ProLiant BL p-Class GbE Interconnect Switch Web-based Interface Reference Guide

Configuring the GbE Interconnect Switch using the Web-based Interface
STP communicates between switches on the network using Bridge Protocol Data Units
(BPDUs). Each BPDU contains the following information:
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The unique identifier of the switch that the transmitting switch currently believes is the
root switch
The path cost to the root from the transmitting port
The port identifier of the transmitting port
The switch sends BPDUs to communicate and construct the spanning-tree topology. All
switches connected to the LAN on which the packet is transmitted will receive the BPDU.
BPDUs are not directly forwarded by the switch, but the receiving switch uses the
information in the frame to calculate a BPDU, and if the topology changes, initiates a BPDU
transmission.
The communication between switches via BPDUs results in the following:
One switch is elected as the root switch.
The shortest distance to the root switch is calculated for switch.
A designated switch is selected. This is the switch closest to the root switch through
which packets will be forwarded to the root.
A port for each switch is selected. This is the port providing the best path from the switch
to the root switch.
Ports included in the STP are selected.
Spanning Tree Protocol (STP) can be enabled or disabled at the switch level. Only one
spanning tree domain per GbE Interconnect Switch is supported. You can configure ports to
participate in that spanning tree domain, by enabling or disabling the STP function on a per
port basis. Ports can also be configured in STP bypass mode (fast forward mode) that allows
the port to skip the initial STP states (listening and learning) before enabling it in the
forwarding state.
IMPORTANT: The GbE Interconnect Switch supports mono-Spanning Tree Protocol. Multiple spanning
tree domains are not supported. This means the Spanning Tree Algorithm makes calculations without
considering the VLAN domains to which the ports belong. All ports that have STP enabled fall under
one STP domain.
NOTE: Refer to Appendix E in the HP ProLiant BL p-Class GbE Interconnect Switch User Guide for
more information on Spanning Tree Protocol.
HP ProLiant BL p-Class GbE Interconnect Switch Web-based Interface Reference Guide 2-19