Comment 1 for bug 859587

I can confirm that proposed fix solves the problem for me:

2011-09-26 14:05:24,098 DEBUG nova.linux_net [-] Starting Bridge interface for eth0 from (pid=890) ensure_bridge /usr/lib/python2.7/dist-packages/nova/network/linux_net.py:931
2011-09-26 14:05:24,098 DEBUG nova.utils [-] Running cmd (subprocess): sudo brctl addbr br100 from (pid=890) execute /usr/lib/python2.7/dist-packages/nova/utils.py:165
2011-09-26 14:05:24,108 DEBUG nova.utils [-] Running cmd (subprocess): sudo brctl setfd br100 0 from (pid=890) execute /usr/lib/python2.7/dist-packages/nova/utils.py:165
2011-09-26 14:05:24,138 DEBUG nova.utils [-] Running cmd (subprocess): sudo brctl stp br100 off from (pid=890) execute /usr/lib/python2.7/dist-packages/nova/utils.py:165
2011-09-26 14:05:24,169 DEBUG nova.utils [-] Running cmd (subprocess): sudo ip link set br100 up from (pid=890) execute /usr/lib/python2.7/dist-packages/nova/utils.py:165
2011-09-26 14:05:24,191 DEBUG nova.utils [-] Running cmd (subprocess): sudo brctl addif br100 eth0 from (pid=890) execute /usr/lib/python2.7/dist-packages/nova/utils.py:165
2011-09-26 14:05:24,203 DEBUG nova.utils [-] Running cmd (subprocess): sudo route -n from (pid=890) execute /usr/lib/python2.7/dist-packages/nova/utils.py:165
2011-09-26 14:05:24,214 DEBUG nova.utils [-] Running cmd (subprocess): sudo route del default gw 192.168.69.1 dev eth0 from (pid=890) execute /usr/lib/python2.7/dist-packages/nova/utils.py:165
2011-09-26 14:05:24,229 DEBUG nova.utils [-] Running cmd (subprocess): sudo ip addr show dev eth0 scope global from (pid=890) execute /usr/lib/python2.7/dist-packages/nova/utils.py:165
2011-09-26 14:05:24,243 DEBUG nova.utils [-] Running cmd (subprocess): sudo ip addr del 192.168.69.107/24 brd 192.168.69.255 scope global dev eth0 from (pid=890) execute /usr/lib/python2.7/dist-p
ackages/nova/utils.py:165
2011-09-26 14:05:24,282 DEBUG nova.utils [-] Running cmd (subprocess): sudo ip addr add 192.168.69.107/24 brd 192.168.69.255 scope global dev br100 from (pid=890) execute /usr/lib/python2.7/dist-
packages/nova/utils.py:165
2011-09-26 14:05:24,292 DEBUG nova.utils [-] Running cmd (subprocess): sudo route add default gw 192.168.69.1 from (pid=890) execute /usr/lib/python2.7/dist-packages/nova/utils.py:165
2011-09-26 14:05:24,302 DEBUG nova.utils [-] Running cmd (subprocess): sudo ip addr show dev br100 scope global from (pid=890) execute /usr/lib/python2.7/dist-packages/nova/utils.py:165
2011-09-26 14:05:24,313 DEBUG nova.utils [-] Running cmd (subprocess): sudo route -n from (pid=890) execute /usr/lib/python2.7/dist-packages/nova/utils.py:165
2011-09-26 14:05:24,325 DEBUG nova.utils [-] Running cmd (subprocess): sudo route del default gw 192.168.69.1 dev br100 from (pid=890) execute /usr/lib/python2.7/dist-packages/nova/utils.py:165
2011-09-26 14:05:24,353 DEBUG nova.utils [-] Running cmd (subprocess): sudo ip addr del 192.168.69.107/24 brd 192.168.69.255 scope global dev br100 from (pid=890) execute /usr/lib/python2.7/dist-
packages/nova/utils.py:165
2011-09-26 14:05:24,374 DEBUG nova.utils [-] Running cmd (subprocess): sudo ip addr add 10.10.0.1/24 brd 10.10.0.255 dev br100 from (pid=890) execute /usr/lib/python2.7/dist-packages/nova/utils.p
y:165
2011-09-26 14:05:24,384 DEBUG nova.utils [-] Running cmd (subprocess): sudo ip addr add 192.168.69.107/24 brd 192.168.69.255 scope global dev br100 from (pid=890) execute /usr/lib/python2.7/dist-
packages/nova/utils.py:165
2011-09-26 14:05:24,394 DEBUG nova.utils [-] Running cmd (subprocess): sudo route add default gw 192.168.69.1 from (pid=890) execute /usr/lib/python2.7/dist-packages/nova/utils.py:165

Route is re-added as a last step.