3Com 3CRUS2475 User Manual page 240

240 C 11: C
HAPTER ONFIGURING
S T
PANNING REE
If the port is a Boundary port, this field also indicates whether the
device on the other side of the link is working in RSTP or STP mode
Master Port — Indicates the port is a master port. A Master port
■
provides connectivity from a MSTP region to the outlying CIST root.
Role — Indicates the port role assigned by the STP algorithm to
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provide to STP paths. The possible field values are:
Root — Provides the lowest cost path to forward packets to the
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root device.
Designated — Indicates the port or LAG through which the
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designated device is attached to the LAN.
Alternate — Provides an alternate path to the root device from the
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root interface.
Backup — Provides a backup path to the designated port path
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toward the Spanning Tree leaves. Backup ports occur only when
two ports are connected in a loop by a point-to-point link or when
a LAN has two or more connections connected to a shared
segment.
Disabled — Indicates the port is not participating in the Spanning
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Tree.
Mode — Indicates the STP mode by which STP is enabled on the
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device. The possible field values are:
Classic STP — Classic STP is enabled on the device. This is the
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default value.
Rapid STP — Rapid STP is enabled on the device.
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Multiple STP — Multiple STP is enabled on the device.
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Interface Priority — Defines the interface priority for the specified
■
instance. The field range is 0-240. The default value is 128.
Path Cost — Indicates the port contribution to the Spanning Tree
■
instance. The range should always be 1-200,000,000.
Designated Bridge ID — Displays the ID of the bridge that connects
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the link or shared LAN to the root.
Designated Port ID — Displays the ID of the port on the designated
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bridge that connects the link or the shared LAN to the root.
Designated Cost — Indicates that the default path cost is assigned
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according to the method selected on the Spanning Tree Global
Settings page.