Chapter 6 - Wireless Networking

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

2312 bytes

25. 802.11ac Wave 2 devices can theoretically support how much maximum throughput?

3.47 Gbps

39. 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?

Wifi analyzer

15. 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

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

probe frame

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

spectrum analyzer

38. 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

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

F

30. Healing messages are a feature of what smart home protocol?

Z-Wave

28.What scenario describes an evil twin attack

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

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

T

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

T

5. 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.

T

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

T

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

T

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

4 data streams

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

6 bytes

36. 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

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

9kHz and 300 GHz

Describe the 802.11a standard, and detail some of its history and advantages / disadvantages versus other 802.11 standards.

Although the 802.11a task group began its standards work before the 802.11b group, 802.11a was released after 802.11b. The higher throughput of 802.11a, as compared with 802.11b, is attributable to its use of higher frequencies, its unique method of modulating data, and more available bandwidth. Perhaps most significant is that the 5-GHz band is not as congested as the 2.4-GHz band. Thus, 802.11a signals are less likely to suffer interference from microwave ovens, cordless phones, motors, and other (incompatible) wireless LAN signals. However, higher-frequency signals require more power to transmit, and they travel shorter distances than lower-frequency signals. As a result, 802.11a networks require a greater density of access points between the wired LAN and wireless clients to cover the same distance that 802.11b networks cover. The additional access points, as well as the nature of 802.11a equipment, make this standard more expensive than either 802.11b or 802.11g. For this and other reasons, 802.11a is rarely preferred.

24. 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)

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

F

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

F

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

F

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

F

12. How does refraction affect the propagation of a wireless transmission?

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

31.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.

33. What is the purpose of the Layer 2 LLC sublayer?

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

20. 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?

MIMO

14. At what layer of the OSI model do the 802.11 standards vary?

Physical Layer

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

RTS/CTS

41. What are some of the different types of wireless topologies that can be created?

Some of the different types of wireless topologies are as follows: * ad hoc-A small number of nodes closely positioned transmit directly to each other without an intervening connectivity device. * infrastructure-An intervening connectivity device, a WAP (wireless access point) or AP (access point), accepts wireless signals from multiple nodes and retransmits them to the rest of the network. To cover its intended range, an access point must have sufficient power and be strategically placed so that all connected nodes can communicate with it. * mesh-Several access points work as peer devices on the same network, where the AP devices cooperate to provide more fault tolerant network access to clients. A wireless controller might be used only initially to configure the APs, or the APs might remain connected to the wireless controller for continued management.

16. 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

40. 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

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

class 1

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

control frames

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

iwconfig

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

management frames

37. 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.

19. 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.

11. 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

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

13.56 MHz