Ospf; Chapter 32 Ospf; Ospf Overview; Ospf Autonomous Systems And Areas - ZyXEL Communications XGS-4728F User Manual

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H A P T E R
This chapter describes the OSPF (Open Shortest Path First) routing protocol and
shows you how to configure OSPF.

32.1 OSPF Overview

OSPF (Open Shortest Path First) is a link-state protocol designed to distribute
routing information within an autonomous system (AS). An autonomous system is
a collection of networks using a common routing protocol to exchange routing
information.
OSPF offers some advantages over traditional vector-space routing protocols
(such as RIP). The following table summarizes some of the major differences
between OSPF and RIP.
Table 94 OSPF vs. RIP
Network
Size
Metrics
Convergenc
e

32.1.1 OSPF Autonomous Systems and Areas

An OSPF autonomous system (AS) can be divided into logical areas. Each area
represents a group of adjacent networks. All areas are connected to a backbone
(also known as area 0). The backbone is the transit area to route packets between
two areas. A stub area, at the edge of an AS is not a transit area since there is
only one connection to the stub area.
XGS-4728F User's Guide

OSPF

Large
Bandwidth, hop count, throughput,
round trip time and reliability.
Fast
32
OSPF
RIP
Small (with up to 15 routers)
Hop count
Slow
273