List of top Computer Networks Questions

Suppose a message of size 15000 bytes is transmitted from a source to a destination using IPv4 protocol via two routers as shown in the figure. Each router has a defined maximum transmission unit (MTU) as shown in the figure, including IP header. The number of fragments that will be delivered to the destination is ___________. (Answer in integer)

Consider a network that uses Ethernet and IPv4. Assume that IPv4 headers do not use any options field. Each Ethernet frame can carry a maximum of 1500 bytes in its data field. A UDP segment is transmitted. The payload (data) in the UDP segment is 7488 bytes. Which ONE of the following choices has the CORRECT total number of fragments transmitted and the size of the last fragment including IPv4 header?

Consider the 3-way handshaking protocol for TCP connection establishment. Let the three packets exchanged during the connection establishment be denoted as P1, P2, and P3, in order. Which of the following option(s) is/are TRUE with respect to TCP header flags that are set in the packets?

Suppose a message of size 15000 bytes is transmitted from a source to a destination using IPv4 protocol via two routers as shown in the figure. Each router has a defined maximum transmission unit (MTU) as shown in the figure, including IP header. The number of fragments that will be delivered to the destination is ___________. (Answer in integer)

Consider a context-free grammar \(G\) with the following 3 rules: \[ S \to aS, \quad S \to aSbS, \quad S \to c \] Let \(w \in L(G)\). Let \(n_a(w), n_b(w), n_c(w)\) denote the number of times \(a, b, c\) occur in \(w\), respectively. Which of the following statements is/are TRUE?

Consider an Ethernet segment with a transmission speed of \(10^8 \, \text{bits/sec}\) and a maximum segment length of \(500 \, \text{meters}\). If the speed of propagation of the signal in the medium is \(2 \times 10^8 \, \text{meters/sec}\), then the minimum frame size (in bits) required for collision detection is ............

A functional dependency \(F: X \to Y\) is termed as a useful functional dependency if and only if it satisfies all the following three conditions: \(X\) is not the empty set. \(Y\) is not the empty set. Intersection of \(X\) and \(Y\) is the empty set. For a relation \(R\) with 4 attributes, the total number of possible useful functional dependencies is ............

Consider a TCP connection operating at a point of time with the congestion window of size \(12 \, \text{MSS}\) (Maximum Segment Size), when a timeout occurs due to packet loss. Assuming that all the segments transmitted in the next two RTTs (Round Trip Time) are acknowledged correctly, the congestion window size (in MSS) during the third RTT will be ............

Let \(G\) be an undirected connected graph in which every edge has a positive integer weight. Suppose that every spanning tree in \(G\) has even weight. Which of the following statements is/are TRUE for every such graph \(G\)?

Let \(x\) and \(y\) be random variables, not necessarily independent, that take real values in the interval \([0, 1]\). Let \(z = xy\) and let the mean values of \(x, y, z\) be \(\bar{x}, \bar{y}, \bar{z}\), respectively. Which one of the following statements is TRUE?

Let \(S1\) and \(S2\) be two stacks. \(S1\) has a capacity of 4 elements, and \(S2\) has a capacity of 2 elements. \(S1\) already has 4 elements: 100, 200, 300, and 400, whereas \(S2\) is empty, as shown below. \begin{center} \includegraphics[width=8cm]{48.png} \end{center} Only the following three operations are available:
\texttt{PushToS2:} Pop the top element from \(S1\) and push it on \(S2\).
\texttt{PushToS1:} Pop the top element from \(S2\) and push it on \(S1\).
\texttt{GenerateOutput:} Pop the top element from \(S1\) and output it to the user. Note: - The pop operation is not allowed on an empty stack.
- The push operation is not allowed on a full stack. Which of the following output sequences can be generated by using the above operations?

Which of the following is/are EQUAL to 224 in radix-5 (i.e., base-5) notation?

You are given a set \(V\) of distinct integers. A binary search tree \(T\) is created by inserting all elements of \(V\) one by one, starting with an empty tree. The tree \(T\) follows the convention that, at each node, all values stored in the left subtree of the node are smaller than the value stored at the node. You are not aware of the sequence in which these values were inserted into \(T\), and you do not have access to \(T\). Which one of the following statements is TRUE?

Which of the following file organizations is/are I/O efficient for the scan operation in DBMS?}

In the context of owner and weak entity sets in the ER (Entity-Relationship) data model, which one of the following statements is TRUE?

What is the full form of IP in the Internet communication system ?

Identify the protocol name(s) used in computer network from the following.
(A) FTP
(B) HTML
(C) HTTP
(D) Telnet
(E) Modem
Choose the correct answer from the options given below:

The full form of MQTT is

Which of the following is not transition strategy from IPv4 to IPv6?

What is the maximum number of subnetworks for the default mask 255.255.0.0 and subnet mask 255.255.224.0?

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?

Consider the resolution of the domain name www.gate.org.in by a DNS resolver. Assume that no resource records are cached anywhere across the DNS servers and that the iterative query mechanism is used in the resolution. The number of DNS query-response pairs involved in completely resolving the domain name is \(\underline{\hspace{1cm}}\).

Consider routing table of an organization's router shown below:\[\begin{array}{|c|c|c|} \hline \textbf{Subnet Number} & \textbf{Subnet Mask} & \textbf{Next Hop} \\ \hline \text{12.20.164.0} & \text{255.255.252.0} & \text{R1} \\ \hline \text{12.20.170.0} & \text{255.255.254.0} & \text{R2} \\ \hline \text{12.20.168.0} & \text{255.255.254.0} & \text{Interface 0} \\ \hline \text{12.20.166.0} & \text{255.255.254.0} & \text{Interface 1} \\ \hline \text{default} & \text{R3} \\ \hline \end{array}\]Which of the following prefixes in CIDR notation can be collectively used to correctly aggregate all of the subnets in the routing table?

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 \(\underline{\hspace{1cm}}\).

Consider a 100 Mbps link between an earth station (sender) and a satellite (receiver) at an altitude of 2100 km. The signal propagates at a speed of \(3 \times 10^8 \ \text{m/s}\). The time taken (in milliseconds, rounded off to two decimal places) for the receiver to completely receive a packet of 1000 bytes transmitted by the sender is