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DTN611S - DATA NETWORKS - 2ND OPP - JULY 2022 |
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n Am I B I A u n IVE Rs I TY
OF SCIEnCE Ano TECHnOLOGY
FACULTY OF COMPUTING AND INFORMATICS
DEPARTMENT OF COMPUTER SCIENCE
QUALIFICATION: BACHELOR OF COMPUTER SCIENCE, BACHELOR OF INFORMATICS
QUALIFICATION CODE: 07BACS, 07BAIF
LEVEL: 7
COURSE NAME: DATA NETWORKS
DATE: JULY 2022
DURATION:2 HOURS
COURSE CODE: DTN611S
PAPER: THEORY
MARKS: 70 (100%}
SECOND OPPORTUNITY/SUPPLEMENTARY EXAMINATION QUESTION PAPER
Examiners
Moderator
MR. NASIMANE EKANDJO, MR SHADRECK CHITAURO, MR. PETER GALLERT, MS
ALBERTINA SHI LONGO
PROF. GUY-ALAIN ZODI
THIS QUESTION PAPERCONSISTSOF 6 PAGES{Including this front page)
INSTRUCTIONS
1) Answer ALL the questions on the answer scripts provided.
2) Write clearly and neatly.
3) Be guided by the number of marks allocated when answering the questions.
4) Show all your calculations.
5) Number your questions clearly.
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Question 1:
1. Which is the binary equivalence of 192.168.3.24?
a) 11000000. 00101000.00000011.00011000
b) 11000000. 10100100.00000010.00011000
c) 01100000. 11101000.00000010.00011000
d) 11000000. 10101000.00000011.00011000
2. Which of the following correctly defines the function of the DNS server on the network?
a) To assign IP address information automatically to devices on the network.
b) To translate IP addresses into Domain names
c) To act as an intermediary between clients and remote servers
d) To host websites.
3. One of the advantages of a Star topology is:
a) Devices are managed centrally in the topology.
b) If the centra device becomes faulty, all devices will be affected.
c) It is very expensive to set up as devices are connected to each other
d) Devices are connected in a circle, if one device becomes faulty, the whole topology is
affected.
4. Wide Area Network could easily be described as a network that spans
a) A country
b) Acity
c) A building
d) A house
5. Which layer of the OSI encapsulates MAC Address to the frame headers?
a) Physical
b) Presentation
c) Application
d) Data Link
6. Which port is used by SMTP to send mails over the network?
a) Port 80
b) Port 21
c) Port 20
d) Port 25
7. The default subnet mask for Class C IP address is:
a) /18
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b) /17
c) /16
d) /24
8. The _______________
is a conceptual framework that enables diverse
communication systems to communicate using standard protocols.
9. The ___________
is an application protocol used to access remote devices on
the network.
10. The _________
network topology gives the network users the greatest amount
of fault tolerance.
11. In e-mails, ___________
is a protocol that enables users to access their mail
from any device connected to the network.
12. Each network interface card comes embedded with a unique address from the
a manufacturer is called --------------
13. The delivery method that sends packets to devices in the network is called ______
_
14. The process of adding layer-specific information is called __________
_
15. The default port number for HTTP is ______
_
16. A hub functions like a router on the network.
a) True
b) False
17. Wired mediums are also regarded as a guided medium
a) True
b) False
18. A session must be terminated at the end of each user datagram protocol sent.
a) True
b) False
19. When accessing a web server, the status code 200 indicates success.
a) True
b) False
20. A network is the interconnection
a) True
b) False
of various networks.
Question 2
20 Marks]
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2.1 List two network architectures and explain the difference in the operation of these architectures.
(4)
2.2. WAP IT Technologies is establishing its new company in Windhoek. They will be providing
networking services to clients all over Namibia. You were recently hired to work
for them as a junior network engineer.
a) Your first project entails designing the company network's topology. Your boss suggests that
you use a bus topology, but you strongly oppose his idea and suggest using a
hybrid topology. Convince your boss about your choice.
(3)
b) The company will also need to provide e-mail services to their clients. Identify and explain
three (3) main protocols required when configuring e-mails.
(6)
c) The company secured a tender to provide networking services to GIPF a state-owned parastatal
with close to 1500 employees and just bought new computing devices for all their employees.
As a Network Administrator, which IP address assignment method will be appropriate in this
environment and why?
(4)
d) In addition to the servers and computers, other components that make up any networks
comprise of routers, hubs, switches, twisted pair cables, wireless access points, and IP phones
amongst others. Classify these devices as either host, communication links, or core network
devices.
(6)
Routers
Switches
Hubs
Cables
IP phones
Access point
e) When data is transmitted on the network, it changes form. What are the units of data processed
by layers 1 to 4 of the OSI model called?
(4)
[27 Marks]
Question 3
Consider the diagram below when answering the questions. The default gateway for each network is
the first usable address.
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-r ,,..-
10. 10.10.0 /24
172.16.10.(J /'30
PC-PT
PC 1
2811
BRANCH 1
.
PC-PT PC-PT
?C 2 PC 3
192.165. 1. 16 /'JB
2811
BRANCH 2
PC-PT
PC 5
192.168.1. 32 /29
a) Determine the IP address subnet mask and Default gateway for PCl, PC2, and PC5.
(6)
PCl
PCS
IP Address
Subnet mask
Default gateway
b) PC3 would like to communicate to PC1. How does PC3 get PCl's IP address?
(2)
c) Considering that this network is configured with NAT, from PCl you would like to access the
internet, what will be the source IP address of your packets and why?
(2)
d) Mention any three (3) types of Ethernet cables used on the LAN
(3)
[13 Marks]
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Question 4
1. Examine the output of the screenshot below to answer the questions that follow.
C:\\Users\\Virtua>tracert
www.unam.na
Tracing route to www.unam.edu.na (41.205.12~.157]
over a maximum of 30 hops:
1
1 ms
2 70 ms
::., 36 ms
4 32 ms
;
12 ms
6 42 ms
-,
I
44 ms
8 47 ms
1 ms
57 ms
40 ms
52 ms
13 ms
45 ms
30 ms
74 ms
1 ms frit:. box [192.168.178.lJ
51 1115 41.205.152.230
44 ms ADSL-41-205-134-241.ipb.na
42 ms ADSL-41-205-129-57.ipb.na
8 ms ADSL-41-205-129-58.ipb.na
45 ms ADSL-41-205-129-157.ipb.na
35 ms ADSL-41-205-129-1.37.ipb.na
1376 ms ADSL-41-205-129-157.ipb.na
Trace complete.
[41.205.134.241]
[41.205.129.57]
[ 41. 205. 129. 58]
[ 41. 205 .129 .157
[41.205.129.157
[ 41. 205 .129 .157
a) What is the name and purpose of the tool that generated output in figure 1
{2)
b) What is the default gateway of the device this screenshot was taken from?
{1)
c) what is the IP address of the UNAM webserver?
(1)
d) Explain the first 4 columns of the output on the screens hot.
(3)
e) If you were to use the same tool from a different network, would you get the same output?
Justify your answers.
(2)
f) Which other command can one use to determine the domain name, given the IP address? {1)
[Tota/Marks:70}
Exam ends
[10 Marks]
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