%Mar 28 22:52:07:228 2019 楼层汇聚交换机13.202 STP/4/STP_DISPUTE: -Slot=2; Instance 1's port GigabitEthernet2/0/1 received an inferior BPDU from a designated port which is in forwarding or learning state.

[楼层汇聚交换机13.202] dis stp ab 

[楼层汇聚交换机13.202]dis stp abnormal-port ? > Redirect it to a file >> Redirect it to a file in append mode | Matching output <cr> 

[楼层汇聚交换机13.202]dis stp abnormal-port ---[GigabitEthernet2/0/1]--- MST ID BlockReason Time 0 Disputed 22:53:36 03/28/2019 0 Disputed 22:53:34 03/28/2019 0 Disputed 22:53:32 03/28/2019 1 Disputed 22:53:36 03/28/2019 1 Disputed 22:53:34 03/28/2019 1 Disputed 22:53:32 03/28/2019 3 Disputed 01:50:58 01/07/2013 3 Disputed 01:50:56 01/07/2013 3 Disputed 01:50:54 01/07/2013

请问 inferior BPDU  这个是什么BPDU

解答：

received an inferior BPDU含义为是交换机上收到低优先级的BPDU，同时该BPDU携带learning或forwarding标志，即认为自己为根端口；查看abnormal-port时发现该端口被disputed，该功能是保护根桥，防止下层网络震荡，一般产生原因为链路单通，对端收不到根桥发送的BPDU报文，从而对端一直发送低优先级的BPDU

交换机上收到低优先级的BPDU，同时该BPDU携带learning或forwarding标志

出现这样的情况，通常确认当前的网络环境以防止攻击。比如网络是否发生变动，是否接入了其他带生成树协议的设备，可以通过拔插端口，逐个端口抓包，看是否存在非根桥发的BPDU

收到了低优先级的BPDU，会造成根桥抢占，造成网络中STP树波动，可能是新接了交换机，mac地址较小，也可能是有恶意攻击。
优化的话，网络中配置根桥，配置根保护；接用户的端口开启edge-port等