PLANET WGSW-52040 - Manual (Page 207)

22.5 MSTP Troubleshooting
 In order to run the MSTP on the switch port, the MSTP has to be enabled globally. If
the MSTP is not enabled globally, it can’t be enabled on the port.
 The MSTP parameters co work with each other, so the parameters should meet the
following conditions. Otherwise, the MSTP may work incorrectly.
2×(Bridge_Forward_Delay -1.0 seconds) >= Bridge_Max_Age
Bridge_Max_Age >= 2 ×(Bridge_Hello_Time + 1.0 seconds)
 When users modify the MSTP parameters, they have to be sure about the changes
of the topologies. The global configuration is based on the bridge. Other
configurations are based on the individual instances.
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