3com 3.01.01 Benutzerhandbuch

You can configure the path cost of a port in the following ways. 

Perform the following configuration in system view. 

Perform the following configuration in Ethernet port view. 

 For more about the commands, see the Switch 8800 Command Reference Guide. 

Upon the change of path cost of a port, MSTP will recalculate the port role and 
transit the state. When instance-id takes 0, it indicates to set the path cost on the 
CIST. 

By default, MSTP is responsible for calculating the port path cost. 

For spanning tree calculation, the port priority is an important factor when 
determining if a port can be elected as the root port. With other attributes being 
equal, the port with the highest priority is elected as the root port. On the MSTP 
switch, a port can have different priorities in different STIs, and play different roles. 
The traffic from different VLANs can run over different physical links, thereby 
implementing the VLAN-based load-balancing. 

You can configure the port priority in the following ways. 

Perform the following configuration in system view. 

Table 14   Configure the Path Cost of a Port

Configure the Path Cost of a port.

stp interface interface-list instance 
instance-id cost cost

Restore the default path cost of a port.

undo stp interface interface-list instance 
instance-id cost

Table 15   Configure the Path Cost of a Port

Configure the Path Cost of a port

stp instance instance-id cost cost

Restore the default path cost of a port.

undo stp instance instance-id cost

Table 16   Configure the Port Priority

Configure the port priority.

stp interface interface-list instance 
instance-id port priority priority

Restore the default port priority. 

undo stp interface interface-list instance 
instance-id port priority