OSPF Introduction Part 2

Question 1

What are multi access segments?

Answer 1

Broadcast and Non Broadcast segments

Question 2

What is DR and BDR?

Answer 2

Designated Router

Backup Designated Router

Question 3

When is DR or BDR used?

Answer 3

In multi-access segment, to avoid multiple OSPF adjacencies across all routers,
a DR and BDR is elected and all OSPF routers form full adjacencies with these DR and BDR routers but do not for full adjacencies with each others, and rely on these DR and BDR for providing update information to all the OSPF routers in the OSPF domain.
Only used in broadcast or non-broadcast, multi-access networks.

Question 4

OSPF metric depends on what factor?

Answer 4

Link speed or the BW of the interface.

Greater the BW Or the speed of the interface lesser is the OSPF cost or the metric.

Question 5

What comand to use to adjust the OSPF reference bandwidth?

Answer 5

auto-cost reference bandwidth

Question 6

How does multi-area OSPF help?

Answer 6

By creating multiple areas it helps us reduce the size of the LSDB

Question 7

Which area is mandatory to have in OSPF?

Answer 7

area 0 or the backbone area. And all the non Area 0 areas will have to connect to the backbone area which is area 0.

Question 8

What is the loop prevention mechanism in OSPF?

Answer 8

Every area in OSPF other than the area 0 (backbone area) will have to connect with the backbone area which is the area 0

Question 9

Features of Multi Area OSPF

Answer 9

1. Enables Scalability
2. Distance Vector behaviour
3. LSA (Link state advertisement) Types