Owner manual
+7(495) 797-3311 www.qtech.ru 
Москва, Новозаводская ул., 18, стр. 1 
149 
18.4 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. 










