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tech:network:cisco:stp:bpduguard:bpduguard

STP: BPDU Guard

Topology

Log

SW1#sh spanning-tree vlan 1

VLAN0001
  Spanning tree enabled protocol ieee
  Root ID    Priority    32769
             Address     0022.bd89.2180
             Cost        19
             Port        4 (FastEthernet1/0/2)
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32769  (priority 32768 sys-id-ext 1)
             Address     e8ed.f315.9380
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time  300 sec

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Fa1/0/1             Altn BLK 19        128.3    P2p 
Fa1/0/2             Root FWD 19        128.4    P2p 


ASW2#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
ASW2(config)#spa
ASW2(config)#spanning-tree vla
ASW2(config)#spanning-tree vlan 1 pri
ASW2(config)#spanning-tree vlan 1 priority 
ASW2(config)#spanning-tree vlan 1 priority ?
  <0-61440>  bridge priority in increments of 4096

ASW2(config)#spanning-tree vlan 1 priority 0
ASW2(config)#
*Mar  1 00:01:42.601: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to down
ASW2(config)#
*Mar  1 00:01:43.599: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to down
ASW2(config)#^Z
ASW2#sh
*Mar  1 00:02:30.734: %SYS-5-CONFIG_I: Configured from console by console
ASW2#sh spa
ASW2#sh spanning-tree int f0/1
no spanning tree info available for FastEthernet0/1 

ASW2#sh spanning-tree int f0/1
no spanning tree info available for FastEthernet0/1 

ASW2#sh spanning-tree         

No spanning tree instance exists.

ASW2#sh spanning-tree 

No spanning tree instance exists.

ASW2#
*Mar  1 00:04:48.953: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to up
*Mar  1 00:04:49.960: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up
ASW2#sh spa
ASW2#sh spanning-tree 

VLAN0001
  Spanning tree enabled protocol ieee
  Root ID    Priority    1
             Address     0026.ca6b.e980
             This bridge is the root
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    1      (priority 0 sys-id-ext 1)
             Address     0026.ca6b.e980
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time  300 sec

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Fa0/1               Desg FWD 19        128.1    P2p 


ASW2#sh spanning-tree f0/1
                      ^
% Invalid input detected at '^' marker.

ASW2#sh spanning-tree int f0/1

Vlan                Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
VLAN0001            Desg FWD 19        128.1    P2p 
ASW2#sh spanning-tree int f0/1 detail
 Port 1 (FastEthernet0/1) of VLAN0001 is designated forwarding 
   Port path cost 19, Port priority 128, Port Identifier 128.1.
   Designated root has priority 1, address 0026.ca6b.e980
   Designated bridge has priority 1, address 0026.ca6b.e980
   Designated port id is 128.1, designated path cost 0
   Timers: message age 0, forward delay 0, hold 0
   Number of transitions to forwarding state: 1
   Link type is point-to-point by default
   BPDU: sent 48, received 1
ASW2#sh spanning-tree int f0/1 detail
 Port 1 (FastEthernet0/1) of VLAN0001 is designated forwarding 
   Port path cost 19, Port priority 128, Port Identifier 128.1.
   Designated root has priority 1, address 0026.ca6b.e980
   Designated bridge has priority 1, address 0026.ca6b.e980
   Designated port id is 128.1, designated path cost 0
   Timers: message age 0, forward delay 0, hold 0
   Number of transitions to forwarding state: 1
   Link type is point-to-point by default
   BPDU: sent 50, received 1
ASW2#
*Mar  1 00:07:10.352: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to down
ASW2#
*Mar  1 00:07:11.350: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to down
ASW2#sh spanning-tree int f0/1 detail
no spanning tree info available for FastEthernet0/1 

ASW2#
*Mar  1 00:47:31.505: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to up
ASW2#
*Mar  1 00:47:32.512: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up
ASW2#
*Mar  1 00:48:07.149: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to down
ASW2#
*Mar  1 00:48:08.147: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to down
ASW2#
*Mar  1 00:48:13.264: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to up
*Mar  1 00:48:14.271: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up
ASW2#sh spa
ASW2#sh spanning-tree 

VLAN0001
  Spanning tree enabled protocol ieee
  Root ID    Priority    1
             Address     0026.ca6b.e980
             This bridge is the root
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    1      (priority 0 sys-id-ext 1)
             Address     0026.ca6b.e980
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time  15  sec

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Fa0/1               Desg LRN 19        128.1    P2p 


ASW2#
*Mar  1 00:49:07.924: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to down
ASW2#
*Mar  1 00:49:08.922: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to down
ASW2#sh spanning-tree 

No spanning tree instance exists.

ASW2#
*Mar  1 00:49:32.368: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to up
*Mar  1 00:49:33.375: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up
ASW2#
*Mar  1 00:50:15.528: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to down
ASW2#
*Mar  1 00:50:16.526: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to down
ASW2#
*Mar  1 00:50:33.404: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to up
*Mar  1 00:50:34.411: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up
ASW2#sh spanning-tree  

VLAN0001
  Spanning tree enabled protocol ieee
  Root ID    Priority    1
             Address     0026.ca6b.e980
             This bridge is the root
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    1      (priority 0 sys-id-ext 1)
             Address     0026.ca6b.e980
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time  15  sec

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Fa0/1               Desg LRN 19        128.1    P2p 


ASW2#
*Mar  1 00:51:12.528: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to down
ASW2#sh spanning-tree 
*Mar  1 00:51:13.527: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to down
ASW2#sh spanning-tree 

No spanning tree instance exists.

ASW2#
Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Fa0/1               Desg FWD 19        128.1    P2p 
Fa0/2               Desg FWD 19        128.2    P2p 
Fa0/4               Desg FWD 19        128.4    P2p 
Fa0/6               Root LIS 19        128.6    P2p 


ASW1(config-if)#spa                       
ASW1(config-if)#spanning-tree po
ASW1(config-if)#spanning-tree portfa
ASW1(config-if)#spanning-tree portfast 
%Warning: portfast should only be enabled on ports connected to a single
 host. Connecting hubs, concentrators, switches, bridges, etc... to this
 interface  when portfast is enabled, can cause temporary bridging loops.
 Use with CAUTION

%Portfast has been configured on FastEthernet0/6 but will only
 have effect when the interface is in a non-trunking mode.
ASW1(config-if)#
*Mar  1 01:22:14.774: %SPANTREE-2-BLOCK_BPDUGUARD: Received BPDU on port FastEthernet0/6 with BPDU Guard enabled. Disabling port.
ASW1(config-if)#
*Mar  1 01:22:14.774: %PM-4-ERR_DISABLE: bpduguard error detected on Fa0/6, putting Fa0/6 in err-disable state
*Mar  1 01:22:15.781: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/6, changed state to down
ASW1(config-if)#
*Mar  1 01:22:16.787: %LINK-3-UPDOWN: Interface FastEthernet0/6, changed state to down
ASW1(config-if)#do sh span vlan 1      

VLAN0001
  Spanning tree enabled protocol ieee
  Root ID    Priority    32769
             Address     0022.bd89.2180
             This bridge is the root
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32769  (priority 32768 sys-id-ext 1)
             Address     0022.bd89.2180
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time  15  sec

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Fa0/1               Desg FWD 19        128.1    P2p 
Fa0/2               Desg FWD 19        128.2    P2p 
Fa0/4               Desg FWD 19        128.4    P2p 


ASW1(config-if)#
*Mar  1 01:25:16.211: %PM-4-ERR_RECOVER: Attempting to recover from bpduguard err-disable state on Fa0/8
ASW1(config-if)#
*Mar  1 01:27:14.776: %PM-4-ERR_RECOVER: Attempting to recover from bpduguard err-disable state on Fa0/6
ASW1(config-if)#
*Mar  1 01:27:17.846: %SPANTREE-2-BLOCK_BPDUGUARD: Received BPDU on port FastEthernet0/6 with BPDU Guard enabled. Disabling port.
ASW1(config-if)#
*Mar  1 01:27:17.846: %PM-4-ERR_DISABLE: bpduguard error detected on Fa0/6, putting Fa0/6 in err-disable state
ASW1(config-if)#
*Mar  1 01:32:17.856: %PM-4-ERR_RECOVER: Attempting to recover from bpduguard err-disable state on Fa0/6
ASW1(config-if)#
*Mar  1 01:32:20.583: %SPANTREE-2-BLOCK_BPDUGUARD: Received BPDU on port FastEthernet0/6 with BPDU Guard enabled. Disabling port.
ASW1(config-if)#
*Mar  1 01:32:20.583: %PM-4-ERR_DISABLE: bpduguard error detected on Fa0/6, putting Fa0/6 in err-disable state
ASW1(config-if)#
ASW1(config-if)#
*Mar  1 01:34:41.184: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/4, changed state to down
ASW1(config-if)#
*Mar  1 01:34:42.182: %LINK-3-UPDOWN: Interface FastEthernet0/4, changed state to down
ASW1(config-if)#
*Mar  1 01:34:57.198: %LINK-3-UPDOWN: Interface FastEthernet0/7, changed state to up
*Mar  1 01:34:58.205: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/7, changed state to up
ASW1(config-if)#
ASW1(config-if)#^Z
ASW1#sh span
*Mar  1 01:35:43.797: %SYS-5-CONFIG_I: Configured from console by console
ASW1#sh spannngi
ASW1#sh spann   
ASW1#sh spanning-tree vlan 1

VLAN0001
  Spanning tree enabled protocol ieee
  Root ID    Priority    1
             Address     0026.ca6b.e980
             Cost        19
             Port        7 (FastEthernet0/7)
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32769  (priority 32768 sys-id-ext 1)
             Address     0022.bd89.2180
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time  15  sec

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Fa0/1               Desg FWD 19        128.1    P2p 
Fa0/2               Desg FWD 19        128.2    P2p 
Fa0/7               Root FWD 19        128.7    P2p 


ASW2#sh spanning-tree vlan 1

VLAN0001
  Spanning tree enabled protocol ieee
  Root ID    Priority    1
             Address     0026.ca6b.e980
             This bridge is the root
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    1      (priority 0 sys-id-ext 1)
             Address     0026.ca6b.e980
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time  300 sec

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Fa0/1               Desg FWD 19        128.1    P2p 


ASW1#
*Mar  1 01:37:20.593: %PM-4-ERR_RECOVER: Attempting to recover from bpduguard err-disable state on Fa0/6
ASW1#
*Mar  1 01:37:24.267: %LINK-3-UPDOWN: Interface FastEthernet0/6, changed state to up
*Mar  1 01:37:25.274: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/6, changed state to up

References

tech/network/cisco/stp/bpduguard/bpduguard.txt · Last modified: 2019/06/08 08:33 by wnoguchi