Gigabit Ethernet Switch User Guide

90 Intel® Gigabit Ethernet Switch AXXSW1GB User Guide
link is up. Fast Link optimizes the STP protocol convergence. STP convergence can
take 30-60 seconds in large networks. The possible field values are:
— Enabled — Port Fast is enabled.
— Auto — Port Fast mode is enabled a few seconds after the interface becomes
active.
— Disabled — Port Fast is disabled.
• Root Guard — Prevents devices outside the network core from being assigned the
spanning tree root.
• Port State — Displays the current STP state of a port. If enabled, the port state
determines what forwarding action is taken on traffic. Possible port states are:
—Forwarding — Indicates that the port can forward traffic or learn MAC
addresses.
— Disabled — Indicates that STP is currently disabled on the port. The port
forwards traffic while learning MAC addresses.
— Discarded — Indicates that the port is currently blocked and cannot forward
traffic or learn MAC addresses.
• Port Role — Displays the port role assigned by the STP algorithm to provide to STP
paths. The possible field values are:
— Root — Provides the lowest cost path to forward packets to the root switch.
— Designated — The port or LAG through which the designated switch is attached
to the LAN.
— Alternate — Provides an alternate path to the root switch 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, or when a LAN has two or more connections
connected to a shared segment.
— Disable — The port is not participating in the Spanning Tree.
• Speed — Indicates the speed at which the port is operating.
• Path Cost — Indicates 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 is re-
routed.
• Priority — Priority value of the port. The priority value influences the port choice
when a bridge has two ports connected in a loop. The priority value is between 0 -240.
The priority value is determined in increments of 16.
• Designated Bridge ID — Indicates the bridge priority and the MAC Address of the
designated bridge.
• Designated Port ID — Indicates the selected port priority and interface.
• Designated Cost — Indicates 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.