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Command Reference for AT-IX5-28GPX High Availability, High Power Video Surveillance PoE Switch
C613-50057-01 REV A
AlliedWare Plus™ Operating System - Version 5.4.5-0.x
S
PANNING
T
REE
C
OMMANDS
SPANNING
-
TREE
PORTFAST
(STP)
spanning-tree portfast (STP)
Overview
Use this command in Interface Configuration mode for a switch port interface only
to set a port as an edge-port. The portfast feature enables a port to rapidly move
to the forwarding state, without having first to pass through the intermediate
spanning tree states. This command has the same effect as the
spanning-tree
edgeport (RSTP and MSTP)
command, but the configuration displays differently in
the output of some show commands.
NOTE
:
You can run either of two additional parameters with this command. To simplify
the syntax these are documented as separate commands. See the following additional
portfast commands:
•
spanning-tree portfast bpdu-filter
command
•
spanning-tree portfast bpdu-guard
command.
You can obtain the same effect by running the
spanning-tree edgeport (RSTP and
MSTP)
command. However, the configuration output may display differently in
some show commands.
Use the
no
variant of this command to set a port to its default state (not an
edge-port).
Syntax
spanning-tree portfast
no spanning-tree portfast
Default
Not an edge port.
Mode
Interface Configuration mode for a switch port interface only.
Usage
Portfast makes a port move from a blocking state to a forwarding state, bypassing
both listening and learning states. The portfast feature is meant to be used for
ports connected to end-user devices. Enabling portfast on ports that are
connected to a workstation or server allows devices to connect to the network
without waiting for spanning-tree to converge.
For example, you may need hosts to receive a DHCP address quickly and waiting
for STP to converge would cause the DHCP request to time out. Ensure you do not
use portfast on any ports connected to another device to avoid creating a
spanning-tree loop on the network.
Use this command on a switch port that connects to a LAN with no other bridges
attached. An edge port should never receive BPDUs. Therefore if an edge port
receives a BPDU, the portfast feature takes one of three actions.
•
Cease to act as an edge port and pass BPDUs as a member of a spanning tree
network (
spanning-tree portfast (STP)
command disabled).
•
Filter out the BPDUs and pass only the data and continue to act as a edge
port (
spanning-tree portfast bpdu-filter
command enabled).
•
Block the port to all BPDUs and data (
spanning-tree portfast bpdu-guard
command enabled).
