Cisco SPS208G User Manual page 206

Spanning Tree
MSTP Interface Settings
SPS208G/SPS224G4/SPS2024 Service Provider Switches User Guide
-
Master Port
— Indicates the port is a master port. A Master port
provides connectivity from a MSTP region to the outlying CIST root.
-
Internal
— Indicates the port is an internal port.
•
Role — Indicates the port role assigned by the STP algorithm in order to
provide to STP paths. The possible field values are:
-
Root
— Provides the lowest cost path to forward packets to root device.
-
Designated
— Indicates the port or LAG via which the designated
device is attached to the LAN.
-
Alternate
— Provides an alternate path to the root device from the root
interface.
-
Backup
— Provides a backup path to the designated port path toward
the Spanning Tree leaves. Backup ports occur only 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 connections connected to a shared
segment.
-
Disabled
— Indicates the port is not participating in the Spanning Tree.
•
Mode — Indicates the current Spanning Tree mode. The possible field
values are:
-
Classic STP
— Indicates that Classic STP is enabled on the port.
-
Rapid STP
— Indicates that Rapid STP is enabled on the port.
•
Interface Priority — Defines the interface priority for specified instance. The
default value is 128.
•
Path Cost — Defines the port contribution to the Spanning Tree instance.
Click Use Default to set the path cost to the default value (depends on the
port speed and the Path Cost Default Values method defined in the
STP Screen
).
•
Designated Bridge ID — Indicates the bridge ID number (priority + MAC
address) that connects the link or shared LAN to the root.
•
Designated Port ID — Indicates the Port ID number (priority + port number)
on the designated bridge that connects the link or the shared LAN to the
root.
•
Designated Cost — DIsplays the cost of the designated 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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Global
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