哪位大神帮忙分析下S5120 为什么上行端口自动shutdown ，其他口discarding

哪位大神帮忙分析下S5120 为什么上行端口自动shutdown ，其他口discarding 部分打印如下：

 Interface 9437231 is Down, ifAdminStatus is 1, ifOperStatus is 2 

H3C MSTP/4/MSTP_BPDU_FORMAT_ERROR: Port GigabitEthernet1/0/48 received MSTP BPDUs of different formats continually. Shut it down in order to prevent broadcast.  

H3C IFNET/3/LINK_UPDOWN: GigabitEthernet1/0/48 link status is DOWN. H3C IFNET/3/LINK_UPDOWN: Vlan-interface1 link status is DOWN. 

H3C IFNET/5/LINEPROTO_UPDOWN: Line protocol on the interface Vlan-interface1 is DOWN Instance 0's Port 0.9437188 has been set to forwarding state! Instance 0's port GigabitEthernet1/0/5 has been set to forwarding state

. 。。。

 H3C MSTP/6/MSTP_FORWARDING: Instance 0's port GigabitEthernet1/0/48 has been set to forwarding state. 

 H3C MSTP/6/MSTP_DETECTED_TC: Instance 0's port GigabitEthernet1/0/48 detected a topology change.

 <hh3cPortMstiStateDiscarding>: Instance 0's Port 0.9437205 has been set to discarding state! Instance 0's Port 0.9437206 has been set to discarding state!  

H3C LLDP/6/LLDP_CREATE_NEIGHBOUR: New neighbor created on Port GigabitEthernet1/0/48 (IfIndex 9437231), Chassis ID is 84d9-31c7-b004, Port ID is GigabitEthernet1/0/24.

组网： 

 核心：H3C S5500-28C-SI

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 1/0/48 接入：H3C S5120

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