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ASSESSMENT 2— Fundamentals of Networks & Security (Level 4)
Student Name: Ivaylo Valeriev Tsvetkov
Student ID: 100785312
Date: 26/11/2025
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Part A: 50%
Task 1: Network Topology Design (10 Marks)
This image shows a classic Cisco Packet Tracer network topology. It represents a Wide Area Network
(WAN) connecng three disnct Local Area Networks (LANs). The topology is divided into three
idencal sites connected linearly: There are 6 PCs which represent the network hosts, three Cisco
2960-24TT switches which act as the central connecon point of each LAN, and three Cisco 1941
routers, which route the trac between dierent networks.
Figure 1 Network Topology Design
Task 2: IP Addressing and Subneng Plan (10 Marks)
These gures show a Network Addressing and Subneng Plan. It’s a blueprint for how small network
is organized into three separate subnets and how they connect to each other. The network is split into
three local district Local Area Networks (LANs). Each has two PCs and one Router interface acng as
the Default Gateway. The routers have two jobs: talking to the local PCs (via Fast Ethernet) and talking
to other routers (via Serial connecons).
Figure 2 IP Addressing Table
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Figure 3 IP Addressing Table Router
Task 3: Router Conguraon (10 Marks)
Router interface conguraon establishes the gateway that allows your LAN to communicate with the
rest of the network. You assign the router a logical identy on the network (e.g., 192.168.10.1). This IP
address must be entered as the Default Gateway on PC0 and PC1 so they know where to send trac
desned for other networks.
Router security sengs protect the router’s management plane, ensuring that only authorized
administrators can change the network conguraon.
Figure 4 Router 0 Conguration
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Figure 5 Router 1 Conguration
Figure 6 Router 2 Conguration
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Task 4: Roung Protocols (10 Marks)
In the 3-router setup, each router needs to be told which “Directly connected" networks it should
share with its neighbours. Roung Informaon Protocol (RIP) is a dynamic roung protocol used in
local area networks to help routers exchange roung informaon. Once all three routers (router0,
router1, and router2) are congured, they exchange informaon.
Figure 7 PC0 Conguration
Figure 8 PC1 Conguration
Figure 9 PC3 Conguration
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Figure 10 PC3 Conguration
Figure 11 PC4 Conguration
Figure 12 PC6 Conguration
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Task 5: VLAN Conguraon and Inter-VLAN Roung (10 Marks)
This image shows a standard Cisco Packet Tracer network topology representing two interconnected
Local Area Networks (LANs) joined by a Wide Area Network (WAN) link. Think of it as two separate
office branches (Branch A and Branch B) that need to communicate with one another. The topology is
built using three primary layers of hardware: End Devices (PCs 1-4) these represent users, Access
Layer (Switches SW1 & SW2) these acts as central hubs and allow multiple PCs to connect to a single
router, and Core Layer (Routers R1 & R2) they decide how to send data from one local network to the
other.
Figure 13 VLAN Conguration
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Part B: 50%
Task 1: Packet Capture & Protocol Analysis (10 Marks)
DNS lter is a display lter that isolates DNS packets from all other network trac (HTTP, TCT, SSL, etc).
Its purpose is to analyse DNS trac specically without the noise of other protocols. DNS ltering helps
you to see what devices are trying to look up, whether they succeed, and how long it takes, which is
crical for troubleshoong issues.
Figure 14 DNS Filter
TCP lters are essenal for isolang and troubleshoong connecon-oriented trac like web browsing
(HTTP/HTTPS), email (SMTP,IMAP), and le transfers (FTP). TCP ltering isolates TCP trac for analysing
reliable, connecon-oriented communicaon between devices.
Figure 15 TCP Filter
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HTTP refers to how web trac appears when captured and analysed using Wireshark network protocol
analyser tool. Modern web mostly uses HTTPS – you will need decrypon setup to see HTTP content in
those cases. HTTP ltering isolates HTP trac to analyse web communicaons, website loading and web
applicaon behaviour.
Figure 16 HTTP Filter
Task 2: Detecng Malicious Trac (10 Marks)
SYN ood is detecng malicious trac (problemac trac). It is a massive wave of TCP SYN Packets from
fake/spoofed IP addresses, overwhelming a target server’s connecon capacity. A SYN ood is an aack
where an aacker sends numerous SYN packets but never competes TCP handshake.
Figure 17 SYN ood
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APR Spoong is fake idencaon (address resoluon protocol). This is when you see device on a
network lying about its MAC address to intercept trac meant for another device. APR Spoong is an
aack, where an aacker sends fake APR messages to link their MAC addresses with a legimate IP
address, intercepng trac.
Figure 18 APR Spoong
Task 3: Encrypon Demonstraon (10 Marks)
HTTP trac in Wireshark is the raw, unedited conversaon between your browser and websites
captured directly from your network connecon. HTTP trac is everything send between your browser
and websites before encrypon became started.
Figure 19 HTTP Traic
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HTTPS trac in Wireshark is encrypted web trac that looks like a random data unless you have the
decrypon key. HTTPS is an encrypted tunnel – you see the entry/exit points and tunnel construcon,
but not what’s traveling inside unless you have the keys.
Figure 20 HTTPS Traic
Task 4: Trac Filtering (10 Marks)
An IP lter in Wireshark is a search command that shows only packets involving specic IP addresses,
hiding all other network trac. IP ltering allows you to isolate trac to/from specic IP addresses and
ranges.
Figure 21 IP lter
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A port lter in Wireshark is a search command that shows only packets involving specic network ports
(like HTTP port 80, HTTPS port 443, etc.) hiding all other trac. Port ltering isolates trac by port
numbers to analyse specic applicaons/services.
Figure 22 Port lter
Port ltering in Wireshark is using display lters to isolate trac based on TCP/UDP port numbers,
allowing you to focus on specic applicaons or services. Port ltering lets you focus on trac to/from
specic network ports, which is crucial troubleshoong applicaon specic issues.
Figure 23 Port Filtering
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Task 5: Performance Monitoring (10 Marks)
The RTT (Round-Trip Time) graph is Wireshark is a visual chart showing how long it takes for data packets
to travel to desnaon and back to your computer. The RTT graph is one of the most powerful analysis
tool for understanding network performance.
Figure 24 Round-Trip Time graph
Packet loss and retransmission in Wireshark is when you see duplicate packets being sent, because the
original packets got lost or arrived damaged in transit. Some of the network packets are failing to reach
their desnaon.
Figure 25 Packet loss and retransmission
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The I/O graph in Wireshark is real-me or historical visualizaon of network trac throughput, showing
data ow rates over me. It is a “network trac speedometer” that shows how much data is owing
through your network interface over me.
Figure 26 I/O graph
A Flow graph in Wireshark is a visual diagram showing the conversaon ow between network devices,
mapping out the sequence and direcon of packets in a connecon. A “conversaon map” that shows
who talked to whom, in what order, and what they said (at the packet level).
Figure 27 Flow Chart
