COSC 6377 : Computer Networks

Fall 2018

TR 1-230pm at F 154

Homework 2: Monitoring Network Packets

Due: 10/16/2018

In this homework, we will learn how to do basic network monitoring. We will focus on capturing packets on the wireless network and performing simple analysis on the packet trace.

Learn how to use Wireshark tool to capture packets from the wireless network. Make sure you are able to capture packets not just from your device or to your device but also the packets that are broadcast in the vicinity for at least two traces. It is ok if you are not able to capture broadcast packets for one of the traces.

Collect a 2-minute packet trace each in three different environments: campus, home, and a public cafe.

1. For each packet trace, show the basic statistics about the type of packet or protocol you managed to capture.

2. Show the plot of total number of HTTP packets as a function of time. Show three lines corresponding to the three traces in a single graph.

3. Count the number of people in the public cafe and see if you can infer the number of people in the cafe by just looking at the packet trace.

4. Use a separate device to generate a large number of packets in the vicinity of your computer running Wireshark. Now, write a simple program in Python to analyze this packet trace. It should output when the surge in packets started and ended, the baseline and surge levels, and the IP address of the device that created this traffic surge. You will have to determine an appropriate format for packet trace export from Wireshark for this part of the assignment. Here is an example output:

Surge start time: 14:10:05
Surge end time: 14:10:32
Baseline level: 8 pkt/s
Surge level: 16 pkt/s
Node IP: A.B.C.D


Please submit a README, a pdf with your answers to the four questions, and a .py file. README should include descriptions of your Python program, including its limitations.