OSPF-7

Question 1

What is Area 0 in OSPF and why is it important?

Answer 1

A: Area 0 is the backbone area in OSPF. All other areas must connect to it directly, except through virtual links when needed.

Explanation: OSPF uses Area 0 to exchange routing information between non-backbone areas, making it the core of an OSPF domain.

Question 2

What is an Area Border Router (ABR)?

Answer 2

A: An ABR connects one or more OSPF areas to Area 0 and has at least one interface in Area 0.

Explanation: It maintains separate link-state databases for each area it connects and summarizes routes between them.

Question 3

What is an Autonomous System Boundary Router (ASBR)?

Answer 3

A: An ASBR connects an OSPF domain to other autonomous systems and advertises external routes into OSPF.

Explanation: ASBRs are used to redistribute routes from other protocols or ASes into OSPF.

Question 4

What is the Router ID (RID) in OSPF?

Answer 4

A: The Router ID is a unique IP address that identifies each router in an OSPF domain.

Explanation: It’s usually the highest loopback address or highest active interface IP if no loopbacks are present.

Question 5

What key parameters must match for OSPF neighbors to form an adjacency?

Answer 5

A:
Area ID
Stub area flag
Authentication password
Hello and Dead intervals

Explanation:
Mismatch in any of these settings will prevent OSPF neighbor relationships from forming.