Port Roles Based On Spanning Tree; Spanning Tree Protocol Port States - Fujitsu XG1200 User Manual

XG1200 User's Guide

4.5.1 Port Roles Based on Spanning Tree

The RSTP assigns one of these port roles to individual ports:
Root port
Provides the best path (lowest cost) when the switch forwards packets to the root switch.
Designated port
Connects to the designated switch toward the leaves of the spanning tree. The port of the specified switch to connect
the designated port serves as a root port.
Alternate Port
Provides an alternative port with the second lowest path cost. In the event that the root port becomes a linkdown state,
alternative port serves as a root port. It does not always send or receive any frames while it is in the blocking state.
Backup Port
Provides an alternative path of the path specified by the specific path. In the event that the specified port becomes a
linkdown state, backup port serves as a designated port. It does not always send or receive any frames while it is in the
blocking state.
Disabled Port
Disabled port, it does not send or receive any frames.

4.5.2 Spanning Tree Protocol Port States

The port states defined by the STP are:
Discard
Shows the port is in "discarding state. BPDUs only are received.
Learn
Shows the port is in "learning" state. A port in the learning state learns the destination MAC address of the receive
frames but does not participate in frame forwarding.
Forward
Shows the port is ready to transmit data traffic.
The STP states "blocking" and "listening" have been merged into a unique RSTP "discarding" state. The correspondence
between STP port states and RTSTP port states is shown below.
Display STP(IEEE802.1D)
Format
Discard Blocking
Discard Listening
Learn Learning
Forward Forwarding
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RSTP(IEEE802.1w)
Discarding
Discarding
Learning
Forwarding