eth0 missing in (/etc/network/) interfaces file

Hi,

   I have the same problem on fresh gutsy installs on a Dell E521 with an integrated network card both for gusty64 bit and the normal gutsy 32 bit

   the network however works correctly and is listed with ifconfig -a

   I have asked some info in a forum about this http://ubuntuforums.org/showthread.php?t=613098

response on the forums was the following :

It is ok for eth0 not to be mentioned in /etc/network/interfaces; it means it is managed in roaming mode by NetworkManager
You can reboot or disable and reenable networking via the NetworkManager applet.

so I suppose the bug is invalid ?

Well, if you intend to let NetworkManager handle all networking, then perhaps this bug is invalid. But not everyone uses NetworkManager - I can't - and for such users this is a problem. So I feel this is a valid bug.

I guess my point is, why should /etc/network/interfaces be tied to NetworkManager exclusively? It isn't a NetworkManager file.

Perhaps the issue is with NetworkManager being installed by default, and dependent on ubuntu-desktop, so it can't be uninstalled without concern. If this is Ubuntu's policy, then NetworkManager should either (1) work perfectly, or (2) not make other networking things fail. Currently it does neither.

I'm not a network expert but as it concerns the network-admin program, I've linked the bug to the gnome-system-tools package

dpkg -S /usr/bin/network-admin
gnome-system-tools: /usr/bin/network-admin

  Koen

The gutsy release notes (https://wiki.ubuntu.com/GutsyGibbon/ReleaseNotes) mentions the following about this

Network Manager
    *
      In Ubuntu 7.10, network-manager only manages interfaces that are marked for roaming. Thus, all interfaces that were previously managed by network-manager will be set to roaming mode during upgrade. Technically, this takes any interface stanzas using the dhcp method with no options and that are marked auto, and removes them from /etc/network/interfaces. If you rely on your interfaces being started by ifupdown when the system starts up, you need to re-enable them in /etc/network/interfaces manually, or disable roaming in System -> Administration -> Network.

That does seem relevant to this issue. I can't see, however, any place to disable roaming in System->Administration->Network.