Assigment 02 Networking
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Assignment 1
Higher National Certificate/Diploma in Computing
Student Name/ID Number:
Huỳnh Trần Anh Khoa GCS200252
Unit Number and Title:
Academic Year:
2021 – 2022
Unit Assessor:
Sam X. Nguyen
Assignment Title:
Issue Date:
September 11th 2021
Submission Date:
September 11th 2021
Internal Verifier Name:
Date:
September 11th 2021
Submission Format:
Format:
● The submission is in the form of an individual written report. This should be written in a concise,
formal business style using single spacing and font size 12. You are required to make use of
headings, paragraphs and subsections as appropriate, and all work must be supported with
research and referenced using the Harvard referencing system. Please also provide a bibliography
using the Harvard referencing system.
Submission
● Students are compulsory to submit the assignment in due date and in a way requested by the
Tutor.
● The form of submission will be a soft copy posted on />● Remember to convert the word file into a PDF file before the submission on CMS.
Note:
● The individual Assignment must be your own work, and not copied by or from another student.
●
If you use ideas, quotes or data (such as diagrams) from books, journals or other sources, you
must reference your sources, using the Harvard style.
● Make sure that you understand and follow the guidelines to avoid plagiarism. Failure to comply
with this requirement will result in a failed assignment.
Unit Learning Outcomes:
Assignment question
LO1: Short discuss one of the protocols (DNS, FTP, HTTP) and explain how it works?
LO2: Investigate the selected protocol using Wireshark?
LO1: Short discuss one of the protocols ( DNS, FTP, HTTP) and explain how it work
● DNS
If any user is using personal computers, laptops, or smartphones, or tablets, accessing the internet and trying to log in to some website that is
already available on the internet then surely the user is using
PCs, laptops, tablets or smartphones do not understand the language of that website address, that is, a domain name like Bugatti.com, to
make them understand the website we are looking for. Therefore, DNS plays a very important role in this regard, it provides the host with the
associated mapped IP address, important software data related to the website's domain name.
From there, DNS makes computers or electronic devices better understand the websites that users are trying to visit or search for.
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As shown by the above images, when we request a certain web page from my laptop on the internet like Laptop24 is requesting
www.bugatti.com, it resolves the domain query and in return. is to provide the corresponding IP address of the DNS server
The DNS server stores a database, the information of all relevant IP addresses mapped to their respective domain names.
DNS query to request domain related IP address goes to DNS1 server from Laptop24, The server checks and checks inside itself, if it has an
IP address related to the query and it returns a response. DNS recovery with resolution
If not, it will forward it to another DNS 2 server to request information and data. This time it gets the resolution from DNS 2 and it is
mapped with the IP address i.e. 12.160.240.24 which corresponds to the Domain in the response and sends it back to Laptop24
Laptop24 now has a destination IP address and it can communicate further with a known IP address by routing
How will the PC come to know which DNS should be used to get the IP address?
When we connect and link our electronic system to the ISP, electronic and network devices such as routers or switches will specify routing
information and other configurations as well as how many hosts to send. DNS server that Laptops or PCs should connect to to receive
translations. You can get a translation of this address through the Wireshark app
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Through the above two images, we can get some of these DNS addresses through the Wireshark application on my personal computer
LO2: Investigate the selected protocol using Wireshark?
● To Start the program, First I choose the Wireshark application and start up. In the capture, there are so many options for you to
choose. If you are using a wired network device then you choose ethernet. As for wireless, then you choose Wifi. My laptop use
wireless, so I choose Wifi
Then, you access the internet, log in to any website, for example youtube, facebook, instagram,....
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After that, you set up the Wifi in Wireshark. On the top, there is a long blank, apply a display filter, you click on that, type with lowercase
DNS word, and enter. It will bring up a lot of addresses, translations, how you log in to the website and detailed information about each
translation. You choose any two subscripts you want.
Finally, you will get the details of these translations by clicking to start getting the information you need out
Information of the packet
-
Arrival time: Sep 11, 2021 09:58:51.463397000SE Asia Standard Time
-
Second packet: 130
-
Capacity: 96 bytes
-
Capture capacity: 96 bytes
Ethernet II
-
Destination: dc:f8:b9:dd:e7:d5
-
Source: 7c:7a:91:b1:0b:66
Internet Protocol version 4
-
Payload length: 42
-
Next Header: UDP (17)
-
Source address: 2402:800:63b7:e87f:1435:bdf5:4e06:a3c9
-
Destination address 2402:800:20ff:6666::1
5
User Datagram Protocol
-
Power port: 49897
-
Destination port: 53
-
Length: 42
DNS query
-
Transaction ID: 0xc32a
-
Number of times asked: 1
-
Query
+ Query name: www.facebook.com
+ Query type: A
+ Grade: IN
Reference
[1] How it works of protocol DNS, 09/2021, Available at />
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