Specifications

B-9
Catalyst 2950 and Catalyst 2955 Switch Command Reference
78-15304-01
Chapter B Debug Commands
debug spanning-tree
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.
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}
Syntax Description
Defaults Debugging is disabled.
Command Modes Privileged EXEC
Command History
Usage Guidelines The undebug spanning-tree command is the same as the no debug spanning-tree command.
all Display all spanning-tree debugging messages.
backbonefast Debug Backbonefast events.
bpdu Debug spanning-tree bridge protocol data units (BPDUs).
bpdu-opt Debug optimized BPDU handling.
config Debug spanning-tree configuration changes.
csuf Debug cross-stack UplinkFast activity.
etherchannel Debug EtherChannel support.
events Debug spanning-tree topology events.
exceptions Debug spanning-tree exceptions.
general Debug general spanning-tree activity.
mstp Debug Multiple Spanning Tree Protocol events.
pvst+ Debug Per-VLAN Spanning Tree Plus (PVST+) events.
root Debug spanning-tree root events.
snmp Debug spanning-tree Simple Network Management Protocol (SNMP)
handling.
switch 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.
uplinkfast Debug UplinkFast events.
Release Modification
12.1(6)EA2 This command was first introduced.
12.1(9)EA1 The mstp and csuf keywords were added.