7-58
Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
OL-8978-04
Chapter 7 Configuring Spanning Tree
Configuring Multiple Spanning Tree on the Switch
Hello: 4, (Local port hello:4)
Inst State Role Cost Prio VLANs
---- ------------- ---- --------- ---- -----------------------------------
0 forwarding DESG 200000 32 None
2 forwarding DESG 200000 16 1
200 forwarding DESG 200000 48 2
Console> (enable)
Mapping and Unmapping VLANs to an MST Instance
By default, all VLANs are mapped to IST (instance 0). For an MST instance (MSTI) 1–15 to be active,
you must map at least one VLAN to that MSTI. IST will always be active whether VLANs are mapped
to IST or not. MST has separate regions, which prevents VLAN mapping conflicts. Follow these
guidelines for mapping and unmapping VLANs to an MST instance:
Note
See
Chapter 11, “Configuring VLANs”
for details on using and configuring VLANs.
•
You can map only Ethernet VLANs to MST instances.
•
At least one VLAN in the instance must have an active port in order for MST to be active.
•
You can map as many Ethernet VLANs as you wish to an MST instance.
•
You cannot map a VLAN to more than one MST instance.
•
The Hello Time, Maximum Age timer, and Forward Delay timer set for mode and all spanning trees
are used globally by MST.
Note
To use VLANs 1025–4094, you must enable MAC address reduction. See the
“Creating Extended-Range
VLANs” section on page 11-7
in
Chapter 11, “Configuring VLANs”
for details on using extended-range
VLANs.
To map a VLAN to an MST instance, perform this task in privileged mode:
This example shows how to map a VLAN to MST instance 1 and verify the mapping:
Console> (enable)
show spantree mst config
Current (NVRAM) MST Region Configuration: 3 instances
Configuration Name:arthur Revision:23703
Instance VLANs
-------- --------------------------------------------------------------
0 1,31-4094
2 2-20
3 21-30
=======================================================================
Console> (enable)
set spantree mst 1400 vlan 900-999
Edit Buffer modified.
Use 'set spantree mst config commit' to apply the changes
Task
Command
Step 1
Map a VLAN to an MST instance.
set spantree mst
instance
vlan
vlan
Step 2
Make the new region mapping effective.
set spantree mst config commit
Step 3
Verify that the VLAN is mapped.
show spantree mst
[
instance
] [
active
]
mod/port