Debug Spanning-Tree - Cisco Catalyst 3550 Command Reference Manual

Appendix B Debug Commands

debug spanning-tree

Use the debug spanning-tree privileged EXEC command to debug spanning-tree activities. Use the no
form of this command to disable debugging output.
Syntax Description
all
backbonefast
bpdu
bpdu-opt
config
csuf
etherchannel
events
exceptions
general
mstp
pvst+
root
snmp
switch
uplinkfast
Defaults
Debugging is disabled.
Command Modes Privileged EXEC
Command History Release
12.1(4)EA1
12.1(9)EA1
Usage Guidelines
The undebug spanning-tree command is the same as the no debug spanning-tree command.
78-11195-09
debug spanning-tree {all | backbonefast | bpdu | bpdu-opt | config | csuf | etherchannel | events
| exceptions | general | mstp | pvst+ | root | snmp | switch | uplinkfast}
no debug spanning-tree {all | backbonefast | bpdu | bpdu-opt | config | csuf | etherchannel |
events | exceptions | general | mstp | pvst+ | root | snmp | switch | uplinkfast}
Display all spanning-tree debugging messages.
Debug Backbonefast events.
Debug spanning-tree bridge protocol data units (BPDUs).
Debug optimized BPDU handling.
Debug spanning-tree configuration changes.
Debug cross-stack UplinkFast activity.
Debug EtherChannel support.
Debug spanning-tree topology events.
Debug spanning-tree exceptions.
Debug general spanning-tree activity.
Debug Multiple Spanning Tree Protocol events.
Debug per-VLAN spanning-tree plus (PVST+) events.
Debug spanning-tree root events.
Debug spanning-tree Simple Network Management Protocol (SNMP)
handling.
Debug switch shim commands. This shim is the software module that is the
interface between the generic Spanning Tree Protocol (STP) code and the
platform-specific code of various switch platforms.
Debug UplinkFast events.
Modification
This command was first introduced.
The mstp and csuf keywords were added.
Catalyst 3550 Multilayer Switch Command Reference
debug spanning-tree
B-31