Using MISTP-PVST+ or MISTP
Mapping VLANs to a MISTP Instance
When you are using MISTP-PVST+ or MISTP on a switch, you must map at least one VLAN to a MISTP
instance in order for MISTP-PVST+ or MISTP to be active.
Note
See
•
•
•
•
To map a VLAN to a MISTP instance, perform this task in privileged mode:
Task
Step 1
Map a VLAN to a MISTP instance.
Step 2
Verify that the VLAN is mapped.
This example shows how to map a VLAN to a MISTP instance 1 and verify the mapping:
Console> (enable) set vlan 6 mistp-instance 1
Vlan 6 configuration successful
Console> (enable) show spantree mist-instance 1
Instance 1
Spanning tree mode
Spanning tree type
Spanning tree instance enabled
Designated Root
Designated Root Priority
Designated Root Cost
Designated Root Port
VLANs mapped:
Root Max Age
Bridge ID MAC ADDR
Bridge ID Priority
VLANs mapped:
Bridge Max Age 20 sec
Port
------------------------ ---- ------------- --------- ---- -------- ----------
2/12
Determining MISTP Instance—VLAN Mapping Conflicts
A VLAN can only be mapped to one MISTP instance. If you attempt to map a VLAN to more than one
instance, all of its ports are set to blocking mode. You can use the show spantree conflicts command to
determine to which MISTP instances you have attempted to map the VLAN.
Software Configuration Guide—Catalyst 4000 Family, Catalyst 2948G, Catalyst 2980G, Releases 6.3 and 6.4
7-26
Chapter 10, "Configuring VLANs"
You can only map Ethernet VLANs to MISTP instances.
At least one VLAN in the instance must have an active port in order for MISTP-PVST+ or MISTP
to be active.
You can map as many Ethernet VLANs as you wish to a MISTP instance.
You cannot map a VLAN to more than one MISTP instance.
20 sec
Hello Time 2
Hello Time 2
Inst Port-State
1
for details on using and configuring VLANs.
Command
set vlan vlan mistp-instance instance
show spantree mistp-instance [instance] [active]
mod/port
MISTP-PVST+
ieee
00-d0-00-4c-18-00
49153
(root priority: 49152, sys ID ext: 1)
0
none
6
sec
Forward Delay 15 sec
00-d0-00-4c-18-00
49153
(bridge priority: 49152, sys ID ext: 1)
6
sec
Forward Delay 15 sec
Cost
forwarding
22222222
Chapter 7
Configuring Spanning Tree
Prio Portfast Channel_id
40 disabled 0
78-12647-02