Chapter 6: Wireless Networking

Due to many vulnerabilities and a short key length, the WPA security standard was replaced with WEP.

False

Infrared technology utilizes an LED that emits light with shorter wavelengths than red light.

False

NFC tags are very expensive and cannot be purchased blank, requiring them to be pre-loaded.

False

The Wi-Fi Protected Setup PIN can be easily cracked through a brute force attack.

True

The most secure Wi-Fi communication is made possible by combining a RADIUS server with WPA or WPA2, known as WPA-Enterprise or WPA2-Enterprise, respectively.

True

The wireless spectrum, as defined by the FCC, spans between which two frequencies?

9 kHz and 300 GHz

802.11ac Wave 2 devices can theoretically support how much maximum throughput?

3.47 Gbps

How many data streams are used in 802.11ac Wave 2 devices?

4 data streams

The LLC sublayer is primarily concerned with managing MAC addresses in message frames.

False

What 802.11 frame type is involved in association and reassociation, including probe and beacon frames?

management frames

In an 802.11 data frame, what is the maximum amount of data that can be sent?

2312 bytes

You've just completed a survey of the wireless signals traversing the airspace in your employer's vicinity, and you've found an unauthorized AP with a very strong signal near the middle of the 100-acre campus. What kind of threat do you need to report to your boss?

Rogue AP

An 802.11 data frame contains four address fields, in contrast to the two address fields in 802.3 Ethernet.

True

The Wireless Personal Area Network (WPAN) is defined in the 802.15 standard.

True

Which Bluetooth class has the highest power output?

Class 1

Which Bluetooth power class allows for a maximum power output of 100 mW and a range of up to 100 m?

Class 1

A wireless node that is in active scanning mode transmits what special type of frame in order to find available access points?

probe frame

What type of device can be used to assess the quality of a wireless signal?

spectrum analyzer

Near-field communication devices send data at what fixed frequency?

13.56 MHz

The use of multiple antennas on an access point to issue a signal to one or more receivers is enabled by what 802.11 innovation?

multiple input-multiple output (MIMO)

What is the purpose of the Layer 2 LLC sublayer?

It is used to handle multiplexing, flow and error control, and reliability.

Diffraction has what affect on a wireless signal's propagation?

The signal is split into secondary waves that continue in the direction in which they split.

A hacker takes advantage of an open Bluetooth connection to send a virus to a user's smartphone. What kind of security breach has occurred?

Bluejacking

Which Carrier Sense technology is used on wireless networks to reduce collisions?

CSMA/CA

The 802.11 standard specifies the use of what technique in order to minimize the potential for collisions?

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

You just settled in for some study time at the local coffee shop, and you pause long enough to connect your smartphone to the Wi-Fi so you can listen to some music while you study. As you're about to sign in, you realize that you clicked on an SSID called "Free Coffee and Internet." What kind of security trap did you almost fall for?

Evil Twin

What technology does Bluetooth use to take advantage of the 79 channels allocated to the Bluetooth band?

FHSS

What optional protocol can be used in 802.11 to reserve the medium for one node's use?

RTS/CTS (Request to Send/Clear to Send)

What scenario describes an evil twin attack?

A malicious access point is configured with thh SSID of a non-malicious public access point.

In an 802.11 data frame, what is the size of the frame check sequence field?

6 bytes

Which of the following statements regarding the 802.11ac standard is NOT accurate?

802.11ac access points function more like a hub than a switch.

Which 802.11 standard functions in both the 2.4-GHz and 5-GHz bands?

802.11n

When troubleshooting wireless issues, what statement is accurate?

Access points that use overlapping channels can cause interference with each other if they are too close.

Z-Wave transmissions have a range of up to 50m per hop, and can tolerate up to 8 hops through repeaters.

False

Which one of the following wireless transmission types requires a clear LOS to function? Bluetooth infrared NFC Wi-FI

Infrared

How does refraction affect the propagation of a wireless transmission?

It distorts the signal as it travels into and through a different transmission medium.

When using RFID, what is an ARPT (Active Reader Passive Tag)?

It is a tag that is activated by an active reader, and uses power from the reader's radio to power its transmission.

What is the lowest layer of the OSI model at which wired and wireless transmissions share the same protocols?

Layer 3

A user swipes her smartphone across a tag on a poster to obtain showtimes for a movie she wants to see later that evening. What wireless technology transmitted the data?

NFC

In Linux, what command can be used for viewing and setting wireless interface parameters?

iwconfig

You are troubleshooting a client's wireless networking issue. Which of the following will prevent the client from connecting to the network?

The client has a wireless profile configured for the "campus" SSID, but the access point is broadcasting the "CAMPUS" SSID.

How does the 802.11 data frame indicate how a large packet should be fragmented?

The sequence control field indicates how packets will be subdivided.

All wireless signals are carried through the air by electromagnetic waves.

True

If you need to evaluate Wi-Fi network availability as well as optimize Wi-Fi signal settings and identify security threats, what tool should you use?

Wi-Fi analyzer

Healing messages are a feature of what smart home protocol?

Z-Wave

In IEEE terminology, a group of stations that share an access point are said to be part of which of the following?

basic service set

What special signal is issued periodically from an AP and contains the network transmission rate and service set identifier (SSID), as well as other information needed for a computer to associate with the AP?

beacon frame

Upon connecting to a Wi-Fi network, you're redirected to a login screen and a request to accept terms of service before being connected. What is this an example of?

captive portal

Which 802.11 frame type is related to medium access and data delivery, and includes ACK and RTS/CTS frames?

Control frames