Concept Guide

spanning-tree MSTi vlan 1 100
spanning-tree MSTi instance 2
spanning-tree MSTi vlan 2 200
spanning-tree MSTi vlan 2 300
(Step 2)
interface 1/0/31
no shutdown
spanning-tree port mode enable
switchport protected 0
exit
interface 1/0/32
no shutdown
spanning-tree port mode enable
switchport protected 0
exit
(Step 3)
interface vlan 100
tagged 1/0/31
tagged 1/0/32
exit
interface vlan 200
tagged 1/0/31
tagged 1/0/32
exit
interface vlan 300
tagged 1/0/31
tagged 1/0/32
exit
Debugging and Verifying MSTP Congurations
To debut and verify MSTP conguration, use the following commands.
• Display BPDUs.
EXEC Privilege mode
debug spanning-tree mstp bpdu
• Display MSTP-triggered topology change messages.
debug spanning-tree mstp events
Examples of Viewing MSTP Congurations
To ensure all the necessary parameters match (region name, region version, and VLAN to instance mapping), examine your individual
routers.
To show various portions of the MSTP conguration, use the show spanning-tree mst commands.
To view the overall MSTP conguration on the router, use the show running-configuration spanning-tree mstp in EXEC
Privilege mode.
To monitor and verify that the MSTP conguration is connected and communicating as desired, use the debug spanning-tree mstp
bpdu
command.
Key items to look for in the debug report include:
• MSTP ags indicate communication received from the same region.
– As shown in the following, the MSTP routers are located in the same region.
600
Multiple Spanning Tree Protocol (MSTP)