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THE
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WITCH
2-54
STP Port and Trunk Information
The Spanning Tree, STP Port Information and Spanning Tree, STP Trunk
Information display the current status of ports and trunks in the Spanning
Tree.
Command Attributes
• STP Status — Displays current state of this port within the Spanning
Tree:
- Discarding — Port receives STP configuration messages, but does
not forward packets.
- Learning — Port has transmitted configuration messages for an
interval set by the Forward Delay parameter without receiving
contradictory information. Port address table is cleared, and the port
begins learning addresses.
- Forwarding — Port forwards packets, and continues learning
addresses.
The rules defining port status are:
- A port on a network segment with no other STA compliant bridging
device is always forwarding.
- If two ports of a switch are connected to the same segment and
there is no other STA device attached to this segment, the port with
the smaller ID forwards packets and the other is discarding.
- All ports are discarding when the switch is booted, then some of
them change state to learning, and then to forwarding.
• Forward Transitions – The number of times this port has
transitioned from the Learning state to the Forwarding state.
• Designated Cost — The cost for a packet to travel from this port to
the root in the current Spanning Tree configuration. The slower the
media, the higher the cost.