14.04 LTS - Network breaks down after a few minutes

**stadt_kartoffel** · July 19th, 2014

Dear community,
since the update to 14.04 my network keeps breaking down. In the beginning it was only unstable but now (after trying to fix the problem with help from forums) it seems to be completely wrecked. At first I couldn't reconnect after sleep mode and had to restart the computer every time. Then I did something that seemed to fix it but it sometimes (seldomly) disconnected. But last week out of the blue it started to disconnect after 5 minutes of working perfectly. The bluetooth symbol in the system tray is also grey (not working) sometimes. When this happens I can't even plug in a cable to get the internet working. The network manager says that my wireless network isn't ready and doesn't show any wifis. Oh and when the problem started it was possible to put the computer to sleepmode and after that it would work again for a few minutes. This doesn't work now. I hope this description is helpful in any way...
Here is the output of the script:

Code:

########## wireless info START ##########

##### release #####

Distributor ID:    Ubuntu
Description:    Ubuntu 14.04 LTS
Release:    14.04
Codename:    trusty

##### kernel #####

Linux miri 3.13.0-32-generic #57-Ubuntu SMP Tue Jul 15 03:51:12 UTC 2014 i686 i686 i686 GNU/Linux

##### lspci #####

09:00.0 Ethernet controller [0200]: Marvell Technology Group Ltd. 88E8040 PCI-E Fast Ethernet Controller [11ab:4354] (rev 12)
    Subsystem: Dell Device [1028:022e]
    Kernel driver in use: sky2
0b:00.0 Network controller [0280]: Intel Corporation PRO/Wireless 4965 AG or AGN [Kedron] Network Connection [8086:4229] (rev 61)
    Subsystem: Intel Corporation Device [8086:1121]
    Kernel driver in use: iwl4965

##### lsusb #####

Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 007 Device 005: ID 0a5c:4503 Broadcom Corp. Mouse (Boot Interface Subclass)
Bus 007 Device 004: ID 0a5c:4502 Broadcom Corp. Keyboard (Boot Interface Subclass)
Bus 007 Device 003: ID 413c:8126 Dell Computer Corp. Wireless 355 Bluetooth
Bus 007 Device 002: ID 0a5c:4500 Broadcom Corp. BCM2046B1 USB 2.0 Hub (part of BCM2046 Bluetooth)
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 002: ID 05a9:2640 OmniVision Technologies, Inc. OV2640 Webcam
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 002: ID 0483:2016 STMicroelectronics Fingerprint Reader
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

##### PCMCIA Card Info #####

##### rfkill #####

0: hci0: Bluetooth
    Soft blocked: no
    Hard blocked: no
1: phy0: Wireless LAN
    Soft blocked: no
    Hard blocked: no

##### lsmod #####

iwl4965               106859  0 
iwlegacy               88016  1 iwl4965
mac80211              546051  2 iwl4965,iwlegacy
cfg80211              409394  3 iwl4965,iwlegacy,mac80211

##### iw reg get #####

country 00:
    (2402 - 2472 @ 40), (3, 20)
    (2457 - 2482 @ 40), (3, 20), PASSIVE-SCAN, NO-IBSS
    (2474 - 2494 @ 20), (3, 20), NO-OFDM, PASSIVE-SCAN, NO-IBSS
    (5170 - 5250 @ 40), (3, 20), PASSIVE-SCAN, NO-IBSS
    (5735 - 5835 @ 40), (3, 20), PASSIVE-SCAN, NO-IBSS

##### interfaces #####

auto lo
iface lo inet loopback

##### iwconfig #####

wlan0     IEEE 802.11abgn  ESSID:"FRITZ!Box Fon WLAN 7170"  
          Mode:Managed  Frequency:2.437 GHz  Access Point: <MAC address removed>   
          Bit Rate=1 Mb/s   Tx-Power=15 dBm   
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Power Management:off
          Link Quality=70/70  Signal level=-36 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:84   Missed beacon:0

##### route #####

Kernel-IP-Routentabelle
Ziel            Router          Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.1.1     0.0.0.0         UG    0      0        0 eth0
192.168.1.0     0.0.0.0         255.255.255.0   U     1      0        0 eth0
192.168.1.0     0.0.0.0         255.255.255.0   U     9      0        0 wlan0

##### resolv.conf #####

nameserver 127.0.1.1
search lan
nameserver 192.168.0.1

##### nm-tool #####

NetworkManager Tool

State: connected (global)

- Device: <MAC address removed> ----------------------------------------------------
  Type:              Bluetooth
  Driver:            bluez
  State:             disconnected
  Default:           no

  Capabilities:

- Device: <MAC address removed> ----------------------------------------------------
  Type:              Bluetooth
  Driver:            bluez
  State:             disconnected
  Default:           no

  Capabilities:

- Device: wlan0  [Auto FRITZ!Box Fon WLAN 7170] --------------------------------
  Type:              802.11 WiFi
  Driver:            iwl4965
  State:             connected
  Default:           no
  HW Address:        <MAC address removed>

  Capabilities:
    Speed:           1 Mb/s

  Wireless Properties
    WEP Encryption:  yes
    WPA Encryption:  yes
    WPA2 Encryption: yes

  Wireless Access Points (* = current AP)
    *FRITZ!Box Fon WLAN 7170: Infra, <MAC address removed>, Freq 2437 MHz, Rate 54 Mb/s, Strength 80 WPA

  IPv4 Settings:
    Address:         192.168.1.141
    Prefix:          24 (255.255.255.0)
    Gateway:         192.168.1.1

    DNS:             192.168.1.1

  IPv6 Settings:
    Address:         2a00:1230:a977:0:300a:ba87:4e04:423
    Prefix:          64
    Gateway:         ::

    Address:         2a00:1230:a977:0:21f:3bff:fe89:2091
    Prefix:          64
    Gateway:         ::

    Address:         fe80::21f:3bff:fe89:2091
    Prefix:          64
    Gateway:         ::

- Device: eth0  [Kabelnetzwerkverbindung 1] ------------------------------------
  Type:              Wired
  Driver:            sky2
  State:             connected
  Default:           yes
  HW Address:        <MAC address removed>

  Capabilities:
    Carrier Detect:  yes
    Speed:           100 Mb/s

  Wired Properties
    Carrier:         on

  IPv4 Settings:
    Address:         192.168.1.130
    Prefix:          24 (255.255.255.0)
    Gateway:         192.168.1.1

    DNS:             192.168.1.1

  IPv6 Settings:
    Address:         2a00:1230:a977:0:5d0e:66d0:919e:12df
    Prefix:          64
    Gateway:         fe80::215:6dff:fed3:9adc

    Address:         2a00:1230:a977:0:21d:9ff:fe52:117e
    Prefix:          64
    Gateway:         fe80::215:6dff:fed3:9adc

    Address:         fe80::21d:9ff:fe52:117e
    Prefix:          64
    Gateway:         fe80::215:6dff:fed3:9adc

##### NetworkManager.state #####

[main]
NetworkingEnabled=true
WirelessEnabled=true
WWANEnabled=true

##### NetworkManager.conf #####

[main]
plugins=ifupdown,keyfile,ofono
dns=dnsmasq

[ifupdown]
managed=false

##### iwlist #####

wlan0     Scan completed :
          Cell 01 - Address: <MAC address removed>
                    Channel:6
                    Frequency:2.437 GHz (Channel 6)
                    Quality=70/70  Signal level=-36 dBm  
                    Encryption key:on
                    ESSID:"FRITZ!Box Fon WLAN 7170"
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s
                    Bit Rates:6 Mb/s; 9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s
                              36 Mb/s; 48 Mb/s; 54 Mb/s
                    Mode:Master
                    Extra:tsf=000000013bcec793
                    Extra: Last beacon: 0ms ago
                    IE: Unknown: 0017465249545A21426F7820466F6E20574C414E2037313730
                    IE: Unknown: 010482848B96
                    IE: Unknown: 030106
                    IE: Unknown: 2A0104
                    IE: Unknown: 32080C1218243048606C
                    IE: WPA Version 1
                        Group Cipher : TKIP
                        Pairwise Ciphers (1) : TKIP
                        Authentication Suites (1) : PSK
                    IE: Unknown: DD0A0800280101000200FF0F
                    IE: Unknown: DD180050F2020101800003A4000027A4000042435E0062322F00

##### iwlist channel #####

wlan0     32 channels in total; available frequencies :
          Channel 01 : 2.412 GHz
          Channel 02 : 2.417 GHz
          Channel 03 : 2.422 GHz
          Channel 04 : 2.427 GHz
          Channel 05 : 2.432 GHz
          Channel 06 : 2.437 GHz
          Channel 07 : 2.442 GHz
          Channel 08 : 2.447 GHz
          Channel 09 : 2.452 GHz
          Channel 10 : 2.457 GHz
          Channel 11 : 2.462 GHz
          Channel 12 : 2.467 GHz
          Channel 13 : 2.472 GHz
          Channel 36 : 5.18 GHz
          Channel 40 : 5.2 GHz
          Channel 44 : 5.22 GHz
          Channel 48 : 5.24 GHz
          Channel 52 : 5.26 GHz
          Channel 56 : 5.28 GHz
          Channel 60 : 5.3 GHz
          Channel 64 : 5.32 GHz
          Channel 100 : 5.5 GHz
          Channel 104 : 5.52 GHz
          Channel 108 : 5.54 GHz
          Channel 112 : 5.56 GHz
          Channel 116 : 5.58 GHz
          Channel 120 : 5.6 GHz
          Channel 124 : 5.62 GHz
          Channel 128 : 5.64 GHz
          Channel 132 : 5.66 GHz
          Channel 136 : 5.68 GHz
          Channel 140 : 5.7 GHz
          Current Frequency=2.437 GHz (Channel 6)

##### modinfo #####

filename:       /lib/modules/3.13.0-32-generic/kernel/drivers/net/wireless/iwlegacy/iwl4965.ko
firmware:       iwlwifi-4965-2.ucode
alias:          iwl4965
license:        GPL
author:         Copyright(c) 2003-2011 Intel Corporation <ilw@linux.intel.com>
version:        in-tree:
description:    Intel(R) Wireless WiFi 4965 driver for Linux
srcversion:     52A3B1E68D22B0078326AC5
alias:          pci:v00008086d00004230sv*sd*bc*sc*i*
alias:          pci:v00008086d00004229sv*sd*bc*sc*i*
depends:        iwlegacy,cfg80211,mac80211
intree:         Y
vermagic:       3.13.0-32-generic SMP mod_unload modversions 686 
signer:         Magrathea: Glacier signing key
sig_key:        <MAC address removed>:8D:85:9A:AE:BD:A2:CA:5D:D0:47:16:24:4F:A0
sig_hashalgo:   sha512
parm:           swcrypto:using crypto in software (default 0 [hardware]) (int)
parm:           queues_num:number of hw queues. (int)
parm:           11n_disable:disable 11n functionality (int)
parm:           amsdu_size_8K:enable 8K amsdu size (int)
parm:           fw_restart:restart firmware in case of error (int)

filename:       /lib/modules/3.13.0-32-generic/kernel/drivers/net/wireless/iwlegacy/iwlegacy.ko
license:        GPL
author:         Copyright(c) 2003-2011 Intel Corporation <ilw@linux.intel.com>
version:        in-tree:
description:    iwl-legacy: common functions for 3945 and 4965
srcversion:     400F302BE5C25B3C98A6CE8
depends:        mac80211,cfg80211
intree:         Y
vermagic:       3.13.0-32-generic SMP mod_unload modversions 686 
signer:         Magrathea: Glacier signing key
sig_key:        <MAC address removed>:8D:85:9A:AE:BD:A2:CA:5D:D0:47:16:24:4F:A0
sig_hashalgo:   sha512
parm:           led_mode:0=system default, 1=On(RF On)/Off(RF Off), 2=blinking (int)
parm:           bt_coex_active:enable wifi/bluetooth co-exist (bool)

##### modules #####

lp

##### blacklist #####

[/etc/modprobe.d/blacklist-ath_pci.conf]
blacklist ath_pci

[/etc/modprobe.d/blacklist.conf]
blacklist evbug
blacklist usbmouse
blacklist usbkbd
blacklist eepro100
blacklist de4x5
blacklist eth1394
blacklist snd_intel8x0m
blacklist snd_aw2
blacklist i2c_i801
blacklist prism54
blacklist bcm43xx
blacklist garmin_gps
blacklist asus_acpi
blacklist snd_pcsp
blacklist pcspkr
blacklist amd76x_edac

[/etc/modprobe.d/fbdev-blacklist.conf]
blacklist arkfb
blacklist aty128fb
blacklist atyfb
blacklist radeonfb
blacklist cirrusfb
blacklist cyber2000fb
blacklist gx1fb
blacklist gxfb
blacklist kyrofb
blacklist matroxfb_base
blacklist mb862xxfb
blacklist neofb
blacklist nvidiafb
blacklist pm2fb
blacklist pm3fb
blacklist s3fb
blacklist savagefb
blacklist sisfb
blacklist tdfxfb
blacklist tridentfb
blacklist viafb
blacklist vt8623fb

[/etc/modprobe.d/libpisock9.conf]
blacklist visor

[/etc/modprobe.d/osspd.conf]
blacklist snd-pcm-oss
blacklist snd-mixer-oss
blacklist snd-seq-oss

##### udev rules #####

# PCI device 0x11ab:0x4354 (sky2)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="<MAC address removed>", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"

# PCI device 0x8086:0x4229 (iwlagn)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="<MAC address removed>", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="wlan*", NAME="wlan0"

##### dmesg #####

[   29.201111] iwl4965: Intel(R) Wireless WiFi 4965 driver for Linux, in-tree:
[   29.201115] iwl4965: Copyright(c) 2003-2011 Intel Corporation
[   29.201160] iwl4965 0000:0b:00.0: can't disable ASPM; OS doesn't have ASPM control
[   29.201345] iwl4965 0000:0b:00.0: Detected Intel(R) Wireless WiFi Link 4965AGN, REV=0x4
[   29.244256] iwl4965 0000:0b:00.0: device EEPROM VER=0x36, CALIB=0x5
[   29.278419] iwl4965 0000:0b:00.0: Tunable channels: 13 802.11bg, 19 802.11a channels
[   29.278525] iwl4965 0000:0b:00.0: irq 46 for MSI/MSI-X
[   29.638198] iwl4965 0000:0b:00.0: loaded firmware version 228.61.2.24
[   29.668060] ieee80211 phy0: Selected rate control algorithm 'iwl-4965-rs'
[   35.166830] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[   35.167393] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[   45.153434] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[   45.841276] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[   87.268301] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[   87.789705] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[   99.721203] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[  100.390797] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[  141.476354] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[  141.830110] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[ 1166.014602] wlan0: authenticate with <MAC address removed>
[ 1166.023699] wlan0: send auth to <MAC address removed> (try 1/3)
[ 1166.025493] wlan0: authenticated
[ 1166.025628] iwl4965 0000:0b:00.0 wlan0: disabling HT/VHT due to WEP/TKIP use
[ 1166.028047] wlan0: associate with <MAC address removed> (try 1/3)
[ 1166.031819] wlan0: RX AssocResp from <MAC address removed> (capab=0x411 status=0 aid=6)
[ 1166.060704] wlan0: associated
[ 1166.060738] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready

########## wireless info END ############

Edit: I can only connect via cable when plugging in before ubuntu is running.

**praseodym** · July 20th, 2014

Check the following settings:

fixed channel
WPA2-AES encryption instead of WPA
network not hidden
MAC address filter off

Check the router manual

**mikewhatever** · July 26th, 2014

There isn't much to be done about Intel's PRO/Wireless 4965. Intel maintains the driver, and is unlikely to ever bother fixing it.

**hwertz10** · February 24th, 2015

I've found a reasonably stable solution actually.
I do have "options iwl4965 swcrypto=1" set in /etc/modprobe.d/iwl4965.conf . But I was still having some instability -- light usage has been no sweat. But heavier traffic? I have found if the signal is somewhat low, sshfs traffic can bring this thing down within minutes.

I read some (2009-era, when the "latest" iwl4965 firmware came out) that people were having problems with it and went to the previous firmware. So I tried it -- and it's stable for me!

So, you get iwl4965-ucode-228.57.2.23.tgz (current is iwlwifi-4965-ucode-228.61.2.24.tgz). This tgz has like a README, a license, and the iwlwifi-4965-2.ucode file. You put that ucode file into /lib/firmware/ and either remove and reload the iwl4965 module or reboot. Keep a backup of that ucode file somewhere, it'll be overwritten if and when the ubuntu package with all the firmware in it gets updated.

You might not need swcrypto=1 with this either. The reports were that the crypto-related problems also begain with the newer 228.61.2.24 firmware! But the CPU use of swcrypto is so low I'm not going to play with it to find out.

**Beliriel** · March 24th, 2015

Hey just wanted to post here and saying that I also had this problem of my network breaking down every few minutes. My "noob fix" was constantly having a stream to the net open like twitch.tv or spotify. It somehow kept the connection, but as soon as I started browsing the net without a stream the connection broke after 5mins on average.

Through the wifiscript I found out I had the Intel PRO/Wireless 4965 network controller and tried hwertz10 method of downgrading my iwl4965-2.ucode file in /lib/firmware and rebooting. It's now been an hour without disconnect (and no stream open) and I'm fairly confident its fixed.

As I'm quite inexpirienced with how to reload these modules, I haven't touched the swcrypto option in iwl4965.conf

Edit: Apparently it didn't work. In these two weeks only at first it seemed to work, but even after reloading the modules connection breaks down.

**andrewj-jones** · September 5th, 2015

I registered just to say that hwertz10's solution above worked for me. I'm absolutely thrilled to have wireless again after so much pain.
I'm using LUbuntu 14.04 (kernel 3.13.0-24-generic), and iwl4965 module. I'm connecting to the network using wicd-curses and it's working brilliantly. Of course I haven't tested it under a heavy load yet.

**praseodym** · September 5th, 2015

3.13.0-24 should be updated soon

**andrewj-jones** · September 5th, 2015

Sorry just to update. I found that since my last post, my internet started dropping in and out, even though the signal strength was 80%. I celebrated too early.
When it was up it was fast, but it kept cutting in and out.

I changed from wicd to nm-applet, and so far everything seems much better (no disconnections yet).