Public bug reported:

My Intel 6250 wireless card works fine on every wireless network I use
except the MIT campus network (MIT SECURE), where it usually disconnects
a few minutes after connecting, and fails to reassociate.

MIT SECURE has a large number of Cisco access points (I see 13 from
where I’m sitting), and uses PEAP+MSCHAPv2 authentication.

Here’s the analysis provided by upstream NetworkManager and kernel wifi
developers, with a potential patch:

"""
The supplicant finds a stronger access point to roam to:

Apr  6 15:59:48 fixed-disk wpa_supplicant[6507]: wlan0: Considering within-ESS 
reassociation
Apr  6 15:59:48 fixed-disk wpa_supplicant[6507]: wlan0: Current BSS: 
00:21:d8:49:d1:9c level=-58
Apr  6 15:59:48 fixed-disk wpa_supplicant[6507]: wlan0: Selected BSS: 
00:21:d8:49:d1:93 level=-45

then the kernel driver attempts to probe the AP and it fails to receive
a response:

Apr  6 15:59:48 fixed-disk kernel: [ 2144.807693] wlan0: direct probe to 
00:21:d8:49:d1:93 (try 2/3)
Apr  6 15:59:48 fixed-disk kernel: [ 2145.011202] wlan0: direct probe to 
00:21:d8:49:d1:93 (try 3/3)
Apr  6 15:59:48 fixed-disk wpa_supplicant[6507]: wlan0: Event AUTH_TIMED_OUT 
(14) received
Apr  6 15:59:48 fixed-disk kernel: [ 2145.214699] wlan0: authentication with 
00:21:d8:49:d1:93 timed out
Apr  6 15:59:48 fixed-disk wpa_supplicant[6507]: wlan0: SME: Authentication 
timed out
Apr  6 15:59:48 fixed-disk wpa_supplicant[6507]: Added BSSID 00:21:d8:49:d1:93 
into blacklist
Apr  6 15:59:48 fixed-disk wpa_supplicant[6507]: wlan0: Another BSS in this ESS 
has been seen; try it next
Apr  6 15:59:48 fixed-disk wpa_supplicant[6507]: BSSID 00:21:d8:49:d1:93 
blacklist count incremented to 2

then the supplicant tries to reassociate to the previous AP, but fails
due to a driver bug:

Apr  6 15:59:49 fixed-disk wpa_supplicant[6507]: nl80211: Authenticate 
(ifindex=7)
Apr  6 15:59:49 fixed-disk wpa_supplicant[6507]:   * bssid=00:21:d8:49:d1:9c
Apr  6 15:59:49 fixed-disk wpa_supplicant[6507]:   * freq=5805
Apr  6 15:59:49 fixed-disk wpa_supplicant[6507]:   * IEs - hexdump(len=0): 
[NULL]
Apr  6 15:59:49 fixed-disk wpa_supplicant[6507]:   * Auth Type 0
Apr  6 15:59:49 fixed-disk wpa_supplicant[6507]: wlan0: nl80211: MLME command 
failed (auth): ret=-114 (Operation already in progress)

So the analysis here indicates that:

1) The supplicant's roaming thresholds are very small, and that means
the supplicant is trying to roam too often; I've patched wpa_supplicant
in Fedora to compensate for this, but it's really a problem in
wpa_supplicant upstream.

2) the Cisco wifi infrastructure may be using "client steering" to load
balance access points and force clients to associate with less-busy
access points; this could be the cause of the failure to probe-request
00:21:d8:49:d1:93.  That's not very nice behavior of the network, but
it's a fact of life and the supplicant and kernel drivers need to handle
this

3) the kernel driver and mac80211 stack have some bugs in your kernel
version, which is the cause of the -114 (operation already in progress)
error.

Discussing this with kernel wifi developers, it appears the mac80211
bits aren't communicating to the cfg80211 layer about the forced
disconnection.

(04:52:36 PM) johill: hmm
(04:52:40 PM) johill: this looks weird/buggy
(04:53:05 PM) johill: it kinda looks like we don't tell cfg80211 we're now 
disconnected?
(04:53:36 PM) dcbw: and so the cfg8021 layer rejects with EINPROGRESS?
(04:53:42 PM) johill: -ealready
(04:53:44 PM) dcbw: ah
(04:54:01 PM) johill: I suspect wdev->current_bss never gets cleared
(04:54:15 PM) johill: and because auth fails it never gets set again either
(04:54:28 PM) johill: so then it's stuck and that's why it's also reporting the 
wrong thing in the scan results

A potential fix for that issue is:

http://p.sipsolutions.net/84770fab4e3fc6ba.txt
"""

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: linux-image-3.8.0-17-generic 3.8.0-17.27
ProcVersionSignature: Ubuntu 3.8.0-17.27-generic 3.8.6
Uname: Linux 3.8.0-17-generic x86_64
NonfreeKernelModules: openafs
ApportVersion: 2.9.2-0ubuntu5
Architecture: amd64
AudioDevicesInUse:
 USER        PID ACCESS COMMAND
 /dev/snd/controlC0:  anders     3423 F.... pulseaudio
Date: Tue Apr  9 04:08:08 2013
EcryptfsInUse: Yes
HibernationDevice: RESUME=UUID=fd305e7c-c58c-4061-8105-5cda63c38849
InstallationDate: Installed on 2010-12-05 (855 days ago)
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Alpha amd64 (20101202)
MachineType: LENOVO 4313CTO
MarkForUpload: True
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.8.0-17-generic 
root=/dev/mapper/fdisk-ubuntu ro crashkernel=384M-2G:64M,2G-:128M quiet splash 
vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.8.0-17-generic N/A
 linux-backports-modules-3.8.0-17-generic  N/A
 linux-firmware                            1.104
SourcePackage: linux
UpgradeStatus: Upgraded to raring on 2012-11-15 (144 days ago)
dmi.bios.date: 09/26/2012
dmi.bios.vendor: LENOVO
dmi.bios.version: 6MET92WW (1.52 )
dmi.board.name: 4313CTO
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: 
dmi:bvnLENOVO:bvr6MET92WW(1.52):bd09/26/2012:svnLENOVO:pn4313CTO:pvrThinkPadT510:rvnLENOVO:rn4313CTO:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 4313CTO
dmi.product.version: ThinkPad T510
dmi.sys.vendor: LENOVO

** Affects: network-manager
     Importance: Unknown
         Status: Unknown

** Affects: linux (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: amd64 apport-bug raring

** Patch added: "84770fab4e3fc6ba.txt"
   
https://bugs.launchpad.net/bugs/1166648/+attachment/3633814/+files/84770fab4e3fc6ba.txt

** Bug watch added: GNOME Bug Tracker #697460
   https://bugzilla.gnome.org/show_bug.cgi?id=697460

** Also affects: network-manager via
   https://bugzilla.gnome.org/show_bug.cgi?id=697460
   Importance: Unknown
       Status: Unknown

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https://bugs.launchpad.net/bugs/1166648

Title:
  Frequent disconnects from MIT wireless network

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