Viewing debug counters for one MST instance
The show spanning-tree debug-counters
instance command allows you to display the aggregate values
of all MSTP debug counters maintained on a switch for a specified
spanning tree instance. These aggregate values are a summary of information
collected from all ports that have VLANs assigned to the specified
instance.
Use this command to troubleshoot the global MSTP
diagnostic information displayed in show spanning-tree debug-counters command output when you suspect unauthorized MSTP activity in a
specific MST instance.
Syntax:
show spanning-tree debug-counters instance instance-id
Displays debug counters for MSTP activity on all ports configured for VLANs in the specified MST instance.
The valid values for instance instance-id are 0 to 16, where 0 specifies
the default MST (CIST) instance and 1 to 16 specify a multiple spanning
tree (MST) instance.
Viewing bug counters for a CIST instance
show spanning-tree debug-counters instance command
when applied to the Common and Internal Spanning Tree (CIST) instance
(default MST instance 0) in the network.switch(config)# show spanning-tree debug-counters instance 0 Status and Counters - CIST Common Debug Counters Information MST Instance ID : 0 Counter Name Aggregated Value Collected From --------------------------------- ---------------- -------------- Invalid BPDUs 0 Ports Errant BPDUs 172603 Ports MST Config Error BPDUs 0 Ports Looped-back BPDUs 0 Ports Starved BPDUs 0 Ports Exceeded Max Age BPDUs 0 Ports Exceeded Max Hops BPDUs 0 Ports Topology Changes Detected 1 Ports Topology Changes Tx 3 Ports Topology Changes Rx 2 Ports Topology Change ACKs Tx 0 Ports Topology Change ACKs Rx 0 Ports TCN BPDUs Tx 0 Ports TCN BPDUs Rx 0 Ports CFG BPDUs Tx 0 Ports CFG BPDUs Rx 0 Ports RST BPDUs Tx 0 Ports RST BPDUs Rx 0 Ports MST BPDUs Tx 5 Ports MST BPDUs Rx 172577 Ports