectively threads about the issue the 2011 hardware; e.g. "never had that with my old MBPro and SL".

So where are the differences on chipset respectively Lion / SL in the handling of WiFi?

Did a bit research as I've some spare time today 'cause it's my home office day.

Found only one major difference between Lion and SL matching the WiFi handling question. Airdrop.

Additional findings where:

• The actual wifi chipset firmware (aka driver) enables the "Airdrop" functionality on the chipset although the Airdrop function is not active (available) in Snow Leopard due to different settings in the controlling configuration file(s)
• Aside of Lion, Airdrop requires as well that all Airdrop using systems are member of the domain "local"

leads to ->

• Having two different domains in a network segment causes name resolution (DNS) trouble.
• Name resolution trouble may cause unwanted network traffic and timeout's and therefore disassociation of clients.

Had a case couple of day's ago with a UK based "My Mac drops network all the time".
Working resolution there was: The guy got a new BT DSL/wifi box which have (not changeable) the local domain "home" fixed. Changing on the Mac the domain from "local" to "home" solves the wireless trouble. To proof the solution I scanned some UK-forum's and found similar reports about the fixed "home" domain on that boxes and that changing (mostly Windows machines involved) Windows default set domain "workgroup" to "home" does the trick.

This will under certain circumstances also explain the wireless trouble in mixed networks or with some router's some users of 2011 Mac's reports as "WiFi drops / bad connection with my new 2011 MB-MBPro-Air".

Eventually also, the used BC-Chipset gets along the activation of Airdrop ability more sensitive on interferences (this cause bad packets) in the wireless stream due to security reasons when password free computer to computer connection for Airdrop.

But that is at now only speculation.

Hope that's a brick more in the wall on sorting out the different wireless problems with 2011 Mac's and/or Lion wireless trouble.

Lupunus

laechleviel wrote:

Of course it can be that "behind the scenes" the problems are not caused by mistakes in Lion but by something which works different (but correct) in Lion

As each case is unique even it looks similar from outside one have to sort out, which portion of the causes and solutions matches the personal case.

Thats the biggest part of the solution finding in the wireless hustle.

At now, we have new suspect's in the interrogation room .

Names are: Airdrop and local.

See posting above.

Peace - Lupunus

This could help to some of you as an interim solution until Apple will come up with a fix.

It seems that drivers for Atheros (Qualcomm) based WiFi cards does have some issue. As a workaround I have downgraded the driver delivered with Lion to the driver deliver with SL.

https://discussions.apple.com/message/16246971#16246971

and more in details here

http://www.ilounge.com/index.php/backstage/comments/os-x-lion-serious-wi-fi-disc onnect-problems-for-macs-and-solutions/

Cheers,

N.

nonix1 wrote:

It seems that drivers for Atheros (Qualcomm) based WiFi cards does have some issue.

Nonix1,

did not see or blinded out the term Atheros in your post over there. Sorry for that.

Well, I've seen a lot of posts about iMac and WiFi problems and I think iMac's are equipped with Atheros wifi chips.

I'd also heard (read) some rumor about driver issues with 2011 Atheros chipsets from the Linux world. As Linux is alike Mac OS X a unixoid system the reasons of wireless issues could be similar and the basic drivers (firmware) will also be similar.

Aside of driver issues or Atheros, the other link you provide to ilounge has also some interesting information, matching to some working solutions found on different Lion / 2011 Mac's / wireless issues.

As are:

Based on testing, we get the impression that the issues stem (at least in part) from some mismatched or messed up settings saved by the Mac relating to specific wireless networks it has connected to before.

Especially the following hints from iLounge where working for some people, regardeless of the chipset manufacturer:

#1 - After changing the passwords on both of our wireless networks, then setting the iMac up with the new passwords, the disconnect issue appeared to go away.

#2 - going into Network Preferences, turning off Wi-Fi, deleting the Wi-Fi service, deleting the Automatic location, using the + button to create Wi-Fi again, and then rejoining the network. Also, under the settings gear icon, choosing Set Service Order and moving Wi-Fi upwards.

These steps cause basically the same in the preferences as a new preference file for the connection get generated. #2 is a bit more rude and create even more new preference files.

It does basically the same, as some hints around here which are suggesting to delete the networks with problems from the "known networks list" - set up a new location and rejoin the network from there. Additional some had to delete the remaining keys from keychain as well before having the solution work for them.

It matches also a bit to a contribution, where someone had the idea, that upgrading to Lion mix up the new configuration files with (re)-imported ones from the private settings of the former OS - X Snow Leopard.

Seems that there are a lot of possible causes and solutions, even if the problem looks at firsthand similar.

Cheers - Lupunus

Message was edited by: lupunus - Oups wrong mouse-click -- was not finnished.

I have an iMac experimenting the WiFi dropping issue from time to time since my upgrade to Lion (with SL no problem).

So I subscribe to this forum and this specific thread, to find some help.  Some proposed solutions , involved a change of settings of the ISP box and other very technical settings.

I am not willing to change the settings of my ISP router, because all my other devices (iPad, iPhone , Windows Laptop, MBPro, TV, PS3 are connecting perfectly).

So I decided to wait Apple to fix the issue. I've surfed other forum on the subject and I found this comment on the site of MacGeneration

D'après nos premiers tests, OS X 10.7.2 règle tout ou partie des problèmes WiFi de Lion, sur Mac portables (testé sur un MacBook Air et un MacBook 2010) et de bureau (testé sur un Mac mini 2011). Les premières builds de la 10.7.2 ne réglaient rien, mais la dernière version, à laquelle les développeurs ont accès, a fait d'énormes progrès.
Bref, cette 10.7.2 devrait régler les problèmes de WiFi de Lion. Et ce n'est pas trop tôt, ces problèmes étant récurrents à chaque mise à jour majeure d'OS X depuis Tiger.

Ok it is in French, here is a tentative translation:

Based on our initial tests, OS X 10.7.2 fix all or most of the WiFi problems Lion on Mac laptops (tested on a MacBook Air and MacBook 2010) and desktop (tested on a Mac mini 2011). The first builds of 10.7.2 did not solve anything, but the latest version, to which developers have access, has made a tremendous progress.

In short, this version should solve the problems 10.7.2 WiFi Lion. And it's about time as these problems are recurring with every major release of OS X since Tiger.

So I will wait the 10.7.2 release, and in the meantime , on my iMac, I just reconnect manually the Wi-Fi from the bar menu when the connection drops.

THIS IS GOOD NEWS!!!

Thanks for posting this!

Let`s hope their statements are right...

Some new Information from Apple's hotline an a resume of the previous findings.

First the news.

Apple phone support told, that some network files can get corrupted over time and should be deleted occasionally, especially if you have installed a new operating environment like Lion.

For that, switch OFF the wireless on the machine you want to tweak.

Delete from the system files:

    * preferences.plist

    * Networkinterfaces.plist

    * com.apple.network.identification.plist

    * com.apple.airport.preferences.plist

    * (and any associated files like above that had ".orig" at the end)

Eventually you should also delete all related entry's from Keychain Access

Reboot and join the network again.

Nevertheless, there could be also different reasons for the problems one experience. For that a resume about the major issues....

In most cases, people blame on firsthand the obvious because they are mostly, by lack of knowledge, not able to see the coherence in a complicated infrastructure as wireless and networking is.

That's pretty normal and o.k. as well as a car driver mostly not have to have any knowledge about the regulations and functions of the fuel injection system.

I've discovered on many troubleshoots around wireless problems regardless of Apple, Linux or Windows, that (except a single reason became valid) in most cases it's a mix of minor issues what leads to major problems; e.g. constantly stream drop out, lousy speed, 3 stations work well but one wont, WiFi drop when a smart phone connects, up to total loss of the WiFi connection.

Although it's sometimes a rough job to find the reasons behind the trouble in networks it's always a fine idea first to eliminate all known or discoverable possible reasons.

What comes out so far?

1. Corrupted or damaged configuration files on client.
2. Different domains in the local network
3. General radio problems in WiFi. Based on disturbance from interferences, obstacles in or reflections of the radio beam
4. Mismatched settings on the network participants
5. Problems with the 802.11b/g/n compatibility mode
6. Hardware fault's or buggy drivers / firmware

...and of course there could be a lot more reasons.

On this I'll follow the numbering above and will also add a short description about possible reasons or a example in a not so technical manner for better understanding.

One may check, which possible solution or combination of solutions may best fit the own problematic.

#1 -> Corrupted or damaged configuration files on client.

Possible reasons: Time, Updates, Upgrades, accidentally power loss on running system and nearly countless more.

Solution: See entry of this post.

Alternative solution:

For those are a bit frightened to delete complete system configuration files. In many cases this "short version" will do the trick too.

    * Switch OFF wifi on the affected machine.

    * Delete all affected networks from the "known networks" list in System Settings

    * Delete all keys pointing to these networks from Keychain Access

    * Reboot

    * Join network again.

#2 -> Different domains in the local network environment.

Description: In a network segment (your home network) all systems have to be member of the same local domain. This allows a clear name resolution (DNS) in the net. Most systems have a default set local domain name in the network configuration to ease joining a network with systems of the same bread.

Windows systems have by default set a own local domain like e.g. "workgroup" (depending on version or localisation). Mac's have by default set the local domain name as "local". Some Routers have by default set one of these, none or a different local domain name; e.g. in UK some BT-DSL/WiFi boxes provide "home" for the local domain name.

Reasons: If there different domains in the same segment (your network), name resolution trouble is programmed and that leads to unwanted network traffic, packet collisions and could at last force stations to disassociate from the network or get disassociated by access point (router) due to time out, bad or wrong response.

User experience: Slow and sluggish network, WiFi or iTunes/Video stream drop, lousy data transfer speed or being unable to open different Internet sites in the browser. Also observations like: My Windows box work well in my wireless but my Mac wont. At the office all is perfect but at home...

Solution: Configure ALL stations (clients) in your network to use the same local domain name, regardless of which name you choose. Eventually set up a second location (profile) for the particular network.

Attention!

If you want to use Apples new child "Airdrop" you must use "local" as the domain name, as Airdrop refuses to work with other local domains or with stations using not "local" for domain name.

#3 -> General radio problems in wireless networks based on disturbance from interferences, obstacles in or reflections of the radio beam

Description: The radio beams of a wireless are not Roentgen X-Ray based and therefore obstacles, interferences from other wireless systems or reflections of the radio beam could cause major disturbance of the wireless network and based on this, the data stream in the network.

Possible reasons:

• Obstacles like Walls, magnetic fields from live high voltage lines, antenna cable or insufficient shielded speaker systems. Metal frames or plating, furniture, bundled water pipes, dry construction plaster walls*, Humans* and much more.
• Interferences from other radio equipment like Bluetooth, cordless phones, neighborhood WiFi, cordless speakers, cordless doorbells, intercoms, ptt units, baby phone's, surveillance and alarm systems, commercial weather radar, some military equipment and so on.

*) Water is a big bar for radio. Plastered dry construction walls and Humans contain a lot of water.

One of the named possible reasons or any combination can cause major annoyance due to unwanted network traffic or packet collisions and could at last force stations to disassociate from the network or get disassociated by access point (router) due to time out or signal loss.

User experience: Heavy fading signal strength, slow and sluggish wireless connection iTunes/Video stream drop, lousy data transfer speed, total connection loss or only time relating disturbances here and there.

Solutions:

Placement of transmitter. Not flat at the wall. Not in a corner, not on the floor, not behind a furniture, not near of other radio sources e.g. cordless phones. Not near of anything that can reflect radio beams. Best: as high as possible; e.g. Airport Extreme mount on ceiling. Maximum possible line of sight to all stations respectively corners of the home.

Placement of stations: see above and below.

Placement of yourself: If possible not between your Mac' antenna(s) and the transmitter.

Radio interferences: Check that the channel you use have at least a 5 channel gap to the two strongest wireless networks around. If possible use the recommended overlapping free channels for your country for best performance. On 2.4GHz networks -> for US-1,6,11 and for Europe 1,5,9,13. If possible swap to 5GHz 802.11n only and force the stations supporting this to use only 5GHz. Disable 802,11a/b/g wireless if possible. Place cordless phone stations as far away from the router (access point) as possible. Eventually disable all radio transmitting equipment in the house. If the wireless then work better, enable one at the time to see which is the disturbing one. Don't forget leaking microwave ovens. A running faulty microwave may drown your complete wireless network at once and your neighbors WiFi too.

#4 -> Mismatched settings on the network participants.

Description: Self describing.

Reasons: New equipment in the network, differences between home and office/work settings.

Solution: Check and change to match. Eventually establish a second location (profile) in System Settings on that.

Remember: Contrary to marketing and promotion, Networking NEVER was easy Plug&Play and at least for the next few years it wont.

#5 -> Problems with the 802.11b/g/n compatibility mode.

Modern WiFi bases pretend to integrate every protocol regardless of age or used hardware in the connected stations. Pretty good idea from the viewpoint of a marketing department. Unfortunately. it could cause major problems in real wireless networks because mixing stone age 802.11a, cable LAN and lightning fast 802.11n 5GHz in the same network is a big challenge. Any minor disturbance in such a constellation may lead to major trouble. Aside from the fact, that the slowest participant in a network dictate the pace, some router's and client's chipsets have problems with that "compatibility mode".

Solution: If ever possible try to force your network on one (fastest) protocol only. If you need 802.11g (iPhone, iPod touch) try to fix your infrastructure on 802.11g 2.4GHz and 802.11n 5GHz or 2.4GHz only with the loss of the possible 5GHz speed.

#6 -> Hardware fault's or buggy drivers / firmware

What's to say? Give a bug report to Apple, wait for a fix with the next update or hope that your system is still under warranty. Eventually roll back to previous OS version or firmware.

Addendum for Airport Extreme or Time Capsule users.

If possible deactivate the "Guest Network". It constantly switches between 2.4GHz and 5GHz band for a maximum of user convenience. Unfortunately this may cause trouble if other disturbances are also in the wireless.

That's for now....

Happy networking - Lupunus

I totally agree with Shivetya. I'm not ready to change the settings of my Wi-Fi network because ALL my other devices are connecting perfectly, the only one is iMac with Lion 10.7.1

I did not revert to SL, because the issue could be solve manually when it occurs , which is about 10 time a day (I'm working with my iMac 3 hours a day).  Each time my WiFi connection drops, I reconnect through the "WiFi icon" in the upper menu bar on the right. I know it is annoying procedure but still bearable for me.

I'm waiting the Lion released 10.7.2 , which I hope will solve the issue. If not, I will go back to SL.

Same problem here - the only help i've got is check your fully updated and make sure Lion hasn't changed any settings. Mine was sorted after that.

aberges wrote:

 

I totally agree with Shivetya. I'm not ready to change the settings of my Wi-Fi network because ALL my other devices are connecting perfectly, the only one is iMac with Lion 10.7.1

On this there where two possible reasons for your iMac's problem left.

1) All other devices are Windows systems. If so, change the local domain of the iMac to match the settings of the Windows machines.

2) The iMac was upgraded to Lion, or if it was a clean install and personal data and settings was restored from a backup, configuration files where mixed up or got corrupted.

If #2 is valid read the following:

Apple phone support told, that some network files can get corrupted over time and should be deleted occasionally, especially if you have installed a new operating environment like Lion.

For that, switch OFF the wireless on the iMac

Delete from the system files:

    * preferences.plist

    * Networkinterfaces.plist

    * com.apple.network.identification.plist

    * com.apple.airport.preferences.plist

    * (and any associated files like above that had ".orig" at the end, if exists on your machine.)

Reboot and join the network again.

Alternatively you may wait a few weeks for 10.7.2 and hope for the best.

Lupunus

This was one of the tips I got from Apple`s support-hotline and it worked for some hours only in my case...

The funny thing is that these files existed when I updated to Lion (which I did first). Now after a clean installation of Lion I cant find them in the library any more...

laechleviel wrote:

Now after a clean installation of Lion I cant find them in the library any more...

Thats really strange.

Normally that files (preferences.plist, Networkinterfaces.plist, com.apple.network.identification.plist, com.apple.airport.preferences.plist) get recreated on reboot because the settings have to be stored somewhere.

Lupunus

These files can be found in following directory:

--> Library --> Preferences --> SystemConfiguration

I have seen on another thread the advice to delete systemconfiguration

I looked for this but could not find it, I went to library/preferences but couldn't find

Systemconfiguration.

Is this a fix?

Thanks

Ben