Computer Network
Q151.
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 ____Q152.
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?Q153.
An IP datagram of size 1000 bytes arrives at a router. The router has to forward this packet on a link whose MTU (maximum transmission unit)is 100bytes. Assume that the size of the IP header is 20bytes. The number of fragments that the IP datagram will be divided into for transmission is _________.Q154.
Consider three machines M, N and P with IP addresses 100.10.5.2, 100.10.5.5 and 100.10.5.6 respectively. The subnet mask is set to 255.255.255.252 for all the three machines. Which one of the following is true?Q155.
Consider an IP packet with a length of 4,500 bytes that includes a 20-byte IPv4 header and a 40-byte TCP header. The packet is forwarded to an IPv4 router that supports a Maximum Transmission Unit (MTU) of 600 bytes. Assume that the length of the IP header in all the outgoing fragments of this packet is 20 bytes. Assume that the fragmentation offset value stored in the first fragment is 0. The fragmentation offset value stored in the third fragment is _______.Q157.
Which of the following statements is/are INCORRECT about the OSPF (Open Shortest Path First) routing protocol used in the Internet?Q158.
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]Q159.
Match with the suitable one:\begin{array}{|l|l|l|l|} \hline & \text { List-1 } & & \text { List-2 } \\ \hline \text { (a) } & \text { Multicast group membership } & \text { i. } & \text { Distance Vector routing } \\ \hline \text { (b) } & \text { Interior gateway protocol } & ii . & \text { IGMP } \\ \hline \text { (c) } & \text { Exterior gateway protocol } & iii . & \text { OSPF } \\ \hline \text { (d) } & \text { RIP } & iv . & \text { BGP } \\ \hline \end{array}Q160.
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?