ITEC 3800 Data Communication
Test 1
Name:
Each multiple choice question is worth 2 points and each short essay question is worth 4
points. There is also a question of 5 extra points. In total there are 105 points.
1. The _____ layer keeps different applications’ data separate from other applications’
data.
a. Session
b. Data Link
c. Network
d. Transport
2. The _____ sublayer defines how data is packaged for the network.
a. Physical
b. LLC
c. MAC
d. Transport
3. _____ different classes of IP addresses exist on the Internet.
a. 3
b. 4
c. 5
d. 6
4. Which layer is represented by frames?
a. Session
b. Data Link
c. Network
5. Routers operate at the _____ layer of the OSI model
a. physical
b. data link
c. network
d. Transport
d. transport
6. Which of the following are associated with the application layer of the OSI model?
(choose two)
a. ping
b. Telnet
c. FTP
d. TCP
e. IP
7. Your router receives a summary address of 192.168.176.0/21. What address range
will your router forward based on this summary address?
a. 192.168.0.1  192.168.255.254
b. 192.168.176.1  192.168.176.255
c. 192.168.176.1  192.168.191.254
d. 192.168.176.1  192.168.183.254
8. Well Known TCP Port _____ is for FTP data transfer.
a. 20
b. 21
c. 22
d. 23
9. The _____ layer provides the encryption services when data encryption is used in
network communications.
a. Presentation
b. Session
c. Network
d. Transport
10. Which subnet mask is the most efficient for point-to-point serial links when using
VLSM?
a. 255.255.255.0 b. 255.255.255.248 c. 255.255.255.252 d. 255.255.255.254
11. For what purpose is an administrative distance (AD) used?
a. To administer a remote network
b. To administer a remote router
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c. To rate the trustworthiness of a remote network
d. To rate the trustworthiness of routing information received on a router from a
neighbor router
12. Segmentation and reassembly of data from the upper-layer applications occurs at
what layer?
a. Application
b. Presentation
c. Session
d. Transport
13. Which command is used to manually encrypt passwords on a Cisco router?
a. Router#service password-encryption
b. Router(config)#service-password-encryption
c. Router(config)#service password-encryption
d. Router(config)#set password encrypt on
14. When data is encapsulated, which is the correct order?
a. Data, frame, packet, segment, bit
b. Segment, data, packet, frame, bit
c. Data, segment, packet, frame, bit
d. Data, segment, frame, packet, bit
15. What type of addresses do bridges use?
a. MAC
b. Logical
c. IP
d. TCP
16. The Host-to-Host layer of the DoD model maps to the _____ layer of the OSI
reference model.
a. Data Link
b. Network
c. Transport d. Session
17. Which of the following is a Class B broadcast?
a. 11.255.255.255
b. 127.5.34.255 c. 174.34.255.255
d. 235.49.234.255
18. The _____ layer of the Cisco hierarchical model is responsible for routing.
a. Internet
b. Core
c. Distribution
d. Network
19. What type of RJ45 UTP cable is used between switches?
a. Straight-through
b. Crossover cable
c. Rolled
d. Twisted cable
20. What protocol is used to find the hardware address of a local device?
a. RARP
b. ARP
c. IARP
d. PARP
21. Which two of the following are private IP address?
a. 12.0.0.1
b. 168.172.19.39
c. 172.20.14.36
d. 172.33.194.30 e. 192.168.24.43
22. What is the subnetwork address for a host with the IP address 200.10.5.68/28?
a. 200.10.5.0
b. 200.10.5.16
c. 200.10.5.32
d. 200.10.5.64
23. You have an interface on a router with the IP address of 192.168.192.10/29. What is
the broadcast address the hosts will use on this LAN?
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a. 192.168.192.7
c. 192.168.192.127
b. 192.168.192.15
d. 192.168.192.255
c. 192.168.192.63
24. Which of the following command will configure all the default VTY ports on a router?
a. Router#line vty 0 4
b. Router(config)#line vty 0 4
c. Router(config)# line console 0 4
d. Router(config)#line vty all
25. You have the following five networks on your router: 172.16.4.0/25, 172.16.4.128/25,
172.16.5.0/24, 172.16.6.0/24 and 172.16.7.0/24. What would be the best summary
address you can configure on your router?
a. 127.0.0.0/8
b. 172.16.0.0/16
c. 172.16.4.0/24
d. 172.16.4.0/22
26. Which of the following are methods of connection to a Cisco router?
a. Console port b. Telnet
c. Auxiliary port
d. All of the above
27. When a router first powers up it will look for and load a valid configuration file from
_______?
a. ROM
b. Flash Memory
c. NVRAM d. DRAM
28. Which mode enables you to view and change the configuration of a Cisco router?
a. Basic Management mode
b. Extended Setup mode
c. User mode
d. Privileged mode
29. On what type of networks can default routing be used?
a. Dynamic
b. Static
c. Stub
d. Homogeneous
30. If you wanted to have 16 subnets with a Class C network ID, which subnet mask
would you use?
a. 255.255.255.252
b. 255.255.255.248
c. 255.255.255.240
d. 255.255.255.255
The objectives of this part of the exam are to test your understanding of subnetting and
also the CIDR and bit-count notation used to express the subnet mask. In this part you
will decode the IP address 126.46.255.255/14 and determine the subnet mask, the
multiplier, the network number, and usuable subnetwork addresses and broadcast
addresses. Determine the class of the network by examining the first octet of the network
address given.
31. What are the network class and the default network mask? Please write the default
network mask and the new subnet mask in decimal.
Class A;
Default mask:
255.0.0.0
New mask:
255.252.0.0
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32. How many usable subnetworks can be created? How many usable hosts per
subnetwork can be created?
In this case, the number of borrowed bits is 6, so:
2^6 = 64 subnets
In this case, the number of remaining bits is 18, therefore:
2^18 – 2 = 262144 – 2 = 262142 hosts
33. What is the multiplier (incremental number) for this subnetting?
Since the new subnet mask written in binary is:
11111111.11111100.00000000.00000000
The last borrowed bit in the second octet is the sixth bit,
so that the block size is 4 (256-252 = 4).
34. How many hosts were lost due to subnetting? (math equation is enough)
2^24 – 2 – 64 * 262142 = 16777214 - 16777088 = 126 hosts
35. Use the multiplier determined in Q33 to determine the first six usable subnetwork
addresses.
126.0.0.0,
126.4.0.0,
126.8.0.0,
126.12.0.0,
126.16.0.0,
126.20.0.0
36. Determine the broadcast addresses on the usable subnetworks listed in last step.
126.3.255.255,
126.7.255.255,
126.11.255.255,
126.15.255.255,
126.19.255.255,
126.23.255.255,
37. What does the address 126.46.255.255 / 14 represent? On what network is this IP
address?
Host address
126.44.0.0
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38. Starting from the user mode, how to set up the router name to be ITEC3800? Also
please add a banner message “Welcome to LabConnection!” Please write all the
commands starting from the user mode, and finally back to the user mode.
Router>
Ans:
Router>en
Router#config t
Router(config)#hostname ITEC3800
ITEC3800(config)#banner motd #
Welcome to LabConnection!#
ITEC3800(config)#exit
ITEC3800#disable
39. Starting from user mode, set the enable password to be “itec3800” and set the enable
secret password to be “datacomm”, then remove them. Please write all the commands
starting from the user mode, and finally back to the user mode.
Router>
Ans:
Router>en
Router#config t
Router(config)#enable password itec3800
Router(config)#enable secret datacomm
Router(config)#no enable password
Router(config)#no enable secret
Router(config)#exit
Router#disable
40. Starting from user mode, setup E0 to be 219.101.110.1 with subnet mask
255.255.255.0.
Router>
Ans:
Router>en
Router#config t
Router(config)#interface ethernet 0
Router(config-if)#ip address 219.101.110.1 255.255.255.0
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Extra Points (5pts)
41. For the following two figures, do they have correct IP settings? If not, explain the
reasons.
Figure 1.
Ans:
192.168.1.91/27 is not in the same subnet as the 192.168.1.100/27.
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Figure 2.
Ans: Correct.
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