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Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
OL-8978-04
Chapter 7 Configuring Spanning Tree
Configuring a Root Switch
Unmapping VLANs from an MISTP Instance
The
none
keyword is used to unmap the specified VLANs from the MISTP instances to which they are
currently mapped. When you unmap a VLAN from an MISTP instance, the resulting state of all the ports
of the VLAN (if the VLAN exists) is
blocking
.
To unmap a VLAN or all VLANs from an MISTP instance, perform this task in privileged mode:
This example shows how to unmap a VLAN from an MISTP instance:
Console> (enable)
set vlan 6 mistp-instance none
Vlan 6 configuration successful
Disabling MISTP-PVST+ or MISTP
When the switch is in MISTP mode, you disable spanning tree on an instance, not for the whole switch.
When you disable spanning tree on an MISTP instance, the instance still exists on the switch, all of the
VLANs mapped to it have all of their ports forwarding, and the instance BPDUs are flooded.
To disable an MISTP instance, perform this task in privileged mode:
This example shows how to disable an MISTP instance:
Console> (enable)
set spantree disable mistp-instance 2
MI-STP instance 2 disabled.
Configuring a Root Switch
These sections describe how to configure a root switch:
•
Configuring a Primary Root Switch, page 7-45
•
Configuring a Secondary Root Switch, page 7-46
•
Configuring a Root Switch to Improve Convergence, page 7-46
•
Using Root Guard—Preventing Switches from Becoming Root, page 7-48
•
Displaying Spanning-Tree BPDU Statistics, page 7-48
Task
Command
Unmap a VLAN from an MISTP instance.
set vlan
vlan
mistp-instance none
Task
Command
Disable an MISTP instance.
set spantree disable mistp-instance
instance
[
all
]