Technical data

BMD00136, November 2009 145
CHAPTER 11
OSPF
BLADE OS supports the Open Shortest Path First (OSPF) routing protocol. The BLADE OS
implementation conforms to the OSPF version 2 specifications detailed in Internet RFC 1583. The
following sections discuss OSPF support for the RackSwitch G8000:
 “OSPF Overview” on page 145. This section provides information on OSPF concepts, such as
types of OSPF areas, types of routing devices, neighbors, adjacencies, link state database,
authentication, and internal versus external routing.
 “OSPF Implementation in BLADE OS” on page 150. This section describes how OSPF is
implemented in BLADE OS, such as configuration parameters, electing the designated router,
summarizing routes, defining route maps and so forth.
 “OSPF Configuration Examples” on page 160. This section provides step-by-step instructions
on configuring different configuration examples:
 Creating a simple OSPF domain
 Creating virtual links
 Summarizing 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.