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Bridging and routing, Bridging, Mac layer bridging – ADC 400F User Manual

Page 72: Spanning treeprotocol, Ridging and, Outing

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Bridging and Routing

64

Megabit Modem 400F User Manual

B

RIDGING AND

R

OUTING

Bridging

You can configure the Megabit Modem 400F as a bridge to forward Ethernet data based on
MAC addresses.

MAC Layer 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. The Megabit Modem 400F provides transparent
Ethernet MAC-layer bridging.

The bridge learns up to 1024 addresses. Additionally, when you configure the modem, you can
add 32 static addresses through the static MAC address configuration page.

Spanning Tree Protocol

The Megabit Modem 400F supports 802.1d Spanning Tree protocol which eliminates loops in
a LAN topology by partitioning out redundant links between LAN segments. This ensures that
there is only one path, or link, between any two nodes on the network. If this link goes down,
Spanning Tree re-enables partitioned links to create a new loop-free topology if possible.

An example of the active topology is shown on

page 65

. In the example, the spanning tree

algorithm partitions out the bridge from LAN A to LAN B, and creates the link from ENET2
to Bridge 5.