3com 4210 PWR 9-Port 3CR17341-91-ME User Manual

<4210> system-view

 

[4210] interface Ethernet1/0/1

 

[4210-Ethernet1/0/1] stp instance 1 cost 2000 

# Configure the path cost of Ethernet 1/0/1 in spanning tree instance 1 to be 
calculated by the MSTP-enabled switch according to the IEEE 802.1D-1998 
standard.

1 Perform this configuration in system view

<4210> system-view

 

[4210] undo stp interface Ethernet1/0/1 instance 1 cost

 

[4210] stp pathcost-standard dot1d-1998 

2 Perform this configuration in Ethernet port view

<4210> system-view

 

[4210] interface Ethernet1/0/1

 

[4210-Ethernet1/0/1] undo stp instance 1 cost

 

[4210-Ethernet1/0/1] quit

 

[4210] stp pathcost-standard dot1d-1998 

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 spanning tree instances. 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.

Changing port priority of a port may change the role of the port and put the port 
into state transition.

Table 126   Configure port priority in system view

Enter system view 

system-view 

- 

Configure port priority for 
specified ports 

stp interface interface-list 
instance instance-id port 
priority priority 

Required

The default port priority is 
128.

Table 127   Configure port priority in Ethernet port view

Enter system view 

system-view 

- 

Enter Ethernet port view 

interface interface-type 
interface-number 

- 

Configure port priority for the 
port 

stp [ instance instance-id ] 
port priority priority 

Required.

The default port priority is 
128.