I have been struggling a lot trying to activate my ethernet connection without success. I am on ubuntu 14.04 LTS on a dell xps8900. I have a dual boot with windows 7 and ethernet is working fine on this one. Here is what I have tried:
1) Verify the ethernet card:
>lspci
00:00.0 Host bridge: Intel Corporation Device 191f (rev 07)
00:01.0 PCI bridge: Intel Corporation Device 1901 (rev 07)
00:14.0 USB controller: Intel Corporation Device a12f (rev 31)
00:14.2 Signal processing controller: Intel Corporation Device a131 (rev 31)
00:16.0 Communication controller: Intel Corporation Device a13a (rev 31)
00:17.0 RAID bus controller: Intel Corporation 82801 SATA Controller [RAID mode] (rev 31)
00:1c.0 PCI bridge: Intel Corporation Device a110 (rev f1)
00:1f.0 ISA bridge: Intel Corporation Device a145 (rev 31)
00:1f.2 Memory controller: Intel Corporation Device a121 (rev 31)
00:1f.3 Audio device: Intel Corporation Device a170 (rev 31)
00:1f.4 SMBus: Intel Corporation Device a123 (rev 31)
00:1f.6 Ethernet controller: Intel Corporation Device 15b8 (rev 31)
01:00.0 VGA compatible controller: NVIDIA Corporation GM107 [GeForce GTX 745] (rev a2)
01:00.1 Audio device: NVIDIA Corporation Device 0fbc (rev a1)
02:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8723BE PCIe Wireless Network Adapter"
2) Then I activated eth0 with ifconfig:
sudo ifconfig wlan0 down
sudo ifconfig eth0 up
eth0: ERROR while getting interface flags: No such device
sudo ifconfig wlan0 up
3) Looking at the error message above, I have modified 70-persistent-net.rules and reboot:
mv /etc/udev/rules.d/70-persistent-net.rules /etc/udev/rules.d/70-persistent-net.rules.old
-> reboot
4) I have also looked at the different "eth":
ifconfig eth0
eth0: error fetching interface information: Device not found
ifconfig eth1
eth1: error fetching interface information: Device not found
ifconfig eth2
eth2: error fetching interface information: Device not found
5) Then I tried:
sudo dhclient
-> reboot
6) Then:
sudo lshw -C network
*-network
description: Wireless interface
product: RTL8723BE PCIe Wireless Network Adapter
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:02:00.0
logical name: wlan0
version: 00
serial: b0:c0:90:4f:dc:c2
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=rtl8723be driverversion=3.16.0-30-generic firmware=N/A latency=0 link=no multicast=yes wireless=IEEE 802.11bgn
resources: irq:16 ioport:d000(size=256) memory:df100000-df103fff
*-network UNCLAIMED
description: Ethernet controller
product: Intel Corporation
vendor: Intel Corporation
physical id: 1f.6
bus info: pci@0000:00:1f.6
version: 31
width: 32 bits
clock: 33MHz
capabilities: pm msi bus_master cap_list
configuration: latency=0
resources: memory:df200000-df21ffff
Any other things to test? Thank you.