Cisco Catalyst 250 Series Command Reference

Displays switch shim command debug messages. 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.
switch
Displays the spanning-tree synchronization event debug
messages.
synchronization
Displays UplinkFast-event debug messages.uplinkfast
Command Default
Debugging is disabled.
Command Modes
Privileged EXEC
Command History
ModificationRelease
This command was introduced.Cisco IOS 15.0(2)EX
Usage Guidelines
The undebug spanning-tree command is the same as the no debug spanning-tree command.
When you enable debugging on a switch stack, it is enabled only on the stack master. To enable debugging
on a stack member, start a session from the stack master by using the session switch-number command in
privileged EXEC mode. Enter the debug command at the command-line prompt of the stack member.
To enable debugging on a stack member without first starting a session on the stack master, use the remote
command switch-number LINE command in privileged EXEC mode.
Examples
This example shows how to display all spanning-tree debug messages:
Switch# debug spanning-tree all
Catalyst 2960-X Switch Layer 2 Command Reference, Cisco IOS Release 15.0(2)EX
OL-29043 -01 39
Layer 2 Commands
debug spanning-tree

Cisco Catalyst 250 Series Specifications

General

Brand	Cisco
Model	Catalyst 250 Series
Category	Switch
Language	English