Basic CS-Networks [3i Infotech Placement]: Sample Questions 28 - 29 of 90

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Question 28

Networks

Question

MCQ▾

For MB memory, the number of address lines required is?

Choices

Choice (4)

a.

24

b.

22

c.

11

d.

20

Answer

d.

Explanation

  • is memory in bytes accessible using n lines (for byte addressable memory)
  • In the questions bytes

  • So, the number of address line required is .

Question 29

Networks
Edit

Describe in Detail

Essay▾

What is OSPF?

Explanation

OSPF Autonomous System
  • Stands for Open Shortest Path First.
  • A routing protocol for internet protocol.
  • Used a link state routing algorithm and falls into the group of interior gateway protocols, operating within a single autonomous system.
  • Outing protocol has largely replaced the older Routing Information Protocol in corporate networks.
  • Link-state routing protocol means that the routers exchange topology information with their nearest neighbour.
  • Calculates end-to-end paths through the autonomous system using a variant of the Dijkstra algorithm.

Working of OSPF

  • OSPF network works based on area and autonomy.
  • OSPF network divided into groups called areas- OSPF is based on functional areas like a building or the floor of a building.
  • Autonomous systems (AS) are collections of areas- for example, every router in an organization cab probably be part of a single AS. These regions are automatically configured and routed by the router.

Advantages:

  • A link state routing protocol like OSPF provides complete knowledge of topology allowing routers to calculate routes satisfying particular criteria- shortest distance, least cost, least time, best QoS etc.
  • For traffic engineering purpose, route can be constrained to meet particular quality of service.

Disadvantages:

  • Link state routing protocol does not scale well with more routers in the routing domain.
  • Number of routers increases the size and frequency of the topology updates, and time taken to calculate routes.

Developed by: