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Here is the thing! am on day 5 of no wired internet connection. I have spent the last 4 days searching through every forum and Q&A sites, until i finally decided to post this, so I have done my homework. Before I take my laptop to maintenance shop for hardware failures i want to check with you guys first.

Problem Description: Like the question says my wired connection stopped working suddenly after an update. I am using ubuntu 12.04 LTS. Network Manager says Wired Networks disconnected. Wireless is working perfectly. And also it doesn't work on Windows 7 too, it says cable unplugged. I have tried the cable on other computer and it works perfectly.

nm-tool output:

NetworkManager Tool

State: connected (global)

- Device: wlan0  [Connectify-me] -----------------------------------------------
  Type:              802.11 WiFi
  Driver:            iwlwifi
  State:             connected
  Default:           yes
  HW Address:        9C:4E:36:29:F7:D4

    Speed:           58 Mb/s

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

  Wireless Access Points (* = current AP)
    TP-LINK_8AB114:  Infra, A0:F3:C1:8A:B1:14, Freq 2452 MHz, Rate 54 Mb/s, Strength 25 WPA2
    ZTE_HG_0:        Infra, 00:1D:0F:BF:BE:61, Freq 2437 MHz, Rate 54 Mb/s, Strength 47
    ZTE_HG_0:        Infra, 00:21:27:C1:19:D9, Freq 2437 MHz, Rate 54 Mb/s, Strength 39
    *Connectify-me:  Infra, E8:39:DF:3E:AF:8E, Freq 2462 MHz, Rate 54 Mb/s, Strength 87 WPA2

  IPv4 Settings:
    Prefix:          24 (


- Device: eth0 -----------------------------------------------------------------
  Type:              Wired
  Driver:            atl1c
  State:             unavailable
  Default:           no
  HW Address:        00:1E:DE:F7:A6:C9

    Carrier Detect:  yes

  Wired Properties
    Carrier:         off

sudo lshw -C network output:

       description: Ethernet interface
       product: AR8152 v2.0 Fast Ethernet
       vendor: Qualcomm Atheros
       physical id: 0
       bus info: pci@0000:01:00.0
       logical name: eth0
       version: c1
       serial: 00:1e:de:f7:a6:c9
       capacity: 100Mbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress vpd bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=atl1c driverversion= latency=0 link=no multicast=yes port=twisted pair
       resources: irq:48 memory:f7e00000-f7e3ffff ioport:e000(size=128)
       description: Wireless interface
       product: Centrino Wireless-N 2200
       vendor: Intel Corporation
       physical id: 0
       bus info: pci@0000:02:00.0
       logical name: wlan0
       version: c4
       serial: 9c:4e:36:29:f7:d4
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=iwlwifi driverversion=3.2.0-57-generic firmware= ip= latency=0 link=yes multicast=yes wireless=IEEE 802.11bgn
resources: irq:46 memory:f7d00000-f7d01fff

ifconfig eth0 output:

eth0      Link encap:Ethernet  HWaddr 00:1e:de:f7:a6:c9  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

So there you have it guys! Let me know if you need additional information. So Please help me!!!

share|improve this question
It is probably a driver problem. Can you please post the output of lspci -vnn | grep -i net – MariusMatutiae Dec 14 '13 at 8:24
01:00.0 Ethernet controller [0200]: Qualcomm Atheros AR8152 v2.0 Fast Ethernet [1969:2062] (rev c1) 02:00.0 Network controller [0280]: Intel Corporation Centrino Wireless-N 2200 [8086:0890] (rev c4) – tekesteg Dec 14 '13 at 8:58
@MariusMatutiae..i have also downloaded compat wireless and loaded the module atl1c, but still no luck. – tekesteg Dec 14 '13 at 9:03
Try mii-tool -r, pls – MariusMatutiae Dec 14 '13 at 11:54
when i tried that without sudo i get SIOCGMIIPHY on 'eth0' failed: Operation not permitted SIOCGMIIPHY on 'eth1' failed: Operation not permitted SIOCGMIIPHY on 'eth2' failed: Operation not permitted SIOCGMIIPHY on 'eth3' failed: Operation not permitted SIOCGMIIPHY on 'eth4' failed: Operation not permitted SIOCGMIIPHY on 'eth5' failed: Operation not permitted SIOCGMIIPHY on 'eth6' failed: Operation not permitted SIOCGMIIPHY on 'eth7' failed: Operation not permitted no MII interfaces found When i use sudo i get restarting autonegotiation... – tekesteg Dec 14 '13 at 15:24

Yours is not a clear-cut situation, so we go by successive approximations.

First, issue these commands:

    sudo service network-manager stop
    sudo ifconfig eth0 down
    sudo ifconfig eth0 up
    sudo dhclient eth0

and see whether this works. In any case, re-issue

    sudo service network-manager start

Second. We may try to install the latest atl1c driver. Go to a convenient, empty directory, and issue these commands:

    sudo apt-get install linux-headers-generic build-essential
    tar xvf compat-wireless.tar.bz2
    cd compat-wireless-2012-12-18/
    scripts/driver-select atl1c
    sudo make install
    sudo rmmod atl1c 
    sudo modprobe atl1c
    sudo ifconfig eth0 down
    sudo ifconfig eth0 up
    sudo dhclient eth0

and see now whether this works. Just let me know, if at all solvable your problem will require a few iterations.

share|improve this answer
All of the above didn't solve the problem. sudo ifconfig eth0 up and sudo ifconfig eth0 down didn't give any response` but sudo dhclient eth0 stays on the prompt without any response, it doesn't close. The output of sudo make install this might be helpful make[1]: Entering directory `/usr/src/linux-headers-3.8.0-34-generic' INSTALL /home/take/trouble/compat-wireless-2012-12-18/compat/compat.ko Can't read private key INSTALL /home/take/trouble/compat-wireless-2012-12-18/drivers/net/ethernet/atheros/atl1c‌​/atl1c.ko Can't read private key DEPMOD 3.8.0-34-generic – tekesteg Dec 14 '13 at 10:45
Can't read private key does not mean anything, just plunge ahead. But did you stop network manager before trying the first method? It is important. – MariusMatutiae Dec 14 '13 at 11:24
yes i did. It stopped my wifi connection too. I re enabled it to post here. – tekesteg Dec 14 '13 at 11:30

Wired properties carrier is off; must activate it:

echo on | sudo tee /sys/class/net/eth0/device/power/control
share|improve this answer
Could you explain your answer little bit more? – VL-80 Feb 28 '14 at 14:33

I had a similar issue and I found that no amount of drivers, bios, or uninstall/reinstalls worked.

Can you try opening your computer case/laptop and resetting the CMOS by

  1. removing/installing battery
  2. simply moving the jumpers from position 1-2 to 2-3, then waiting about 10 seconds, then reverting back to their default 1-2 spot?

The only way I was able to solve this was the CMOS method, as it appears as though my computer might have been subject to some kind of power surge or failure (even though everything was on surge protectors).

On a side note I probably need to get better surge protectors.

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