[Pkg-utopia-maintainers] Bug#755202: network-manager: keeps creating and using new connection "eth0" that does not work

[Magnus Holmgren]

fredagen den 18 juli 2014 21.35.52 skrev du:
> NetworkManager has started creating a new wired connection "eth0"
> after/during boot; this connection has ipv4 (and ipv6) disabled, and
> thus provides no connectivity.  I can manually select my original
> wired connection (standard dhcp) in gnome3 (or using nmcli), but it
> keeps creating the "eth0" interface and using it after restarting.

I had the same or similar problem, except that only IPv4 was disabled. It 
seems that the cause in my case was that I tried to load netconsole on the 
kernel command line, which I think worked before I switched to systemd and/or 
stopped using ifupdown. Now when didn't try to load netconsole automatically, 
no automatic connection was created, but the interface was renamed from eth0 
to eth1. systemd still reported that mounting remote file systems failed, but 
the network connection came up and /home was mounted eventually nonetheless.

Strangely enough, checking /etc/udev/rules.d/70-persistent-net.rules (last 
modified in August), there is an eth0 line with a MAC address that doesn't 
match the current address of my NIC, and an eth1 line that does, but I'm 
pretty sure that the actual address hasn't been changing, and it matches 
/etc/NetworkManager/system-connections/eth0, which hasn't been changed since 
before the last boot.

I did also rename the connection in NetworkManager, but that should't have any 
consequences, should it?

I suppose it would have been possible to work around the problem by adding a 
no-auto-default setting to NetworkManager.conf.

I'm not sure what to make of this but it seems that loading netconsole was 
bringing the interface up early (but leaving it unconfigured), which may have 
confused NM. It may also have prevented udev from renaming it, but I don't 
know if these points are related.

-- 
Magnus Holmgren        holmgren at debian.org
Debian Developer