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Flashcards in Final Exam Questions Review Deck (87):
1

A ________ is the path that a frame takes across a single switched network.

Route

2

[True or False]
A frame usually is carried inside a packet.

False

3

Which gives you the IP address of a host you wish to communicate with?

DNS

4

When messages of different users share a transmission line, this is ________.

multiplexing

5

Your ISP gives your home a single IP address. What in the access router allows you to have multiple devices share a single IP address?

NAT

6

[True or False]
B2-CC-67-0D-5E is a valid MAC adress

False

7

How long are IPv6 addresses?

128 bits

8

How long are IPv4 addresses?

32 bits

9

When I first connect to a network, my computer receives its _____________.

IP address from the DHCP server

10

The top layer of the TCP/IP stack is the ________ layer.

application

11

Transport Layer: Host P transmits a SYN to Host Q. If host Q is willing to open the connection, it will transmit a(n) _______ segment.

SYN/ACK

12

Transport Layer: If the destination host does not receive a segment, it will _______.

Transmit nothing

13

In an Ethernet frame, the IP packet is carried in the _____ field.

data

14

UDP checks messages for error but does not correct them. UDP is ________.

Unreliable

15

What is (are) the well-known port number(s) for HTTP?

80

16

A client is attempting to send an HTTP request. After the internet layer process on the client does data encapsulation, it passes the IP packet to the ______ layer process.

data link

17

A message always has a ________ at the transport layer.

header

18

"Octet" is the same as ______.

"byte"

19

How long are IPv4 addresses?

32 bits

20

In HTTP, which host initiates the 3-way open at the transport layer?

Client Web Browser

21

Wireless network standards operate at which layer?.

The Data Link layer

22

Wi-Fi standards are created by the _______ Working Group.

802.11

23

Frequency is measured in terms of ______.

hertz

24

What propagation problem is especially bad in moist air?

Absorptive attentuation

25

A channel extends from 55 MHz to 60 MHz. Its bandwidth is ______.

5 MHz

26

The 2.4 GHz band supports _______ possible non-overlapping 20 MHz channel(s).

3

27

A wireless host sends a packet to a server on the company's wired Ethernet LAN via an access point. How many frames will be involved in this one-way transmission?

2

28

What happens if two nearby access points use the same channel?

They will interfere with each other.

29

What is the newest Wi-Fi standard?

802.11ac

30

Which of the following is usually optional in wireless access point operation?

RTS/CTS

31

Alice is going to make an online purchase at petsmart.com. She wants to ensure that her credit card number will be encryped when she places the order. Where does Alice's computer obtain petsmart.com's public key?

Alice's computer gets the public key from the petsmart digital certificate (which petsmart gets from CA).

32

When I want to view the webpage for Barnes & Noble, a process occurs but it is not visible to me through my web browser interface. Describe the steps that occur in a TCP session for such an example. Be sure to mention how error detection and correction might occur during this session.

1. The TCP session begins with my computer sending a SYN to the B&N webserver, to start the 3-way open.
2. Once the TCP conenciton is open, the HTTP request/response cycle occurs, followed by the 4-way close.

Error Detection: If a host receives an ACK, the it knows the segment was received. If a host does not recieve an ACK, then it re-transmits the segment. (Error Correction)

33

In the TCP/IP architecture, which layer is responsible for facilitating communication within a single network?

Data Link

34

DDoS attacks are attacks on ______.

Availability

35

[True or False]
Passwords are widely used because they offer a very strong authentication.

False

36

In TCP, the receiver sends ______ if the message is received correctly.

an ACK message

37

If an Ethernet frame passes from a source computer through two Ethernet switches, then to the destination computer, how many data links will there be?

1

38

Applications that must flow in real time (e.g. voice over IP) typically use ______ as the standard at the Transport Layer.

UDP

39

The most popular symmetric key encryption today is ______.

AES

40

Source and destination port numbers are found in the header of _______.

http GET requests

41

Of the major protocols discussed in class thus far, ______ is (are) connection-oriented.

TCP

42

At what layer is the EUI-48 address added to an outgoing message?

data link

43

A message always has a _______.

header

44

UDP checks messages for errors but does not correct them. UDP is _______.

unreliable

45

Jitter is a problem for ________.

VoIP and Steaming Media

46

Throughput is _______.

The speed the network actually provides to users.

47

Transmission speed is normally measured in ________.

bits per second

48

Overprovisioning means _______.

Adding much more switching and transmission line capacity than will be needed most of the time.

49

An attacker must break through two firewalls to get to a host. This illustrates the principal called _________.

defense in depth

50

[True or False]
Social Engineering is an old hacker technique, and therefore it does not work well today.

False

51

What IEE working group creates the Ethernet LAN standards?

802.3

52

What IEE working group creates the wireless LAN standards?

802.11

53

When untwisting wire pairs in UTP, we do not untwist more than 1.25 cm (a half inch) at their ends. This helps reduce a type of interference known as _________.

Terminal crosstalk interference

54

The Frequency spectrum is divided into ____(a)_____ which are further divided into ____(b)____.

A) Service Bands
B) Frequencies

55

IEE 802.11n uses what two unlicensed bands for data transmission?

2.4 GHz & 5 GHz

56

Name and describe thee of the five wireless propagation problems we discussed.

Shadow/Dead Zones - Places where the signal just cannot reach or it just dies.

EMI (Electromagnetic Interference) - Where the wireless signals from other devices create interference in wireless propagation.

Inverse Square Law: As the wireless signal goes out further it will get weaker.

57

Name and describe the primary propagation problem with Multimodal Fiber Optic transmission lines.

Modal Dispersion: Signals enter the fiber at different angles (or modes) causing them to travel different distances as they reflect off the walls of the cord. As a result, signal may arrive out of order.

58

You are setting up an Ethernet LAN in a small office space. The longest run of cabling you need is 70 meters. Your network need a rated speed of 1 Gbps. You are considering using either 100Base-TX, 1000Base-T, or 1000Base-SX. Which one(s) will work in your setup?

1000Base-T and 1000Base-SX

59

Users of an access point share the transmission capacity of the access point. The throughput they share is called _________.

Aggregate throughput

60

A wireless host located at Company A sends a packet to a server on Company A's wired Ethernet LAN via an access point. How many frames will be involve din this one-way transmission?

2

61

In digital signaling there is (are) _____ state(s).

a finite number of states

62

How will a stateful packet inspection (SPI) firewall handle an incoming packet containing a TCP segment which is an acknowledgement?

pass it if it is part of an approved connection

63

[True or False]
As a signal propagates down a UTP cord, greater propagation distance will result in more noise errors, even if the average noise level is constant.

True

64

When one pair in a UTP cord interferes with signal in other pairs, this is _______.

Crosstalk interference

65

How many wires will you find in a Cat 5e UTP cord?

8

66

[True or False]
A binary signal is also a digital signal

True

67

Modern Ethernet networks use which kind of topology?

Hierarchical Star

68

A 2.4 GHz band supports ____ nonoverlapping 20 MHz channel(s).

3

69

What is usually optional in access point operation?

RTS/CTS

70

How will a stateful packet inspection (SPI) firewall handle an incoming packet containing a TCP SYN segment?

process it through the Access Control List (ACL)

71

We discussed two advantages of using the 5 GHz frequency over the 2.4 GHz frequency. What is one of the advantages?

The 5 GHz is going to give you a stronger signal in a smaller space with more channels to choose from on this frequency. So if you live in a studio apartment where distance is not a large concern, the 5 GHz frequency could be a good option for you.

72

If an 802.11n access point and an 802.11g client communicate, they communicate using _____.

802.11g

73

Which offers strong security?
a. WPA
b. 802.11i
c. Both are equall strong

b. 802.11i

74

In what mode of 802.11i operation is a central authentication server used?

802.11X mode

75

What does the Wi-Fi Alliance call the 802.11i?

WPA2

76

When a wireless computer wishes to communicate with a server, ______ can secure the communication again evil twin attacks.

a VPN

77

In the IPv4 address 1.2.3.4, what is the network part?

We cannot say

78

According to the guest speaker, Greg James, how many "denies" do our firewalls experience on a typical day?

11 million

79

Beamforming can allow an access point to _____.

direct power to individual clients AND send signals to two different clients at the same time

80

In a network mask, the 1s correspond to the ______.

network part

81

Near-field communication has a maximum transmission of about _____.

a) 400 cm/200in
b) The devices must be physically touching
c) 40 cm/20 in
d) 4 cm/2 in

d) 4cm/2 in

82

Abigail and Bert are using public-private key encryption to exchange information. They want to ensure all of their communications remain confidential. Abigail will use ____(a)____ to encrypt a message for Bert. Bert will use ____(b)____ to decrypt the message. Bert will use ____(c)____ to encrypt a message for Abigail.

a) Bert's public key
b) Bert's private key
c) Abigail's public key

83

When a user is trying to visit a webpage, before the user PC can contact the webserver it must first contact the DNS server.
(a) What information does the user PC send to the DNS server?
(b) What information does the DNS server send back?

(a) The user sends the URL of the webpage in a DNS request.
(b) The DNS server sends the IP of webpage in a DNS response.

84

In the TCP/IP architecture, which layer is responsible for the bit-by-bit transmission of data?

Transport

85

In the TCP/IP architecture, which layer is responsible for facilitating communication between two applications?

Application

86

In the TCP/IP architecture, which layer is responsible for transmission of packets between networks?

Internet

87

In the TCP/IP architecture, which layer is responsible for facilitating communication between two computers, regardless of their platforms or internal hardware?

Application