Reference Guide

318 Spanning Tree
– Role — Displays the port role assigned by the STP algorithm that
provides STP paths. The possible options are:
•
Root — This port provides the lowest cost path to forward packets
to root switch.
•
Designated — This port is the interface through which the bridge
is connected to the LAN, which provides the lowest cost path
from the LAN to the Root Bridge.
•
Alternate — This port provides an alternate LAG to the root
switch from the root interface.
•
Backup — This port provides a backup path to the designated
port. 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 — This port is not participating in the Spanning Tree.
–
Speed — Displays the speed at which the port is operating.
–
Path Cost (1-200000000) — Enter the port contribution to the root
path cost. The path cost is adjusted to a higher or lower value, and is
used to forward traffic when a path being rerouted.
–
Default Path Cost — Check to use the default path cost.
–
Priority — Select the priority value that influences the port choice
when a bridge has two ports connected in a loop. The priority value is
provided in increments of 16.
–
Designated Bridge ID — Displays the bridge priority and the MAC
address of the designated bridge.
–
Designated Port ID — Displays the designated port’s priority and
interface.
–
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.
–
Forward Transitions — Displays the number of times the port has
changed from the
Forwarding state to Blocking .
–
LAG — Displays the LAG to which the port is attached.