Setting The Bridge Priority; Setting A Port Priority; Assigning Port Costs - Cabletron Systems IA1100 User's Reference Manual

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:
Set the bridge priority for default
spanning tree.
Set the bridge priority for a
particular instance of spanning tree.

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:
Establish a priority for a specified
interface for default spanning tree.
Establish a priority for a specified
interface for a particular instance of
spanning tree.

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 a different port cost other than
the defaults for default spanning
tree.
Set a different port cost other than
the defaults for a particular instance
of spanning tree.
Internet Appliance User Reference Manual
Chapter 2: Bridging Configuration Guide
stp set bridging priority
pvst set bridging spanning-tree
<num>
priority
<port-list>
stp set port
<port-list>
pvst set port
<string>
priority
<port-list>
stp set port
<port-list>
pvst set port
<string>
port-cost
<num>
<string>
<num>
priority
spanning-tree
<num>
port-cost <num>
spanning-tree
<num>
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