Gutsy and renumbered network interfaces?

Wenzhuo Zhang wenzhuo at
Thu Jun 21 14:42:01 UTC 2007

I filed a bug about it the other day.

According to the developer, /etc/iftab is deprecated. But still, the new
persistent net udev rules seems to be rather buggy. The only NIC in my
NIC is named eth2 in Feisty, while eth0 and eth1 are for non-existent
e1000 cards.

Derek Broughton wrote:
> Marius Gedminas wrote:
>> On Wed, Jun 20, 2007 at 08:27:19AM -0400, Matthew Carpenter wrote:
>>> On Wednesday 20 June 2007, Andreas Schildbach wrote:
>>>> Does anyone know why since a recent "apt-get dist-upgrade" on Gutsy my
>>>> Ethernet is now mapped to eth3 (was: eth0) and my WLAN to eth2 (was:
>>>> eth1)?
>>>> Is this a bug, or is it intentional?
>>> I'm not running Gutsy yet, but could it have anything to do with
>>> /etc/iftab? This one bit me recently with VMs, where I copied a VM and
>>> suddenly I had no eth0 but an eth1, because the MAC address had changed.
>> I think I've read on this list that Gutsy no longer uses /etc/iftab, but
>> /etc/udev/rules.d/70-persistent-net.rules to record the mapping from MAC
>> addresses to interface names.
> I'm not running gutsy, but that doesn't make much sense to me.  I'd still
> expect udev to take those rules from /etc/iftab if it exists, if only to
> maintain backward compatibility,  While anybody can write udev rules, udev
> development so far has tended to avoid _forcing_ us to write the rules
> specifically (and even in earlier releases, udev is what actually handles
> interface naming - but they use iftab if it exists).

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