'create a qbr linux bridge for neutron security group'

def _create_linux_bridge(self, vif_rec):

    iface_id = vif_rec['other_config']['neutron-port-id']
    linux_br_name = self._get_qbr_name(iface_id)
    if (not self._device_exists(linux_br_name)):
        LOG.debug('Create    linux    bridge    %s', linux_br_name)
        host_network.brctl_add_br(self._session, linux_br_name)
        host_network.brctl_set_fd(self._session, linux_br_name, '0')
        host_network.brctl_set_stp(self._session, linux_br_name, 'off')
        host_network.ip_link_set_dev(self._session, linux_br_name, 'up')
    (qvb_name, qvo_name) = self._get_veth_pair_names(iface_id)
    if (not self._device_exists(qvo_name)):
        self._create_veth_pair(qvb_name, qvo_name)
        host_network.brctl_add_if(self._session, linux_br_name, qvb_name)
        host_network.ovs_create_port(self._session, CONF.xenserver.ovs_integration_bridge, qvo_name, iface_id, vif_rec['MAC'], 'active')
    return linux_br_name
