ADC 410F, User Manual

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Chapter 9: Technical Reference
Megabit Modem 410F and 420F User Manual 69
B
RIDGING AND
R
OUTING
Bridging
You can configure the Megabit Modem 410F and 420F 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 410F and 420F provide
transparent Ethernet MAC-layer bridging. The bridge learns up to 1024 addresses.
Spanning Tree Protocol
The Megabit Modem 410F and 420F support the 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 70 . In this example, the spanning tree
algorithm partitions out the bridge from LAN A to LAN B and the link from ENET2 to
Bridge 5.