CE6870 port usage get high randomly when receives TC BPDU

1. Checking the log information of the switch, there are many TC protection enable record, it means that there are many TC BPDU receives by the CE6870. After receive TC BPDU, the mac address table and arp table will be refreshed. After refresh the mac address table and arp table, there will be broadcast to learn mac and arp again, that cause the traffic increase on the ports.

Apr  1 2018 06:59:45+05:30 SYSCON_NETMAGIC_CORE_SWITCH %MSTP/4/MSTPLOG_PROTC_GUARDED(l):CID=0x80542724;With the TC protection enabled, if TC BPDUs were received after the number of TC BPDUs received by an instance exceeded the threshold, these TC BPDUs were processed after the TC protection time expires. (ProcessID=0, InstanceID=1)

2. Checking the log record, there are many bandwidth usage exceeded record and the timing match the TC BPDU receives. 

After receive TC BPDU, the mac address table and arp table will be refreshed. After refresh the mac address table and arp table, there will be broadcast to learn mac and arp again, that cause the traffic increase on the ports. Root cause is that find out the TC resource and fix it.