Comment 5 for bug 997978

I tried building the container this morning using both your file above, and the following:
lxc.network.type=veth
lxc.network.link=br0
lxc.network.flags=up
lxc.network.ipv4=212.XX.239.103/28
lxc.network.name=eth0

# lxc-create -t ubuntu -f lxc.conf -n lxc1
debootstrap is /usr/sbin/debootstrap
Checking cache download in /var/cache/lxc/precise/rootfs-amd64 ...
Copy /var/cache/lxc/precise/rootfs-amd64 to /var/lib/lxc/lxc1/rootfs ...
Copying rootfs to /var/lib/lxc/lxc1/rootfs ...

##
# The default user is 'ubuntu' with password 'ubuntu'!
# Use the 'sudo' command to run tasks as root in the container.
##

'ubuntu' template installed
'lxc1' created

But it fails to start:

# lxc-start -n lxc1
lxc-start: failed to spawn 'lxc1'

/var/log/syslog shows:
May 12 09:47:12 dom0 kernel: [ 1107.903216] device vethHzjri2 entered promiscuous mode
May 12 09:47:12 dom0 kernel: [ 1107.905151] ADDRCONF(NETDEV_UP): vethHzjri2: link is not ready

ifconfig shows a load of virtual devices and brctl shows:

# brctl show
bridge name bridge id STP enabled interfaces
br0 8000.0649d9be1876 no eth0
       veth4bkC47
       vethHzjri2
       vethNBwjzP
       vethZo4vwt
       vethhzluzM
       vethidQWcJ
       vethmtoeDY
       vethuPj7Qk
       vethuxztRp
       vnet1

(I've tried starting the contain a few times).

I'm happy to debug this with you, but lxc isn't software I'm familiar with, unfortunately. Any ideas?