Spanning-Tree Portfast (Global Configuration) - Cisco ME 3400 Command Reference Manual

spanning-tree portfast (global configuration)

spanning-tree portfast (global configuration)
Use the spanning-tree portfast global configuration command to globally enable bridge protocol data
unit (BPDU) filtering on Port Fast-enabled network node interfaces (NNIs) or enhanced network
interfaces (ENIs) on which Spanning Tree Protocol (STP) has been enabled, to enable the BPDU guard
feature on Port Fast-enabled STP ports, or the Port Fast feature on all nontrunking STP ports. The BPDU
filtering feature prevents the switch STP port from sending or receiving BPDUs. The BPDU guard
feature puts Port Fast-enabled STP ports that receive BPDUs in an error-disabled state. Use the no form
of this command to return to the default settings.
Syntax Description
bpdufilter default
bpduguard default
default
Defaults The BPDU filtering, the BPDU guard, and the Port Fast features are disabled on all NNIs or ENIs unless
they are individually configured.
Command Modes Global configuration
Command History Release
12.2(25)EX
Usage Guidelines STP is not supported on user network interfaces (UNIs) on the switch. Spanning-tree configuration
affects only NNIs or ENIs on which STP has been enabled. To set a port as an ENI or NNI, enter the
port-type {eni | nni} interface configuration command. To enable STP on an ENI, enter the
spanning-tree interface configuration command.
UNIs are typically customer-facing ports and do not participate in the spanning tree of the service
provider. However, if you configure a customer-facing port as an ENI and enable spanning tree, the ENI
could become the spanning tree root port unless you configure root guard on the port by using the
spanning-tree guard root interface configuration command. A customer-facing ENI with STP enabled
participates in the same spanning tree as the service-provider facing NNI.
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spanning-tree portfast {bpdufilter default | bpduguard default | default}
no spanning-tree portfast {bpdufilter default | bpduguard default | default}
Globally enable BPDU filtering on Port Fast-enabled STP ports, and prevent
the switch STP port connected to end stations from sending or receiving
BPDUs.
Globally enable the BPDU guard feature on Port Fast-enabled STP ports, and
place the STP ports that receive BPDUs in an error-disabled state.
Globally enable the Port Fast feature on all nontrunking STP ports. When the
Port Fast feature is enabled, the STP port changes directly from a blocking
state to a forwarding state without making the intermediate spanning-tree
state changes.
Modification
This command was introduced.
Chapter 2 Cisco ME 3400 Ethernet Access Switch Cisco IOS Commands
OL-9640-07