member interfaces of Eth-trunk up/down cause STP/MSTP unstable

Publication Date:  2014-09-15 Views:  1213 Downloads:  0
Issue Description
The member intefaces of eth-trunk appeared that frequently  up/down , but eth-trunk is up all the time, and MSTP topology changed all the time.
Alarm Information
Handling Process
Set a fexed  STP cost for  eth-trunk
[HUAWEI] interface Eth-trunk 1
[HUAWEI- Eth-trunk 1] stp instance 2 cost 200

Root Cause
The member interfaces of eth-trunk's phenomenon of  up/down would cause the cost of STP change, and then  STP/MSTP would recalculate which caused topology changed.
We suggest to set a fixed STP cost for eth-trunk in the network with  STP /MSTP.