User Guide

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Learning—The port on this instance is in Learning mode. The port cannot
forward traffic, but it can learn new MAC addresses.
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Forwarding—The port on this instance is in Forwarding mode. The port can
forward traffic and learn new MAC addresses.
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Boundary—The port on this instance is a boundary port. It inherits its state
from instance 0 and can be viewed on the STP Interface Settings page.
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Port Role—Displays the port or LAG role, per port or LAG per instance, assigned by
the MSTP algorithm to provide STP paths:
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Root—Forwarding packets through this interface provides the lowest cost
path for forwarding packets to the root device.
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Designated—The interface through which the bridge is connected to the
LAN, which provides the lowest root path cost from the LAN to the Root
Bridge for the MST instance.
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Alternate—The interface provides an alternate path to the root device
from the root interface.
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Backup—The interface provides a backup path to the designated port path
toward the Spanning Tree leaves. Backup ports occur when two ports are
connected in a loop by a point-to-point link. Backup ports also occur when a
LAN has two or more established connections to a shared segment.
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Disabled—The interface does not participate in the Spanning Tree.
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Boundary—The port on this instance is a boundary port. It inherits its state
from instance 0 and can be viewed on the STP Interface Settings page.
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Mode—Displays the current interface Spanning Tree mode.
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If the link partner is using MSTP or RSTP, the displayed port mode is RSTP.
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If the link partner is using STP, the displayed port mode is STP.
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Type—Displays the MST type of the port.
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Boundary—A Boundary port attaches MST bridges to a LAN in a remote
region. If the port is a boundary port, it also indicates whether the device on
the other side of the link is working in RSTP or STP mode.
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Internal—The port is an internal port.
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Designated Bridge ID—Displays the ID number of the bridge that connects the link
or shared LAN to the root.
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Designated Port ID—Displays the Port ID number on the designated bridge that
connects the link or the shared LAN to the root.
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Designated Cost—Displays the cost of the port participating in the STP topology.
Ports with a lower cost are less likely to be blocked if STP detects loops.
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Remain Hops—Displays the hops remaining to the next destination.