Wired connection not working, ubuntu 14.04

**leroyklotz** · October 7th, 2014

Wireless works fine without any problem, but wired connection is not working for me.

I'm running Ubuntu 14.04.
I have tried to follow a number of different topics, mainly these; http://ubuntuforums.org/showthread.php?t=1504618, http://ubuntuforums.org/showthread.php?t=1494628. But so far, still no connection with my cable.
I have edited these files quite a bit because everyone is giving different instructions for similar issues, however I cant seem to get it right. Please someone help me out..

ifconfig:

Code:

eth0      Link encap:Ethernet  HWaddr ac:22:0b:b0:91:3e  
          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)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:2424 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2424 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:241074 (241.0 KB)  TX bytes:241074 (241.0 KB)

wlan0     Link encap:Ethernet  HWaddr 48:d2:24:3d:bc:42  
          inet addr:192.168.0.101  Bcast:192.168.0.255  Mask:255.255.255.0
          inet6 addr: fe80::4ad2:24ff:fe3d:bc42/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:10494 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8782 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:8283223 (8.2 MB)  TX bytes:1409996 (1.4 MB)

/etc/network/interfaces:

Code:

 #This file describes the network interfaces available on your system
 #and how to activate them. For more information, see interfaces(5).

 #The loopback network interface
 auto lo
 iface lo inet loopback
 address 127.0.0.1
 netmask 255.0.0.0

 #The primary network interface
 auto eth0
 iface eth0 inet dhcp

/etc/resolv.conf:

Code:

 #Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
 #DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
 nameserver 127.0.1.1
 nameserver 192.168.0.1
 nameserver 94.208.107.35
 #search WL309

**varunendra** · October 8th, 2014

Assuming you are using the default Network Manager program, delete everything in the /etc/network/interfaces file leaving only the two default lines -

Code:

auto lo
iface lo inet loopback

Then try to connect with Network Manager, and if it fails, or if the connection appears to be disabled, please post back the outputs of the following commands -

Code:

sudo lshw -C network
nm-tool
cat /etc/network/interfaces
cat /etc/NetworkManager/NetworkManager.conf
cat /var/lib/NetworkManager/NetworkManager.state

While posting the outputs, please use 'Code' tags. It preserves the output's formatting and makes the post cleaner, compact and more readable. To see a quick 'HowTo' with screenshots, please follow the "Use Code Tags" link in my signature.

**leroyklotz** · October 8th, 2014

Thank you sir, this seemingly easy fix has solved my problem.

**andy102** · October 8th, 2014

From time to time, this issue pops its ugly head up. I have seen it with everything from the latest Ubuntu, to Puppy, Threads like these are great, when Im dead in the water, I grab my cell phone and do a wild search for my issue. uduslly comes right here in this forum. That said thank you both.

**varunendra** · October 8th, 2014

Awesome! I really never expected it to be that easy. Although I'm not surprised either.

Welcome both of you!

@leroyklotz,

If the fix seems to be permanent (not a happy but short-lived mysterious coincidence), please mark the thread as [SOLVED] using "Thread Tools" link above the top post. It makes a solved thread more useful to other users by indicating that it contains a possible fix to the mentioned problem. Of course feel free to post back the output I asked if the problem comes back.

**leroyklotz** · October 9th, 2014

I've ticked the solved marker. Thanks again for helping out!

**rshetty112** · September 1st, 2015

Hi, I'm facing the same issue. I'm posting the outputs here:

sudo lshw -C network:

Code:

Code:

*-network               
       description: Wireless interface
       product: AR9485 Wireless Network Adapter
       vendor: Qualcomm Atheros
       physical id: 0
       bus info: pci@0000:02:00.0
       logical name: wlan0
       version: 01
       serial: 84:4b:f5:cf:ac:3f
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list rom ethernet physical wireless
       configuration: broadcast=yes driver=ath9k  driverversion=3.19.0-25-generic firmware=N/A latency=0 link=no  multicast=yes wireless=IEEE 802.11bgn
       resources: irq:16 memory:f7d00000-f7d7ffff memory:f7d80000-f7d8ffff
  *-network
       description: Ethernet interface
       product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
       vendor: Realtek Semiconductor Co., Ltd.
       physical id: 0
       bus info: pci@0000:04:00.0
       logical name: eth0
       version: 07
       serial: 54:53:ed:a7:11:d9
       size: 100Mbit/s
       capacity: 1Gbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix vpd bus_master cap_list  ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd  autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=r8169  driverversion=2.3LK-NAPI duplex=full firmware=rtl8168e-3_0.0.4 03/27/12  latency=0 link=yes multicast=yes port=MII speed=100Mbit/s
       resources: irq:27 ioport:c000(size=256) memory:f0a04000-f0a04fff memory:f0a00000-f0a03fff

nm-tool:

Code:

NetworkManager Tool

State: disconnected

- Device: eth0 -----------------------------------------------------------------
  Type:              Wired
  Driver:            r8169
  State:             disconnected
  Default:           no
  HW Address:        54:53:ED:A7:11:grin:9

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

  Wired Properties
    Carrier:         on


- Device: wlan0 ----------------------------------------------------------------
  Type:              802.11 WiFi
  Driver:            ath9k
  State:             disconnected
  Default:           no
  HW Address:        84:4B:F5:CF:AC:3F

  Capabilities:

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

  Wireless Access Points 
    Tenda_5A17E0:    Infra, C8:3A:35:5A:17:E0, Freq 2447 MHz, Rate 54 Mb/s, Strength 70 WPA
    PartyVan:        Infra, E8:94:F6:F2:EC:CB, Freq 2447 MHz, Rate 54 Mb/s, Strength 54 WPA WPA2
    NETGEAR50:       Infra, C4:04:15:4F:C4:00, Freq 2437 MHz, Rate 54 Mb/s, Strength 47 WPA2
    Free Candy:      Infra, 38:2C:4A:E9:83:F0, Freq 2412 MHz, Rate 54 Mb/s, Strength 40 WPA WPA2
    ali:             Infra, C0:3F:0E:2A:71:48, Freq 2437 MHz, Rate 54 Mb/s, Strength 24 WPA2
    TP_ALink:        Infra, 22:CA:94:00:03:A7, Freq 2462 MHz, Rate 54 Mb/s, Strength 25 WPA2
    ALL0237R:        Infra, 00:0F:C9:0E:32:6A, Freq 2412 MHz, Rate 54 Mb/s, Strength 22 WPA WPA2
    Connectify-me:   Infra, 5A:grin:D:08:ED:C1:A5, Freq 2412 MHz, Rate 54 Mb/s, Strength 22 WPA2
    TP-LINK_SYT:     Infra, C4:E9:84:6D:88:1E, Freq 2457 MHz, Rate 54 Mb/s, Strength 20 WPA2
    yachen:          Infra, 68:A3:C4:8C:0C:AC, Freq 2457 MHz, Rate 54 Mb/s, Strength 10 WPA2

cat /etc/network/interfaces

Code:

 
# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback

cat /etc/NetworkManager/NetworkManager.conf

Code:

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

[ifupdown]
managed=false

cat /var/lib/NetworkManager/NetworkManager.state

Code:

NetworkingEnabled=true
WirelessEnabled=true
WWANEnabled=true
WimaxEnabled=true

Thanks

**alameenn** · April 6th, 2016

Hi all. I'm facing the same problem. However, this fix didn't work for me. What else should I do?

**rdlichfield** · June 6th, 2016

I have the same issue. However, my PC works on one network and not the other. I'm not sure what else to try but both networks require static IP addressing. If I arp I get the gateway address and that's it. But, I can't ping it or any other machine on the network.

**fatboyslim2** · October 5th, 2016

Hi guys

I am on linux mint (currently 17.3) which is pretty much the same Ubuntu with just more comfortable interface and 'sexy' staff.
So I just fixed the same issue with LAN disconnection reading below link:

http://www.pcworld.com/article/24559...ntu-linux.html

to make long story short manual input of ip, netmask, gateway and dns solved the issue for me.
Hope this could be of any help to you as well.

BR