Chapter 20: Wireless Networks Flashcards

1
Q

IEEE 802.11

A

WiFi standard

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2
Q

Connecting NIC to a client

A

Through a PCIe port or external USB

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3
Q

WAP

A

Wireless Access Point

Act like a hub, but could also be routers/switches

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4
Q

PoE

A

Power over Ethernet

Must come from a PoE capable switch

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5
Q

PoE Standards

A

802.3af (PoE)
802.3at(PoE+)
802.3bt (PoE++)

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6
Q

PoE Injector

A

Pushes PoE up to 100m

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7
Q

CSMA/CA

A

Carrier Sense Multiple access/collision avoidance

client will listen to see if another client is broadcasting, then waits random time before retrying it’s own broadcast

Due to all the overhead of constant frames, can impede performance

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8
Q

RTS/CTS

A

Request to Send/Clear to Send

Protocol that asks permission, then acts once permission is received

RTS frame gets sent, CTS frame gets received

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9
Q

ACK

A

Acknowledgement Frame

Client waits for this after sending data before next packet is sent

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10
Q

BSS

A

Basic Service Set - the WAP for a particular area

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11
Q

EBSS

A

Extended Basic Service Set - Multiple WAPs

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12
Q

Repeaters/Extenders

A

Rebroadcast signals to cover dead zones

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13
Q

Long Range Fixed Wireless

A

Uses directional antennas, interconnects remote buildings, can reach up to miles

Also known as point-to-point connections

May use proprietary protocols, may need FCC approval, may have reserved channels

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14
Q

WMN

A

Wireless Mesh Networks - devices act like routers, forwarding traffic.

devices are not WAPS, but “nodes.” Can communicate to each other, even if one node happens to be outside of another node’s range, as long as they have a path through intermediary nodes

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15
Q

3 methods of wireless security (and the two A+ methods)

A

1) MAC Address Filtering
2) Authentication
3) Data encryption

1) Disable broadcast (hidden network)
2) Change your channel

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16
Q

SSID

A

Service Set Identifier (network name)

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17
Q

SSID practices

A

1) Always change the default
2) Each WAP needs to share SSID in a network
3) SSID is included in all packets
4) disabling SSID broadcast hides network

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18
Q

WAP Setup

A

1) Consider location/placement
2) Decrease radio power so signal only reaches desired limit (trial and error)
3) Disable guest access
4)MAC address filtering (WAP will store given MACs)

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19
Q

Depreciated security methods

A

WEP (Wired Equivalent Privacy)
WPA (Wi-Fi PRotected Access)

WEP uses encryption level, passphrase, and a default key

WPA uses Personal/Pre-shared Key (PSK) or Enterprise configuration

20
Q

WPS

A

Wi-Fi Protected Setup

21
Q

WPA2

A

Uses AES (Advanced Encryption Standard)

Also compatible with TKIP (Temporal Key Integrity Protocol)
TKIP is an older encryption method, typically used for backwards compatibility

22
Q

WPA3

A

Upgrades some security and usability issues with WPA2

23
Q

Spread-spectrum

A

Radio waves send data in small, discrete chunks (how Wi-Fi works)

24
Q

Bands for IEEE 802.11

A

2.4GHz, 5GHz, 6Ghz

25
Q

Channels

A

20 MHz each, can be bonded

26
Q

2.5GHz Band

A

11 or 13 Channels, but many overlap

Only 1, 6, and 11 are discrete with no overlap

27
Q

5GHz Band

A

25 channels, no overlap

Channels can be bonded into wide (40Mhz) and ultrawide (80MHz), but this opens up to interference

28
Q

6GHz Band

A

Could bond 8 channels into “superwide” 160MHz

29
Q

AFC

A

Automate Frequency Coordination

WAP sends details about itself (location, height, etc) to central database, gets told what channels it should use

30
Q

802.11a

A

First standard to use 5GHz band, has good throughput.

Max 54Mbps with 150ft range, really gets more like 25Mbps

31
Q

802.11b

A

Uses 2.4GHz band, first ubiquitous standard. 11Mbps lab, 4-6Mbps reality.

Max range 300 ft

32
Q

802.11g

A

2.4GHz band, backwards compatible with b devices

Combines best of a and b

Speed of a (54MBps) with range of b (300 ft)

33
Q

802.11n

A

“Wi-Fi 4”

Dual band, both 2.4 and 5 simultaneously

MIMO - Multiple in, multiple out for simultaneous connections (more than one antenna)

lab 600Mbps, reality 100+ mbps

WAPs use trasmit beamforming to optimize signal and reduce deadspots

34
Q

802.11ac

A

“Wi-Fi 5”

5Ghz only, allows for dual banding but applies 802.11n for 2.4 GHz band

Maxes at 1+Gbps

35
Q

802.11ax

A

“High Efficiency Wireless (HEW) or Wi-Fi 6/Wi-Fi 6e”

2.4 and 5, 6e adds 6GHz band

36
Q

Interference

A

Impact on data transmission, caused by things like large electrical appliances or too many smaller devices on the same channel (baby monitors, etc)

Signal strength can be checked in Network and Sharing settings, look at adapter settings

37
Q

Omnidirectional vs Directional Antenna

A

Omnidirectional uses a dipole antenne

Directional typically uses a dish-type antenna

38
Q

PAN

A

Personal Area Network, typically bluetooth enabled

39
Q

Bluetooth versions and speeds

A

1 - 1 Mbps
2 - 3 Mbps (uses EDR)
3 - 24 Mbps (uses 802.11 protocol)
4 - Focused on Qol improvements, less power consupmtion “Bluetooth Smart”
5 - increased throughput, decreased range

40
Q

Bluetooth benefit

A

resistant to interference, rapidly changes channels in 2.4Ghz band

41
Q

Classes of Bluetooth Devices

A

Class - Power - Range
1 - 100Mw - 100m
2 - 2.5Mw - 10m
3 - 1Mw - 1m

42
Q

Configurating a WAP

A

Use a wireless analyzer to pick the “quietest” channel

Apply MAC filtering

43
Q

RADIUS

A

Remote Authentication Dial-In User Service

Security measure for accessing wifi

Open standard, partially encrypted, uses UDP ports 1812 & 1813

44
Q

TACACS+

A

Terminal Access Controller Access-Control System Plus

Cisco developed, but opened a version for public use, uses TCP port 49

45
Q

AAA

A

Authentication, Authorization, Accounting