Configuring MST
S e n d f e e d b a c k t o n x 5 0 0 0 - d o c f e e d b a c k @ c i s c o . c o m
To enable a secondary root bridge, perform this task:
Command
Step 1
switch# configure terminal
Step 2
switch(config)# spanning-tree mst
instance-id root {primary | secondary}
[diameter dia [hello-time hello-time]]
This example shows how to configure the switch as the secondary root switch for MSTI 5:
switch# configure terminal
switch(config)# spanning-tree mst 5 root secondary
To disable the secondary root bridge configuration, perform this task:
Command
switch(config)# no spanning-tree mst
instance-id root
Configuring the Port Priority
If a loop occurs, MST uses the port priority when selecting an interface to put into the forwarding state.
You can assign lower priority values to interfaces that you want selected first and higher priority values
to the interface that you want selected last. If all interfaces have the same priority value, MST puts the
interface with the lowest interface number in the forwarding state and blocks the other interfaces.
To configure the port priority, perform this task:
Command
Step 1
switch# configure terminal
Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
9-18
Purpose
Enters configuration mode.
Configures a switch as the secondary root bridge as
follows:
•
For instance-id, you can specify a single instance,
a range of instances separated by a hyphen, or a
series of instances separated by a comma. The
range is from 1 to 4094.
For diameter net-diameter, specify the maximum
•
number of hops between any two end stations.
The default is 7. This keyword is available only
for MST instance 0.
•
For hello-time seconds, specify the interval in
seconds between the generation of configuration
messages by the root bridge. The range is from 1
to 10 seconds; the default is 2 seconds.
Purpose
Returns the switch priority, diameter, and hello-time
to default values.
Purpose
Enters configuration mode.
Chapter 9
Configuring MST
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