Blade ICE G8124-E Manuale Utente

BMD00220, October 2010

Chapter 20: OSPF  

  275

As shown in 

, OSPF uses the following types of routing devices:

Internal Router (IR)—a router that has all of its interfaces within the same area. IRs maintain 
LSDBs identical to those of other routing devices within the local area.

Area Border Router (ABR)—a router that has interfaces in multiple areas. ABRs maintain one 
LSDB for each connected area and disseminate routing information between areas.

Autonomous System Boundary Router (ASBR)—a router that acts as a gateway between the 
OSPF domain and non-OSPF domains, such as RIP, BGP, and static routes.

OSPF Domain and an Autonomous System

Backbone

Area 0

Area 3

Area 2

Area 1

Inter-Area Routes

(Summary Routes)

External

Routes

BGP

RIP