H3C Technologies H3C S12500 Series Switches - Manual (Page 95)

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[Sysname] stp pathcost-standard dot1d-1998
[Sysname] interface gigabitethernet 3/0/3
[Sysname-GigabitEthernet3/0/3] stp instance 2 cost 200
# In PVST mode, specify the switch to calculate the default path costs of its ports by using IEEE
802.1d-1998, and set the path cost of GigabitEthernet 3/0/3 to 2000 on VLANs 20 through 30.
<Sysname> system-view
[Sysname] stp mode pvst
[Sysname] stp pathcost-standard dot1d-1998
[Sysname] interface gigabitethernet 3/0/3
[Sysname-GigabitEthernet3/0/3] stp vlan 20 to 30 cost 2000
Configuring the 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 a spanning tree device, a port can have different priorities and play different roles in different
spanning trees, so that data of different VLANs can be propagated along different physical paths,
implementing per-VLAN load balancing. You can set port priority values based on the actual networking
requirements.
To configure the priority of a port or a group of ports:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter interface view or port group
view.
• Enter Ethernet interface view or
Layer 2 aggregate interface view:
interface interface-type
interface-number
• Enter port group view:
port-group manual
port-group-name
Use either command.
3. Configure the port priority.
• In STP/RSTP mode:
stp port priority priority
• In PVST mode:
stp vlan vlan-list port priority
priority
• In MSTP mode:
stp [ instance instance-id ] port
priority priority
Use any command.
The default setting is
128 for all ports.
NOTE:
If the port priority changes, the system re-calculates the port role and initiate a state transition.