'We may have "lost" buffers -- packets we got but didn\'t know
where to send at the time.  We may know now.  Try and see.'

def _send_lost_buffers(self, dpid, ipaddr, macaddr, port):

    if ((dpid, ipaddr) in self.lost_buffers):
        bucket = self.lost_buffers[(dpid, ipaddr)]
        del self.lost_buffers[(dpid, ipaddr)]
        log.debug(('Sending    %i    buffered    packets    to    %s    from    %s' % (len(bucket), ipaddr, dpid_to_str(dpid))))
        for (_, buffer_id, in_port) in bucket:
            po = of.ofp_packet_out(buffer_id=buffer_id, in_port=in_port)
            po.actions.append(of.ofp_action_dl_addr.set_dst(macaddr))
            po.actions.append(of.ofp_action_output(port=port))
            core.openflow.sendToDPID(dpid, po)
