Reference Guide

322 Spanning Tree
• Designated — This LAG 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 LAG provides an alternate LAG to the root
switch from the root interface.
•
Backup — This LAG 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 LAG is not participating in the Spanning Tree.
–
Path Cost (1-200000000) — Enter the amount the LAG contributes
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 is being rerouted.
The path cost has a value of 1 to 200000000.
–
Default Path Cost — Check for the device to use the default path
cost.
–
Priority — Select the priority value of the LAG. The priority value
influences the LAG choice when a bridge has looped ports. The
priority value is given in steps of 16.
–
Designated Bridge ID — Displays the priority and the MAC address
of the designated bridge.
–
Designated Port ID — Displays the ID of the selected 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 LAG State
has changed from the
Forwarding state to a Blocking state .
Defining STP LAG Settings Using CLI Commands
For information about CLI commands for defining STP LAG settings, see
Table 13-2.