ADC Campus-REX RS Interface Card Manuel D’Utilisation
Internetworking and Management Overview
7-2
Campus-REX RS Interface Card User Manual
MAC-L
EVEL
B
RIDGING
AND
S
PANNING
T
REE
P
ROTOCOL
The following sections describe the MAC-level bridge and the Spanning Tree
algorithm function.
algorithm function.
MAC-Level Bridging
A bridge moves information across an internetwork from a source to a
destination at the link layer (of an OSI reference model). The information is
sent to a physical address known as a Media Access Control (MAC) address.
destination at the link layer (of an OSI reference model). The information is
sent to a physical address known as a Media Access Control (MAC) address.
The Campus-REX provides transparent Ethernet MAC-level bridging. It is a
completely self-contained bridge with a CPU, memory subsystems (RAM,
Flash, etc.), an Ethernet controller and Ethernet drivers, and other glue logic.
It provides complete main bridging tasks of learning, forwarding, filtering,
and hashing/buffer management. Additionally, it offers 802.1d Spanning
Tree protocol, packet encapsulation (through HDLC or PPP framing), and
other local tasks.
completely self-contained bridge with a CPU, memory subsystems (RAM,
Flash, etc.), an Ethernet controller and Ethernet drivers, and other glue logic.
It provides complete main bridging tasks of learning, forwarding, filtering,
and hashing/buffer management. Additionally, it offers 802.1d Spanning
Tree protocol, packet encapsulation (through HDLC or PPP framing), and
other local tasks.
Forwarding performance is at a full serial line rate and filtering performance
is at a full Ethernet rate of 14 kpps for 64-byte frames (minimum size).
is at a full Ethernet rate of 14 kpps for 64-byte frames (minimum size).
Spanning Tree
Spanning Tree protocol creates a logical topology to overlay a physical
network. This overlay disables all loops in the data path. Enabling Spanning
Tree ensures a unique, primary path from any node on a network to any other
node. Also, if the primary path is lost, Spanning Tree creates a new primary
path by enabling links in the physical network that were previously disabled
in creating the active topology. The following figure shows an example of
Spanning Tree.
network. This overlay disables all loops in the data path. Enabling Spanning
Tree ensures a unique, primary path from any node on a network to any other
node. Also, if the primary path is lost, Spanning Tree creates a new primary
path by enabling links in the physical network that were previously disabled
in creating the active topology. The following figure shows an example of
Spanning Tree.
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