Configuring Port Priority - H3C S5100-SI Operation Manual

Changing the path cost of a port may change the role of the port and put it in state transition. Executing
the stp cost command with the instance-id argument being 0 sets the path cost on the CIST for the port.
Configuration example (A)
# Configure the path cost of GigabitEthernet 1/0/1 in MSTI 1 to be 2,000.
1) Perform this configuration in system view
<Sysname> system-view
[Sysname] stp interface GigabitEthernet 1/0/1 instance 1 cost 2000
2) Perform this configuration in Ethernet port view
<Sysname> system-view
[Sysname] interface GigabitEthernet 1/0/1
[Sysname-GigabitEthernet1/0/1] stp instance 1 cost 2000
Configuration example (B)
# Configure the path cost of GigabitEthernet 1/0/1 in MSTI 1 to be calculated by the MSTP-enabled
switch according to the IEEE 802.1D-1998 standard.
1) Perform this configuration in system view
<Sysname> system-view
[Sysname] undo stp interface GigabitEthernet 1/0/1 instance 1 cost
[Sysname] stp pathcost-standard dot1d-1998
2) Perform this configuration in Ethernet port view
<Sysname> system-view
[Sysname] interface GigabitEthernet 1/0/1
[Sysname-GigabitEthernet1/0/1] undo stp instance 1 cost
[Sysname-GigabitEthernet1/0/1] quit
[Sysname] stp pathcost-standard dot1d-1998

Configuring Port Priority

Port priority is an important criterion on determining the root port. In the same condition, the port with the
smallest port priority value becomes the root port.
A port on an MSTP-enabled switch can have different port priorities and play different roles in different
MSTIs. This enables packets of different VLANs to be forwarded along different physical paths, so that
VLAN-based load balancing can be implemented.
You can configure port priority in one of the following two ways.
Configure port priority in system view
Follow these steps to configure port priority in system view:
To do...
Enter system view
Configure port priority for
specified ports
Use the command...
system-view
stp interface interface-list
instance instance-id port
priority priority
1-32
Remarks
—
Required
The default port priority is 128.