Contents
- 1 What is inter area routes in OSPF?
- 2 How do you perform an inter area summarization in OSPF?
- 3 What are two features of OSPF inter area route summarization?
- 4 What is the use of OSPF virtual link?
- 5 Where does the summary LSA live in OSPF?
- 6 What’s the difference between inter area and intra area routes?
What is inter area routes in OSPF?
Inter-area routes refer to updates that are passed between areas. External routes refer to updates passed from another routing protocol into the OSPF domain by the Autonomous System Border Router (ASBR).
How do you perform an inter area summarization in OSPF?
- OSPF is link state routing protocol that works on the concept of areas.
- Summarization between areas can be done on ABR by using single command under OSPF process:
- A) area-id= Identifier of the area about which routes are to be summarized.
- B) [ ip-address ] [mask]= Summary route to be advertise in areas.
What is LSA in OSPF?
The link-state advertisement (LSA) is a basic communication means of the OSPF routing protocol for the Internet Protocol (IP). It communicates the router’s local routing topology to all other local routers in the same OSPF area.
How does OSPF build routing table?
OSPF propagates link-state advertisements (LSAs) rather than routing table updates. Because only LSAs are exchanged instead of the entire routing tables, OSPF networks converge in a timely manner. OSPF uses a link-state algorithm to build and calculate the shortest path to all known destinations.
What are two features of OSPF inter area route summarization?
What are two features of OSPF interarea route summarization? (Choose two.)
- Route summarization results in high network traffic and router overhead.
- Routes within an area are summarized by the ABR.
- Type 3 and type 5 LSAs are used to propagate summarized routes by default.
- ASBRs perform all OSPF summarization.
What is the use of OSPF virtual link?
What Are Virtual Links? All areas in an OSPF autonomous system must be physically connected to the backbone area (area 0). In some cases where this physical connection is not possible, you can use a virtual link to connect to the backbone through a non-backbone area.
Which is the inter area router in OSPF?
The Border router will also take the intra area routes for area 0 and will generate type 3 LSAs for area 5 and will advertise the type 3 LSAs to other OSPF routers in area 5. As John tells us in the route table the inter area routes are identified as O IA.
How to show OSPF database summary in IP OSPF?
They are flooded only within the area in which they originate. show ip ospf database summary —Displays the area border router (ABR) summary links. Since Router 2.2.2.2 is the ABR, it has the database for both areas that it is connected to.
Where does the summary LSA live in OSPF?
C. Any summary LSAs already within area 0 (the result of another ABR generating type 3 LSA into area 0) will be regenerated into area 1. This will involve generating a new type 3 with an updated cost and this LSA will live in the area 1 LSDB.
What’s the difference between inter area and intra area routes?
Intra Area routes are the “O” routes that you see in the routing table. These routes are routes that are in the same area. Inter-area routes are the “O IA” routes that are learned in different areas. If you have 2 areas, area 0 and 1, the routes that are originated in Area 0 and learned by other routers in Area 0 are intra-area routes.