1

I'm running Ubuntu 14.04 and the network manager suddenly stopped working so I can't access the internet. The network manager icon doesn't appear in the bar. When I access the network manager from settings, there is a blank window (usually there is a history of wifi connections as far as I remember).

On the last session it worked properly. Today suddenly it's not working - neither via ethernet nor via wifi. Although on the Windows internet connection is working properly.

I tried to restart the network manager via the terminal using this command:

sudo service network-manager restart

The output was: "Stop: Unknown instance: network-manager start/running, process 2256"

... but the network manager still isn't working (nor after I restarted the PC).

That's all I figured out with my ubuntu skills so I ask for your help. I'll appreciate any tips!

František Kopřiva
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  • Same problem here. Apparently the same happened a few months ago to people with the -proposed repository enabled. Did they push the update without fixing it? That's appalling, I think I'll finally stop using Ubuntu after this. http://askubuntu.com/questions/727127/last-upgrade-crashes-network-manager-no-internet-connection-no-applet – fqq May 13 '16 at 20:10

4 Answers4

2

First, I used these commands (thanks, Beleriand):

sudo ifconfig eth0 up
sudo dhclient eth0

Then I solved it by upgrading the network manager: 14.04 - Network manager stopped working

Thank you!

Community
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František Kopřiva
  • 31
  • 2
    Further to the František Kopřiva's answer, this appears to be a problem relating to network manager not having been upgraded yet, but libnl3 has been, causing a conflict. Once you've got a working network connection by the above method, you should be able to get network manager upgraded using sudo apt-get update and then sudo apt-get upgrade – fred2 May 14 '16 at 14:32
1

  1. Boot a Ubuntu live CD in "Try without installing". Make sure you are connected to the internet.

  2. In terminal type:

    sudo mount --bind /dev /<chrootlocation>/dev
sudo mount --bind /proc /<chrootlocation>/proc
sudo mount --bind /sys /<chrootlocation>/sys
sudo cp /etc/resolv.conf /<chrootlocation>/etc/resolv.conf
sudo chroot /<chrootlocation>

    You will need to replace with the appropriate location of your Ubuntu install, typically the label of the partition it's installed on. The partition must also be mounted so that you can access it.

  3. In terminal type:

    sudo apt-get update
sudo apt-get install network-manager

  4. In terminal type exit. This exits you from the chroot environment.

  5. In terminal type sudo reboot to reboot your computer.

Kulfy
  • 17,696
Deepak Sankar
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0

Same problem here as many other users have this after todays update.

sudo ifconfig eth0 up
sudo dhclient eth0

will fix the problem temporarily but after reboot it wont work

Beleriand
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0

I am having the same problem, out of the sudden network manager disappeared and I cannot access the internet. It seems to be a problem related to Network Manager (the app). I tried to reinstall it but it did not worked. There is a couple of tests that you can do on Terminal

sudo lshw -C network
iwconfig
ifconfig -a
nm-tool
rfkill list wifi

It is really important you try these commands on Terminal for anyone to know what is happening in your computer.

My results: 

$ sudo lshw -C network

  *-network DESABILITADO 
       descrição: Interface sem fio
       produto: RT3290 Wireless 802.11n 1T/1R PCIe
       fabricante: Ralink corp.
       ID físico: 0
       informações do barramento: pci@0000:01:00.0
       nome lógico: wlan0
       versão: 00
       serial: 80:56:f2:cb:01:19
       largura: 32 bits
       clock: 33MHz
       capacidades: pm msi pciexpress bus_master cap_list ethernet physical wireless
       configuração: broadcast=yes driver=rt2800pci driverversion=3.19.0-47-generic firmware=N/A latency=0 link=no multicast=yes wireless=IEEE 802.11bgn
       recursos: irq:16 memória:52510000-5251ffff
  *-network DESABILITADO
       descrição: Ethernet interface
       produto: RTL8101/2/6E PCI Express Fast/Gigabit Ethernet controller
       fabricante: Realtek Semiconductor Co., Ltd.
       ID físico: 0
       informações do barramento: pci@0000:02:00.0
       nome lógico: eth0
       versão: 05
       serial: a0:d3:c1:6a:3a:5c
       tamanho: 10Mbit/s
       capacidade: 100Mbit/s
       largura: 64 bits
       clock: 33MHz
       capacidades: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
       configuração: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half latency=0 link=no multicast=yes port=MII speed=10Mbit/s
       recursos: irq:28 porta de E/S:3000(tamanho=256) memória:52404000-52404fff memória:52400000-52403fff

This means my Network is disabled (desabilitado)

$ iwconfig

eth0      no wireless extensions.

wlan0     IEEE 802.11bgn  ESSID:off/any 
          Mode:Managed  Access Point: Not-Associated   Tx-Power=0 dBm   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Power Management:off

lo        no wireless extensions.

$ ifconfig -a

eth0      Link encap:Ethernet  Endereço de HW a0:d3:c1:6a:3a:5c 
          BROADCAST MULTICAST  MTU:1500  Métrica:1
          pacotes RX:0 erros:0 descartados:0 excesso:0 quadro:0
          Pacotes TX:0 erros:0 descartados:0 excesso:0 portadora:0
          colisões:0 txqueuelen:1000
          RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)

lo        Link encap:Loopback Local 
          inet end.: 127.0.0.1  Masc:255.0.0.0
          endereço inet6: ::1/128 Escopo:Máquina
          UP LOOPBACK RUNNING  MTU:65536  Métrica:1
          pacotes RX:1906 erros:0 descartados:0 excesso:0 quadro:0
          Pacotes TX:1906 erros:0 descartados:0 excesso:0 portadora:0
          colisões:0 txqueuelen:0
          RX bytes:167560 (167.5 KB) TX bytes:167560 (167.5 KB)

wlan0     Link encap:Ethernet  Endereço de HW 80:56:f2:cb:01:19 
          BROADCAST MULTICAST  MTU:1500  Métrica:1
          pacotes RX:0 erros:0 descartados:0 excesso:0 quadro:0
          Pacotes TX:0 erros:0 descartados:0 excesso:0 portadora:0
          colisões:0 txqueuelen:1000
          RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)

$ nm-tool

** (process:7376): WARNING **: Could not initialize NMClient /org/freedesktop/NetworkManager: The name org.freedesktop.NetworkManager was not provided by any .service files

NetworkManager Tool

State: unknown


** (process:7376): WARNING **: error: could not connect to NetworkManager

This means that the computer simply cannot access network manager.

$ rfkill list wifi

0: phy0: Wireless LAN
   Soft blocked: no
   Hard blocked: no

This means that there is no software or hardware blocking the network adapter.

So far I did not manage to solve my problem yet.

But as far as I know, if your rfkill list wifi shows it is hard blocked, there is probably a switch and you can turn your network adapter on through FN+f12 or by looking into a proper switch (Physical).

I hope it helps

Kulfy
  • 17,696
Cassio
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