Viewing debug counters for all MST instances

The show spanning-tree debug-counters command allows you to display the aggregate values of all MSTP debug counters that are maintained on a switch. These aggregate values are a summary of the information collected from all ports and from all spanning tree instances that forward traffic on switch ports.

Use the displayed diagnostic information to globally monitor MSTP operation on a per-switch basis.


show spanning-tree debug-counters

Displays debug counters for MSTP activity on all ports configured for VLANs used in spanning tree instances.

Viewing output for debug counters

The following example shows sample output of the show spanning-tree debug-counters command for all ports.

switch(config)# show spanning-tree debug-counters

 Status and Counters - MSTP Bridge Common Debug Counters Information

  Counter Name                      Aggregated Value Collected From
  --------------------------------- ---------------- -------------- 
  Invalid BPDUs                     0                CIST
  Errant BPDUs                      170927           CIST 
  MST Config Error BPDUs            0                CIST 
  Looped-back BPDUs                 0                CIST
  Starved BPDUs/MSTI MSGs           0                CIST/MSTIs 
  Exceeded Max Age BPDUs            0                CIST 
  Exceeded Max Hops BPDUs/MSTI MSGs 0                CIST/MSTIs 
  Topology Changes Detected         2                CIST/MSTIs
  Topology Changes Tx               6                CIST/MSTIs 
  Topology Changes Rx               4                CIST/MSTIs 
  Topology Change ACKs Tx           0                CIST 
  Topology Change ACKs Rx           0                CIST
  TCN BPDUs Tx                      0                CIST
  TCN BPDUs Rx                      0                CIST 
  CFG BPDUs Tx                      0                CIST 
  CFG BPDUs Rx                      0                CIST 
  RST BPDUs Tx                      0                CIST 
  RST BPDUs Rx                      0                CIST
  MST BPDUs/MSTI MSGs Tx            10               CIST/MSTIs
  MST BPDUs/MSTI MSGs Rx            341802           CIST/MSTIs