3Com 3.01.01 Switch User Manual


 
Configuring MSTP 259
You can configure the path cost of a port in the following ways.
Configuring in System View
Perform the following configuration in system view.
Configuring in Ethernet Port 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.
Configuring the Priority
of a Port
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.
Configuring in System View
Perform the following configuration in system view.
Table 14 Configure the Path Cost of a Port
Operation Command
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
Operation Command
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
Operation Command
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