Posted by: antonio lorusso

After the new kernel upgrade to 2.6.20-16-generic on the Ubuntu Server 7.04, I had a strage error after the reboot: no network device were found!
On a shell window, I restarted the network this way:

sudo /etc/init.d/networking restart

that gave me following error:

SIOCSIFADDR: No such device eth0
eth0: ERROR while getting interface flags: No such device

I was desperate and I started googling around till I found a an answer to this error that make me understand! Well I discovered that the problem is common and it depends from the mac address. The mac address has changed even if I haven’t changed any hardware part!
In fact you can see that the current mac address
antonio@UbuntuServer:~$ dmesg | grep eth0
[ 19.728029] eth0: VIA Rhine II at 0×1d000, 00:00:00:00:01:f8, IRQ 19. is not like the one stored in /etc/iftab
antonio@UbuntuServer:~$ cat /etc/iftab
# This file assigns persistent names to network interfaces.
# See iftab(5) for syntax. eth0 mac 00:13:d4:c6:4d:ec arp 1
then 00:00:00:00:01:f8 is not 00:13:d4:c6:4d:ec obviously!

Solution

change the mac address in /etc/iftab with the new one and restart the machine (you cant just restart the networking service)

Hope you are smiling now