Types Of Ospf Routing Devices - Lenovo RackSwitch G8264 Application Manual

ABR
Internal LSA
Routes
Not-So-Stubby Area
(NSSA)
External LSA
Routes
Non-OSPF Area
RIP/BGP AS

Types of OSPF Routing Devices

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Figure 48. OSPF Area Types
(Also a Transit Area)
No External Routes
ASBR
ABR = Area Border Router
ASBR = Autonomous System
As shown in Figure 49, 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.
Backbone
Area 0
ABR
Stub Area
from Backbone
Boundary Router
ABR
Virtual
Link
Transit Area
ABR
Stub Area, NSSA,
or Transit Area
Connected to Backbone
via Virtual Link
Chapter 35: Open Shortest Path First
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