NetworkManager fails to manage eth0 even though "iface eth0" is not defined in /e/n/i -- r8169

[Stephan Diestelhorst]

Binary package hint: network-manager

Since 2010-05-09, my wired ethernet is suddenly unmanaged with the KDE network manager applet hover text is "Unmanaged" ("Unverwaltet" in German) and clicking on it shows only grey text "Network management disabled" ("Netzwerkverwaltung deaktiviert.").

I can still get an IP manually through "sudo dhclient eth0".

Strange thing is that "Auto eth0" was gone already 2010-05-08, and I had to manually re-add a DHCP wired connection. But as of now, even this does not help.

I have attached a recent copy of the daemon.log.

[Stephan Diestelhorst (syon)]

This seems to be a late incarnation of http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=530024
Indeed, my setup I like this:

~$ cat /etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
#iface eth0 inet dhcp

~$ cat /etc/NetworkManager/nm-system-settings.conf
# This file is installed into /etc/NetworkManager, and is loaded by
# NetworkManager by default. To override, specify: '--config file'
# during NM startup. This can be done by appending to DAEMON_OPTS in
# the file:
#
# /etc/default/NetworkManager
#

[main]
plugins=ifupdown,keyfile

[ifupdown]
managed=false

I remember to have configured eth0 in interfaces, to give the machine an IP w/o needing to be logged in. Something here must have been broken. Why does the old way through interfaces not work anymore?

[Stephan Diestelhorst (syon)]

Well, uncommenting the last line in /etc/network/interfaces now maes the old behaviour work again.
~$ cat /etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet dhcp

Maybe this uncommenting and the semi-baked transition to NetworkManager should be fixed.
Either through not touching interfaces, or in a way that makes NetworkManager usable, i.e.
by commenting out *all* lines related to eth0.

[Thomas Hood (jdthood)]

Does removing "auto eth0" fix the problem?

[penalvch (penalvch)]

Stephan Diestelhorst, thank you for taking the time to report this bug and helping to make Ubuntu better. Please execute the following command, as it will automatically gather debugging information, in a terminal:
apport-collect BUGNUMBER
When reporting bugs in the future please use apport by using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.

[Thomas Hood (jdthood)]

Stephan made it clear that he was able to configure his wired interface in the traditional way using ifup. This of course required an "iface eth0" stanza in /etc/network/interfaces.

Stephan has not yet made it clear whether or not removing all references to eth0 from /etc/network/interfaces was enough to get NetworkManager to manage eth0. If NM does manage eth0 under these circumstances then either there is no bug left or perhaps there is a bug in the code that comments things out of /e/n/i. If NM does not manage eth0 under these circumstances then I would start suspecting driver problems --- e.g., carrier detect --- but we can research that when we hear back from Stephan.

[Thomas Hood (jdthood)]

Reading the log file that Stephan supplied...

First we see three cases of successful connection.

May 8 14:12:32 d-charms NetworkManager: <info> (eth0): carrier is OFF
May 8 14:12:32 d-charms NetworkManager: <info> (eth0): new Ethernet device (driver: 'r8169')
May 8 14:12:32 d-charms NetworkManager: <info> (eth0): exported as /org/freedesktop/NetworkManager/Devices/0
May 8 14:12:32 d-charms NetworkManager: <info> (eth0): now managed
May 8 14:12:32 d-charms NetworkManager: <info> (eth0): device state change: 1 -> 2 (reason 2)
May 8 14:12:32 d-charms NetworkManager: <info> (eth0): bringing up device.
[...]

Then three cases, on the date that Stephan said things stopped working, where NM does nothing further with eth0 than the following.

May 9 23:07:08 d-charms NetworkManager: <info> (eth0): carrier is OFF
May 9 23:07:08 d-charms NetworkManager: <info> (eth0): new Ethernet device (driver: 'r8169')
May 9 23:07:08 d-charms NetworkManager: <info> (eth0): exported as /org/freedesktop/NetworkManager/Devices/0

There is no reboot between the first group and the second group.

Stephen: What happened between May 9 18:19:15 and May 9 23:07:08? Did you upgrade network-manager?

[Stephan Diestelhorst (syon)]

Thanks for looking into this! This is two years back, but I believe I filed the bug report after an upgrade. In the meantime, I have updated the box to 12.04 LTS. Will see if the problem persits (and how if so) and send updates, here.

[Bryan Quigley (bryanquigley)]

This bug was marked Incomplete some time ago and was supposed to autoclose after 90 days. I'm going to close it manually due to no activity (and likely the issue has gone away/been fixed).