Term 1, 2019 COIT20261: Network Routing and Switching Assignment 1

This document provides a comprehensive solution to the COIT20261 Network Routing and Switching Assignment 1, completed in Term 1, 2019. The assignment covers core networking concepts, including subnetting calculations, IP addressing, and network protocols. Question 1 addresses subnetting, requiring the identification of network and broadcast addresses, and the number of available host addresses within a given subnet. Question 2 focuses on subnetting, requiring calculation of the number of addresses for various subnets. Question 3 analyzes network traffic using Wireshark, examining Ethernet interfaces, TCP protocols, and the TIME_WAIT state. It also involves the use of the tracert command to determine the route packets take to reach a destination server. The solution demonstrates a clear understanding of network fundamentals and provides detailed explanations for each step.

COIT20261 Network Routing and SwitchingTerm 1, 2019
Assignment item —Written Assessment-1
ANSWER TEMPLATE ASSIGNMENT ONE
Type your answers in the spaces provided
Marking criteria: Your answers will be marked based on technical correctness,
completeness, clarity and relevance. Questions that ask you to show your working or
calculations or the steps you took to arrive at your answers, may have marks deducted if
such information is not provided. If a question requires you to submit a graphic (e.g. a
screenshot or a diagram), the graphic must have sufficient resolution to show all its
details clearly and be of a reasonable size for normal reader viewing, with all or any text
within the graphic being legible and readable, in order to be marked.
First Name:_________________________ Last Name:____________________________
Student ID: __________________________
Questions Mark
allocated
Mark
earned
Question 1: (3 marks) 3
a)
b)
c)
/26 converted to decimal becomes 255.255.255.192.
256-192=64, possible subnets are 0, 64, 128 …
215.150.68.98 lies in sub 64 ie 64-128, therefore;
Network address: 215.150.68.64/26
This is given by next subnet minus 2 ie 128-2=126
Last usable address: 215.150.68.126/26
The broadcast address is given by next subnet minus 1 ie 128-1=127
Direct broadcast address :215.150.68.127
Number of available addresses =2n-2 where n is the number of
zeroes ie 26-2 =62
Available as host addresses : 62
1 mark
each
item,
total 3

COIT20261 Network Routing and SwitchingTerm 1, 2019
Assignment item —Written Assessment-1
Question 2: (8 marks) 8
Show the correct number of addresses for each subnet in the table for b)
in the second column labelled “No. addresses”.
2
Subnet No. addresses Subnet address Mask /n
1 126 172.38.0.0 /25
2 126 172.38.0.128 /25
3 62 172.38.1.0 /26
4 62 172.38.1.64 /26
5 30 172.38.1.128 /27
6 30 172.38.1.160 /27
Your Calculations:
To calculate the number of addresses, we use the formula 2n-2 = >
number of hosts where n=number of zeroes
Subnet 1 – 2n-2=>100
=2n =>102
=2n =128 ; we picked 128 because it is the nearest higher divisor of 2
N=7, ie 27= 128, therefore number of addresses = 128-2
=126
Note that the same formular is applied for subnet 2,3,4,5 and 6.
6
Question 3: (4 marks) 4
a)
i) Frame 4: Ethernet interface was used. By right clicking the packet and
click on filter capture, eth is displayed in the search area indicating that
this is an Ethernet interface.
2
1 mark
each
item,
total 2

COIT20261 Network Routing and SwitchingTerm 1, 2019
Assignment item —Written Assessment-1
ii)
TCP protocol was used.
Frame 22406:
This message helped us to access packet numbered 22406 directly rather
than scrolling all the way. The size of the packet is 1077. This is
indicated in the packet details area.
for 3a.
b) The TIME_WAIT shows that this side has shut down the linking, though
the connection is being kept around so as the delayed packets can be
matched to this connection and handled correctly.
1
c) Paste the output of your TRACERT here, along with your answer.
Tracert command is normally used to discover the routes which packets
take when travelling from source host to destination. Every hop is
represented by a unique line. Each hop is numbered, hence, you can it
took 12 hops to reach the destination hop whose IP address is
104.244.42.1 which is the server that is hosting twitter.com site. Note
that every row is represented in five columns i.e.
1 2 ms 1 ms 2 ms 192.168.43.1
The first column represent hop number
Every tracert command sends 3 packets of data and measure the time for
each, in our hop results, the first, second and third packet took 2ms, 1ms
and 2ms respectively. The 192.168.43.1 is the first hop that was
1

COIT20261 Network Routing and SwitchingTerm 1, 2019
Assignment item —Written Assessment-1
encountered.
Total marks awarded 15 (max)
Less late penalties
Less plagiarism penalties
Total marks earned
Markers comments: