在网络运行中，发现设备 CPU 长时间占用过高，经检查发现下图中的 "Number of topology changes" 值频繁变化，可初步判断该故障由（  ）导致，可能的原因是（  ）。

<Switch>display stp topology-change                                                   CIST topology change information         Number of topology changes                     :35         Time since last topology change                 :0 days 1h:7m:30s Topology change initiator(notified)             :GigabitEthernet2/0/6 Topology change  last received  from          :101b-5498-d3e0 Number of generated topologychange traps:        38 Number of suppressed topologychange traps:        8