Have the same issue not juju related at all : created a single LXC container on ubuntu precise :
Here are the value for multicast querier
cat /sys/devices/virtual/net/lxcbr0/bridge/multicast_querier
1
From container : ping 239.255.255.250 (UPnP adress) does not work but works fine on host. Otherwise container network is fine.
Have the same issue not juju related at all : created a single LXC container on ubuntu precise : virtual/ net/lxcbr0/ bridge/ multicast_ querier
Here are the value for multicast querier
cat /sys/devices/
1
From container : ping 239.255.255.250 (UPnP adress) does not work but works fine on host. Otherwise container network is fine.