Assignment 1

Due Wednesday, February 13, 2007 8:25pm in class
(at the start of recitation)

Introduction

Please answer the questions precisely and concisely. You may need to do a bit of web surfing for many of these questions. Every question can be answered in one or at most a few sentences. I will not have the patience to read long paragraphs or essays and you may lose credit for possibly correct answers.

Write neatly. If I have to struggle to figure out what you wrote, you will lose credit. Type your answers if your penmanship is poor.

In the "I shouldn't have to tell you this" department... Should you feel the need to use multiple pages, please fasten the sheets securely. Use a stapler or other permanent fastener. Avoid paper clips since sheets can slide out.

Questions

  1. Read How NAT Works.
    1. What is the difference between Port Address Translation (PAT) and Dynamic NAT?
    2. How does NAT increase the security within the internal network?
  2. Read (skim) Comparing Traffic Policing and Traffic Shaping for Bandwidth Limiting
  3. What is the difference between traffic shaping and traffic policing?
  4. Read Sample Chapter 2: How Does DNS Work?.
    1. Delegation is a central component of DNS. What does it accomplish?
    2. What does the name server do?
    3. What does a resolver do?
  5. These questions are about ARP.
    1. What is the purpose of the Address Resolution Protocol (ARP)?
    2. What is an ARP poisoning attack?
    3. What is Proxy ARP used for?
  6. List some of the information that a machine gets from the DHCP (Dynamic Host Configuration Protocol)? (You can find a quick answer here.)
  7. Which of the following addresses matches the CIDR address 15.56.0.0/13?
    1. 15.46.12.5
    2. 15.32.92.121
    3. 15.63.15.2
    4. 15.55.251.255
    1. The connect system call would seem to make no sense for datagram sockets since they have no concept of a connection. What does connect do for datagram sockets?
    2. Why would the read and write calls be unusable on datagram sockets without a connect?
    All the answers you need are in the on-line man pages - use the man 2 connect command on most Unix/Linux/OS X systems (or look here). Also, look at the UDP man page.