Ubuntu server eth0 renamed to eth1

Question

I am running an Ubuntu server(9.04) virtual machine(virtualbox) on my computer at work and one night Win 7 rebooted after some security updates. After bringing the VM back up again the network didn't work.

The only thing I can see in the dmesg log is:

[] eth0: registered as PCnet/FAST III 79c973
[] udev: renamed network interface eth0 to eth1

My /etc/network/interfaces looks like:

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp

The iconfig shows only lo interface.

If I try:

sudo ifup eth0 
SIOCSIFADDR: No such device
eth0: ERROR while getting interface flags: No such device
...............

sudo ifup eth1
Ignoring unknown interface eth1=eth1

I am not a ubuntu geek, just use it as a git repository, any help to bring the network up again will be appreciated.

Answer 1

Perhaps mac address or driver has changed for the network card.

Remove /etc/udev/rules.d/*-persistent-net.rules and reboot vm.

Answer 2

Edit "/etc/udev/rules.d/70-persistent-net.rules".

Answer 3

Seems like there is a hardware change in your virtual machine. Changing the "eth0"s to "eth1"s in the /etc/network/interfaces file might help. After this, you should at least restart your networking service by typing "sudo service networking restart" in the console but a full restart is better in this situation.

Answer 4

All the above are correct. Udev has mapped eth0 to a MAC address that, for some reason has disappeared. Looks like the reboot caused your VM to assign a new MAC address to the VM's NIC. You can either:

• edit /etc/udev/rules.d/70-persistent-net.rules and correct the eth0 to MAC address mapping, or
• edit /etc/network/interfaces and change eth0 to eth1

Answer 5

The ifup and ifdown commands look inside of /etc/network/interfaces to find the configuration for an interface. If you don't have it declared there, it won't be found. Try this instead to bring up the interface:

sudo ifconfig eth1 up