Debug Spanning-Tree - Cisco Catalyst 4500 Series Command Reference Manual

Chapter 2 Cisco IOS Commands for the Catalyst 4500 Series Switches

debug spanning-tree

To debug the spanning tree activities, use the debug spanning-tree command. To disable the debugging
output, use the no form of this command.
Syntax Description
all
backbonefast
bpdu
bpdu-opt
etherchannel
config
events
exceptions
general
ha
mstp
pvst+
root
snmp
switch
synchronization
uplinkfast
Defaults
This command has no default settings.
Command Modes
Privileged EXEC mode
Command History Release
12.1(8a)EW
Examples
This example shows how to debug the spanning-tree PVST+:
Switch# debug spanning-tree pvst+
Spanning Tree PVST+ debugging is on
Switch#
OL-25342 -01
debug spanning-tree {all | backbonefast | bpdu | bpdu-opt | etherchannel | config | events |
exceptions | general | ha | mstp | pvst+ | root | snmp | switch | synchronization | uplinkfast}
no debug spanning-tree {all | bpdu | bpdu-opt | etherchannel | config | events | exceptions |
general | mst | pvst+ | root | snmp}
Displays all the spanning tree debugging messages.
Debugs the BackboneFast events.
Debugs the spanningtree BPDU.
Debugs the optimized BPDU handling.
Debugs the spanning tree EtherChannel support.
Debugs the spanning tree configuration changes.
Debugs the TCAM events.
Debugs the spanning tree exceptions.
Debugs the general spanning tree activity.
Debugs the HA events.
Debugs the multiple spanning tree events.
Debugs the PVST+ events.
Debugs the spanning tree root events.
Debugs the spanning tree SNMP events.
Debugs the switch debug events.
Debugs the STP state synchronization events.
Debugs the UplinkFast events.
Modification
Support for this command was introduced on the Catalyst 4500 series switch.
Catalyst 4500 Series Switch Cisco IOS Command Reference—Release IOS XE 3.3.0SG and IOS 15.1(1)SG)
debug spanning-tree
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