Intel ER8100STUS - Express 8100 Router, Reference Manual

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Reference.bok : Chapter10 93 Wed Apr 22 10:58:08 1998
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Chapter 10
WAN Bridging Services
In this chapter
This chapter describes configuring the Intel Express 8100 Router to use bridging
services and to use Spanning Tree Algorithm.
Introduction to WAN Bridging
WAN Bridging
The Intel Express 8100 Router can bridge packets between the LAN and a WAN
link or between the two WAN links—this is known as WAN Bridging.
Background knowledge
It is assumed that you have a basic knowledge of the terminology used in bridged
environments.
Note
When the router is operating as a bridge, it is referred to as a bridge in
this chapter.
The purpose of bridging
in the router
The purpose of WAN Bridging is to extend the router with bridging services so
that the router can also act as a bridge.
Bridging concept Bridging in the router conforms to the following standards:
■
IEEE 802.1D—Local MAC Bridging
■
IEEE 802.1G—Remote MAC Bridging
Bridging relies on MAC layer addressing (specified by IEEE 802.3) and is inde-
pendent of Network layer protocols.
Bridging is used by the Intel Express 8100 Router for protocols which cannot be
routed by the router. However, if a routing protocol is disabled, the protocol is
bridged if bridging services are enabled.
Spanning Tree Algorithm
The Spanning Tree Algorithm is implemented for bridging in the router. The
Spanning Tree Algorithm gives the possibility of having redundant paths within
a bridged environment, allowing stand-by bridges to be implemented which are
ready to start forwarding packets if another bridge is powered off or fails during
operation.