Routing Overview; Routing Terms - Juniper J2300 User Manual

Chapter 12

Routing Overview

Routing Terms

Table 102: Routing Terms
Term
adjacency
area
area border router (ABR)
At its most fundamental level, routing is the process of delivering a message across
a network or networks. This task is divided into two primary components: the
exchange of routing information to accurately forward packets from source to
destination and the packet-forwarding process.
To use the routing capabilities of a J-series Services Router, you must understand the
fundamentals of IP routing and the routing protocols that are primarily responsible
for the transmission of unicast traffic. To read this chapter, you need a basic
understanding of IP addressing and TCP/IP.
This chapter includes the following topics. For more information, see the JUNOS
Routing Protocols Configuration Guide.
Routing Terms on page 255
Routing Overview on page 259
RIP Overview on page 265
OSPF Overview on page 269
BGP Overview on page 274
To understand routing, become familiar with the terms defined in Table 102 .
Definition
Portion of the local routing information that pertains to the reachability of a single neighbor
over a single circuit or interface.
Administrative group of OSPF networks within an autonomous system (AS) that operates
independently from other areas in the AS. Multiple areas within an AS reduce the amount of
link-state advertisement (LSA) traffic on the network and the size of topology databases.
In OSPF, a router having interfaces in multiple areas of an autonomous system (AS) so that
it can link the areas to each other. An area border router maintains a separate topological
database for each area it is connected to and shares topology information between areas.
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Routing Terms