Layer 2 Commands
spanning-tree backbonefast
To enable BackboneFast to allow a blocked port on a switch to change immediately to a listening mode, use
the spanning-tree backbonefast command in global configuration mode. To return to the default setting, use
the no form of this command.
spanning-tree backbonefast
no spanning-tree backbonefast
Syntax Description
This command has no arguments or keywords.
Command Default
BackboneFast is disabled.
Command Modes
Global configuration
Command History
Release
Cisco IOS 15.0(2)EX
Usage Guidelines
Enable BackboneFast so that the switch detects indirect link failures and starts the spanning-tree reconfiguration
sooner than it would under normal spanning-tree rules.
You can configure BackboneFast for rapid PVST+ or for multiple spanning-tree (MST) mode; however, the
feature remains disabled until you change the spanning-tree mode to PVST+.
Use the show spanning-tree privileged EXEC command to verify your settings.
Examples
The following example shows how to enable BackboneFast on the switch:
Switch(config)# spanning-tree backbonefast
Related Commands
Command
show spanning-tree
OL-29043 -01
Modification
This command was introduced.
Description
Displays spanning-tree information.
Catalyst 2960-X Switch Layer 2 Command Reference, Cisco IOS Release 15.0(2)EX
spanning-tree backbonefast
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