# Instance creation with Local network failed when using ML2 linuxbridge mechanism driver

Hi All

i am working with Juno (2014.2.3) both controller and compute

the compute neutron ml2 mechanism driver is set to linuxbridge

what happen is that it success to launch instance with local network

however the taps assoicated with qbr### type of bridge instead of brq### one and the brq### bridge created with no associated ports

so if i make two VMs with same local network i am expecting to get

tapX -- brq  -- tapY


tapX -- qbrX
tapY -- qbrY
brq### without any ports


btw, other networks of type vlan or flat are made only with brq### bridge , as expected

of course after that i get errors that are sympthom of this such as

device tap82788db3-56 is already enslave it to bridge brqb6a9480f-cd


when creating VMs

any way to avoid making the qbr bridges and just associating two taps to same bridge in order to chain VMs ?