Configuring Spanning Tree STP/RSTP Configurations
Configuration Guide  
  309
1)  In the Port Config section, configure STP/RSTP parameters on ports.
UNIT Select the desired unit or LAGs.
Status Enable or disable spanning tree function on the desired port.
Priority Specify the Priority for the desired port. The value should be an integral 
multiple of 16, ranging from 0 to 240.
The port with lower value has the higher priority. When the root path of the 
port is the same as other ports’, the switch will compare the port priorities 
between these port and select a root port with the highest priority.
Ext-Path Cost Enter the value of the external path cost. The valid values are from 0 to 
2000000. The default setting is Auto, which means the port calculates the 
external path cost automatically according to the port’s link speed.
For STP/RSTP, external path cost indicates the path cost of the port in 
spanning tree. The port with the lowest root path cost will be elected as the 
root port of the switch.
For MSTP, external path cost indicates the path cost of the port in CST.
Int-Path Cost Enter the value of the internal path cost. The default setting is Auto, which 
means the port calculates the internal path cost automatically according to 
the port’s link speed. This parameter is only used in MSTP and you need not 
to configure it if the spanning tree mode is STP/RSTP.
For MSTP, internal path cost is used to calculate the path cost in IST. The 
port with the lowest root path cost will be elected as the root port of the 
switch in IST.
Edge Port Select Enable to set the port as an edge port.
When the topology is changed, the edge port can transit its state from 
blocking to forwarding directly. For the quick generation of the spanning tree, 
it is recommended to set the ports that are connected to the end devices as 
edge ports. 
P2P Link Select the status of the P2P (Point-to-Point) link to which the ports are 
connected. During the regeneration of the spanning tree, if the port of P2P 
link is elected as the root port or the designated port, it can transit its state 
to forwarding directly.
Three options are supported: Auto, Open(Force) and Closed(Force). By 
default, it is Auto.
Auto: The switch automatically checks if the port is connected to a P2P link, 
then sets the status as Open or Closed.
Open(Force): A port is set as the one that is connected to a P2P link. You 
should check the link first.
Close(Force): A port is set as the one that is not connected to a P2P link. You 
should check the link first.