NM disables virtual machine manager's virbr0

[Avi Greenbury]

This is similar to #961089 and may well be a duplicate, but I believe that there's a distinction since NM is disabling a bridge that's been created automatically by virt-manager, and so the explanation that it's not a normal way of configuring bridges doesn't (or at least shouldn't) apply.

Basically, what I've done is:

1) Install virt-manager
2) Create some VMs
3) Leave my machine on for a while
4) Notice that the bridge disappears and none of the machines can speak to the host (or get DHCP leases).

I noticed this earlier today, and so added the mac address of the bridge to Network Manager's config, but it appears to have ignored this, too:

root@amazing:/home/avi# tail -n1 /etc/NetworkManager/NetworkManager.conf
unmanaged-devices=mac:fe:54:00:43:19:37
root@amazing:/home/avi# ifconfig virbr0
virbr0 Link encap:Ethernet HWaddr fe:54:00:43:19:37
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:1723 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2140 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:200990 (200.9 KB) TX bytes:1822872 (1.8 MB)

root@amazing:/home/avi#

I see this in syslog at about the same time (grepping for virbr0):

Jan 15 17:50:13 amazing NetworkManager[1261]: <info> (virbr0): now managed
Jan 15 17:50:13 amazing NetworkManager[1261]: <info> (virbr0): device state change: unmanaged -> unavailable (reason 'managed') [10 20 2]
Jan 15 17:50:13 amazing NetworkManager[1261]: <info> (virbr0): bringing up device.
Jan 15 17:50:13 amazing avahi-daemon[652]: Joining mDNS multicast group on interface virbr0.IPv4 with address 192.168.122.1.
Jan 15 17:50:13 amazing avahi-daemon[652]: New relevant interface virbr0.IPv4 for mDNS.
Jan 15 17:50:13 amazing avahi-daemon[652]: Registering new address record for 192.168.122.1 on virbr0.IPv4.
Jan 15 17:50:13 amazing NetworkManager[1261]: <info> (virbr0): carrier now ON (device state 20)
Jan 15 17:50:13 amazing NetworkManager[1261]: <info> (virbr0): deactivating device (reason 'managed') [2]
Jan 15 17:50:13 amazing avahi-daemon[652]: Withdrawing address record for 192.168.122.1 on virbr0.
Jan 15 17:50:13 amazing avahi-daemon[652]: Leaving mDNS multicast group on interface virbr0.IPv4 with address 192.168.122.1.
Jan 15 17:50:13 amazing avahi-daemon[652]: Interface virbr0.IPv4 no longer relevant for mDNS.
Jan 15 17:50:13 amazing NetworkManager[1261]: <info> (virbr0): device state change: unavailable -> disconnected (reason 'none') [20 30 0]
Jan 15 17:50:17 amazing dnsmasq-dhcp[1932]: DHCP packet received on virbr0 which has no address
Jan 15 17:50:19 amazing dnsmasq-dhcp[1932]: DHCP packet received on virbr0 which has no address
Jan 15 17:50:26 amazing dnsmasq-dhcp[1932]: DHCP packet received on virbr0 which has no address
Jan 15 17:50:27 amazing dnsmasq-dhcp[1932]: DHCP packet received on virbr0 which has no address

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: network-manager 0.9.6.0+git201301021750.e78c3e8-0ubuntu1
ProcVersionSignature: Ubuntu 3.7.0-7.15-generic 3.7.0
Uname: Linux 3.7.0-7-generic x86_64
ApportVersion: 2.7-0ubuntu2
Architecture: amd64
Date: Tue Jan 15 17:57:47 2013
EcryptfsInUse: Yes
IfupdownConfig:
 auto lo
 iface lo inet loopback
InstallationDate: Installed on 2012-09-10 (127 days ago)
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Alpha amd64 (20120910)
IpRoute:
 default via 192.168.1.254 dev wlan0 proto static
 169.254.0.0/16 dev wlan0 scope link metric 1000
 192.168.1.0/24 dev wlan0 proto kernel scope link src 192.168.1.67 metric 9
MarkForUpload: True
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=true
 WWANEnabled=true
 WimaxEnabled=true
SourcePackage: network-manager
UpgradeStatus: Upgraded to raring on 2012-11-26 (50 days ago)
mtime.conffile..etc.NetworkManager.NetworkManager.conf: 2013-01-15T16:36:47.133697
nmcli-dev:
 DEVICE TYPE STATE DBUS-PATH
 virbr0 bridge disconnected /org/freedesktop/NetworkManager/Devices/2
 wlan0 802-11-wireless connected /org/freedesktop/NetworkManager/Devices/1
 eth0 802-3-ethernet unavailable /org/freedesktop/NetworkManager/Devices/0
nmcli-nm:
 RUNNING VERSION STATE NET-ENABLED WIFI-HARDWARE WIFI WWAN-HARDWARE WWAN
 running 0.9.7.0 connected enabled enabled enabled enabled enabled

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.