Configuring The Port Priority - H3C SR8800 Configuration Manual

Step
1. Enter system view.
2. Enter interface view or port
group view.
3. Configure the path cost of
the ports.
NOTE:
When the path cost of a port changes, the system re-calculates the role of the port and initiates a state
transition.
Configuration example
# In MSTP mode, specify the router to calculate the default path costs of its ports by using IEEE
802.1d- 1 998, and set the path cost of GigabitEthernet 3/1/3 to 200 on MSTI 2.
<Sysname> system-view
[Sysname] stp pathcost-standard dot1d-1998
[Sysname] interface gigabitethernet 3/1/3
[Sysname-GigabitEthernet3/1/3] stp instance 2 cost 200

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 router. If all other conditions are the same, the port with the highest priority will be elected as
the root port.
On a spanning tree router, 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
Enter system view.
1.
Command
system-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
•
In STP/RSTP mode:
stp cost cost
•
In MSTP mode:
stp [ instance instance-id ] cost cost
Command
system-view
50
Remarks
N/A
Use one of the commands.
Use one of the commands.
By default, the system
automatically calculates the
path cost of each port.
Remarks
N/A