100 TOP COMPUTER NETWORKS Multiple Choice Questions and AnswersFull description
Overview on audit
Full description
Computer NetworksFull description
computer networkFull description
manacFull description
Computer
Computer Fundamentals by P.K SinhaFull description
FIFTH SEMESTER COMPUTER CS6551 NETWORKS TWO MARK WITH ANSWER
Fundamentals of Computer Graphics 4th
Full description
GATE Computer Networks book is very useful for student who want to prepare for GATE. This book is part of GATE correspondence course study material by THE GATE ACADEMY. http://thegateacademy.com/
Full description
Full description
A ppt on COMPUTER NETWORKS by KUMAR ABHISHEK(3RB06CS045) from REC BHALKI(KARNATAKA)......
basic mcq questionFull description
Computer Networks MCQFull description
It is the interconnection of multiple devices, generally termed as Hosts connected using multiple paths for the purpose of sending receiving data or media. There are also multiple devices or mediums which helps in the communication between two differ
Fundamentals of Database Systems Answers for chapter 8 of 4th edition, also similar to 5th chapter of 6th editionFull description
Full description
Student Name
Student ID Number
COMP247 Data Communications Quiz 1-1. Duration: 30 minutes, no reading time. Questions: 6 of equal value. Instructions
Place your student ID on the desk near you throughout the quiz and until your paper has been collected.
Answer quiz questions on this paper and return it.
Answer all questions.
If you wish to make rough notes, use the back of pages in this paper.
Calculators are not allowed.
Dictionaries are not allowed.
Every attempt has been made to make the questions unambiguous. However, if you think that a question requires additional i nformation, make a reasonable assumption, state it at the start of your answer, and answer the question.
Question 1 When a message is sent through a network, the message must normally contain a destination address. Under what circumstances can a message not contain a destination address and still be successfully transmitted through the network? Explain.
Answer: If the message is being sent from one end of a point-to-point link to the other end, then addressing is unnecessary because the receiver at the other end processes all messages that arrive to it. Alt answer: If the message is being broadcast to all nodes then it does not need the destination address of an individual recipient. If the network only supported broadcast traffic then there would be no need for destination addresses at all. However, networks like Ethernet provide addressing so that messages can be sent to a specific destination; in such networks, broadcast messages must have an explicit broadcast address.
Question 2 An organisation has been assigned the CIDR block 12.128.64.0/20. It requires four subnets, including the all 0’s and all 1’s subnets. What is the network mask of the #1 subnet (in dotted decimal
notation)? Write the network ID of the #1 subnet in CIDR notation.
Answer: Subnets will be /22. Subnet mask is 255.255.252.0. #1 subnet is 12.128.68.0/22.
Question 3 Consider the following network diagram. 192.168.0.0/24 is a private network and R is a NAT router. If host A sends an HTTP request to server S through router R, what are the source and destination IP addresses and port numbers when the request leaves router R ? If you don’t know some particular IP address or port number, explain why and suggest a possible value.
Answer: From 107.18.23.9:unknown to 186.11.19.3:80. Unknown port is assigned dynamically by the NAT router and may be 58001 for example. Note that the source IP address and port number are reassigned by the NAT router compared to what they were when they left the host A. Also, note that every router has an IP address on each interface, and that IP address is suitable for the network to which it is attached. The source IP address in the packet must be a public IP – it cannot be 192.168.0.1.
Question 4 Consider the following LAN design. Assume that host A has no entries in its ARP table. When host A wishes to send a packet to host B, which IP address will be in the ARP request that host A issues? Why?
10.3.0.1
10.4.0.1
10.1.0.1
10.2.0.3 B:
10.2.0.1
A:
10.1.1.3
10.1.0.3
10.3.1.4
10.4.2.5
10.4.2.1
10.4.1.3
10.2.0.2 10.3.1.7
10.1.1.5
10.1.0.17
Answer: A will determine that B is not local, so it will issue an ARP request for the router’s IP
address which is 10.1.0.1 on the local network for A. We know that B is not local because it is on a different subnet. (The subnets would appear to be 10.1/16, 10.2/16, 10.3/16 and 10.4/16.)
Question 5 TCP provides reliable connection- oriented server on top of IP’s unreliable datagram service. How does TCP ensure that information is delivered in the correct sequence and i s not reordered when IP packets may be delivered out of sequence by the network layer?
Answer: TCP uses sequence numbers on TCP segments to ensure that information is delivered in the correct sequence. Each TCP segment that is sent is numbered. The receiver delivers the segments in order of the numbers.
Question 6 Host A has the IP address 18.19.20.21 and subnet mask 255.255.192.0. Which of the following IP addresses is in the same network as host A? Show your working.
18.19.90.91?
18.19.140.141?
Answer: Neither. Converting the third byte to binary: The subnet mask has 192 which is 11000000. 20 is 00010100. 90 is 01011010. 140 is 10001100. Both 140 and 90 differ in the first two bits from 20. If you want the full answer, then convert 18.29.20.21 to binary and AND it with 255.255.192.0. I.e. 00010010.00010011.00010100.00010101 AND 11111111.11111111.11000000.00000000 result is 00010010.00010011.00000000.00000000 Compare that with converting 18.19.90.91 to binary and AND it with 255.255.192.0 i.e. 00010010.00010011.01011010.010110111 AND 1111111.11111111.11000000.00000000 result is 00010010.00010011.01000000.00000000 which is not the same. Similarly, 18.19.140.141 convert to binary and AND with 255.255.192.0 i.e. . 00010010.00010011.10001100.10001101 AND 1111111.11111111.11000000.00000000 result is 00010010.00010011.10000000.00000000 which is not the same as the first result.
