Wireless Networks

Question 1

Wireless Router

Answer 1

Combination Box(what you’d have at home)

Question 2

What is a WAP/AP?

Answer 2

WAP(wireless access point) or AP(access point) - expands wired LAN into the wireless domain

not a router

functions as a hub(dumb)

Question 3

Infrastructure

Answer 3

When wireless devices connect to other devices(wired or wireless) through a wireless router or access point.

Question 4

Ad Hoc

Answer 4

When wireless devices connect directly with each other.

Question 5

Site Survey

Answer 5

used to determine coverage for wireless signal like heat map

Question 6

AP placement within 2.4Ghz

Answer 6

Overlapping circles - connecting circles cannot be on the same channel(frequency) otherwise they will cancel out. 10% to 15% coverage overlap in coverage area

Question 7

AP placement within 5Ghz

Answer 7

Honeycomb - Placed next to eachother however do not overlap

Question 8

Mesh Topology

Answer 8

Wireless

Combination of wireless technologies defines the Network

WiFi / Microwave / Cellular etc..

Question 9

ESS

Answer 9

Extended Service Set (ESS)

Contains multiple APs to provide coverage (i.e office building with separate floors)

Question 10

BSS

Answer 10

Basic Service Set (BSS)

Devices connected wirelessly however only one AP connected to the Network

Question 11

IBSS

Answer 11

Ad Hoc Mode = Independent Basic Service Set (IBSS)

Contains only devices/clients wit no APS (no access to the internet/network)

Question 12

Types of Antenna

Answer 12

Omnidirectional (found in a router)

Unidirectional (focus power in one directional usually at another antenna to cover larger distance)

Parabolic (satellite tv)

Question 13

Factors of Antennas effectiveness

Answer 13

Distance

Pattern of Wireless Coverage

Environment (indoor/outdoor)

Avoiding Interference with other APs

Question 14

CSMA/CA

Answer 14

Collision avoidance which listens for transmission to determine if its safe to transmit.

RTS(ready to send) > waits for ack > if rx’d responds with CTS(clear to send) > if not received device starts random back off timer

Question 15

RFI

Answer 15

Radio Frequency Interference

caused by using similar frequencies to WLAN;

wifi devices, phones, home devices such as microwave, security systems, walls

Question 16

2.4 Ghz Channels

Answer 16

1, 6 & 11

Question 17

802.11 Frequencies

Answer 17

2.4Ghz

5Ghz

Question 18

Spread Spectrum Wireless Transmissions

Answer 18

▪ Direct-Sequence Spread Spectrum (DSSS)

▪ Frequency-Hopping Spread Spectrum (FHSS)

▪ Orthogonal Frequency-Division Multiplexing (OFDM)

Question 19

Unsecured Wireless Networks

Answer 19

War Driving

War Chalking

Question 20

Rogue Access Point

Answer 20

▪ Malicious users set up an AP to lure legitimate users to connect to the AP

▪ Malicious users can then capture all the packets (data) going through the rogue access point

Question 21

NAC

Answer 21

NAC - Network Admission Control

Checks operating system / virus software up to date before allowing device on network

Question 22

Security Measures on Home Network

Answer 22

Disable SSID(Server Set ID)
Enable MAC Filtering

Question 23

Geofencing

Answer 23

GPS or RFID defines real-world boundaries

Barriers can be active or passive

Device can send alerts if it leaves area

Network authentication can use it to determine access

Question 24

Captive Portals

Answer 24

Web page that appears before the user is able to access the network resources(think wifi at a hotel)

Question 25

OPEN
WEP
WPA
WPA2

Answer 25

No Security
IV
TKIP / TC4
CCMP / AES