On Wed, 22 Sep 2010 17:11:22 -0400 (EDT), Hugo Vanwoerkom wrote:
I couldn't figure out why the network wouldn't come up, untill I saw this:
hugo@debian:~$ dmesg | grep -i eth
[ 1.181349] 8139cp: 10/100 PCI Ethernet driver v1.3 (Mar 22, 2004)
[ 1.229553] 8139too Fast Ethernet driver 0.9.28
[ 1.231041] eth0: RealTek RTL8139 at 0x3000, 00:0a:e4:eb:04:59, IRQ 20
[ 9.727658] udev: renamed network interface eth0 to eth1
[ 21.532930] eth1: link up, 100Mbps, full-duplex, lpa 0x45E1
[ 32.464023] eth1: no IPv6 routers present
Why would udev rename the interface?
udev tries to keep the correspondence between ethernet device names and
MAC addresses the same. If the MAC address changes, you're likely to
get a device name change to eth1, since it is reserving eth0 for the
original MAC address. The MAC address may change under the following
conditions:
(1) Your network card goes bad, so you replace it with another network
card of the same or a different type.
(2) Your motherboard, which contains a built-in ethernet adapter, goes
bad and you have to replace it.
(3) You make an image backup of your hard disk on one PC, then restore
the image to another identically-configured PC.
(4) You physically move a hard disk from one PC to another.
If you only have one network interface, the quickest way to solve this
problem is to erase (rm) the file /etc/udev/rules.d/70-persistent-net.rules.
Upon reboot, a new one will be created. If you have more than one network
interface (not counting lo), it may be safer to edit the file and
change the MAC address from the old one to the new one.