Chapter 15: Wireless Networking Flashcards Preview

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Flashcards in Chapter 15: Wireless Networking Deck (70):
1

Wireless Network

A network that uses radio frequency waves to enable devices to communicate.

2

802.11

IEEE subcommittee that defined the standards for wireless

3

Wireless Access Point (WAP)

A device designed to interconnect wireless network nodes with wired networks. (The thing you unplug and plug back in in your house when the internet isn't working!)

4

Link State

Indicates whether your wireless device is connected

5

Signal Strength

Measurement of how well your wireless device connecting to other devices.

6

Ad Hoc 802.11

-Two or more devices communicate directly without any other intermediary hardware.
-Uncommon

7

Infrastructure 802.11

Uses a WAP that acts as a hub for all wireless clients

8

Independent Basic Service Set (IBSS)

Two or more wireless nodes communicating in ad hoc mode

9

Basic Service Set (BSS)

A single WAP servicing a given area.

10

Extended Service Set (ESS)

When you add more WAPs to a BSS

11

Service Set Identifier (SSID)

A 32-bit identification string that's sometimes called the network name.

12

Roaming

A process where clients change WAP connections depending on whichever WAP has the strongest signal covered by the broadcast area.

13

What are the two broadcasting frequencies that 802.11 sepcifies?

2.4 GHz
and
5.0 GHz

14

Spread Spectrum

Broadcasts data in small discrete chunks over the different frequencies available within a certain frequency range.

15

Direct-Sequence Spread-Spectrum (DSSS)

Sends data out on different frequencies at the same time

16

Frequency-Hopping Spread-Spectrum (FHSS)

Sends data out on one frequency at a time, constantly hopping frequencies

17

Orthogonal Frequency Division Multiplexing (OFDM)

Combines the multiple frequencies of DSSS with FHSS's hopping capability. So best!

18

Goodput

The actual number of useful bits per second

19

How many channels are there on the 2.4 GHz band?

14 channels
Must be configured

20

How many channels are there on the 5.0 GHz band?

40 channels
Automatically configured

21

Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA)

Access method used mainly on wireless networks, which allows hosts to check if the network is free before sending data.

22

Why can't wireless devices detect collisions?

1) Radio is a half-duplex transmission method
2) No electrical peak to detect

23

802.11-1997
1) Frequency
2) Spectrum
3) Speed
4) Range
5) Compatibility

1) 2.4 GHz
2) DSSS
3) 2 Mbps
4) 300 feet
5) 802.11-1997

24

802.11b
1) Frequency
2) Spectrum
3) Speed
4) Range
5) Compatibility

1) 2.4 GHz
2) DSSS
3) 11 Mbps
4) 300 feet
5) 802.11b

25

802.11a
1) Frequency
2) Spectrum
3) Speed
4) Range
5) Compatibility

1) 5.0 GHz
2) DSSS
3) 54 Mbps
4) 150 feet
5) 802.11a

26

802.11g
1) Frequency
2) Spectrum
3) Speed
4) Range
5) Compatibility

1) 2.4 GHz
2) OFDM
3) 54 Mbps
4) 300 feet
5) 802.11g/b

27

802.11n
1) Frequency
2) Spectrum
3) Speed
4) Range
5) Compatibility

1) 2.4 GHz
2) OFDM
3) 100+ Mbps
4) 300 feet
5) 802.11b/g/n

28

802.11ac
1) Frequency
2) Spectrum
3) Speed
4) Range
5) Compatibility

1) 5.0 GHz
2) OFDM
3) 1 Gbps
4) 300 feet
5) 802.11a

29

802.11g Native Mode

How the network runs when only 802.11g devices are connected.
54 Mbps

30

802.11g Mixed Mode

How the network runs when 802.11b devices connect.
11 Mbps

31

Channel Bonding

Wireless technology that enables WAPs to use two channels for transmission

32

Multiple In/Multiple Out (MIMO)

-A feature in 802.11 WAPs that enables them to make multiple simultaneous connections.
-Required by 802.11n for all but mobile devices.

33

Transmit Beamforming

A multiple-antenna technology in 802.11n WAPs that helps get rid of dead spots.

34

802.11n Legacy Mode

The WAP sends out separate packets just for legacy devices

35

802.11n Mixed Mode/802.11g-ht

The WAP sends special packets that support the older standards yet also can improve the speed of those standards

36

802.11n Greenfield Mode

Exclusively for 802.11n-only networks

37

Quadruple-Amplitude Modulated (QAM)

A special version of OFDM used by 802.11n and 802.11ac

38

Wi-Fi Protected Setup (WPS)

Automated process to connect a wireless device to a WAP.

39

MAC address filtering

A method that enables you to limit access to your network based on MAC address.

40

whitelist

The specific computers you do want to have access

41

blacklist

The specific computers you don't want to have access.

42

802.11i

-A wireless standard that added security features.
-Uses 802.1X

43

Wired Equivalent Privacy (WEP)

-A wireless security protocol that uses a 64-bit encryption algorithm to scramble data packets.
-Not so good, don't use it

44

Wi-Fi Protected Access (WPA)

A wireless security protocol that offers security enhancements such as dynamic encryption key generation.

45

Temporal Key Integrity Protocol (TKIP)

The extra security that WPA adds on top of WEP.

46

Wifi Protected Access 2 (WPA2)

The current top security standard.
Uses AES encryption

47

WPA2-PSK

The most common way to setup WPA encryption where you create a secret key that must be added to any device that is going to be on that SSID.

48

WPA2-Enterprise

When you use a RADIUS server for authentication with WPA2.

49

Wireless Controller

Central controlling device for thin client WAPs.

50

Thick Client

A WAP that you can access directly and configure singularly via its own interface

51

Thin Client

A WAP that can only be configured by a wireless controller

52

Lightweight Access Point Protocol (LWAPP)

Ensures interoperability between thin and thick clients.

53

VLAN pooling

A setup where multiple VLANs share a common domain. Used to keep broadcast traffic to manageable levels.

54

802.3af

Power over Ethernet, which enables WAPs to receive their power from the same Ethernet cables that transfer their data.

55

Personal Area Networks (PAN)

The network created among bluetooth devices.

56

Site Survey

A process that enables you to determine any obstacles to creating the wireless network you want.

57

Wireless Analyzer

Any device that looks for and documents all existing wireless networks in the area.

58

Heat Map

A graphical representation of the RF sources on your site.

59

Omnidirectional Antenna

-Radiates outward from the WAP in all directions.
-Place in center of the room usually

60

Setting Up an Infrastructure Network

1) Determine optimal location for your WAP
2) Configure the WAP
3) Configure any clients to access that WAP

61

Setting Up an Ad Hoc Network

1) Each Node must be configured to use the same SSID
2) IP addresses will happen with DHCP prolly
3) Set channel
4) Ensure the file and printer sharing service is running on all nodes.

62

Unidirectional Antenna

Focuses radio waves into a beam of sorts.

63

Patch Antenna

Flat, plate-shaped antennas that generate a half-sphere beam. Always placed on walls.

64

Configure the Access Point

1) Configure the SSID
2) Configure MAC address filtering if you wish
3) Set encryption mode
4) Configure channel and frequency if necessary

65

Wireless Bridge

Device used to connect two wireless network segments together, or to join wireless and wired networks together

66

Multipath Null

The result of the signal from an omnidirectional antenna bouncing off a solid object and multiple versions of a single signal hit the node, some stronger than others.

67

Bounce

A signal sent by one device taking many different paths to get to the receiving systems.

68

Evil Twin

An attack that lures people into logging into a rogue access point that looks similar to a legitimate access point

69

Rogue Access Point

An unauthorized WAP installed in a computer network.

70

War Driving

Nerdy types looking for wireless networks by using omnidirectional antennas connected to laptops.