Ethernet not working (not even detected) in Ubuntu 12.04

**chetanbhasin** · April 2nd, 2013

Ethernet is not being detected on my computer running Ubuntu 12.04 with LAMP. The last thing I remember doing is following this tutorial: http://www.howtoforge.com/linux-basi...c-ip-on-ubuntu
Here are the checks that I have performed. Hope it could help. Thanks!

Code:

vest@vest-blue-server:~$ ifconfig
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:16436  Metric:1
          RX packets:224 errors:0 dropped:0 overruns:0 frame:0
          TX packets:224 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:16736 (16.7 KB)  TX bytes:16736 (16.7 KB)

vest@vest-blue-server:~$ clear

vest@vest-blue-server:~$ lspci -nnk | grep -iA2 net
00:07.0 Bridge [0680]: NVIDIA Corporation MCP61 Ethernet [10de:03ef] (rev a2)
    Subsystem: ASUSTeK Computer Inc. M4N68T series motherboard [1043:83a4]
    Kernel driver in use: forcedeth
vest@vest-blue-server:~$ ifconfig -a
eth0      Link encap:Ethernet  HWaddr 48:5b:39:eb:72:8e  
          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)
          Interrupt:23 Base address:0xe000 

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:16436  Metric:1
          RX packets:240 errors:0 dropped:0 overruns:0 frame:0
          TX packets:240 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:17680 (17.6 KB)  TX bytes:17680 (17.6 KB)

vest@vest-blue-server:~$ cat /etc/network/interfaces
auto lo
iface lo inet loopback
iface eth0 inet ghcp
vest@vest-blue-server:~$ cat /etc/resolv.conf
# 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
vest@vest-blue-server:~$ lsmod
Module                  Size  Used by
snd_hda_codec_realtek   224066  1 
snd_hda_intel          33773  3 
snd_hda_codec         127706  2 snd_hda_codec_realtek,snd_hda_intel
snd_hwdep              13668  1 snd_hda_codec
snd_pcm                97188  2 snd_hda_intel,snd_hda_codec
snd_seq_midi           13324  0 
nouveau               774641  3 
snd_rawmidi            30748  1 snd_seq_midi
snd_seq_midi_event     14899  1 snd_seq_midi
snd_seq                61896  2 snd_seq_midi,snd_seq_midi_event
ttm                    76949  1 nouveau
drm_kms_helper         46978  1 nouveau
serio_raw              13211  0 
drm                   242038  5 nouveau,ttm,drm_kms_helper
snd_timer              29990  2 snd_pcm,snd_seq
snd_seq_device         14540  3 snd_seq_midi,snd_rawmidi,snd_seq
k8temp                 13057  0 
edac_core              53746  0 
i2c_algo_bit           13423  1 nouveau
mxm_wmi                12979  1 nouveau
wmi                    19256  1 mxm_wmi
edac_mce_amd           23709  0 
snd                    78855  15 snd_hda_codec_realtek,snd_hda_intel,snd_hda_codec,snd_hwdep,snd_pcm,snd_rawmidi,snd_seq,snd_timer,snd_seq_device
video                  19596  1 nouveau
soundcore              15091  1 snd
snd_page_alloc         18529  2 snd_hda_intel,snd_pcm
bnep                   18281  2 
bluetooth             180104  7 bnep
parport_pc             32866  1 
ppdev                  17113  0 
asus_atk0110           18078  0 
i2c_nforce2            13058  0 
mac_hid                13253  0 
lp                     17799  0 
parport                46562  3 parport_pc,ppdev,lp
usbhid                 47199  0 
hid                    99559  1 usbhid
sata_nv                32286  2 
forcedeth              63460  0 
pata_amd               14118  0 
vest@vest-blue-server:~$ cat /etc/udev/rules.d/70-persistent-net.rules
# This file was automatically generated by the /lib/udev/write_net_rules
# program, run by the persistent-net-generator.rules rules file.
#
# You can modify it, as long as you keep each rule on a single
# line, and change only the value of the NAME= key.

# PCI device 0x10de:/sys/devices/pci0000:00/0000:00:07.0 (forcedeth)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="48:5b:39:eb:72:8e", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"

Edit:
I updated my /etc/network/interfaces file to look like this:

Code:

auto lo iface lo inet loopback  auto eth0 iface eth0 inet dhcp

Now, the network icon is showing up, but it is still not connecting. I have checked the cables properly.

**prodigy_** · April 2nd, 2013

Run

Code:

sudo lshw -С network

command and post the output here.

**Iowan** · April 2nd, 2013

Is that supposed to be DHCP?
There's no auto eth0, either.

[EDIT] OOPS, just noticed the update...

Originally Posted by chetanbhasin

Now, the network icon is showing up, but it is still not connecting. I have checked the cables properly.

Network icon? So, this is a desktop running LAMP stack?
You should be able to do the configuration directly from Network Manager (Comment out - or remove the eth0 stuff from /etc/network/interfaces)
It may not show in NM if configured elsewhere. (/etc/network/interfaces)

**jdthood** · April 3rd, 2013

Is there a DHCP server on your network?

What happens if you do "sudo ifup eth0" in a terminal window?

Another contributor mentioned NetworkManager. Are you using NetworkManager? If you are using NetworkManager then you shouldn't use /etc/network/interfaces to configure anything except the "lo" interface; instead use the Connection Editor. But since you have LAMP installed I presume you installed Ubuntu Server in which case you probably aren't using NetworkManager.

**chetanbhasin** · April 9th, 2013

Alright folks! Thanks for the replies, unfortunately though I didn't notice. I'm very sorry for that!

P.S. here is what I tried and worked for me:

Changing etc/network/interfaces to

Code: