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CMN620S - COMMUNICATION NETWORKS- 1ST OPP - NOV 2024 |
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nAmlBIA UnlVERSITY
OF SCIEnCE Ano TECHnOLOGY
Faculty of Computing and Informatics
Department of Computer Science
QUALIFICATION:BACHELOR OF COMPUTER SCIENCEIN CYBERSECURITY
BACHELOR OF COMPTER SCIENCE
QUALIFICATIONCODE: 07BCCS; 07BCMS
LEVEL: 7
COURSE:COMMUNICATION NETWORKS
COURSECODE: CMN620S
DATE:NOVEMBER 2024
SESSION: PAPER 1
DURATION: 2 HOURS 30 MINUTES
MARKS: 80
EXAMINER(S)
MODERATOR:
FIRSTOPPORTUNITYEXAMINATION QUESTION PAPER
MR. NASIMANE EKANDJO
MS. LOINI IIYAMBO
MS. HELENA HAINANA
MR. BEN MWASHEKUNA
MR. SHOOPALA NAMBAHU
MS. TALENI ANDJAMBA
MS. ADELHEID GEINGOS
MR. EDWARD NEPOLO
THIS QUESTIONPAPERCONSISTSOF 7 PAGES
(Excluding this front page)
INSTRUCTIONS
1. Answer ALL the questions.
2. Write clearly and neatly.
3. Number the answers clearly.
4. When answering questions you should be guided by the allocation of
marks. Do not give too few or too many facts in your answers.
PERMISSIBLEMATERIALS
1. Non-programmable calculator.
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Question 1
For the following questions, answer True/False.
[S]
1.1 The DHCPNAKis message from the client to the server in response to a DHCPREQUESTT. he
DHCPNAK indicates that the client does not acknowledge the request and does not agree
to lease the specified IP address.
1.2 DHCPis a TCPService and it runs on port 21 and 23.
1.3 Outside Global - the actual address assigned to an outside host (public address).
1.4 The maximum hop count for RIP is 15.
1.5 An IP address 172.47.17.1 can be issued to a LAN because it is a private IP address.
Question 2
Choose the correct answer from the multiple choice questions below.
[S]
2.1 What does the cost metric in OSFPdepend on by default?
a) Bandwidth
b) Latency
c) Hop count
d) Delay
2.2 Which protocol is used for sending emails?
a) DNS
b) SNMP
c) SMTP
d) ICMP
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2.3 The IP address 255.255.255.255 is:
a) A reserved IP address
b) Addressing all hosts in the local network.
c) Unavailable for configuration on any interface.
d) All of the above
2.4 Which of the following values, a default route will have all Os?
a) Source IP network
b) Destination IP network
c) Destination MAC address
d) Source MAC address
2.5 You are connecting a computer directly to a router. Which type of cable should you use?
a) Crossover
b) Coaxial
c) Roll over
d) Straight-through
Question 3
Define the following concepts/key words used in communication networks.
3.1 Subnetting
[2]
3.2 ARP
[2]
Question 4
4.1 Differentiate between contiguous and discontiguous network.
[2]
4.2 Discontiguous subnets have several advantages over contiguous subnets. (Yes or No?)
[1]
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Question 5
As a Network Administrator, you can either make use of a twisted pair, coaxial or fiber optic cables
as a means of data transmission medium.
5.1 Describe the physical construction characteristics of twisted pair cables in comparison to
coaxial cables.
[3]
5.2 In terms of distance and data rate, differentiate between twisted pair and fiber optic cables.
[3]
Question 6
6.1 Name the three IP address allocation mechanisms that are supported by DHCP.
[3]
6.2 What is DHCPRelay Agent used for?
[2]
6.3 Mention any three drawbacks of utilizing DHCPservices on a network.
[3]
Question 7
Assume packets are being transmitted from a host source to a host destination through some
network devices.
7.1 Define packet switching in networks.
[2]
7.2 Explain how does loss and delay of such packets can occur.
[2]
7.3 Explain how a router can overcome loss and delay.
[2]
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Question 8
Consider the topology below and answer the questions that follow.
Steyn
20.20.20.0 /16
L---liJ.i'
PC-PT
Eclah
2911
N.America
Area 1
Area 2
2911
S.America
----.,,-,. -
8.1 You are requested to configure Asia router with OSPFas a routing protocol. Write down all
the required commands to achieve this. Assume you are in this router mode: Asia> [3]
8.2 You would want to confirm if Asia router has learned any network route. What command
will you use to check this?
[1]
8.3 How do you understand by the command default-information
how is it useful?
originate
and
[2]
8.4 Below is an extract of Europe router that is configured with OSPF. List down any two
networks that have been learned by this router.
[2]
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E1.1ropejl
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external,
0 - OSPF, IA - OSPF inter area
Nl - OSPF NSSA external type 1, H2 - OSPF NSSA external type 2
El - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, Ll - IS-IS level-1,
L2 - IS-IS level-2,
ia - IS-IS inter area
• - candidate defa1.1lt, U - per-user static route, o - ODR
P - periodic downloaded static route
Gateway of last resort is not set
10.0.0.0/16
is s1.1J:metted, l subnets
O
10.10.0.0/16
[110/65] via 192.168.100.l,
00:14:12, Serial0/3/0
20. 0. 0. 0/ Hi is sttbnetted,
l s1.1bnets
0
20.20.0.0/16
[110/65] via 192.168.100.l,
00:14:12, Serial0/3/0
172.16.0.0/16
is variably subnetted,
3 subnets, 2 masks
C
172.16.0.Q/24
is directly connected, GigabitEthernet0/0
L
172.16.0.1/32
is directly connected, GigabitEthernetO/Q
0 IA
172.16.10.0/24
[110/129] via 192.1€8.100.1,
00:QE:33, Serial0/3/Q
192.1€8.100.0/24
is variably s1.1bnetted, 2 subnets, 2 masks
C
192.1€8.100.Q/30
is directly
connected,
Serial0/3/0
L
192.168.100.2/32
is directly
connected,
Serial0/3/0
192.168.200.0/30
is subnetted,
l subnets
0
192.168.200.0/30
[110/128] via 192.1€8.100.l,
00:14:12, Serial0/3/0
Europe#
Question 9
Consider the figure below and answer the questions that follow:
PC_1
10.0.37.205
209.165.128.128/29
Sw ch4
~-'c..-._ .,,,l~
172.16.-16.0/28
Internet
2911
Router0
192.168.95.108
Inside: 172.16.16.1
Ouside: 64.100.50.1
Server-PT
Server_1
9.1 Write down the full command that will create a static NAT translation to map the Server_l
inside address to its outside address.
[3]
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9.2 Mention any other method that can be used to configure NAT.
[1]
9.3 Write down the commands that will configure the correct inside and outside interfaces on
the router. Write separate commands for each of the two interfaces.
(4)
9.4 Write down the command that you can issue on the router to verify the static NAT
configurations.
(2)
Question 10
As a Network Administrator of a company, you are given a class B IP address block:
192.168.7.0 /24
Utulising CIDR,calculate the subnets that will be assigned to each department of the company. You
are informed that each department requires 16 users:
As per your subnetting, clearly indicate:
10.1 Number of subnets that will be created.
(2)
10.2 Number of usable hosts per subnet.
[2]
10.3 Answer the questions below regarding the subnets created.
a) Subnet 1:
[2]
b) The very last subnet:
[2]
c) Usable host range for subnet 1:
[2]
d) Broadcast address of subnet 1:
[1]
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Question 11
You have been allocated the class C IP address block 172.20.20.0 /16.
Subnet this IP address block to provide valid IP addresses to all users in the four LANs. You are
required to re-draw the table below and fill it in.
[14]
LAN
Rehoboth: 8000 Users
Karibib: 4000 Users
Rundu: 250 Users
Outjo: 6 Users
Network number
Range
Marks distribution:
[1.5 marks for each network]
[1 mark for each range]
[1 mark for each subnet mask(/)]
Total: 14 marks
Subnet mask (/)
End of Paper
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