Chapter 6: Wireless Networking
Question 11.7 A type of antenna that issues wireless signals along a single direction, or path. Also called a directional antenna.
g. unidirectional antenna
Question 23. At what two layers do wireless LANs operate at? a. Layer 3 b. Layer 1 c. Layer 2 d. Layer 4
b. Layer 1 c. Layer 2
Question 13. At what layer of the OSI model do the 802.11 standards vary? a. Transport layer b. Physical layer c. Network layer d. Data link layer
b. Physical layer
Question 6. Explain the difference between a unidirectional antenna and an omnidirectional antenna.
The difference between an Omnidirection Antenna and a Directional Antenna is that a Omnidirectinal are best suited for applications requiring good all round coverage. While Directional focuses it's energy in one paricular direcion.
Question 7. Describe the hidden node problem, and explain how it can be mitigated.
A Hidden Node Problem is where a node is not visible to other nodes on the other side of the coverage area. Ways to mitigate this, is by: Increasing transmitting power, moving the node, and removing any obstacles. There are other methods, depending on the size of the network, using Omnidirectional antennas since they're widespread since directionals nodes must be seen by each other in order to appear as "Visible"
Question 21. NFC tags are very expensive and cannot be purchased blank, requiring them to be pre-loaded. True or False?
False
Question 10. Provide information on fading, and describe the different effects that fading can have on wireless transmissions.
No matter what paths wireless signals take, they are bound to run into obstacles. When they do, the original signal issued by the transmitter will experience fading, or a variation in signal strength as a result of some of the electromagnetic energy being scattered, reflected, or diffracted after being issued by the transmitter. Because of fading, the strength of the signal that reaches the receiver is lower than the transmitted signal's strength.
Question 19. Describe the 802.11a standard, and detail some of its history and advantages / disadvantages versus other 802.11 standards.
The 802.11a standard was work on before the 802.11b group standard, but was release after 802.11b group. 802.11a uses higher throughput compared to 802.11b, which attributes to its use of higher frequencies, unique methods of modulating data, and access to more bandwidth. Advantages of 802.11a signals are less likely to be disturbed from microwaves, motors, cordless phones, and incompatible wireless LAN signals.Disadvantages of 802.11a signals is their more expensive, covers less distances, and needs more power to transmit.
Question 20. Elaborate on the three different types of wireless network topologies.
The three types of wireless network topologies are: Star: All nodes are individually connected to a central connection point Bus: All the nodes are connected to a single cable. The cable to which the nodes connect is called a "backbone". Ring: Device connections create a circular data path. Each networked device is connected to two others, like points on a circle.
Question 1. The WPS PIN is vulnerable to brute force attacks. True or False?
True
Question 12. All wireless signals are carried through the air by electromagnetic waves. True of False?
True
Question 5. Multipath signaling is a significant cause of fading. True or False?
True
Question 4. How many address fields exist in an 802.11 frame? a. 4 b. 3 c. 6 d. 2
a. 4
Question 25. How many data streams are used in 802.11ac Wave 2 devices? a. 4 data streams b. 8 data streams c. 2 data streams d. 3 data streams
a. 4 data streams
Question 11.3 A method used by wireless stations to detect the presence of an access point. Using this method, the station issues a probe to each channel in its frequency range and waits for the access point to respond.
a. active scanning
Question 18. Ideally, stations must remain within what range of an access point in order to maintain optimal transmission speeds? a. 300 feet b. 200 feet c. 600 feet d. 100 feet
a. 300 feet
Question 2. Select below the name for the special signal that contains information that a wireless node requires in order to associate itself with an access point: a. beacon frame b. announcement message c. hello packet d. broadcast frame
a. beacon frame
Question 8. What signal propagation phenomena causes a wireless signal to split into secondary waves when it encounters an obstruction? a. diffraction b. scattering c. reflection d. bounce
a. diffraction
Question 11.10 An attack in which a Bluetooth connection is used to download data from a device without the owner ' s permission.
b. bluesnarfing
Question 15. Select below the band that is not one of the four frequency bands used in the 5 GHz range for wireless LANs: a. 5.4 GHz b. 5.9 GHz c. 5.3 GHz d. 5.1 GHz
b. 5.9 GHz
Question 16. How does the 802.11 data frame indicate how a large packet should be fragmented? a. The duration field determines how long the station can transmit a packet, which then determines how it is divided. b. The sequence control field indicates how packets will be subdivided c. The frame check sequence dictates packet size d. It uses the preamble header
b. The sequence control field indicates how packets will be subdivided
Question 9. What 802.11 frame type is involved in association and reassociation, including probe and beacon frames? a. extended frames b. management frames c. data frames d. control frames
b. management frames
Question 22. In IEEE terminology, a group of stations that share an access point are said to be part of what option below? a. modified service set b. extended service set c. basic service set d. generic service set
c. basic service set
Question 11.2 An 802.11 frame type that is responsible for carrying data between stations. Two other frame types include management frames, which are involved in association and reassociation, and control frames, which are related to medium access and data delivery.
c. data frame
Question 14. Select below the network topology that is not a valid wireless network topology: a. infrastructure b. mesh c. ad hoc d. bu
d. bus
Question 11.1 In the context of wireless signal propagation, the phenomenon that occurs when an electromagnetic wave encounters an obstruction and splits into secondary waves. The secondary waves continue to propagate in the direction in which they were split.
d. diffraction
Question 17. In an 802.11 data frame, what is the size of the frame check sequence field? a. 4 bytes b. 2 bytes c. 8 bytes d. 6 bytes
d. 6 bytes
Question 11.6 The throughput experienced at the application level, such as the quality of a video feed or the speed of a Web page loading in the browser.
e. goodput
Question 11.8 A type of antenna that issues and receives wireless signals with equal strength and clarity in all directions. This type of antenna is used when many different receivers must be able to pick up the signal, or when the receiver ' s location is highly mobile.
f. omnidirectional antenna
Question 11.9 The use of chalk to draw symbols on a sidewalk or wall within range of an access point. The symbols, patterned after marks that hobos devised to indicate hospitable places for food or rest, indicate the access point ' s SSID and whether it ' s secured.
h. war chalking
Question 24. All 802.11 standards use ______________ signaling, meaning a wireless station can only transmit or receive, but cannot do both simultaneously.
half-duplex
Question 11.4 The act of driving around an area while running a laptop configured to detect and capture wireless data transmissions.
i. war driving
Question 11.5 A security exploit in which a WPS PIN is discovered by means of a brute force attack, giving the attacker access to the network ' s WPA2 key. The PIN feature in WPS should be disabled if possible.
j. WPS attack
Question 3. Access points that include routing functions are also called _______________.
wireless routers or wireless gateways
