Configuring Multiple Spanning Tree
DETAILED STEPS
Command or Action
Step 1
switch# configure terminal
Step 2
switch(config)# spanning-tree mst
instance-id root {primary | secondary}
[diameter dia [hello-time hello-time]]
Step 3
switch(config)# no spanning-tree mst
instance-id root
This example shows how to configure the switch as the root switch for MSTI 5:
switch# configure terminal
switch(config)# spanning-tree mst 5 root primary
Configuring a Secondary Root Bridge
You can execute this command on more than one switch to configure multiple backup root bridges. Enter the
same network diameter and hello-time values that you used when you configured the primary root bridge with
the spanning-tree mst root primary configuration command.
SUMMARY STEPS
1. switch# configure terminal
2. switch(config)# spanning-tree mst instance-id root {primary | secondary} [diameter dia [hello-time
hello-time]]
3. (Optional) switch(config)# no spanning-tree mst instance-id root
DETAILED STEPS
Command or Action
Step 1
switch# configure terminal
Purpose
Enters configuration mode.
Configures a switch as the 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.
(Optional)
Returns the switch priority, diameter, and hello time to default values.
Purpose
Enters configuration mode.
Cisco Nexus 5000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.0(3)N1(1)
Configuring a Secondary Root Bridge
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