Cisco Catalyst 2960 Command Reference Manual page 732

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 2960 Switch Command Reference
B-64
Description
Displays information about the types of debugging that are enabled.
Displays spanning-tree state information.
Appendix B Catalyst 2960 Switch Debug Commands
OL-8604-03