Comment 0 for bug 1512749

After initial upgrade from Ubuntu 15.04 to Ubuntu 15.10 LXC worked for a couple days then failed. I found that the lxcbr0 interface no longer existed.

I reported this on the lxc-user alias and about the same time several others had this happen to them also.

Serge Hallyn requested I open a launchpad bug and post some info but before I could gather that info the system returned to normal (re lxcbr0 was back) the next day after the server was booted up again.

note: at least one other person had this happen to them also (lxcbr0 came back by itself).

Today, I booted this server again and ... again lxcbr0 was missing where it had been working last night.

Below is all of the Info Serge Hallyn asked me to post.

$ ifconfig lxcbr0
lxcbr0: error fetching interface information: Device not found

$ journalctl -u lxc-net
-- Logs begin at Tue 2015-11-03 07:25:22 EST, end at Tue 2015-11-03 10:02:08 EST
Nov 03 07:25:48 server3 systemd[1]: Starting LXC network bridge setup...
Nov 03 07:25:50 server3 lxc-net[913]: dnsmasq: failed to create listening socket
Nov 03 07:25:50 server3 lxc-net[913]: Failed to setup lxc-net.
Nov 03 07:25:50 server3 systemd[1]: Started LXC network bridge setup.

root@server3:/home/bmullan# /usr/lib/x86_64-linux-gnu/lxc/lxc-net stop # note - execution just returns to command line
root@server3:/home/bmullan#

>> and lxcbr0 is still missing

# ifconfig lxcbr0
lxcbr0: error fetching interface information: Device not found

root@server3:/home/bmullan# /usr/lib/x86_64-linux-gnu/lxc/lxc-net start

dnsmasq: failed to create listening socket for 10.0.3.1: Cannot assign requested address
Failed to setup lxc-net.
root@server3:/home/bmullan#

$ uname -a
Linux server3 4.2.0-16-generic #19-Ubuntu SMP Thu Oct 8 15:35:06 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 15.10
Release: 15.10
Codename: wily