[network-admin] breaks /etc/network/interfaces

[skotti]

Description:
Enabling a wireless adapter causes the networking tool to write incomplete/invalid data into /etc/networking/interfaces.

Involved hardware:
Intel Corporation PRO/Wireless 3945ABG Network Connection (rev 0.2)
Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+ (rev 10)

Output from /etc/init.d/networking restart:
root@wintermute:/etc/init.d# ./networking restart
 * Reconfiguring network interfaces... /etc/network/interfaces:14: too few parameters for iface line
ifdown: couldn't read interfaces file "/etc/network/interfaces"
/etc/network/interfaces:14: too few parameters for iface line
ifup: couldn't read interfaces file "/etc/network/interfaces"

Reproduction:
- open network config tool, i find three unnamed devices listed
  * wireless
  * cabled
  * modem
  cabled is checked and working (RTL-8139/8139C/8139C+)
- add a profile name, e.g. "Homebase", click the ok-button
- configure the wireless adapter: SSID, WEP, KEY, DHCP, close dialog
-> Progressbar appears

After the progressbar closes all network connections are non functional and there is no way returning to a working configuration using the Network tool.

More things i tried:
- Adding another WLAN adapter that is known to work out of the box (orinoco driver)
  * Adapter is detected and listed as eth2, configuration fails
- Restoring cabled network by entering static ip information
  * No go, none of the adapters work

Sample of a working /etc/network/interfaces:
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp

Sample of a defective /etc/network/interfaces:
auto lo
iface lo inet loopback

auto eth2
iface eth2 inet dhcp

auto ath0
iface ath0 inet dhcp

auto wlan0
iface wlan0 inet dhcp

iface eth0 inet
address 192.168.1.4
netmask 255.255.255.0
gateway 192.168.1.254

auto eth0

[Sebastien Bacher (seb128)]

Thank you for your bug. What version of Ubuntu do you use?

[xodut (petr-odut)]

I can confirm the bug. I'm using 7.04 with latest updates.

[Patrick Hetu (patrick-hetu)]

I also confirm the bug. I'm using 7.04 with gnome-system-tools 2.17.5-0ubuntu1

[robepisc (robepisc)]

What's wrong with the defective /etc/network/interfaces file g-s-t generates is that "iface eth0 inet" should really be "iface eth0 inet static".

This issue was already reported as LP#80622.