User's Manual

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 Configuring Backbone Fast
 Configuring Root Guard
 Configuring Loop Guard
 Configuring Loop Fast
 Configuring Address Table Aging Protection
 Configuring FDB-Flush
 Configuring BPDU Terminal
37.2.2 Configuring Port Fast
In SSTP/PVST mode, Port Fast immediately brings an interface to the forwarding state, bypassing the listening
and learning states. The function is invalid in other STP mode.
Use the following command to configure the port fast feature in the global configuration mode:
Command Purpose
spanning-tree portfast default
Globally enables port fast feature. It is valid to all
interfaces.
no spanning-tree portfast default
Globally disables port fast feature. It has no
effect on the interface configuration.
Note:
The port fast feature only applies to the interface that connects to the host. The BPDU Guard or BPDU Filter
must be configured at the same time when the port fast feature is configured globally.
Use the following command to configure the port fast feature in the interface configuration mode:
Command Purpose
spanning-tree portfast
Disables port fast feature on the interface. It has
no effect on the global configuration.
no spanning-tree portfast
Globally disables port fast feature. It has no
effect on the interface configuration.
37.2.3 Configuring BPDU Guard
BPDU Guard feature acts when receiving BPDU. The interface configured BPDU Guard feature will not send
BPDU.
In different STP modes, BPDU Guard acts differently. In SSTP/PVST mode, if a configured port that has the
BPDU Guard function and the Portfast function receives BPDU, this port will be shut down mandatorily. You
have to configure the port manually to resume this port. In RSTP/MSTP mode, if a BPDU-Guard-configured
port receives BPDU, the port will be set to the Blocking state in a period of time.
In global configuration mode, run command BPDU Guard: