eth-trunk member port up / down cause STP / MSTP network flapping

Publication Date:  2013-12-24 Views:  415 Downloads:  0
Issue Description
eth-trunk member port due to physical factors appear up/down flapping , but the eth-trunk port is aways up, and the MSTP network topology occur flapping.
Alarm Information
Handling Process
 Fixed the eth-trunk port STP Cost

[HUAWEI] interface Eth-trunk 1
[HUAWEI- Eth-trunk 1] stp instance 2 cost 200

Note: Make sure unifiy calculations of stp pathcost-standard in the network before setting STP Cost and the path cost recommended values ​​refer to the recommendation list in "stp pathcost-standard" command parsing of product manual.
Root Cause
eth-trunk member port  flapping will cause STP Cost changes, which can lead to STP / MSTP topology recalculation, causing Network flapping.
In STP / MSTP network, to eliminate this impact, we'd better fixed the eth-trunk port STP Cost.