CS 331 Computer Networks
Project 1

Due: Tuesday, March 2, 2021, 11:59 pm

Tasks

Problem Set:

  1. Finish the following questions in Chapter 1 of the textbook
    • Homework Problems and Questions - R16 and R22
    • Problems - P25 and P28

    You can also find above questions here (Colby IP needed).

  2. Answer the following questions:
    1. What is the range of IP addresses covered by prefix 137.146.12.192/28?
    2. Give the prefix to cover the IP addresses in range 10.20.30.12 - 10.20.30.123.
    3. What is the netmask that corresponds to /21 prefix length?
    4. What prefix length corresponds to netmask 255.255.224.0?

    You are expected to show how you got the answer to each of the above questions (e.g., by showing the binary representation of the address).

  3. Assume a router with four interfaces (A, B, C, and D) and routing table that contains four entries (prefix, interface): (132.177.21.0/24, A), (132.177.20.0/22, B), (132.177.0.0/16, C), and (0.0.0.0/0, D). For each of the following destination addresses indicate all matching routing table entries and the interface to which it is going to be routed.
    • 132.176.20.1
    • 132.177.20.2
    • 132.177.21.3
    • 132.177.22.4
    • 132.177.37.5
  4. Using command-line commands to find the following information of your laptop:
    1. IP address, hostname, subnet id, prefix, and subnet mask,
    2. content of the routing table and the default gateway, and
    3. content of the ARP table
  5. In this part of the project, you will analyze a short network traffic trace. You can download the trace from here and open it by any of the standard network traffic sniffers, such as Wireshark or the standard command-line utility tcpdump.

    Examine the trace and answer the following questions:

    1. What is the activity captured by the trace? Briefly describe what is going on in the trace.
    2. What command-line command triggered the traffic captured the trace?
    3. What was the hostname of the target of the command?
    4. Can you find the hostname of the node where the command was executed?
    5. Can yo tell the manufacturers of the network interfaces? What information from the trace does Wireshark use to determine the manufacturers of the network interfaces?

Programming assignment:

The purpose of this part of the assignment is to learn and practice the basic calculation used to calculate IPv4 subnets.

Write a simple program that takes an IPv4 address and a prefix length and calculates:

  1. The subnet address
  2. The address of the first host on the network
  3. The address of the last host on the network
  4. The subnet broadcast address
  5. The subnet mask

The program should perform basic error checking on the user input (e.g., values out of range). The IP address can be entered as 4 values for each of its bytes. A run of your program may look like this (bold font indicates user input):

 Enter IP address: 192.168.0.1
 Enter prefix length: 24


 Subnet ID:          192.168.0.0
 First host:         192.168.0.1
 Last host:          192.168.0.254
 Broadcast address:  192.168.0.255
 Subbet mask:        255.255.255.0

Your are allowed to use any programming language, platform, and development environment. However, keep in mind that project 3 will ask you to implement the same calculation as a part of a web service.

Extensions

  1. Use a different approach to implement the programming assignment.
  2. Redo Problem 4 of the problem set, and find those pieces of information on a different platform (e.g., your smartphone, tablet, etc.)
  3. Create a filter on Wireshark (e.g. capture the network traffic for opening a website).
  4. Do some interesting experiments with Wireshark. Explain the purposes of your experiments, the experiment setup, and your findings.

Submission

Please follow the submission instructions to turn in your work.

© 2021 Ying Li. Page last modified: .