Network Router User Manual

SmartSwitch Router User Reference Manual 29
Chapter 3: Bridging Configuration Guide
Setting the Bridge Priority
You can globally configure the priority of an individual bridge when two bridges tie for
position as the root bridge, or you can configure the likelihood that a bridge will be
selected as the root bridge. The lower the bridge's priority, the more likely the bridge will
be selected as the root bridge. This priority is determined by default; however, you can
change it.
To set the bridge priority, enter the following command in Configure mode:
Setting a Port Priority
You can set a priority for an interface. When two bridges tie for position as the root bridge,
you configure an interface priority to break the tie. The bridge with the lowest interface
value is elected.
To set an interface priority, enter the following command in Configure mode:
Assigning Port Costs
Each interface has a port cost associated with it. By convention, the port cost is 1000/data
rate of the attached LAN, in Mbps. You can set different port costs.
To assign port costs, enter the following command in Configure mode:
Set the bridge priority for default
spanning tree.
stp set bridging priority <num>
Set the bridge priority for a
particular instance of spanning tree.
pvst set bridging spanning-tree <string>
priority <num>
Establish a priority for a specified
interface for default spanning tree.
stp set port <port-list> priority <num>
Establish a priority for a specified
interface for a particular instance of
spanning tree.
pvst set port <port-list> spanning-tree
<string> priority <num>
Set a different port cost other than
the defaults for default spanning
tree.
stp set port <port-list> port-cost <num>
Set a different port cost other than
the defaults for a particular instance
of spanning tree.
pvst set port <port-list> spanning-tree
<string> port-cost <num>