Q: Lion WiFi Connection Problem

OuweEgberts

I connect my iMac 2011 Lion to a 2T TC, which is an Airport Extreme with 2T disk, nothing special. Created separate 2.4 GHz and 5 GHz networks, and in Network prefs, Wifi, Advanced, let the iMac connect to 5 GHz first. Security WPA2 only. Never had any dropout, and my AVM Fritz!Box from the ISP still does not work together. Tip: AExtremes are cheaper refurbished in the shop. I also use Airport Expresses at 5 GHz: perfect.

If this is the good file, I am afraid there is nothing on terminal  screen, just the time of last loggin.

I am now firm: drops in wifi are much more frequents since the update and it is really getting annoying to be interrupted all the time.

I rechange MTU form automatic to manual  1450, not sure what its correspond to

I am basic in mac and not able to follow on on all discussions, I need simple fix if ever it could be done....

jeroen184 wrote:

 

OuweEgberts

I connect my iMac 2011 Lion to a 2T TC, which is an Airport Extreme with 2T disk, nothing special. Created separate 2.4 GHz and 5 GHz networks, and in Network prefs, Wifi, Advanced, let the iMac connect to 5 GHz first. Security WPA2 only. Never had any dropout, and my AVM Fritz!Box from the ISP still does not work together. Tip: AExtremes are cheaper refurbished in the shop. I also use Airport Expresses at 5 GHz: perfect.

There seems to be several Friz!Box users on this forum who have had better results when using a different brand router.  That's an interesting data point.  I don't know anything about that company, because I am in the US where we use Netgear, Linksys, D-Link and Apple as the prominate venders of network gear.  Online information for some of the AVM models doesn't reveal anything "bad" in general.  So, it could be more about noise on 2.4ghz and your replacement Time Capsule provided 5ghz that solved your problems.

snipjo wrote:

 

If this is the good file, I am afraid there is nothing on terminal  screen, just the time of last loggin.

I am now firm: drops in wifi are much more frequents since the update and it is really getting annoying to be interrupted all the time.

I rechange MTU form automatic to manual  1450, not sure what its correspond to

 

I am basic in mac and not able to follow on on all discussions, I need simple fix if ever it could be done....

I've been reluctant to post something like the following, but it just seems more and more necessary to try and help people understand that this is not a simple issue, and that your belief that only Apple could be at fault is perhaps not well founded.  Since there continue to be these kinds of statements on this forum, I'm going to post some information which hopefully by volume and complexity will illustrate just what is happening under the covers.

There are 7 layers of functionality in the ISO networking stack.

Below, I've described some of the things which happen across the

entire network stack.  This is by no means all-inclusive, but

provides some details of the types of things which happen under

the covers.

At layer 1 is your hardware layer such as ethernet, or WiFi.  This

is the "hose" between devices.  The Ethernet MAC address is used

to control where packets go at this layer.  The Address Resolution

Protocol (ARP) is used at this layer, to ask all devices on the

physical network (LAN not WAN), which MAC address is associated

with a particular IP Address.  All equipment talking to other

equipment on the same Ethernet "segment" will use ARP to see how

it should address a packet to send it to a local device.  If you

have a wirelessly connected shared disk, printer or other similar

local device, your computer will use ARP to find the MAC address

of that device when it needs to send packets to it.  When your

device is setup to use the Dynamic Host Configuration Protocol

(DHCP), it sends out a broadcast packet at layer 1, asking for

someone to provide it some configuration for Layer 2, so that it

can have a IP network address, a default route, DNS servers etc.

At layer 2 are protocls like IP (Internet Protocol) which provides

address based packet routing.  IP adddresses, in concert with domain

name services (DNS), "virtualizes" communications between devices

by allowing domain names to be associated with IP addresses so that

computers can talk to each other using well known names.  The only

network layer validation that occurs here, is that the "header" of

IP datagrams (packets of data), is checksummed, so that when it is

received, the from address and the to address and the layer three

protocol number and other header fields can be validated.  Packets

that don't checksum correctly are just dropped on the floor.  Higher

level protocols are responsibile for fixing problems with unreceived

packets by using some appropriate mechanism.

Certain events at layer 2 can result in advisory error messages

being sent between machines.  There are packets sent using the

Internet Control Message Protocol (ICMP) that say things like "slow

down, I'm dropping packets".  The User Datagram Protocol (UDP)

operates at this level.  It is used to send "single packet" data

between systems, and eliminates the overhead of TCP at layer 3, but

can't guarentee delivery.  An application using layer 2 itself must

implement some of the strategies of layer 3 in order to provide

some guarentees to the data it is passing.  Many real-time applications

such as gaming, audio/video streaming etc use layer 2 in preference

to layer 3 so that the user doesn't end up with a "back log" of

data to process anytime that there is a delay in the network or

equipment.  For audio and video this can create some cut ups in the

data, but when you are receiving data, you are always up to date/on

time.

Also at Layer 2, there are broadcast (to all devices on the network),

multi-cast (to all devices listening for particular broadcast types)

and routing and network control packets used to do all kinds of

things.

At Layer 3 are protocols such as TCP (Transmission Control Protocol)

which provides guarantees of packet flow. Sequence numbers make it

clear which packets have arrived, and in what order they should be

strung together.  IP can send packets of data down different network

paths if Routing specifies/requires such, and this can cause some

IP packets to arrive out of order.  So, TCP fixes that and provides

a "stream" of data on the remote end, that is checksummed and ordered

to be 100% correct.  So, for TCP delivered data, if it arrives it

is correct.  The extra bit of information that TCP has, is the "port" number. 

The port number really means "a particular application's address".

That is to say, the computer has an address, and then each application

or "hose" between applications on different computers has a port number

that designates which "hose" is which.

At layer 4, we get to the first part of the application layer that

uses all the layers below.  So, your HTTP connection to a web page

has to have all the previously described details, functioning,

completely before it will work.

So, when you turn on your computer, there first has to be "pipe"

between your computer and your router.  For WiFi, there is an

exchange of radio tranismission which allow your computer to first

see that a router is on.  Next, based on your configuration, it

will pick a router to talk to, and then authenticate as needed.

Finally, there is now a functioning hose for data to go across, so

the DHCP client application, seeing a functioning "hose" will send

out a DHCP request at layer 1.

The DHCP request will hopefully arrive at the router, but do the

fact that it's at layer 1, there are no guarentees.  So, if a DHCP

reply is not received after the appropriate timeout, the DHCP request

will be retried, over and over, until a reply is received.  If you

have tons of interfering wireless communications around you, this

DHCP request and reply might be delayed for some time, if it can

ever complete.

Once DHCP succeeds in getting an IP address and other information,

then layer 2 and layer 3 will become active, and the operating

system will allow network connections (called sockets by most

developers) with those protocols needed, to be created.

The original TCP/IP networking stack was developed as a U.S.  Military

research project at U.C. Berkley using the Berkely Standard

Distribution (BSD UNIX) of the original AT&T UNIX Operating system

which was licensed out to universities for study.

After the mid 1980's, everyone derived their own implementations

of TCP/IP from that source, so many operated with similar behaviors

to error handling early in that adoption, but over time everything

has diverged as operating system vendors have had to fix performance

issues, bugs and add features for things that only they do.  There

are now lots of implementations with completely different sets of

bugs and behaviors.

Some operating systems will handle particular errors in different

ways.  So, this "Apple WiFi problem" (we don't know what the problem

actually is), could well be a problem with a router, which other

operating systems handle okay, but which Apple can't deal with,

because that routers bug is not supposed to be acceptable behavior.

There are some important things about "error codes" and these various

layers and how applications use the layers.  There error message, at

from TCP, of "Connection Refused", means that the remote host, reported

that there was no such port (or hose) available/active there.

The important thing here is that services such as DNS can use TCP

to take a hostname, and look up its IP address using a TCP connection.

If error messages and state are not tracked, an application reporting

"Connection refused", could be indicating that it could not use DNS

services, rather than reporting that the service on the other end,

such as an HTTP server is not working.

So, when debugging DHCP functionality, using IP addresses instead

of host names can eliminate DNS failures from the "puzzle" and let

you focus on just seeing whether the network is functioning correctly.

This discussion should help you understand how many different ways

your networking could have problems which are related to something

related to the "hose", or on the other end of the hose that your

computer uses to get to your router.

Hi gphonei,

The AVM Fritz is a high quality and fully customizable modem/router/WLAN. For the WLAN part between modem and iMac, I used the same setup as the TC, that is: in settings, so also in 5 GHz exclusively etc etc, same results, problem exists with AVM, not TC.

The only difference is the entire implementation in the modem by Apple and AVM, which is complex. I was lucky to have the TC for backup purposes, while the modem is supplied by the ISP, and just ethernetted the two together. I hate it, but buying a simple Apple AP Express may solve a lot of people's problem. You have to weigh between the time to solve the issue if possible, the distance to lay a cable, or the money to by an AP Express. Tip again: refurbished ones.

--

Anyone,

Next to my iMac with Lion/Wifi problems, I also am on an 11'' Air:

Software Versions:

  CoreWLAN:    2.1.2 (212.2)

  CoreWLANKit:    1.0.3 (103.2)

  Menu Extra:    7.1 (710.1)

  configd plug-in:    7.2.1 (721.3)

  System Profiler:    7.0 (700.3)

  IO80211 Family:    4.2 (420.3)

  WiFi Diagnostics:    1.0.2 (102)

  AirPort Utility:    6.1 (610.31)

  Interfaces:

en0:

  Card Type:    AirPort Extreme  (0x14E4, 0xE9)

  Firmware Version:    Broadcom BCM43xx 1.0 (5.106.198.4.20)

  MAC Address:    10:40:f3:7c:2c:20

  Locale:    ETSI

  Country Code:    AT

  Supported PHY Modes:    802.11 a/b/g/n

  Supported Channels:    1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 36, 40, 44, 48, 52, 56, 60, 64, 100, 104, 108, 112, 116, 120, 124, 128, 132, 136, 140

  Wake On Wireless:    Supported

  AirDrop:    Supported

  Status:    Off  [On purpose, are on cable now, Jeroen]

This Air was a Dutch (NL) model, while the Airport Extreme card Country Code is AT which is Austria.

Question: can different country codes have any influence, like using channels allowed in the one country but not in the other? I was explained that some overlap exists between channels and they could perhaps connect, but with failures, such as our Wifi problem.

Just speculating by the layman, but any ideas?

jeroen184 wrote:

 

...

 

This Air was a Dutch (NL) model, while the Airport Extreme card Country Code is AT which is Austria.

 

Question: can different country codes have any influence, like using channels allowed in the one country but not in the other? I was explained that some overlap exists between channels and they could perhaps connect, but with failures, such as our Wifi problem.

 

Just speculating by the layman, but any ideas?

http://en.wikipedia.org/wiki/List_of_WLAN_channels has some discussion about different areas of the world, and lists of frequencies.  I don't know if this is correct information or not, but may provide some insight into this issue.

the only success and not permananet at that i have had is to change my dlink DIR 628 router from allowing WPA and WPA2 to just WPA2

that keeps the IP address held for about 15-20 minutes

2.4ghz router

auto channel select

i tried the other solutions like deleting wifi connection and starting over

didn't work

tried changing channel and that didn't work

uh oh.... seems it is getting worse even with the WPA2 only

just had a IP address released and renewed event

shoudl i be waiting for another tim cook apology letter?

No, it would prove a distraction from the success of their latest iPhone ..... Hmmmmm wait a minute i think you may have something there.

kulyk wrote:

 

the only success and not permananet at that i have had is to change my dlink DIR 628 router from allowing WPA and WPA2 to just WPA2

 

that keeps the IP address held for about 15-20 minutes

 

2.4ghz router

auto channel select

 

i tried the other solutions like deleting wifi connection and starting over

didn't work

 

tried changing channel and that didn't work

 

uh oh.... seems it is getting worse even with the WPA2 only

 

just had a IP address released and renewed event

 

shoudl i be waiting for another tim cook apology letter?

Check the time interval that a lease is allowed to persist in your router, what does it say there? 

Did you try just WPA?

Do you see your WiFi bars go to grey on the airport icon, or do the stay black, even though you can't connect?

You say that you see an address release/renew event, are you using some monitoring software, or one Apple's diagnostics tools or debug logging and 'tailing' the log file?

I don't know anything about the DIR 628, but see that the latest model is dual band, so it seems if you have a 2.4ghz version, it is an older router/version.  Is there any uninstalled firmware updates available to install?

I have have been hesitant to post this as I don’t want to jinx my greatly improved wifi connection and also because I really don’t know what I did to improve it (or if in fact the improvement is only temporary).  My original problem started shortly after upgrading to Lion.  Up until then,  I didn’t pay much attention to my wifi connection.  It just always seemed to be there - I guess I took it for granted just as I have all of the other seamless operations of my iMac.  Since switching from  a PC about 4 years ago, my computing has generally  been smooth sailing.  After upgrading to Lion (mainly because of mobilme),  I started to notice that my wifi seemed to take a long time to “hook up” after booting up or when it came out of the sleep mode.  I didn’t pay much attention until I installed 10.7.4.  After that, I had the same symptoms, plus my wifi started to drop out periodically when in use.  I started to read postings from this and other wifi connection forums, and tried many of the “fixes” suggested, but nothing seemed to help, so I “upgraded” to 10.7.5, and then the problem got worse.  My wifi went away entirely, replaced by a message that I had “no hardware installed” when I would click on the wifi icon.  I ran an ethernet cable downstairs to my router and started to search for an answer on these forums.  I ended up reinstalling 10.7.4 from my back up disk and managed to get my wifi back, complete with all the old problems.  Again,  I scoured the postings about wifi problems, and tried many of the solutions.  Here are some of the things that I did ( at least the ones I can remember):

Set my netgear router to 802.11g

Set channel from “auto” to channel 6

Set configure IPv6 to OFF

Changed security form WAP2 to NONE

Reinstalled ‘patch’ of the old IO80211Family.kext system extension.

Deleted and reinstalled the wifi connections in system preferences

Under Hardware is system pref:

Changed configure from auto to manual, MTU custom - 1450

My wifi is still a little slow connecting when my computer comes out of sleep. but I do not have the random drops now.  I would like to go back to a secure router, but when I change security from none to WAP2, the dropping problem comes back.  I have also not “upgraded” again to 10.7.5 as I am hesitant to do so.  My wifi connection is better, but not at all seamless as it seemed to be prior to Lion.

Anyway, thanks to all in the forum for their support and all the ideas - I will continue to follow to see if any other “solutions” arise (maybe even one from Apple)

norgard wrote:

 

I have have been hesitant to post this as I don’t want to jinx my greatly improved wifi connection and also because I really don’t know what I did to improve it (or if in fact the improvement is only temporary).  My original problem started shortly after upgrading to Lion.  Up until then,  I didn’t pay much attention to my wifi connection.  It just always seemed to be there - I guess I took it for granted just as I have all of the other seamless operations of my iMac.  Since switching from  a PC about 4 years ago, my computing has generally  been smooth sailing.  After upgrading to Lion (mainly because of mobilme),  I started to notice that my wifi seemed to take a long time to “hook up” after booting up or when it came out of the sleep mode.  I didn’t pay much attention until I installed 10.7.4.  After that, I had the same symptoms, plus my wifi started to drop out periodically when in use.  I started to read postings from this and other wifi connection forums, and tried many of the “fixes” suggested, but nothing seemed to help, so I “upgraded” to 10.7.5, and then the problem got worse.  My wifi went away entirely, replaced by a message that I had “no hardware installed” when I would click on the wifi icon.  I ran an ethernet cable downstairs to my router and started to search for an answer on these forums.  I ended up reinstalling 10.7.4 from my back up disk and managed to get my wifi back, complete with all the old problems.  Again,  I scoured the postings about wifi problems, and tried many of the solutions.  Here are some of the things that I did ( at least the ones I can remember):

Set my netgear router to 802.11g

 

Set channel from “auto” to channel 6

As a general rule of thumb, for quite some time, Channel 6 has been the default channel for WiFi manufactures here in the US that used to ship with a "fixed" channel assignment.  Thus, it could easily become over used and create problems.   When switching from Automatic Channel selection, I'd suggest channel 1 first, then channel 11, and only after those show no change for the better, try channel 6.

Lucciluccilucci's fix worked for me after hours of trying to figure out what was wrong. I use my MBA all over the place and this is the only location I couldn't connect via wireless. I did have to call my DSL provider for the login info to the Westell router.  Thanks for taking the time to document your steps.

Hey there. I had the same issue as soon as I updated to 10.7.5 (Lion) on Friday morning. After spending countless hours troubleshooting my router and my MacBook Air, talking to Apple Care, visiting the Genius at the store and searching the forums/net for an answer, I got the issue fixed. I also use a Netgear router and there are a couple of issues with the update, one being that it doesn't work with the old Netgear firmware.  Here's a complete step-by-step on how to get it resolved. My internet is working flawless now for a few hours and faster than before.

1. Update Netgear Firmware: If you can't of course do this from your laptop, try another device (phone, iPad, tablet, etc...). 

Enable the Wi-Fi, connect to the router, and go to:

http://192.168.1.1  Type in username: admin password: password

Should automatically tell you there is a new software update. If not, go to Router Upgrade.

2. Go to Wireless Settings (in Netgear): --> CHANGE CHANNEL to 3 or 9. --> CHANCE SECURITY to WPA2-PSK [AES]

3. Let it refresh. (Wi-Fi goes offline and then back on).

4. Go to Network Preferences on the MacBook (or laptop device) ---> Advanced --> and delete your router from the preferred list.

5. Go to Macintosh HD (hard drive) --> LIBRARY --> PREFERENCES --> SYSTEM CONFIGURATION --> and under developer, DELETE the following three (3) files:

com.apple.airport.preferences.plist

com.apple.network.identification.plist

NetworkInterfaces.plist

6. RESTART the computer.

7. Go to Network Preferences: At the top, click on LOCATIONS and add a new one. Call it whatever you want. Then make sure when you are done, that it is now working off the NEW location.

8. At the left, you see the pane that has the Wi-Fi or Bluetooth or whatever device listed. Click on the gear at the bottom --> SET SERVICE ORDER.  Again, make sure the Location is the new one you just created. Choose Wi-Fi.

9. Connect to your router: Make sure you are using the NEW location.

10. RESTART computer.

Check and make sure you are connected. If you aren't connected, let me know.

Just an FYI: 

If you call Apple Care (whether you are in warranty or not) let the first POC (verification department) know you are calling about a software update issue. They will transfer you to tech support. Once they transfer you, tell the tech specialist you want to be transferred to the Wi-Fi specialists. Yes, they actually have a team of Wi-Fi specialists!!

Most of the steps I got from reading the Apple forums here. The only thing I didn't see anywhere was to change the channel to 9. She said it might get busy so remember the channel setting process and change to 3 or vice versa.

Don't listen to any of these that say download this patch or revert to 10.7.4, etc... Just keep 10.7.5 and do these things.

Hope it helps! Let me know

eshghoolak wrote:

 

Hey there. I had the same issue as soon as I updated to 10.7.5 (Lion) on Friday morning. After spending countless hours troubleshooting my router and my MacBook Air, talking to Apple Care, visiting the Genius at the store and searching the forums/net for an answer, I got the issue fixed. I also use a Netgear router and there are a couple of issues with the update, one being that it doesn't work with the old Netgear firmware.  Here's a complete step-by-step on how to get it resolved. My internet is working flawless now for a few hours and faster than before.

 

...

2. Go to Wireless Settings (in Netgear): --> CHANGE CHANNEL to 3 or 9

. --> CHANCE SECURITY to WPA2-PSK [AES]

Note that using anything besides channels 1, 6 or 11, will put 802.11n users on top of two different segments of the network with more routers, potentially interferring with your wifi signal.  If you have wireless networking "inspection" tools available, look to see what channels the routers around you are on,. and pick channel 1, 6 or 11 to stay away from the largest number of routers.  By strateling two segments, you might succeed, if there are not "close-by" or powerful routers on either of the segments you are strateling.