H3C Technologies H3C S7500E Series Switches - Manual (Page 181)

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<Sysname> system-view
[Sysname] stp pathcost-standard dot1d-1998
# Set the path cost of GigabitEthernet 2/0/3 on MSTI 2 to 200.
<Sysname> system-view
[Sysname] interface gigabitethernet 2/0/3
[Sysname-GigabitEthernet2/0/3] stp instance 2 cost 200
Configuring Port Priority
The priority of a port is an important factor in determining whether the port can be elected as the root
port of a device. If all other conditions are the same, the port with the highest priority will be elected as
the root port.
On an MSTP-enabled device, a port can have different priorities in different MSTIs, and the same port
can play different roles in different MSTIs, so that data of different VLANs can be propagated along
different physical paths, thus implementing per-VLAN load balancing. You can set port priority values
based on the actual networking requirements.
Make this configuration on the leaf nodes only.
Follow these steps to configure the priority of a port or a group of ports:
To do... Use the command... Remarks
Enter system view system-view —
Enter Ethernet interface
view, or Layer 2 aggregate
interface view
interface interface-type
interface-number
Enter interface
view or port
group view
Enter port group view
port-group manual
port-group-name
Required
Use either command.
Configure the port priority
stp [ instance instance-id ]
port priority priority
Optional
128 for all ports by default.
When the priority of a port is changed, MSTP will re-calculate the role of the port and initiate a
state transition.
Generally, a lower priority value indicates a higher priority. If you configure the same priority value
for all the ports on a device, the specific priority of a port depends on the index number of the port.
A lower index number means a higher priority. Changing the priority of a port triggers a new
spanning tree calculation process.