8086:4238 Intel Centrino Ultimate-N 6300 poor networking, packet loss and very slow Lenovo X201 and T500 laptops

[Dave Russell]

This may be either network-manager or kernel, depending on triage...

I have verified this on both a Lenovo X201 and a Lenovo T500 laptop.

Both work perfectly with fully updated 10.10 and 11.04 versions of Ubuntu.

However, booting into a fully updated 11.10 (as of 28/08/11) I get very poor wireless networking performance. Between 6-10% packet loss, very very slow connection and transfer rate. All in all, practically unusable.

I have reported the bug on the X201 laptop, I will add the similar logs from the T500 also if required.

As soon as I swap back to either 10.10 or 11.04 I get perfect wireless, it's only on 11.10 that I get problems, this would suggest it's not hardware or configuration on my side.

I have had this since first installing 11.10 which was a little after Alpha 2.

Wired connection is fine.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: network-manager 0.9.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-9.14-generic 3.0.3
Uname: Linux 3.0.0-9-generic x86_64
Architecture: amd64
CRDA: Error: [Errno 2] No such file or directory
Date: Sun Aug 28 21:26:05 2011
EcryptfsInUse: Yes
Gconf:

IfupdownConfig:
 auto lo
 iface lo inet loopback
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Alpha amd64 (20110803.1)
IpRoute:
 default via 192.168.100.1 dev eth0 proto static
 192.168.100.0/24 dev eth0 proto kernel scope link src 192.168.100.41
Keyfiles: Error: [Errno 2] No such file or directory
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=true
 WWANEnabled=true
 WimaxEnabled=true
ProcEnviron:
 LANGUAGE=en_GB:en
 PATH=(custom, user)
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
SourcePackage: network-manager
UpgradeStatus: No upgrade log present (probably fresh install)

[Mario Verbelen (mario-verbelen)]

I'm Having a Dell XT2
previus ubuntu and other linux's no problem
oneiric ... very slow networking

very slow wifi and very slow ehternet

via wifi I have a download lower than 1k
via ethernet I can have a download of 2k

u2date oneiric of today (6sept)
Linux xt2 3.0.0-10-generic-pae #16-Ubuntu SMP Fri Sep 2 20:09:42 UTC 2011 i686 i686 i386 GNU/Linux

Ethernet controller: Intel Corporation 82567LM Gigabit Network Connection
Network controller: Intel Corporation WiFi Link 5100

lspci ...
00:00.0 Host bridge: Intel Corporation Mobile 4 Series Chipset Memory Controller Hub (rev 07)
00:02.0 VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07)
00:02.1 Display controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07)
00:19.0 Ethernet controller: Intel Corporation 82567LM Gigabit Network Connection (rev 03)
00:1a.0 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #4 (rev 03)
00:1a.1 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #5 (rev 03)
00:1a.2 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #6 (rev 03)
00:1a.7 USB Controller: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #2 (rev 03)
00:1b.0 Audio device: Intel Corporation 82801I (ICH9 Family) HD Audio Controller (rev 03)
00:1c.0 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 1 (rev 03)
00:1c.1 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 2 (rev 03)
00:1c.3 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 4 (rev 03)
00:1d.0 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #1 (rev 03)
00:1d.1 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #2 (rev 03)
00:1d.2 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #3 (rev 03)
00:1d.7 USB Controller: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #1 (rev 03)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev 93)
00:1f.0 ISA bridge: Intel Corporation ICH9M-E LPC Interface Controller (rev 03)
00:1f.2 RAID bus controller: Intel Corporation Mobile 82801 SATA RAID Controller (rev 03)
00:1f.3 SMBus: Intel Corporation 82801I (ICH9 Family) SMBus Controller (rev 03)
02:01.0 CardBus bridge: Texas Instruments PCIxx12 Cardbus Controller
02:01.1 FireWire (IEEE 1394): Texas Instruments PCIxx12 OHCI Compliant IEEE 1394 Host Controller
02:01.3 SD Host controller: Texas Instruments PCIxx12 SDA Standard Compliant SD Host Controller
0c:00.0 Network controller: Intel Corporation WiFi Link 5100

[Matthieu (m-cramet)]

Same problem than drussel here. I have a Thinkpad X201S.

[Dustin Kirkland  (kirkland)]

I've have the same problem on an x201, but only when I'm connected over wireless-n, not b or g which work fine.

[Dave Russell (drussell)]

Dustin - good catch... I can confirm it's only wireless-n connections that expose the problem. Just tried connecting to phone hotspot and that works fine.

[Martin Pool (mbp)]

bug 833479 might be a dupe? I also have an x201 and am seeing intermittently very bad network performance, but there it's affecting both wlan0 and the onboard e1000e.

[Mathieu Trudel-Lapierre (cyphermox)]

It's unclear that this is caused by network-manager yet, seeing as it's device-specific (or at least system-specific, since I'm getting very decent speeds here on a Dell system). Anyway, I'll take care of the network-manager task if something needs to be done (I'll still try to reproduce and debug at the NM level).

[arsenix (arsenix)]

   I am also experiencing this issue after upgrade to oneiric. Machine is HP Elitebook 8540w. Wired ethernet (Intel Corporation 82577LM Gigabit Network Connection) seems to perform fine. Wifi card is Centrino Ultimate-N 6300. As reported by others it affects only 802.11N connections... not G.

James

[Alex Chiang (achiang)]

Turned on NM debugging as per: http://live.gnome.org/NetworkManager/Debugging

Environment is 802.11 b+g+n on my router with bssid 'pinga'.

Attempted an rsync, and experienced symptoms in this bug.

Attaching partial /var/log/syslog. Seems like there are a lot of rescans, not sure if this is normal.

 Let me know if there are other logs I can attach or other debug output you'd like.

[DJ (dhananjaj)]

Hi All,

I'm having this issue on a Lenovo T510.

hardware is a Centrino Ultimate N 6300.

also did you guys upgrade or fresh install? I did an upgrade. if you want all the logs I can get it later, i'm booted into W7 cause Ubuntu is unusable.

thanks,
DJ

[Mathieu Trudel-Lapierre (cyphermox)]

Are any of these issues directly related to having both wired and wireless connected at the same time? Because then this would not be device-specific, and is in fact an issue with libnl.

[Alex Chiang (achiang)]

In my reproduction case, I do not have wired ethernet connected.

[DJ (dhananjaj)]

same with me.

I was not able to connect at all in N-only mode, in N/G mixed mode i can connect but unusably slow. What shocks me is that if this is an issue with iwlagn or network manager shouldn't this be effecting more people?

what could have changed in the parts specific to the Centrino Ultimate N from 11.04 to 11.10?

do any of you guys have any work-a-rounds that make the system usable? have you tried a fresh install?

cheers,

[DJ (dhananjaj)]

does this mean i can ubuntu update to get these changes? or do i need to get it from a special ppa? thanks

[Mark Baker (distobj)]

FWIW, I just finished installing beta2 this evening on my Dell Studio XPS 16 with an Intel Wifi Link 5100, and immediately noticed this problem. I have no wired connection, and have tried each of B/G/N-only on my router and observed no change in performance.

[Philip Muškovac (yofel)]

Some data from me:

Sitting around 3m away from the router I get:
Wifi quality: 150Mbps, 89%
--- google.com ping statistics ---
1035 packets transmitted, 1035 received, 0% packet loss, time 1039286ms
rtt min/avg/max/mdev = 22.178/33.084/1276.174/59.218 ms, pipe 2

System:
Thinkpad T510 on Kubuntu oneiric
03:00.0 Network controller: Intel Corporation Centrino Ultimate-N 6300 (rev 35)
Linux yofel-T510 3.0.0-12-generic #19-Ubuntu SMP Fri Sep 23 21:23:39 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux
WIFI SSID: W920V

So I can't really complain about my N performance and can't say I've ever noticed this during oneiric.

[dekeyserkarel (dekeyserkarel)]

Don't know if it is the same, but I can't connect to my wireless network from a Dell Studio 1749. It seems like my networkcard starts to rescan before it even can't connect.

Everything was working well on 11.04 and shortly after an update to 11.10beta. Troubles began with updating about a week ago.

[Boris Rybalkin (ribalkin)]

Wifi is very slow, but ethernet is OK.

Upload:
wifi: ~30 KiB/s
ethernet: ~400 KiB/s

Tried Kubuntu 10.04 Live CD - wifi speed is good.

I am ready to do any testing as this is my wife's laptop and she wants to switch back to slow Vista :)

$ lspci
00:00.0 Host bridge: Intel Corporation Mobile PM965/GM965/GL960 Memory Controller Hub (rev 0c)
00:01.0 PCI bridge: Intel Corporation Mobile PM965/GM965/GL960 PCI Express Root Port (rev 0c)
00:1a.0 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #4 (rev 03)
00:1a.1 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #5 (rev 03)
00:1a.7 USB Controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI Controller #2 (rev 03)
00:1b.0 Audio device: Intel Corporation 82801H (ICH8 Family) HD Audio Controller (rev 03)
00:1c.0 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 1 (rev 03)
00:1c.1 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 2 (rev 03)
00:1c.5 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 6 (rev 03)
00:1d.0 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #1 (rev 03)
00:1d.1 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #2 (rev 03)
00:1d.2 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #3 (rev 03)
00:1d.7 USB Controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI Controller #1 (rev 03)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev f3)
00:1f.0 ISA bridge: Intel Corporation 82801HEM (ICH8M) LPC Interface Controller (rev 03)
00:1f.1 IDE interface: Intel Corporation 82801HBM/HEM (ICH8M/ICH8M-E) IDE Controller (rev 03)
00:1f.2 SATA controller: Intel Corporation 82801HBM/HEM (ICH8M/ICH8M-E) SATA AHCI Controller (rev 03)
00:1f.3 SMBus: Intel Corporation 82801H (ICH8 Family) SMBus Controller (rev 03)
01:00.0 VGA compatible controller: nVidia Corporation G86 [GeForce 8400M GS] (rev a1)
02:00.0 Network controller: Intel Corporation PRO/Wireless 4965 AG or AGN [Kedron] Network Connection (rev 61)
08:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller (rev 01)
09:09.0 FireWire (IEEE 1394): Ricoh Co Ltd R5C832 IEEE 1394 Controller (rev 05)
09:09.1 SD Host controller: Ricoh Co Ltd R5C822 SD/SDIO/MMC/MS/MSPro Host Adapter (rev 22)
09:09.2 System peripheral: Ricoh Co Ltd R5C592 Memory Stick Bus Host Adapter (rev 12)
09:09.3 System peripheral: Ricoh Co Ltd xD-Picture Card Controller (rev 12)

$ uname -a
Linux nata 3.0.0-12-generic #19-Ubuntu SMP Fri Sep 23 21:23:39 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux

syslog:
Oct 6 21:23:58 nata NetworkManager[1096]: <info> (eth0): carrier now OFF (device state 100, deferring action for 4 seconds)
Oct 6 21:24:03 nata NetworkManager[1096]: <info> (eth0): device state change: activated -> unavailable (reason 'carrier-changed') [100 20 40]
Oct 6 21:24:03 nata NetworkManager[1096]: <info> (eth0): deactivating device (reason 'carrier-changed') [40]
Oct 6 21:24:03 nata NetworkManager[1096]: <info> (eth0): canceled DHCP transaction, DHCP client pid 7928
Oct 6 21:24:03 nata avahi-daemon[1085]: Wit...

[dekeyserkarel (dekeyserkarel)]

My problem got fixed by updating...

[arsenix (arsenix)]

Problem still exists for me after latest update. Still very slow on 802.11N connection, normal on 802.11G/B. I have two access points on same network so I can easily test back to back.

[Nebula (yanick-delarbre)]

I have this problem too.

My network controler is: Ultimate-n 6300

Desactiving 802.11N on router solves the problem.

[Franz (franzbischoff)]

Same problem here:

Laptop ASUS z53sv, with wi-fi module iwl4965, Ubuntu 11.10 (worked fine ultil ubuntu 11.04)

Wifi very slow with router at 802.11B/N. When disabled 802.11B/N and force only 802.11B, wireless came back to normal.

[Alex Cabal (acabal)]

I have this problem after upgrading to Oneiric with an Intel Advanced-N 6200 wifi card. I seem to have temporarily fixed the problem by adding this line to /etc/modprobe.d/intel-6200.conf:

options iwlagn 11n_disable=1

[David Small (dasmall)]

I have an Intel 5300 in my laptop and was also facing the problems with N, it was actually locking up my router within a few seconds of connecting. 15 minutes now after applying Alex's temporary fix all seems well.

[Richard Widerberg (rwiderberg)]

I have a lenovo thinkpad e320 with Intel Centrino Wireless-N 1000 card with the same problem running Oneiric. Can anyone tell me how to disable wireless N with my card? There is no conf file for it in my modprobe.d folder.

[asampal (nmanole)]

I'm also seeing very slow speeds with Wireless-N using an Intel Advanced-N 6205 adapter, after updating to Oneiric (did the update about a week ago, before the final came out). Have applied all updates. Tried to create the file Alex mentioned above, but it didn't seem to improve things.

I'm getting about 20 Mbps from my ThinkPad running Windows 7 and just under 4 Mbps with Oneiric from my Dell Latitude e6420, connected to the same router.

[asampal (nmanole)]

Just re-booted and I'm getting somewhat better speeds with now - not sure if the "networking restart" that that I had tried before actually restarted networking, since there was a message about that method being deprecated, but maybe the conf file does disable N for this adapter (wasn't sure what to call the file, but I guess the 6205 is in the 6200 family).

[ragnaroknroll (ragnaroknroll)]

On a Dell Studio and just upgraded from Ubuntu 11.04 to 11.10...

Had perfect, strong wi-fi connection with 11.04 at a moderate distance from router...

On upgrade to 11.10, connection strength shows as very weak at same distance from router and keeps disconnecting automatically every few minutes... Impossible to work...

[manuel fernandez (mfg)]

same problem here with dell latitude 6410, intel centrino ultimate N6300

[manuel fernandez (mfg)]

Solved it following a mimic of alex solution (#23)
added archive
/etc/modeprobe.d/intel-6300.config

with line
options iwlagn 11n_disable=1

[Rich R (rich-randall)]

I'm getting this too. Intel Centrino Wireless-N 1000 on a Lenovo E420s.
Was fine under Natty. Frustratingly slow connection under Oneiric.
I can't easily get access to the router. Is there a corresponding work-around for this card?

[tuximero (tuximero)]

Very slow wireless-n connection here too. Connection speed down to 1 MBit/s.
lenovo ThinkPad T410 running Kubuntu 11.10 Oneiric.
Network controller: Intel Corporation Centrino Ultimate-N 6300 (rev 35)

[Wim (wim-prevoo)]

Same here, wireless very slow, running on a lenovo ThinkPad T410. Wired connection is ok.
Workaround: disable 11n (sudo modprobe iwlagn 11n_disable=1) in /etc/modprobe.d/options.conf

[Bernhard Fisseni (bernhard-fisseni)]

Also on a T410. When using n connections, my router (Speedport 504V, Type A) gets so confused that after some seconds, the T410's and all other connections are cancelled and the router takes some minutes to regain composure. Deactivating n, everything works well.

[Julie (januaryj)]

I'm not sure if I have the same problem, but I think so. I have a Packard Bell Ml61, and after upgrading to Oneiric I have trouble with the wireless. I can connect, but it takes ages and I have to keep typing in the password (it's set as automatic connection). When I'm finally connected, the internet is good, but when I turn off the computer or reboot, the problem keeps occurring. No problems with the wireless on my Dell Latitude D620 (Natty) or my old iPod Touch.

[rkrizan (ryankrizan)]

I had this issue on 2 laptops, both with Intel cards. One was an Intel WiFi Link 5100, the other was an Intel Pro 4965AGN

[Doug Bates (coloneldare)]

Me too! With my Acer AspireOne/Intel Centrino Wireless-N 1000 card. Acer works fine on 11.04 (which I have had to fall back to.)
11.10 works with ethernet (c. 800KiB/s) but 0 - ten's or hundreds of B/s (not KiB) so totally unusable, tho some connectivity.
11.10 works fine on my Broadcom based laptop, but not Intel based Acer
Love 11.10 otherwise so can someone fix it please? Thanks.

[G. Tasseron (tasseron)]

I have the same problem with my HP Elitebook 8540w, Centrino Intel-N 7300.
However I notice something else as well, that has to do with this matter. The notebook has a button with which you can enable/disable wireless, the light on the button will then change from blue(enabled) to orange(disabled).
With 11.10 when wireless is enabled, the button flashes irregular but fast (more than once a second) and a lot of packet loss (till 30%).
A similar solution as the one of manuel fernandez #30 fixed the issue with packet loss and slow internet. However... the light still flashes on and off, while it was constant blue(enabled) in 11.04.

[Matthieu (m-cramet)]

Is someone working on this bug? It's a pretty common one shared by quite a number of people over ubuntu forums. Appart from status updates, their has been no input from any dev.

Is their a mailing list where we can follow any news relative to this issue?

[Xyliosist (xyliosist)]

I'm having the same problem. Working on TravelMate 5720, previously on Kubuntu 11.04 worked fine, now on 11.10 I'm having like 40-80% packet loss.
lspci:
Intel Corporation PRO/Wireless 4965 AG or AGN [Kedron] Network Connection (rev 61)

[Karl Frisk (karl-frisk)]

This bug affects my laptop with Centrino Ultimate-N 6300 as well.

I think I have tried all the workarounds in this thread but the only thing that helped was turning on the swcrypto parameter. My /etc/modprobe.d/iwlwifi.conf now looks like this:

options iwlwifi 11n_disable=1 led_mode=1 swcrypto=1

And I can use wifi without problems. However, the fact that n-networks can not be used remains annoying.

[nh2 (nh2)]

In the Intel bug linked above (http://bugzilla.intellinuxwireless.org/show_bug.cgi?id=2315) they posted two new patches about hardware bugs that seem to have gone into the mainline Linux git yesterday.

Compile and try, anyone?

@zeitkunst
You are not alone in your frustration with university networks. Follow the advice above and try wicd. It might work better for you (which I don't understand, because in the end, wicd and network-manager are based on the same tools).

[Karl Frisk (karl-frisk)]

nh2, these commits have been merged to mainline for kernel version 3.4.3 (posted to mainline ppa on june 17). I think they have also been merged to the 3.2 branch.

Unfortunately they did not help with this bug.

[nh2 (nh2)]

@Karl Frisk: Oh, then cgit tricked me somehow, I thought they were just merged yesterday. Sorry for the false alarm.

[Developer (lunixhacker)]

For me wireless is working again on 12.10, but I noticed the speed was only about 12MB/s compared to 54MB/s on Windows 7. So i tried iwlagn 11n_disable=1 and it solved the problem, now I have the same speeds as on Windows 7.
What are the disadvantages of iwlagn 11n_disable=1?

[nh2 (nh2)]

What are the disadvantages of iwlagn 11n_disable=1?

11n should theoretically give you higher throughput and interference.

[Steven Keys (steevven1)]

I see that the "assignee" has been changed to "nobody," and the activity on this bug has died down. Is there no hope of this ever getting fixed? My wifi is unacceptably bad on a majority of routers, especially (but not only) public hotspots. Would it help if I put a $20 bounty on the implemented solution to this bug? :-p

[DDC (coquet)]

I went back and did some testing on 3.2.0-30-generic and 3.4.0-030400-generic from the mainline PPA (both AMD64) and my results are the same as I mentioned in #158. With the Linksys e3000, I get very good performance and with the Buffalo WZR-HP-G300NH router, I get unusable performance.

Both routers were operating in mixed bgn with mixed WPA/WPA2.

[Georg (georgsorst)]

Just reporting that I have also had huge problems with the stability of my Wi-Fi connection. The following fixed this so far:

sudo modprobe iwlwifi bt_coex_active=0 swcrypto=1

I am still getting excessive amounts of Tx excessive retries, but my connection is fast and stable.

My environment:

Ubuntu: Precise
Kernel: 3.2.0-31
Laptop: Dell Vostro 3460
Wi-FI: Intel Corporation Centrino Wireless-N 2230 (rev c4)

Thanks for all the hints!

[Ryan Reich (ryan-reich)]

I am not using Ubuntu but I suffer this problem with my Asus Zenbook Prime (wireless is Intel Centrino Advanced-N 6235 (rev 24)). In short, either of the following two actions fix the network slowness.

1. Disable 11n capability via `modprobe iwlwifi 11n_disable=1` or the kernel boot option `iwlwifi.11n_disable=1`, depending on whether iwlwifi is a module or not. Everything else works great but you have to use 11g.

2. Disable power management via `iwconfig wlan0 power off` or the appropriate setting in a power management tool, laptop-mode tools, etc. With this option there are still many Tx excessive retries but 11n works otherwise.

[Ryan Reich (ryan-reich)]

In response to Georg's above comment, I also tested the options he gives; neither bt_coex_active=0 nor sw_ctypto=1 does anything to help the slow connection. However, `iwconfig wlan0 power off/on` is effectively a "work/don't work" switch for 11n capability.

[penalvch (penalvch)]

Dave Russell, and only Dave Russell, could you please execute the following in a terminal:
apport-collect 836250

[Janne Kronbäck (janne-kronback)]

Seem to have the same problem with Centrino 1030N.

Previously on 12.04, disabling N worked. Then somewhere along the line the network became bad again.
I upgraded to 12.10, but the problem remains, nor do the solutions above help.

[penalvch (penalvch)]

Janne Kronbäck, if you have a bug in Ubuntu, could you please file a new report by executing the following in a terminal:
ubuntu-bug linux

For more on this, please see the Ubuntu Kernel team article:
https://wiki.ubuntu.com/KernelTeam/KernelTeamBugPolicies#Filing_Kernel_Bug_reports

the Ubuntu Bug Control team and Ubuntu Bug Squad team article:
https://wiki.ubuntu.com/Bugs/BestPractices#X.2BAC8-Reporting.Focus_on_One_Issue

and Ubuntu Community article:
https://help.ubuntu.com/community/ReportingBugs#Bug_reporting_etiquette

When opening up the new report, please feel free to subscribe me to it.

Please note, not filing a new report may delay your problem being addressed as quickly as possible.

Thank you for your understanding.

[arsenix (arsenix)]

Another thing I have noticed. The ping times to the router on the HP Elitebook are consistently 3ms when running quantal. The "working" test configurations (HP Elitebook/Lucid,HP Elitebook/Windows7,Thinkpad T61p/Quantal) all show consistently under 1ms. This is when the connection is working stably, after a time when the connection starts degrading (tx fifo queu failure messages), ping times start to go up considerably and become highly erratic. Ping is a limited test tool but this is curious.

[Moritz Heiber (moritz-heiber)]

There finally seems to have been a patch posted at the Intel bugtracker fixing this particular bug. Could somebody please take a look at it and, if necessary, update the packages accordingly?

This has been going on for ages it feels like.

[Maximilian Federle (ppd)]

I applied the above mentioned patch to rarings 3.8.0-1 and rebuilt. Unfortunately I still need 11n_disable for a limited but usable connection.

[nh2 (nh2)]

The Intel wifi bugzilla is down (DNS record gone). Response from Intel:

"The bugzilla has been disabled, we're working to see if we can track things elsewhere, but it's not clear yet where we could."

I will attach the patch that was posted there, and also a "backported" version of the patch for the 12.04 kernel (3.2).

[nh2 (nh2)]

Test (patch attachments don't seem to work for me currently?)

[nh2 (nh2)]

And here we have the adjusted patch for Ubuntu 12.04.

It works very well for me so far, connectivity "feels" way better.

I currently still use "options iwlwifi 11n_disable=1" and haven't tried how it is now with n mode enabled.

[Tim Flubshi (flubshi)]

Will this patch be a part of one of the next kernel (3.8 or 3.9)?

[nh2 (nh2)]

With the bugtracker being down, I have no clue.

I suggest that at least success/failure reports shall go here in the meantime so that we can give then Intel developers some feedback once we can talk to them again.

[Marco Cè (marco89-7)]

I think I have the same problem on a Dell XPS 13 (Centrino Advanced-N 6235). On 12.04 with kernel 3.2, after some activity the connection drops and I have to reboot. I tried some iwlwifi kernel module options (11n_disable=1, swcrypto=1, bt_coex_active=0) and turning off power managment (iwconfig wlan0 power off), but nothing works, eventually after some time the connection drops.
I have done a fresh install of 13.04 with last daily image, and with the 3.8.0-13.23 kernel the problem is still there. Again, none of the iwlwifi module options solves the problem.
Any news on when the patch will be applied to kernel packages?

[Marco Cè (marco89-7)]

I tried to apply the Intel patch to last ubuntu 13.04 kernel, but it seems to me that in linux 3.8.0-13.23 package this patch is already include. If I am correct, then this patch does not solve the bug for me. Maybe I have a different bug.

[2xyo (2xyo)]

Stll visible on :

$ lspci|grep Network
03:00.0 Network controller: Intel Corporation Centrino Advanced-N 6235 (rev 24)

$ lsb_release -r
Release: 13.04

$ uname -a
Linux yoyo-laptop 3.8.0-16-generic #26-Ubuntu SMP Mon Apr 1 19:52:57 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

$ sudo dmidecode | grep -e Version -e ASUS |head -n 2
 Version: UX32VD.211
 Manufacturer: ASUSTeK COMPUTER INC.

[Mechanical snail (replicator-snail)]

I'm seeing a very similar-looking intermittent packet loss issue on Precise, with this same wireless interface (Centrino Ultimate-N 6300 [8086:4238] on a Thinkpad X201). I get the error message "ping: sendmsg: No buffer space available" when attempting to ping. Asked at: http://askubuntu.com/questions/210451/what-does-ping-sendmsg-no-buffer-space-available-mean

Is this the same bug?

[Mechanical snail (replicator-snail)]

intellinuxwireless is dead

[dino99 (9d9)]

Can someone affected resume the actual situation with the recent upstream kernels (3.8 / 3.9 / 3.10)

[Anssi Saari (9-as)]

I'm not Ubuntu user but on Sabayon Linux, Thinkpad X201, Centrino 6300, kernel 3.10.0 I don't think this is fixed. Quite simply there are long pauses in network activity which makes interactive use a pain and downloads slow.

For example, some ping statistics of my base station just a few feet away:

30 packets transmitted, 18 received, 40% packet loss, time 29025ms
rtt min/avg/max/mdev = 3.105/14.805/195.911/43.949 ms

Average download speeds vary between 2-3 MB/s so not great. This with 100 Mbps downstream and the other end can saturate that easy if using ethernet reaching about 11MB/s. My ancient Toshiba Portege R500 also maxes that out with wireless...

Power saving on the wireless adapter don't seem to make much difference.

[ian (ian6)]

This is still an issue with recent kernels. I tested Quantal and one of the Saucy dailies (3.10) on my laptop with an Intel 6205 card, both had about half the throughput (~50Mb/s vs ~100Mb/s) that it gets under Windows, occasional stalls (that don't happen under Windows), and huge "tx excessive retries" numbers when, say, wgetting from kernel.org.

[Ben Hilburn (bhilburn)]

I am running an up-to-date Ubuntu 13.04, and seeing this problem on my Lenovo T430s. Many of my coworkers have this same laptop, and we are all experiencing serious problems.

The card:

03:00.0 Network controller: Intel Corporation Centrino Ultimate-N 6300 (rev 3e)
 Subsystem: Intel Corporation Centrino Ultimate-N 6300 3x3 AGN

You can see the excessive retries bit here:

wlan0 IEEE 802.11abgn ESSID:"NI"
          Mode:Managed Frequency:2.462 GHz Access Point: CC:D5:39:BB:73:D0
          Bit Rate=65 Mb/s Tx-Power=15 dBm
          Retry long limit:7 RTS thr:off Fragment thr:off
          Encryption key:off
          Power Management:off
          Link Quality=46/70 Signal level=-64 dBm
          Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
          Tx excessive retries:2432 Invalid misc:96 Missed beacon:0

Kernel:

          Linux 3.8.0-27-generic #40-Ubuntu SMP Tue Jul 9 00:17:05 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

Disappointing that this has been a bug for ~2 years - it's fairly serious.

[dino99 (9d9)]

hello Dave,

Oneiric have reached End of Life a while back; so it wont get fix now.

and post the output requested at #243 above please.

Still needs confirmation of that issue with a fresh recent ubuntu install (from scratch to avoid oldish settings/configs disturbing the system)

[David G. Johnson (n-david-johnson)]

Having the same issue in Precise with Intel Corporation Centrino Advanced-N 6205 (rev 34).

B/G are fine. N works really well at first then plummets in speed to less than 1 Mb/s and becomes unusable. Rebooting the router causes it to work again (really fast), then it plummets again.

Using the iwlwifi 11n_disable=1 is the only way I can work wirelessly with my router.

[penalvch (penalvch)]

David G. Johnson, if you have a bug in Ubuntu, the Ubuntu Kernel team, Ubuntu Bug Control team, and Ubuntu Bug Squad would like you to please file a new report by executing the following in a terminal while booted into a Ubuntu repository kernel (not a mainline one) via:
ubuntu-bug linux

For more on this, please read the official Ubuntu documentation:
Ubuntu Bug Control and Ubuntu Bug Squad: https://wiki.ubuntu.com/Bugs/BestPractices
Ubuntu Kernel Team: https://wiki.ubuntu.com/KernelTeam/KernelTeamBugPolicies
Ubuntu Community: https://wiki.ubuntu.com/ReportingBugs

When opening up the new report, please feel free to subscribe me to it.

Please note, not filing a new report would delay your problem being addressed as quickly as possible.

No need exists to comment here at this time. If you have further questions, you are welcome to redirect them to the appropriate mailing list or forum via http://www.ubuntu.com/support/community/mailinglists , or you may contact me directly.

Thank you for your understanding.

[dino99 (9d9)]

@David

Please glance at lp:1201470 which seems close to your issue, and got fixed with the latest 3.11.0-3.8 kernel.

[Björn Jacke (bjoern-j3e)]

even with current 5.4 kernels from 20.04 (9 years after this bug was reported), it's neccessary to set

options iwlwifi 11n_disable=2

if you have a Intel Centrino Ultimate-N 6300 card. Otherwise there is packet loss that prevents usable throughput rates.

If this is not getting fixed upstream in the kernel, then Ubuntu should ship a configuration for systems with those chipsets, that mitigates the problem. Finding the cause of this problem is only possible for people with expert knowledge. Can you please add a mitigation for this issue in Ubuntu by default?