ifconfig eth0 eth0: error fetching interface information: Device not found

Question

I'm new to Ubuntu. In my system WIFI is working fine but Ethernet is not working fine.

ifconfig -a

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:13703 errors:0 dropped:0 overruns:0 frame:0
          TX packets:13703 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:1263769 (1.2 MB)  TX bytes:1263769 (1.2 MB)

wlan0     Link encap:Ethernet  HWaddr 0c:60:76:65:d7:c2  
          inet addr:10.67.110.56  Bcast:10.67.110.255  Mask:255.255.255.0
          inet6 addr: fe80::e60:76ff:fe65:d7c2/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:418816 errors:0 dropped:0 overruns:0 frame:464023
          TX packets:367793 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:544360588 (544.3 MB)  TX bytes:32354669 (32.3 MB)
          Interrupt:17 Base address:0xc000 

when I'm trying to get eth0 i am getting an message like

ifconfig etho

etho: error fetching interface information: Device not found" 

and I have done lspci | grep -i eth it returns nothing.

could you provide solutions for this?

Answer 1

The fact that ifconfig -a does not list eth0 means that your wired adapter hasn't been found. Things to check:

• lspci - is you network adapter listed?
• Reboot and enter bios setup. Check if the built in network adapter is enabled.

Answer 2

In my case I solved a problem where I had no wired ethernet (but wireless worked). I tried sudo dhclient and that did not fix the issue, at least right away. Next, I rebooted and toggled the 'Enable Onboard LAN' setting from the BIOS. Then wired ethernet worked again for me.

Note that to get into the BIOS, you'll need to press F2 or F10 or your system's specified key, and then in once in the BIOS you'll need to find the 'Onboard LAN' setting.

Answer 3

Also adding few points that has helped me solve similar problems alongside what @sMurf has replied to;

You can verify if the MAC address found on the device is same as that present in the /etc/udev/rules.d/*-persistent-net.rules

This is more relevant if you are making use of a VDI image in Virtual Box or the equivalent environment. If in Virtual Box environment, goto "Machine -> Settings -> Network" and verify that the MAC address' match. If they don't, then you can edit with the correct fields in the above mentioned file and restart the VM.

Answer 4

To create the tun0 virtual interface, use 2 configuration files for systemd-networkd.service. These are tun0.netdev and tun0.network in the /etc/systemd/network/ directory, but keep in mind in the first way of to create tun0 interface that any changes will be lost after rebooting the computer.

way 1:

$ sudo ip tuntap add dev tun0 mode tun
$ sudo ip address add 192.168.99.1/30 dev tun0
$ sudo ip address show tun0

way 2:

$ sudo nano /etc/systemd/network/tun0.netdev

Enter the following:

[NetDev]
Name=tun0
Kind=tun

$ sudo nano /etc/systemd/network/tun0.network

Enter the following:

[Match]
Name=tun0

[Network]
Address=192.168.98.1/30

$ ifconfig -a

As a result, I get:

tun0: flags=4240<POINTOPOINT,NOARP,MULTICAST>  mtu 1500
        inet 192.168.99.1  netmask 255.255.255.252  destination 192.168.99.1
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 500  (UNSPEC)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
(UNSPEC)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0