Switch 7700 Command reference Guide, v2.0

326 CHAPTER 8: USING STP COMMANDS
View
Ethernet port view
Parameter
instance instance-id: Specifies the spanning tree instance ID, ranging from 0
to 16. The Instance 0 represents CIST.
cost cost: Specifies the port path cost, ranging from 1 to 200000.
Description
■ Use the stp instance cost command to configure the port path cost on the
specified STI for the current port.
■ Use the undo stp instance cost command to restore the path cost on the
specified STI.
By default, the path costs of a port on different STIs take the values associated
with the port speeds. For more description, refer to the table offered in the
configuration guideline of the
stp interface instance cost command.
You may specify the instance-id parameter as 0 to configure CIST path cost of
the port. The path cost has effect on the port role selection. A port can be
configured with different path costs on different MSTIs. Thus the traffic from
different VLANs can run over different physical links, thereby implementing the
VLAN-based load-balancing. MSTP will recalculate the port role and transit its
state, upon the port path cost changes.
Related commands: stp interface instance cost.
Example
Set the path cost of Ethernet5/0/3 on STI 2 to 200.
[SW7700-Ethernet5/0/3]stp instance 2 cost 200
stp instance port priority Syntax
stp instance instance-id port priority priority
undo stp instance instance-id port priority
View
Ethernet port view
Parameter
instance instance-id: Specifies the spanning tree instance ID, ranging from 0
to 16. The Instance 0 represents CIST.
port priority priority: Specifies the port priority, ranging from 0 to 240, with
a step length of 16, e.g., 0, 16, and 32. By default, the priorities of a port on the
STIs are 128.
Description
■ Use the stp instance port priority command to configure the priority of a
port on a specified STI.