I have the same problem for more than one year. Sometime I even felt a little disappointed about Linux (This not only happened under Ubuntu, It happened under some other distributions too, for example, Arch), especially when I was having a meeting and wanting to show something to the professor over ssh: the network just dropped out every minutes or just can not connect.
Back to about two years ago, I used Ubuntu 10.04, there is no this problem. I switched to then newer 11.04 because of a problem with the display card driver, then this problem started to occur. I goggled and tried every workaround I found (I even bought a new network card), no one can completely solve the problem. I can connect to my home network without a problem, but when came to the campus network, many problems happened: I can connect to it in my office with several dropouts a day. I can not connect to it or the network dropped out every minutes when I was in a professors office, which is in the same building but on a different floor, and can not connect to it in the library in the same building . I kept installing new versions of Ubuntu and upgraded to new kernels, but the problem is still here. >From the output of dmesg, I noticed that there were usually two cases: 1. authentication timed out. 2. deauthenticated from the network quickly after a successful connection by local choice with reason number either 2 or 3. I don't think this is overcrowd related, because Windows works, iOS works, and even wicd works(not perfectly). And this also happens on another Ubuntu laptop of one of my office mates. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to network-manager in Ubuntu. https://bugs.launchpad.net/bugs/924082 Title: NM fails to connect to campus Wi-Fi network; wicd succeeds -- Centrino Ultimate-N 6300 iwlwifi Status in “network-manager” package in Ubuntu: Confirmed Bug description: The iwlwifi drivers give exceptional performance on all APs I have connected to, be they WEP, WPA or open. The only time this system lets me down is when connecting to my campus wireless network. NetworkManager will only sometimes connect, and even manually configuring with iwconfig does not always work. The error usually given is either: Jan 30 01:07:51 Beast kernel: [ 8777.748471] wlan0: direct probe to 00:1a:1e:a0:3b:c0 (try 1/3) Jan 30 01:07:51 Beast kernel: [ 8777.945384] wlan0: direct probe to 00:1a:1e:a0:3b:c0 (try 2/3) Jan 30 01:07:51 Beast kernel: [ 8778.144952] wlan0: direct probe to 00:1a:1e:a0:3b:c0 (try 3/3) Jan 30 01:07:52 Beast kernel: [ 8778.344474] wlan0: direct probe to 00:1a:1e:a0:3b:c0 timed out or: Nov 30 19:01:27 Beast kernel: [ 1924.850725] wlan0: authenticate with 00:24:6c:60:d0:00 (try 1) Nov 30 19:01:27 Beast kernel: [ 1924.852183] wlan0: 00:24:6c:60:d0:00 denied authentication (status 17) Other people report that this error may be linked to MAC filtering by the AP, but this should not be the case: my old computer with a Broadcom BCM4312 had no trouble. This bug is also different from several bug reports that complain of limited speed or packet loss: when I can connect, the connection is flawless. But very often I cannot connecct. The connection is generally worse in crowded areas, or areas with many access points. lspci: Network controller [0280]: Intel Corporation Centrino Ultimate-N 6300 [8086:4238] (rev 3e) ifconfig wlan0: wlan0 Link encap:Ethernet HWaddr 24:77:03:26:e8:50 inet addr:130.64.153.137 Bcast:130.64.153.255 Mask:255.255.255.0 inet6 addr: fe80::2677:3ff:fe26:e850/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:1288307 errors:0 dropped:0 overruns:0 frame:0 TX packets:296448 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1016044127 (1.0 GB) TX bytes:27674773 (27.6 MB) iwconfig wlan0: wlan0 IEEE 802.11abgn ESSID:"tuftswireless" Mode:Managed Frequency:5.785 GHz Access Point: 00:24:6C:60:D0:10 Bit Rate=300 Mb/s Tx-Power=15 dBm Retry long limit:7 RTS thr:off Fragment thr:off Power Management:off Link Quality=61/70 Signal level=-49 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:2749 Invalid misc:7 Missed beacon:0 lsmod | grep iw: iwlwifi 320164 0 mac80211 506154 1 iwlwifi cfg80211 209294 2 iwlwifi,mac80211 dmesg | grep wlan: [ 12.059405] wlan0: direct probe to 00:24:6c:60:d0:00 (try 1/3) [ 12.258109] wlan0: direct probe to 00:24:6c:60:d0:00 (try 2/3) [ 12.457695] wlan0: direct probe to 00:24:6c:60:d0:00 (try 3/3) [ 12.657205] wlan0: direct probe to 00:24:6c:60:d0:00 timed out [ 20.624778] wlan0: direct probe to 00:24:6c:60:d0:00 (try 1/3) [ 20.822683] wlan0: direct probe to 00:24:6c:60:d0:00 (try 2/3) [ 21.022217] wlan0: direct probe to 00:24:6c:60:d0:00 (try 3/3) [ 21.221788] wlan0: direct probe to 00:24:6c:60:d0:00 timed out [ 29.105117] wlan0: direct probe to 00:24:6c:60:d0:00 (try 1/3) [ 29.303463] wlan0: direct probe to 00:24:6c:60:d0:00 (try 2/3) [ 29.503007] wlan0: direct probe to 00:24:6c:60:d0:00 (try 3/3) [ 29.702581] wlan0: direct probe to 00:24:6c:60:d0:00 timed out [ 37.888734] wlan0: direct probe to 00:24:6c:60:d0:00 (try 1/3) [ 38.087513] wlan0: direct probe to 00:24:6c:60:d0:00 (try 2/3) [ 38.287083] wlan0: direct probe to 00:24:6c:60:d0:00 (try 3/3) [ 38.486602] wlan0: direct probe to 00:24:6c:60:d0:00 timed out [ 46.376942] wlan0: authenticate with 00:24:6c:60:d0:00 (try 1) [ 46.411091] wlan0: 00:24:6c:60:d0:00 denied authentication (status 17) syslog: Nov 30 19:01:27 Beast kernel: [ 1924.850725] wlan0: authenticate with 00:24:6c:60:d0:00 (try 1) Nov 30 19:01:27 Beast kernel: [ 1924.852183] wlan0: 00:24:6c:60:d0:00 denied authentication (status 17) Nov 30 19:02:24 Beast NetworkManager[1332]: <warn> Activation (wlan0/wireless): association took too long, failing activation. Nov 30 19:02:24 Beast NetworkManager[1332]: <info> (wlan0): device state change: config -> failed (reason 'supplicant-timeout') [50 120 11] Nov 30 19:02:24 Beast NetworkManager[1332]: <warn> Activation (wlan0) failed for access point (tuftswireless) Nov 30 19:02:24 Beast NetworkManager[1332]: <warn> Activation (wlan0) failed. Nov 30 19:02:24 Beast NetworkManager[1332]: <info> (wlan0): device state change: failed -> disconnected (reason 'none') [120 30 0] Nov 30 19:02:24 Beast NetworkManager[1332]: <info> (wlan0): deactivating device (reason 'none') [0] Nov 30 19:02:24 Beast NetworkManager[1332]: <info> (wlan0): supplicant interface state: authenticating -> disconnected Nov 30 19:02:24 Beast NetworkManager[1332]: <warn> Couldn't disconnect supplicant interface: This interface is not connected. Nov 30 19:02:27 Beast NetworkManager[1332]: <info> Auto-activating connection 'Auto hpsetup'. Nov 30 19:02:27 Beast NetworkManager[1332]: <info> Activation (wlan0) starting connection 'Auto hpsetup' Nov 30 19:02:27 Beast NetworkManager[1332]: <info> (wlan0): device state change: disconnected -> prepare (reason 'none') [30 40 0] Nov 30 19:02:27 Beast NetworkManager[1332]: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) scheduled... Nov 30 19:02:27 Beast NetworkManager[1332]: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) started... Nov 30 19:02:27 Beast NetworkManager[1332]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) scheduled... Nov 30 19:02:27 Beast NetworkManager[1332]: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) complete. Nov 30 19:02:27 Beast NetworkManager[1332]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) starting... Nov 30 19:02:27 Beast NetworkManager[1332]: <info> (wlan0): device state change: prepare -> config (reason 'none') [40 50 0] Nov 30 19:02:27 Beast NetworkManager[1332]: <info> Activation (wlan0/wireless): connection 'Auto hpsetup' requires no security. No secrets needed. Nov 30 19:02:27 Beast NetworkManager[1332]: <info> Config: added 'ssid' value 'tuftswireless' Nov 30 19:02:27 Beast NetworkManager[1332]: <info> Config: added 'scan_ssid' value '1' Nov 30 19:02:27 Beast NetworkManager[1332]: <info> Config: added 'key_mgmt' value 'NONE' Nov 30 19:02:27 Beast NetworkManager[1332]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) complete. Nov 30 19:02:27 Beast NetworkManager[1332]: <info> Config: set interface ap_scan to 1 Nov 30 19:02:27 Beast NetworkManager[1332]: <info> (wlan0): supplicant interface state: disconnected -> scanning Nov 30 19:02:30 Beast wpa_supplicant[6090]: Trying to authenticate with 00:24:6c:60:d0:00 (SSID='tuftswireless' freq=2437 MHz) Nov 30 19:02:30 Beast NetworkManager[1332]: <info> (wlan0): supplicant interface state: scanning -> authenticating Nov 30 19:02:30 Beast kernel: [ 1987.684183] wlan0: authenticate with 00:24:6c:60:d0:00 (try 1) Nov 30 19:02:30 Beast kernel: [ 1987.687421] wlan0: 00:24:6c:60:d0:00 denied authentication (status 17) sudo iwlist scan: wlan0 Scan completed : Cell 01 - Address: 00:24:6C:60:D0:10 Channel:157 Frequency:5.785 GHz Quality=57/70 Signal level=-53 dBm Encryption key:off ESSID:"tuftswireless" Bit Rates:12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s; 48 Mb/s 54 Mb/s Mode:Master Extra:tsf=0000005a132e5c6a Extra: Last beacon: 76ms ago IE: Unknown: 000D7475667473776972656C657373 IE: Unknown: 010698243048606C IE: Unknown: 03019D IE: Unknown: 2D1A4E001BFFFF000000000000000000000000000000000000000000 IE: Unknown: 3D169D051B000000FF000000000000000000000000000000 IE: Unknown: DD1E00904C334E001BFFFF000000000000000000000000000000000000000000 IE: Unknown: DD1A00904C349D051B000000FF000000000000000000000000000000 IE: Unknown: DD180050F2020101800003A4000027A4000042435E0062322F00 IE: Unknown: DD0A00037F04010000000000 Cell 02 - Address: 00:0B:86:58:19:A0 Channel:1 Frequency:2.412 GHz (Channel 1) Quality=39/70 Signal level=-71 dBm Encryption key:off ESSID:"tuftswireless" Bit Rates:2 Mb/s; 6 Mb/s; 9 Mb/s; 11 Mb/s; 12 Mb/s 18 Mb/s; 24 Mb/s; 36 Mb/s Bit Rates:48 Mb/s; 54 Mb/s Mode:Master Extra:tsf=0000000202533181 Extra: Last beacon: 9104ms ago IE: Unknown: 000D7475667473776972656C657373 IE: Unknown: 0108840C121618243048 IE: Unknown: 030101 IE: Unknown: 2A0100 IE: Unknown: 3202606C IE: Unknown: DD180050F2020101800003A4000027A4000042435E0062322F00 IE: Unknown: DD0A00037F04010000000000 Cell 03 - Address: 00:24:6C:60:CF:A0 Channel:6 Frequency:2.437 GHz (Channel 6) Quality=50/70 Signal level=-60 dBm Encryption key:off ESSID:"tuftswireless" Bit Rates:2 Mb/s; 11 Mb/s; 6 Mb/s; 9 Mb/s; 12 Mb/s 18 Mb/s; 24 Mb/s; 36 Mb/s Bit Rates:48 Mb/s; 54 Mb/s Mode:Master Extra:tsf=0000000c808e35af Extra: Last beacon: 8704ms ago IE: Unknown: 000D7475667473776972656C657373 IE: Unknown: 010884160C1218243048 IE: Unknown: 030106 IE: Unknown: 050400010100 IE: Unknown: 2A0100 IE: Unknown: 3202606C IE: Unknown: 2D1A4C101BFFFF000000000000000000000000000000000000000000 IE: Unknown: 3D1606001B000000FF000000000000000000000000000000 IE: Unknown: DD1E00904C334C101BFFFF000000000000000000000000000000000000000000 IE: Unknown: DD1A00904C3406001B000000FF000000000000000000000000000000 IE: Unknown: DD180050F2020101800003A4000027A4000042435E0062322F00 IE: Unknown: DD0A00037F04010000000000 Cell 04 - Address: 00:0B:86:58:1F:A0 Channel:11 Frequency:2.462 GHz (Channel 11) Quality=38/70 Signal level=-72 dBm Encryption key:off ESSID:"tuftswireless" Bit Rates:2 Mb/s; 11 Mb/s; 6 Mb/s; 9 Mb/s; 12 Mb/s 18 Mb/s; 24 Mb/s; 36 Mb/s Bit Rates:48 Mb/s; 54 Mb/s Mode:Master Extra:tsf=00000006687da181 Extra: Last beacon: 7328ms ago IE: Unknown: 000D7475667473776972656C657373 IE: Unknown: 010884160C1218243048 IE: Unknown: 03010B IE: Unknown: 050400010180 IE: Unknown: 2A0102 IE: Unknown: 3202606C IE: Unknown: DD180050F2020101800003A4000027A4000042435E0062322F00 IE: Unknown: DD0A00037F04010000000000 Cell 05 - Address: 00:24:6C:60:CF:B0 Channel:36 Frequency:5.18 GHz (Channel 36) Quality=41/70 Signal level=-69 dBm Encryption key:off ESSID:"tuftswireless" Bit Rates:12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s; 48 Mb/s 54 Mb/s Mode:Master Extra:tsf=0000002e94c969ed Extra: Last beacon: 7072ms ago IE: Unknown: 000D7475667473776972656C657373 IE: Unknown: 010698243048606C IE: Unknown: 030124 IE: Unknown: 2D1A4E001BFFFF000000000000000000000000000000000000000000 IE: Unknown: 3D1624050A000000FF000000000000000000000000000000 IE: Unknown: DD1E00904C334E001BFFFF000000000000000000000000000000000000000000 IE: Unknown: DD1A00904C3424050A000000FF000000000000000000000000000000 IE: Unknown: DD180050F2020101800003A4000027A4000042435E0062322F00 IE: Unknown: DD0A00037F04010000000000 Cell 06 - Address: 00:0B:86:59:FD:C8 Channel:40 Frequency:5.2 GHz (Channel 40) Quality=31/70 Signal level=-79 dBm Encryption key:off ESSID:"tuftswireless" Bit Rates:12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s; 48 Mb/s 54 Mb/s Mode:Master Extra:tsf=0000005a137c235f Extra: Last beacon: 6560ms ago IE: Unknown: 000D7475667473776972656C657373 IE: Unknown: 010698243048606C IE: Unknown: 030128 IE: Unknown: DD180050F2020101800003A4000027A4000042435E0062322F00 IE: Unknown: DD0A00037F04010000000000 Cell 07 - Address: 00:24:6C:60:D5:50 Channel:44 Frequency:5.22 GHz (Channel 44) Quality=37/70 Signal level=-73 dBm Encryption key:off ESSID:"tuftswireless" Bit Rates:12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s; 48 Mb/s 54 Mb/s Mode:Master Extra:tsf=0000005a1328778d Extra: Last beacon: 6336ms ago IE: Unknown: 000D7475667473776972656C657373 IE: Unknown: 010698243048606C IE: Unknown: 03012C IE: Unknown: 2D1A4E001BFFFF000000000000000000000000000000000000000000 IE: Unknown: 3D162C0508000000FF000000000000000000000000000000 IE: Unknown: DD1E00904C334E001BFFFF000000000000000000000000000000000000000000 IE: Unknown: DD1A00904C342C0508000000FF000000000000000000000000000000 IE: Unknown: DD180050F2020101800003A4000027A4000042435E0062322F00 IE: Unknown: DD0A00037F04010000000000 Cell 08 - Address: 00:0B:86:58:1F:A8 Channel:48 Frequency:5.24 GHz (Channel 48) Quality=34/70 Signal level=-76 dBm Encryption key:off ESSID:"tuftswireless" Bit Rates:12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s; 48 Mb/s 54 Mb/s Mode:Master Extra:tsf=0000005a13a8e1c3 Extra: Last beacon: 6124ms ago IE: Unknown: 000D7475667473776972656C657373 IE: Unknown: 010698243048606C IE: Unknown: 030130 IE: Unknown: DD180050F2020101800003A4000027A4000042435E0062322F00 IE: Unknown: DD0A00037F04010000000000 Cell 09 - Address: 00:24:6C:60:CF:F0 Channel:149 Frequency:5.745 GHz Quality=37/70 Signal level=-73 dBm Encryption key:off ESSID:"tuftswireless" Bit Rates:12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s; 48 Mb/s 54 Mb/s Mode:Master Extra:tsf=0000005a131955bb Extra: Last beacon: 764ms ago IE: Unknown: 000D7475667473776972656C657373 IE: Unknown: 010698243048606C IE: Unknown: 030195 IE: Unknown: 2D1A4E001BFFFF000000000000000000000000000000000000000000 IE: Unknown: 3D16950508000000FF000000000000000000000000000000 IE: Unknown: DD1E00904C334E001BFFFF000000000000000000000000000000000000000000 IE: Unknown: DD1A00904C34950508000000FF000000000000000000000000000000 IE: Unknown: DD180050F2020101800003A4000027A4000042435E0062322F00 IE: Unknown: DD0A00037F04010000000000 lsb_release -d: Description: Ubuntu 11.10 uname -a: Linux Beast 3.0.0-13-generic #22-Ubuntu SMP Wed Nov 2 13:27:26 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/924082/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
