HP 3600 v2 Series Command Reference Manual page 138

Default level
2: System level
Parameters
instance instance-id: Sets the path cost of the ports in a particular MSTI. The value of instance-id ranges
from 0 to 32, where 0 represents the CIST.
vlan vlan-list: Specifies a VLAN list in the format of vlan-list = { vlan-id [ to vlan-id ] }&<1- 1 0>, where the
vlan-id argument represents the VLAN ID, in the range of 1 to 4094, and &<1- 1 0> indicates that you can
specify up to 10 VLAN IDs or VLAN ID ranges.
cost: Specifies the path cost of the port, with an effective range that depends on the path cost calculation
standard adopted.
With the IEEE 802.1d- 1 998 standard selected for path cost calculation, the cost argument ranges
•
from 1 to 65535.
With the IEEE 802.1t standard selected for path cost calculation, the cost argument ranges from 1
•
to 200000000.
• With the private standard selected for path cost calculation, the cost argument ranges from 1 to
200000.
Description
Use stp cost to set the path cost of the port or ports.
Use undo stp cost to restore the default.
By default, the device automatically calculates the path costs of ports in each spanning tree based on the
corresponding standard.
Configured in Ethernet interface view, the setting takes effect only on the interface.
Configured in port group view, the setting takes effect on all ports in the port group.
Configured in Layer 2 aggregate interface view, the setting takes effect only on the aggregate interface.
Configured on a member port in an aggregation group, the setting takes effect only after the port leaves
the aggregation group.
To set the path cost of an MSTP port in a specific MSTI, use this command with the MSTI specified. To set
the path cost of a PVST port in a specific VLAN, use this command with the VLAN specified. To set the
path cost of an MSTP port in the CIST or an STP/RSTP port, use this command without specifying any
MSTI and VLAN.
Path cost is an important factor in spanning tree calculation. Setting different path costs for a port in
MSTIs allows VLAN traffic flows to be forwarded along different physical links, which results in
VLAN-based load balancing.
The path cost setting of a port can affect the role selection of the port. When the path cost of a port is
changed, the system will re-calculate the role of the port and initiate a state transition.
Related commands: display stp and stp pathcost-standard.
Examples
# In MSTP mode, set the path cost of port Ethernet 1/0/3 in MSTI 2 to 200.
<Sysname> system-view
[Sysname] interface ethernet 1/0/3
[Sysname-Ethernet1/0/3] stp instance 2 cost 200
# In PVST mode, set the path cost of port Ethernet 1/0/3 in VLAN 2 to 200.
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