Cisco Catalyst 3750 Metro Command Reference Manual page 912

debug spanning-tree
Usage Guidelines The undebug spanning-tree command is the same as the no debug spanning-tree command.
Related Commands Command
show debugging
show spanning-tree
Catalyst 3750 Metro Switch Command Reference
B-86
Description
Displays information about the types of debugging that are enabled.
Displays spanning-tree state information.
Appendix B Catalyst 3750 Metro Switch Debug Commands
OL-9645-10