Network Layer Protocol
Q1.
An organization requires a range of IP address to assign one to each of its 1500 computers. The organization has approached an Internet Service Provider (ISP) for this task. The ISP uses CIDR and serves the requests from the available IP address space 202.61.0.0/17. The ISP wants to assign an address space to the organization which will minimize the number of routing entries in the ISP?s router using route aggregation. Which of the following address spaces are potential candidates from which the ISP can allot any one of the organization? I. 202.61.84.0/21II. 202.61.104.0/21III. 202.61.64.0/21IV. 202.61.144.0/21Q2.
Which of the following statements is/are INCORRECT about the OSPF (Open Shortest Path First) routing protocol used in the Internet?Q3.
Which of the following classes of languages can validate an IPv4 address in dotted decimal format? It is to be ensured that the decimal values lie between 0 and 255.Q4.
Consider a computer network using the distance vector routing algorithm in its network layer. The partial topology of the network is shown below. The objective is to find the shortest-cost path from the router R to routers P and Q. Assume that R does not initially know the shortest routes to P and Q. Assume that R has three neighboring routers denoted as X, Y and Z. During one iteration, R measures its distance to its neighbors X, Y, and Z as 3, 2 and 5, respectively. Router R gets routing vectors from its neighbors that indicate that the distance to router P from routers X, Y and Z are 7, 6 and 5, respectively. The routing vector also indicates that the distance to router Q from routers X, Y and Z are 4, 6 and 8 respectively. Which of the following statement(s) is/are correct with respect to the new routing table o R, after updation during this iteration?[MSQ]Q5.
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?MSQQ6.
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 ____Q7.
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 _____.Q8.
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?Q9.
onsider the following statements about the functionality of an IP based router. I. A router does not modify the IP packets during forwarding. II. It is not necessary for a router to implement any routing protocol. III. A router should reassemble IP fragments if the MTU of the outgoing link is larger than the size of the incoming IP packet. Which of the above statements is/are TRUE?