Attempt all questions.

This is an individual assignment, and it is expected students answer the questions themselves. Discussion of approaches to solving questions is allowed (and encouraged), however each student should develop and write-up their own answers. See CQUniversity resources on Referencing and Plagiarism. Guidelines for this assignment include:

  • Do not exchange files (reports, captures, diagrams) with other students.
  • Complete tasks with virtnet yourself – do not use results from another student.
  • Draw your own diagrams. Do not use diagrams from other sources (Internet, textbooks) or from other students.
  • Write your own explanations. In some cases, students may arrive at the same numerical answer, however their explanation of the answer should always be their own.
  • Do not copy text from websites or During research you should read and understand what others have written, and then write in your own words.
  • Perform the tasks using the correct values listed in the question and using the correct file names.

File Names and Parameters

Where you see [StudentID] in the text, replace it with your actual student ID. If your student ID contains a letter (e.g. “s1234567”), make sure the letter is in lowercase.

Where you see [FirstName] in the text, replace it with your actual first name. If you do not have a first name, then use your last name. Do NOT include any spaces or other non- alphabetical characters (e.g. “-“).


Submit two files on Moodle only:

  1. The report, based on the answer template, called [StudentID]-report.docx.
  2. Submit the packet capture [StudentID]-https.pcap on Moodle

Marking Scheme

A separate spreadsheet lists the detailed marking criteria.


Questions 1 and 3 require you to use virtnet topology 5. The questions are related, so you must use the same nodes for all three questions.

  • node1: client; assumed to be external from the perspective of the perspective of the firewall.
  • node2: router; gateway between the internal network and external network. Also runs the internal network and external network. Also runs the firewall.
  • node3: server; assumed to be internal from the perspective of the firewall. Runs a web server with HTTPS and a SSH server for external users (e.g. on node1) to login to. Will contain accounts for multiple users.

Question 1. HTTPS and Certificates [10]

For this question you must use virtnet (as used in the Tutorials) to study HTTPS and certificates. This assumes you have already setup and are familiar with virtnet. See Moodle and workshop instructions for information on setting up and using virtnet, deploying the website, and testing the website.

Your task is to setup a web server that supports HTTPS. The tasks and sub-questions are grouped into multiple phases.

Phase 1: Setup Topology

  1. Create topology 5 in virtnet.
  2. Deploy the MyUni demo website, with node3 being the real web server.

Phase 2: Certificate Creation

  1. Using[studentID]-keypair.pem from Assignment 1, generate a Certificate Signing Request called [StudentID]-csr.pem. CSR must contain these field values:
    • State: state of your campus
    • Locality: city of your campus
    • Organisation Name: your full name
    • Common Name:
    • Email address:
    • Other field values must be selected

Now you will change role to be a CA. A different public/private key pair has been created for your CA as [StudentID]-ca-keypair.pem. As the CA you must:

  1. Setup the files/directories for a demoCA
  2. Create a self-signed certificate for the CA called [StudentID]-ca-cert.pem.
  3. Using the CSR from step 1 issue a certificate for [StudentID].edu called

Phase 3: HTTPS Configuration

  1. Configure Apache web server on node3 to use HTTPS where the domain name is [StudentID].edu
  2. Load the CA certificate into the client on [StudentID]-cert.pem.

Phase 4: Testing

1.Start capturing on node2 using tcpdump.

2.On node1, use lynx to visit and login to view somegrades.

3. Demonstrate to your tutor that your secure website is operating correctly. [4 marks]

4. Exit lynx.

5. Stop the capturing and save the file as [StudentID]-https.pcap.

When capturing, make sure you capture a full HTTPS session, and avoiding capturing multiple sessions.

For on-campus students: Step 3 of above should be demonstrated in your allocated Week 9, 10, 11 or Week 12 tutorial class. Your local tutor will be informed you when your demonstration is passed.

For distance students: Unit Coordinator will organise a time for you to demonstrate step 3.

Phase 5: Analysis

  • Demonstration of secure web site [4 marks]
  • Submit the following packet capture [StudentID]-https.pcap on Moodle [0.5 mark]
  • Draw a message sequence diagram that illustrates the TLS/SSL packets belonging to the first HTTPS session in the Refer to the instructions in assignment 1 for drawing a message sequence diagram, as well as these additional requirements:
    • Only draw the TLS/SSL packets; do not draw the 3-way handshake, TCP ACKs or connection close. Hint: identify which packets belong to the first TCP connection and then filter with “ssl” in Depending on your Wireshark version, the protocol may show as “TLSv1.2”.
    • A single TCP packet may contain one or more SSL messages (in Wireshark look inside the packet for each “Record Layer” entry to find the SSL message names). Make sure you draw each SSL message. If a TCP packet contains multiple SSL messages, then draw multiple arrows, one for each SSL message, and clearly label each with SSL message name.
    • Clearly mark which packets/messages are [2.5 marks]


  • Generally, Certificate Authorities must keep their private keys very secure by storing them offline in special hardware How attackers can introduce attacks to if they able to compromise the CA private key. [3 mark]

Question 2. Attack Detection from Real Intrusion Dataset [10 marks]

This task is the continuation of the question 2 Assignment 1 where you have evaluated the UNSW-NB15 dataset with three different classifiers where you did not apply any feature selection techniques. Feature selection is one of the key principles that greatly impacts the model’s efficacy by selecting only those features that are most relevant and thereby, reduces over-fitting, improves accuracy and reduces training time. Here you need to explore different built-in feature selection techniques (at least three) in WEKA and identify the best features for each classifier.

For this task you will need two files available on Moodle:

  • arff and test.arff.

You need to follow the following steps:

  • Step 1: Import data in the arff into WEKA (explorer).
  • Step 2: Select the attributes by using Attribute evaluator (at least 2) and search method in WEKA and update your datasets accordingly.
  • Step 3: Select the classifier that you used in Assignment 1 Question 2.
  • Step 4: Specify the test option as Use ‘training set’ and the column of class.
  • Step 5: Supply the test dataset (test.arff) to evaluate the classifier.
  • Step 6: Re-evaluate model on current test set to perform the evaluation.
  • Repeat the step 2 to 7 for other two classifiers.

You need to include in your report the following:

  • Screenshot of the selected attributes and evaluation result for each [2 marks]
  • Compare your current outcomes with the outcomes of Question 2 Assignment 1 in term of Accuracy, precision, recall, F1-Score and false positive [2 marks]


  • Have you achieved better performance after applying the feature selection technique for each classifier? If yes, why you have achieved that. If yes, explain why you believe that was achieved. If not, explain why you believe it was not achieved. [3 marks]
  • In the UNSW-NB15 dataset, there are nine types of network attacks available. Among these nine attacks which three attacks are highly detected by the classifiers? Please give a short explanation of these three [3 marks]

Question 3. Firewalls and Wi-Fi Security[15]

 You are tasked with designing a network upgrade for a manufacturing institute. The institute currently has a wired network (Ethernet LAN) across three floors of their office building, connecting approximately 50 desktop computers, several servers and 15’s of other devices (e.g., printers, payment terminals, machinery). There are currently 80 full-time and part-time employees, some working in the office while others are outside or in an external workshop. The network upgrade has two main components:

  • A wireless LAN to allow all employees access to the internal network from within the office, outside and in the workshop. Customers of the business may also be granted guest access to the wireless LAN. The wireless LAN will most likely need more than 20 APs and have 120 to 170 clients.
  • A VPN to allow selected employees to access the internal network from home or when visiting customers at other locations.

Assume the network has the following internal servers:

  • A web server that supports HTTPS only and is accessible to the
  • An email server accessible to the
  • A SSH server accessible only to a small selection of employees when they are outside of the (The VPN is not needed for these employees to access the SSH server)

The institute has one IT employee who is capable with computer networking (e.g., they previously setup the wired LAN), but has little knowledge of security. Answer the following questions assuming that you are explaining to the IT employee (as they need to build the network).

  • Draw a network diagram that illustrates the wired network, wireless network, and You should not draw all users and devices; only draw a sample of the users and devices. For example, several switches, several APs, several wired computers, several WiFi users, 1 or 2 VPN external users. (Several may be 2 to 5). Also, clearly indicate which portions of the network have data encrypted due to either WiFi encryption or the VPN (for example, mark those paths that have encryption in red or some other clear label). [3 marks]
  • Explain where you would locate the firewall and justify that [2 marks]
  • Design a set of firewall rules for the organisation. Implement a set of firewall rules in virtnet on node2 in topology 5 using Explain any rules that are important for the institute, but you are not able to implement it because of limited virtnet environment with iptables. Include the iptables rules in your report. [2+2+2 = 6 marks]
  • The institute network included a wireless LAN Based on “Wi-Fi Security” research article, recommend two security mechanisms that the institute could use to reduce the risk of the threats. For each security mechanism you recommend, explain what the security mechanism does, which threat(s) it addresses, and how it reduces the threat. [4 marks]

Maintaining Journal [5 marks]

 Whenever you perform tasks, you should be recording important information in your online journal. This may include notes, commands you have run, parts of files you edited, and screenshots. You will be marked on how well you have maintained your journal (including technical depth) and how accurately it captures your tutorial and assignment practical activities from Week 6 to Week 10. Your online journal may be also referred to when marking your submission. For example, if the marker sees two student submissions with very similar answers, they may refer to the journal to review the entries that indicate that both students performed the tasks independently.

To gain the full 5 marks, your journal at least has to contain evidence on the following practical tasks:

  • Firewalls (week 6)
  • Authentication (week 7)
  • Access control (week 8)
  • Wireless security (week 10)