3com WX4400 3CRWX440095A Manuel D’Utilisation

C

HAPTER

 17: C

ONFIGURING

 

AND

 M

ANAGING

 S

PANNING

 T

REE

 P

ROTOCOL

STP is disabled by default. You can enable STP globally or on individual 
VLANs. 

To enable STP, use the following command:

set spantree {enable | disable} 
[{all | vlan vlan-id | port port-list vlan-id}]

To enable STP on all VLANs configured on a WX switch, type the 
following command:

WX1200# set spantree enable
success: change accepted.

To verify the STP state and display the STP parameter settings, enter the 
display spantree command. For information, see “Displaying Spanning 
Tree Information” on page 361.

You can change the following standard STP parameters:

„

Bridge priority

„

Port cost

„

Port priority

The bridge priority determines the WX switch’s eligibility to become the 
root bridge. You can set this parameter globally or on individual VLANs.

The root bridge is elected based on the bridge priority of each device in 
the spanning tree. The device with the highest bridge priority is elected to 
be the root bridge for the spanning tree. The bridge priority is a numeric 
value from 0 through 65,535. Lower numeric values represent higher 
priorities. The highest priority is 0, and the lowest priority is 65,535. The 
default bridge priority for all devices is 32,768. 

If more than one device has the highest bridge priority (lowest numeric 
value), the device with the lowest MAC address becomes the root bridge.

If the root bridge fails, STP elects a new root bridge based on the bridge 
priorities of the remaining bridges.