Cabletron Systems SmartSTACK 10 ELS10-26, Руководство пользователя

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Introduction
1-9
By forwarding only packets addressed to devices on other network
segments, the SmartSTACK 10 ELS10-26 reduces unnecessary
traffic and thereby enhances the overall performance of the
network.
Note:
If the packet address is not found in the Bridge Address Table, it
will be forwarded (flooded) to all network segments.
Spanning Tree Algorithm
The SmartSTACK 10 ELS10-26 supports the IEEE 802.1d Spanning
Tree algorithm. The Spanning Tree algorithm converts multiple
LANs into a “spanning tree” of networks. It is used to prevent
bridging loops. This standard defines a logical (not physical)
network configuration consisting of one extended LAN without
active duplicate paths between spanning tree bridges.
The SmartSTACK 10 ELS10-26, along with other IEEE 802.1d
Spanning Tree compliant bridges in the network, dynamically
configure the network topology into a single Spanning Tree by
exchanging Bridge Protocol Data Units (BPDUs). Typically, each
LAN segment is sent one BPDU every two seconds (this is the
default setting).
When there are multiple SmartSTACK 10 ELS10-26s connecting
LANs in a loop, the Spanning Tree algorithm determines which
SmartSTACK 10 ELS10-26 should forward packets to the LAN. If
there is a cable break or a port failure, the network topology is
automatically reconfigured by the Spanning Tree protocol to create
an alternate path to the LAN.
1.5.2 SmartSTACK 10 ELS10-26 Bridge Address Table
The SmartSTACK 10 ELS10-26 creates and maintains a dynamic
database of addresses called the Bridge Address Table. The
SmartSTACK 10 ELS10-26 examines every packet to determine its
source address and LAN segment origin. It then compares the
source address and segment information it finds to the entries in
the Bridge Address Table.