Question 1 |

The forwarding table of a router is shown below.

\begin{array}{|c|c|c|c|} \hline \\ Subnet \; Number&Subnet \;Mask&Interface ID \\ \hline 200.150.0.0 &255.255.0.0& 1\\ \hline 200.150.64.0 &255.255.224.0 &2\\ \hline 200.150.68.0 &255.255.255.0 &3\\ \hline 200.150.68.64 &255.255.255.224 &4 \\ \hline Default & &0\\ \hline \end{array}

A packet addressed to a destination address 200.150.68.118 arrives at the router. It will be forwarded to the interface with ID _____.

\begin{array}{|c|c|c|c|} \hline \\ Subnet \; Number&Subnet \;Mask&Interface ID \\ \hline 200.150.0.0 &255.255.0.0& 1\\ \hline 200.150.64.0 &255.255.224.0 &2\\ \hline 200.150.68.0 &255.255.255.0 &3\\ \hline 200.150.68.64 &255.255.255.224 &4 \\ \hline Default & &0\\ \hline \end{array}

A packet addressed to a destination address 200.150.68.118 arrives at the router. It will be forwarded to the interface with ID _____.

1 | |

2 | |

3 | |

4 |

Question 1 Explanation:

Question 2 |

Which of the following statements is/are INCORRECT about
the OSPF (Open Shortest Path First) routing protocol used in the Internet?

OSPF implements Bellman-Ford algorithm to find shortest paths. | |

OSPF uses Dijkstra's shortest path algorithm to implement least-cost path routing | |

OSPF is used as an inter-domain routing protocol | |

OSPF implements hierarchical routing. |

Question 2 Explanation:

Question 3 |

Consider a network with three routers P, Q, R shown in the figure below. All the links have cost of unity.

The routers exchange distance vector routing information and have converged on the routing tables, after which the link Q-R fails. Assume that P and Q send out routing updates at random times, each at the same average rate. The probability of a routing loop formation (rounded off to one decimal place) between P and Q, leading to count-to-infinity problem, is ____

The routers exchange distance vector routing information and have converged on the routing tables, after which the link Q-R fails. Assume that P and Q send out routing updates at random times, each at the same average rate. The probability of a routing loop formation (rounded off to one decimal place) between P and Q, leading to count-to-infinity problem, is ____

0.25 | |

0.33 | |

0.50 | |

0.75 |

Question 3 Explanation:

Question 4 |

Consider routing table of an organization's router shown below:

\begin{array}{|l|l|l|} Subnet Number & Subnet Mask & Next Hop \\ 12.20.164.0 & 255.255.252.0 & R1 \\ 12.20.170.0 & 255.255.254.0 & R2 \\ 12.20.168.0 & 255.255.254.0 & Interface 0 \\ 12.20.166.0 & 255.255.254.0 & Interface 1 \\ default & ~ & R3 \\ \hline \end{array}

Which of the following prefixes in CIDR notation can be collectively used to correctly aggregate all of the subnets in the routing table?

\begin{array}{|l|l|l|} Subnet Number & Subnet Mask & Next Hop \\ 12.20.164.0 & 255.255.252.0 & R1 \\ 12.20.170.0 & 255.255.254.0 & R2 \\ 12.20.168.0 & 255.255.254.0 & Interface 0 \\ 12.20.166.0 & 255.255.254.0 & Interface 1 \\ default & ~ & R3 \\ \hline \end{array}

Which of the following prefixes in CIDR notation can be collectively used to correctly aggregate all of the subnets in the routing table?

**MSQ**12.20.164.0/20 | |

12.20.164.0/22 | |

12.20.164.0/21 | |

12.20.168.0/22 |

Question 4 Explanation:

Question 5 |

Consider an enterprise network with two Ethernet segments, a web server and a firewall, connected via three routers as shown below.

What is the number of subnets inside the enterprise network?

What is the number of subnets inside the enterprise network?

3 | |

12 | |

6 | |

8 |

Question 5 Explanation:

There are 5 questions to complete.