Recent questions in Computer Networks

0 votes

0 answers

1

Andrew S. Tanenbaum Edition 5th Exercise 8 Question 22 (Page No. 873)
A math class has 25 students. Assuming that all of the students were born in the first half of the year—between January 1st and June 30th— what is the probability that at least two students have the same birthday? Assume that nobody was born on leap day, so there are 181 possible birthdays.

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 3 views

0 votes

0 answers

2

Andrew S. Tanenbaum Edition 5th Exercise 8 Question 33 (Page No. 874)
33. Two users can establish a shared secret key using the Diffie-Hellman algorithm, even if they have never met, share no secrets, and have no certificates (a) Explain how this algorithm is susceptible to a man-in-the-middle attack. (b) How would this susceptibility change if n or g were secret?

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 1 view

0 votes

0 answers

3

Andrew S. Tanenbaum Edition 5th Exercise 8 Question 32 (Page No. 874)
The Diffie-Hellman key exchange is being used to establish a secret key between Alice and Bob. Alice sends Bob (227, 5, 82). Bob responds with (125). Alice’s secret number, x, is 12, and Bob’s secret number, y, is 3. Show how Alice and Bob compute the secret key.

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 2 views

0 votes

0 answers

4

Andrew S. Tanenbaum Edition 5th Exercise 8 Question 25 (Page No. 873)
Alice wants to communicate with Bob, using public-key cryptography. She establishes a connection to someone she hopes is Bob. She asks him for his public key and he sends it to her in plaintext along with an X.509 certificate signed ... that Bob does not care who he is talking to (e.g., Bob is some kind of public service).

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 3 views

0 votes

0 answers

5

Andrew S. Tanenbaum Edition 5th Exercise 8 Question 18 (Page No. 873)
Alice and Bob use RSA public key encryption in order to communicate between them. Trudy finds out that Alice and Bob shared one of the primes used to determine the number n of their public key pairs. In other words, Trudy found out that na = pa × q and nb = pb × q. How can Trudy use this information to break Alice’s code?

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 1 view

0 votes

1 answer

6

Andrew S. Tanenbaum Edition 5th Exercise 8 Question 17 (Page No. 873)
Using the RSA public key cryptosystem, with a = 1, b = 2 . . . y = 25, z = 26. (a) If p = 5 and q = 13, list five legal values for d. (b) If p = 5, q = 31, and d = 37, find e. (c) Using p = 3, q = 11, and d = 9, find e and encrypt ‘‘hello’’.

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 4 views

0 votes

0 answers

7

Andrew S. Tanenbaum Edition 5th Exercise 7 Question 32 (Page No. 761)
Write a program in JavaScript that accepts an integer greater than 2 and tells whether it is a prime number. Note that JavaScript has if and while statements with the same syntax as C and Java. The modulo operator is %. If you need the square root of x, use Math.sqrt (x).

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 2 views

0 votes

0 answers

8

Andrew S. Tanenbaum Edition 5th Exercise 7 Question 46 (Page No. 762)
Some cybersquatters have registered domain names that are misspellings of common corporate sites, for example, www.microsfot.com. Make a list of at least five such domains.

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 1 view

0 votes

0 answers

9

Andrew S. Tanenbaum Edition 5th Exercise 7 Question 47 (Page No. 762)
Numerous people have registered DNS names that consist of www.word.com, where word is a common word. For each of the following categories, list five such Web sites and briefly summarize what it is (e.g., www.stomach. ... , foods, household objects, and body parts. For the last category, please stick to body parts above the waist.

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 2 views

0 votes

0 answers

10

Andrew S. Tanenbaum Edition 5th Exercise 7 Question 48 (Page No. 762)
Rewrite the server of Fig. 6-6 as a true Web server using the GET command for HTTP 1.1. It should also accept the Host message. The server should maintain a cache of files recently fetched from the disk and serve requests from the cache when possible.

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 2 views

0 votes

0 answers

11

Andrew S. Tanenbaum Edition 5th Exercise 7 Question 23 (Page No. 759)
Imagine that someone in the math department at Stanford has just written a new document including a proof that he wants to distribute by FTP for his colleagues to review. He puts the program in the FTP directory ftp/pub/forReview/newProof.pdf. What is the URL for this program likely to be?

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 1 view

0 votes

0 answers

12

Andrew S. Tanenbaum Edition 5th Exercise 7 Question 23 (Page No. 759)
Although it was not mentioned in the text, an alternative form for a URL is to use the IP address instead of its DNS name. Use this information to explain why a DNS name cannot end with a digit.

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 1 view

0 votes

0 answers

13

Andrew S. Tanenbaum Edition 5th Exercise 7 Question 20 (Page No. 759)
Does Webmail use POP3, IMAP, or neither? If one of these, why was that one chosen? If neither, which one is it closer to in spirit?

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 3 views

0 votes

0 answers

14

Andrew S. Tanenbaum Edition 5th Exercise 7 Question 15 (Page No. 759)
In any standard, such as RFC 5322, a precise grammar of what is allowed is needed so that different implementations can interwork. Even simple items have to be defined carefully. The SMTP headers allow white space between the tokens. Give two plausible alternative definitions of white space between tokens.

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 4 views

0 votes

0 answers

15

Andrew S. Tanenbaum Edition 5th Exercise 7 Question 14 (Page No. 759)
Suppose that John just set up an auto-forwarding mechanism on his work email address, which receives all of his business-related emails, to forward them to his personal email address, which he shares with his wife. John' ... vacation daemon on his work machine. What happens when an email is received at John's work email address?

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 6 views

0 votes

0 answers

16

Andrew S. Tanenbaum Edition 5th Exercise 7 Question 10 (Page No. 759)
A large law firm, which has many employees, provides a single email address for each employee. Each employee's email address is <login>@lawfirm.com. However, the firm did not explicitly define the format of the login. ... for the email addresses of all its employees. How can this be done without rocking the boat too much?

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 1 view

0 votes

0 answers

17

Andrew S. Tanenbaum Edition 5th Exercise 7 Question 9 (Page No. 759)
Electronic mail systems need directories so people’s email addresses can be looked up. To build such directories, names should be broken up into standard components (e.g., first name, last name) to make searching possible. Discuss some problems that must be solved for a worldwide standard to be acceptable.

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 1 view

0 votes

0 answers

18

Andrew S. Tanenbaum Edition 5th Exercise 7 Question 8 (Page No. 759)
Some email systems support a Content Return: header field. It specifies whether the body of a message is to be returned in the event of nondelivery. Does this field belong to the envelope or to the header?

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 2 views

0 votes

0 answers

19

Andrew S. Tanenbaum Edition 5th Exercise 7 Question 7 (Page No. 759)
The number of companies with a Web site has grown explosively in recent years. As a result, thousands of companies are registered in the com domain, causing a heavy load on the top-level server for this domain. ... introducing new top-level domain names). It is permitted that your solution requires changes to the client code.

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 1 view

0 votes

0 answers

20

Andrew S. Tanenbaum Edition 5th Exercise 7 Question 3 (Page No. 759)
The number of companies with a Web site has grown explosively in recent years. As a result, thousands of companies are registered in the com domain, causing a heavy load on the top-level server for this domain. ... introducing new top-level domain names). It is permitted that your solution requires changes to the client code.

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 0 views

0 votes

0 answers

21

Andrew S. Tanenbaum Edition 5th Exercise 7 Question 6 (Page No. 759)
Can a machine with a single DNS name have multiple IP addresses? How could this occur?

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 2 views

0 votes

0 answers

22

Andrew S. Tanenbaum Edition 5th Exercise 7 Question 4 (Page No. 759)
John wants to have an original domain name and uses a randomized program to generate a secondary domain name for him. He wants to register this domain name in the com generic domain. The domain name that was generated is 253 characters long. Will the com registrar allow this domain name to be registered?

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 1 view

0 votes

0 answers

23

Andrew S. Tanenbaum Edition 5th Exercise 7 Question 4 (Page No. 759)
DNS uses UDP instead of TCP. If a DNS packet is lost, there is no automatic recovery. Does this cause a problem, and if so, how is it solved?

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 1 view

0 votes

0 answers

24

Andrew S. Tanenbaum Edition 5th Exercise 7 Question 3 (Page No. 759)
Consider a situation in which a cyberterrorist makes all the DNS servers in the world crash simultaneously. How does this change one’s ability to use the Internet?

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 2 views

0 votes

0 answers

25

Andrew S. Tanenbaum Edition 5th Exercise 7 Question 1 (Page No. 759)
Many business Computers have three distinct world wide unique identifiers. what are they?

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 2 views

0 votes

0 answers

26

Andrew S. Tanenbaum Edition 5th Exercise 6 Question 46 (Page No. 610)
Design and implement a chat system that allows multiple groups of users to chat. A chat coordinator resides at a well-known network address, uses UDP for communication with chat clients, sets up chat servers for each chat ... to start, join, and leave a chat session. Design and implement the coordinator, server, and client code.

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 3 views

0 votes

1 answer

27

Andrew S. Tanenbaum Edition 5th Exercise 6 Question 43 (Page No. 610)
What is the bandwidth-delay product for a 50-Mbps channel on a geostationary satellite? If the packets are all 1500 bytes (including overhead), how big should the window be in packets?

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 7 views

0 votes

0 answers

28

Andrew S. Tanenbaum Edition 5th Exercise 6 Question 39 (Page No. 609)
To get around the problem of sequence numbers wrapping around while old packets still exist, one could use 64-bit sequence numbers. However, theoretically, an optical fiber can run at 75 Tbps. What maximum packet lifetime is ... even with 64-bit sequence numbers? Assume that each byte has its own sequence number, as TCP does.

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 3 views

0 votes

0 answers

29

Andrew S. Tanenbaum Edition 5th Exercise 6 Question 37 (Page No. 609)
A CPU executes instructions at the rate of 1000 MIPS. Data can be copied 64 bits at a time, with each word copied costing 10 instructions. If an coming packet has to be copied four times, can this system handle a ... , assume that all instructions, even those instructions that read or write memory, run at the full 1000-MIPS rate.

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 4 views

0 votes

0 answers

30

Andrew S. Tanenbaum Edition 5th Exercise 6 Question 37 (Page No. 609)
Suppose that you are measuring the time to receive a segment. When an interrupt occurs, you read out the system clock in milliseconds. When the segment is fully processed, you read out the clock again. You measure 0 msec 270,000 times and 1 msec 730,000 times. How long does it take to receive a segment?

asked 1 day ago in Computer Networks by ajaysoni1924 Loyal (6.4k points) | 3 views

tags	tag:apple
author	user:martin
title	title:apple
content	content:apple
exclude	-tag:apple
force match	+apple
views	views:100
score	score:10
answers	answers:2
is accepted	isaccepted:true
is closed	isclosed:true

Recent questions in Computer Networks

Recent Posts

Recent Blog Comments