SW1#show spanning-tree vlan 10

VLAN0010
  Spanning tree enabled protocol rstp
  Root ID    Priority    32778
             Address     5254.0049.f8d5
             Cost        100
             Port        1 (Ethernet0/0)
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32778  (priority 32768 sys-id-ext 10)
             Address     aabb.cc00.0100
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time  300 sec

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Et0/0               Root FWD 100       128.1    P2p 
Et0/1               Altn BLK 100       128.2    P2p 

SW1#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
SW1(config)#int e0/0
SW1(config-if)#shut
SW1(config-if)#end
*Apr  1 00:34:15.192: RSTP(10): updt roles, root port Et0/0 going down
*Apr  1 00:34:15.192: RSTP(10): Et0/1 is now root port
*Apr  1 00:34:15.194: RSTP(10): starting topology change timer for 35 seconds
*Apr  1 00:34:15.194: STP[10]: Generating TC trap for port Ethernet0/1
*Apr  1 00:34:15.908: %SYS-5-CONFIG_I: Configured from console by console
*Apr  1 00:34:17.192: %LINK-5-CHANGED: Interface Ethernet0/0, changed state to administratively down
*Apr  1 00:34:18.206: %LINEPROTO-5-UPDOWN: Line protocol on Interface Ethernet0/0, changed state to down

SW1#show spanning-tree vlan 10

VLAN0010
  Spanning tree enabled protocol rstp
  Root ID    Priority    32778
             Address     5254.0049.f8d5
             Cost        104
             Port        2 (Ethernet0/1)
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32778  (priority 32768 sys-id-ext 10)
             Address     aabb.cc00.0100
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time  300 sec

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Et0/1               Root FWD 100       128.2    P2p