Configuring Spanning Tree Configuration Example for MSTP
Configuration Guide  
  259
Interface    Prio     Cost            Role      Status     LAG
---------      ----      --------        ------     -----          ----
Gi1/0/1      128     400000       Root      Fwd         N/A
Gi1/0/2      128     200000       Altn        Blk           N/A
Verify the configurations of Switch A in instance 2:
Switch(config)#show spanning-tree mst instance 2
MST-Instance 2
Root Bridge
Priority      : 0
Address       : 3c-46-d8-9d-88-f7
Internal Cost : 200000
Root Port     : 2
Designated Bridge
Priority      : 0
Address       : 3c-46-d8-9d-88-f7
Local Bridge
Priority      : 32768
Address       : 00-0a-eb-13-23-97
Interface   Prio     Cost         Role       Status     LAG
---------      ----      --------    -------     -------     ----
Gi1/0/1     128      200000    Desg       Fwd        N/A
Gi1/0/2     128      200000    Root        Fwd        N/A
Switch B
Verify the configurations of Switch B in instance 1:
Switch(config)#show spanning-tree mst instance 1
MST-Instance 1
Root Bridge
Priority      : 0
Address       : 00-0a-eb-13-12-ba