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Cisco Catalyst Blade Switch 3030 Command Reference
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Chapter 2 Cisco
Catalyst
Blade Switch 3030 Cisco IOS Commands
spanning-tree portfast (interface configuration)
spanning-tree portfast (interface configuration)
Use the
spanning-tree portfast
interface configuration command to enable the Port Fast feature on an
interface in all its associated VLANs. When the Port Fast feature is enabled, the interface changes
directly from a blocking state to a forwarding state without making the intermediate spanning-tree state
changes. Use the
no
form of this command to return to the default setting.
spanning-tree portfast
[
disable
|
trunk
]
no spanning-tree portfast
Syntax Description
Defaults
The Port Fast feature is disabled on all interfaces; however, it is automatically enabled on
dynamic-access ports.
Command Modes
Interface configuration
Command History
Usage Guidelines
Use this feature only on interfaces that connect to end stations; otherwise, an accidental topology loop
could cause a data packet loop and disrupt switch and network operation.
To enable Port Fast on trunk ports, you must use the
spanning-tree portfast
trunk
interface
configuration command. The
spanning-tree portfast
command is not supported on trunk ports.
You can enable this feature when the switch is operating in the per-VLAN spanning-tree plus (PVST+),
rapid-PVST+, or the multiple spanning-tree (MST) mode.
This feature affects all VLANs on the interface.
An interface with the Port Fast feature enabled is moved directly to the spanning-tree forwarding state
without the standard forward-time delay.
You can use the
spanning-tree portfast default
global configuration command to globally enable the
Port Fast feature on all nontrunking interfaces. However, the
spanning-tree portfast
interface
configuration command can override the global setting.
If you configure the
spanning-tree portfast default
global configuration command, you can disable
Port Fast on an interface that is not a trunk interface by using the
spanning-tree portfast disable
interface configuration command.
disable
(Optional) Disable the Port Fast feature on the specified interface.
trunk
(Optional) Enable the Port Fast feature on a trunking interface.
Release
Modification
12.2(25)SEE
This command was introduced.