Nortel Networks WEB OS 212777 - Manual (Page 69)

212777-A, February 2002
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HAPTER
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OSPF
Web OS 10.0 supports the Open Shortest Path First (OSPF) routing protocol. The Web OS
implementation conforms to the OSPF version 2 specifications detailed in Internet RFC 1583.
The following sections discuss OSPF support for the Alteon AD4/184 Web switches:
n
“OSPF Overview” on page 69 . This section provides information on OSPF concepts, such
as types of OSPF areas, types of routing devices, neighbors, adjacencies, link state data-
base, authentication, and internal versus external routing.
n
“OSPF Implementation in Web OS” on page 74 . This section describes how OSPF is
implemented in Web OS, such as configuration parameters, electing the designated router,
summarizing routes, defining route maps and so forth.
n
“OSPF Configuration Examples” on page 83 . This section provides step-by-step instruc-
tions on configuring four different configuration examples:
o Creating a simple OSPF domain
o Creating virtual links
o Summarizing routes
o Creating host routes
OSPF Overview
OSPF is designed for routing traffic within a single IP domain called an Autonomous System
(AS). The AS can be divided into smaller logical units known as areas.
All routing devices maintain link information in their own Link State Database (LSDB). The
LSDB for all routing devices within an area is identical but is not exchanged between different
areas. Only routing updates are exchanged between areas, thereby significantly reducing the
overhead for maintaining routing information on a large, dynamic network.
The following sections describe key OSPF concepts.