Unit:

Network Security Threats and Defence

Mechanisms
Assignment title:
Network Security Threats and Defence for a
Small/Medium Enterprise
Spring 2023 - Winter 2024

Important notes
• Please refer to the Assignment Presentation Requirements for advice on how to set
out your assignment. These can be found on the NCC Education website. Click on
‘Policies and Procedures’ on the main menu and then navigate to ‘Student Support’.
• You must read the NCC Education document Academic Misconduct Policy and
ensure that you acknowledge all the sources that you use in your work. These
documents are available on the NCC Education website. Click on ‘Policies and
Procedures’ on the main menu and then navigate to ‘Student Support’.
• You must complete the Statement and Confirmation of Own Work. The form is
available on the NCC Education website. Click on ‘Policies and Procedures’ on the
main menu and then navigate to ‘Student Support’.
• Please make a note of the recommended word count as stated in the brief.
The maximum word count limit is the recommended work count plus 10%
leeway. Submissions which exceed the maximum word count limit will be
marked only up to the maximum word count limit. Any text that exceeds the
maximum word count limit will not be marked. You must follow the note on
word count as stated in the Submission Requirements section of the brief.
• You must submit a paper copy and digital copy (on disk or similarly acceptable
medium). Media containing viruses, or media that cannot be run directly, will result
in a fail grade being awarded for this assessment.
• All electronic media will be checked for plagiarism.
Introduction

The purpose of this assignment is to assess your knowledge of computer networks and
security. You should read the following scenario carefully and provide a written response to
the FOUR (4) tasks. Where you need to make any assumptions, you should state them
clearly in your answer.

Scenario
A small travel agency in a town has a LAN similar to the image below. Their head office is
located in London.

Fig.1 Travel Agency LAN Structure

They recently experienced some security issues and the following incidents:
1- On a Monday morning, the organisation’s help desk received calls from three users on
the same floor of a building who stated that they were having problems with their
wireless access. A network administrator who was asked to assist in resolving the
problem took a laptop with wireless access to the users’ floor. As he viewed his
wireless networking configuration, he noticed that there was a new access point listed
as being available. He checked with his teammates and determined that this access
point was not deployed by his team, so that it is most likely a rogue access point that
was established without permission. They later discovered that network traffic has
been accessed and analysed by the attacker.

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 2- On a Saturday afternoon, external users started having problems accessing the
organisation’s public websites. Over the next hour, the problems worsened to the point
where nearly every access attempt failed. Meanwhile, a member of the organisation’s
networking staff responded to alerts from an Internet border router and determined that
the organisation’s Internet bandwidth was being consumed by an unusually large
volume of User Datagram Protocol (UDP) packets to and from both of the
organisation’s public DNS servers. Analysis of the traffic showed that the DNS servers
were receiving high volumes of requests from a single external IP address. Also, all
the DNS requests from that address came from the same source port.

Details of the Tasks

Each task outlines and examines your knowledge and understanding of the unit outcomes. As
the network administrator of this organisation, you will need to have proper understanding of
the structure and architecture of the organisation’s LAN, also you need to understand and
have knowledge of the security incidents that have happened and propose solutions for them.

Task 1 (30 Marks)

a) Explain the topology of the LAN in Fig.1.

Identify the type of network components that you would use in different areas of the
LAN in Fig.1 (1,2,3,4,5,6,7,8). For each of the network components that you pick,
explain their purpose and function, location in the TCP/IP model, any similarities and
differences, and their advantages and disadvantages.
You must provide a clear justification for each component you select.
(15 Marks)

b) Which class of IP addressing will you consider for the LAN in Fig 1? You must give the
reasons and allocate sample IP addresses.

Explain what is subnetting and how it may be used in the LAN in Fig 1 giving an
example.
(15 Marks)

Task 2 (20 Marks)

a) Which Computer Network Defence (CND) technologies have already been

implemented in the LAN in Fig 1?
Explain how they work to protect the network.
Explain which CND service would be used to connect this LAN to the company head office
in London and which components should be added to this LAN for this purpose?
(10 Marks)
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 b) Discuss what type of physical securities would you implement to safeguard
the servers on the first floor?
(10 Marks)

Task 3 (30 Marks)

a) What type of network attack is occurring in incident number ONE (1)?

Which tools/techniques may have been used to run this attack?

Which vulnerabilities have allowed this?

As the administrator of this network, which strategies, technologies, controls or

measures will you use to avoid similar attacks in the future? (Your answers should
cover a broad area of solutions from controls, technologies to periodic and long-term
defence plans.)
(15 Marks)

b) What type of network attack is occurring in incident number TWO (2)?

Which vulnerabilities have allowed this threat and how they may impact the business
continuity of this organisation?

As the administrator of this network, which strategies, technologies or measures will

you use to avoid similar attacks in the future? (Your answers should cover a broad
area of solutions from controls, technologies to periodic and long-term defence plans.

(15 Marks)

Task 4 (20 Marks)

a) Review and update TWO (2) security policies of the company with regards to incident
1. Which security policies you would review and how?

(10 Marks)

b) ONE (1) of the desktops in the second floor is the company’s manager workstation
in which she keeps confidential files of the company. What type of host security
controls would you consider for her system to secure the accesses to the files?

(10 Marks)

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Guidance
Consult with your tutor if you are uncertain about any aspect of this assignment.

Submission requirements
You must submit a word-processed report.

Your report should answer Tasks 1, 2, 3 and 4. The word count for your report is 4000
words.

Word Count
The word count for this assignment is 4,000 words. Pay careful attention to the mark
allocation for each task so you don’t spend too much time on any ONE (1) section.
You MUST state the word count in the header of your assignment and declare the number of
words on your assignment cover sheet. You MUST confirm that you have not exceeded the
stipulated word limit by more than 10%.
Any words written beyond the stipulated limit will not be read by the examiners; no marks will
be awarded, and no feedback provided for any text beyond the prescribed limit.
In accordance with accepted academic practice, the notion of a word count includes the
following without exception:

• All titles or headings that form part of the actual text. This does not include the fly (or
cover) page or reference list.
• All words that form the actual essay
• All words forming the titles for figures, tables, and boxes. However, this does not
include the text within boxes, tables, or figures themselves.
• All in-text (bracketed) references
• All directly quoted material.

Candidate checklist
Please use the following checklist to ensure that your work is ready for submission.
Have you read the NCC Education document Academic Misconduct Policy and
ensure that you have acknowledged all the sources that you have used in your work? ❑
Have you completed the Statement and Confirmation of Own Work form and
attached it to your assignment? You must do this. ❑
Have you ensured you have followed guidance about the length of this
assignment? ❑
Have you ensured that your work does not contain viruses and can be run directly?
❑
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