Q&A Hero

Q: In 802.11i PSK mode, the pass phrase should be at least ________ characters long. A) 8 B) 12 C) 20 D) 128

Q: Which of the following is a risk in 802.11i PSK mode? A) WPS can easily be cracked if it is used. B) Unauthorized sharing of the pre-shared key. C) A weak passphrase may be selected. D) all of the above

Q: Session keys are used to ________. A) make cryptanalysis more difficult B) improve authentication C) both A and B D) neither A nor B

Q: For post-authentication communication with an access point, the client in 802.11i PSK mode will ________ for subsequent communication. A) always use the same preshared key each time it is connected B) always use the same session key each time it is connected C) both A and B D) neither A nor B

Q: After two wireless clients authenticate themselves via PSK to an access point, they will use ________ to communicate with the access point. A) the preshared key B) an 802.1X key C) WPS keys D) different session keys

Q: After authentication in 80.11i PSK mode, a wireless client communicates with the access point via a(n) ________ key. A) VPN B) session C) 802.1X D) preshared

Q: In 802.11i ________, hosts must know a shared initial key. A) 802.1X mode B) PSK mode C) both A and B D) neither A nor B

Q: In what mode of 802.11i operation is a central authentication server used? A) 802.1X mode B) PSK mode C) both A and B D) neither A nor B

Q: What is the strongest security protocol for 802.11 today? A) 802.11i B) 802.11s C) 802.11X D) WPA

Q: Which offers stronger security? A) WPA B) 802.11i C) Both A and B offer equally strong security.

Q: Which 802 working group created 802.11i? A) 802.1 B) 802.3 C) 802.11 D) It was not an 802 working group. It was the Wi-Fi Alliance

Q: In 802.11i, protection is provided between the client and the ________. A) access point B) switch C) router D) server

Q: 802.11i provides ________. A) confidentiality B) message integrity C) both A and B D) neither A nor B

Q: Breaking into WLANs from outside the premises is ________. A) drive-by hacking B) war driving

Q: To drive around a city looking for working access points that are unprotected is ________. A) drive-by hacking B) war driving

Q: Wireless LAN standards come from ________. A) OSI B) TCP/IP C) both A and B D) neither A nor B

Q: In the TJX breach, attackers first got into the network through ________. A) spear phishing B) an inside conspirator C) the use of weak wireless encryption D) all of the above

Q: The 802.11 standard for mesh networking is ________. A) 802.11m B) 802.11r C) 802.11ac D) 802.11s

Q: Mesh networking in 802.11 is likely to use ________. A) only wireless devices B) wireless devices and the site's wired LAN C) both A and B

Q: If two products both comply with 802.11 ac, they should have close to the same performance.

Q: If an 802.11n client tries to use an 802.11ac access point, ________. A) they will not be able to communicate B) they will communicate using 802.11n C) they will communicate using 802.11ac D) either B or C

Q: If more users move to an access point, this decreases ________. A) individual throughput B) aggregate throughput C) both A and B D) neither A nor B

Q: An access point can transmit to more than one wireless client at a time with ________. A) bonding B) MIMO C) Multiuser MIMO D) CSMC/CA+ACK

Q: Beamforming can allow an access point to ________. A) direct power to individual clients B) send signals to two different clients at the same time C) both A and B D) neither A nor B

Q: MIMO ________. A) increases throughput B) lowers propagation distance C) both A and B D) neither A nor B

Q: MIMO ________. A) bonds two or more channels for higher speed B) is used in all forms of 802.11 C) uses a single spatial stream but multiple signals D) transmits multiple signals in the same channel

Q: In the 5 GHz band, how many channels can you have with 802.11ac with 80 GHz channels? A) 1 B) 6 C) 12 D) 24

Q: In 802.11g, channel bandwidth usually is ________. A) 20 GHz B) 40 GHz C) 20 MHz D) 40 MHz

Q: Which of the following only operates in the 5 GHz band? A) 802.11b B) 802.11ac C) 802.11g D) 802.11n

Q: Wider channel bandwidth ________. A) increases transmission speed B) allows more channels to be used in a service band C) both A and B D) neither A nor B

Q: Today, Wi-Fi sales are dominated by ________. A) 802.11a B) 802.11g C) 802.11n D) 802.11ac

Q: Which of the following is the newest Wi-Fi standard? A) 802.11ac B) 802.11g C) 802.11n D) 802.11b

Q: Which of the following is more efficient and faster? A) CSMA/CA+ACK B) RTS/CTS C) Both are about equally efficient and fast.

Q: CSMA/CA+ACK usually is ________. A) mandatory B) optional C) not important D) efficient

Q: The 802.11 standard has two mechanisms for media access control. One of two mechanisms is mandatory; it is ________. A) MAC B) CSMA/CA+ACK C) RTS/CTS D) CSMA/CD

Q: In ________, when a wireless host wishes to send, it first sends a message to the wireless access point asking for permission to send. When the access point sends back a response, the host sending the original message may transmit. All other hosts must wait. A) CSMA/CA+ACK B) CSMA/CA C) CSMA/CD D) RTS/CTS

Q: CSMA/CD+ACK is ________. A) unreliable B) reliable C) semireliable

Q: In CSMA/CD+ACK, when a wireless NIC wishes to transmit, it listens for traffic. If there is traffic, it waits. When the traffic stops, it may transmit immediately. A) always true B) sometimes true C) always false

Q: Media access control governs transmission by ________. A) access points B) wireless hosts C) both A and B D) neither A nor B

Q: ________ is a technique for preventing two wireless stations from transmitting at the same time and therefore interfering with each other. A) Creating extended service sets B) Roaming C) The distribution system D) Media access control

Q: There is an access point that serves eight wireless hosts. On how many channels will these devices transmit and receive during the course of an hour or two? A) 1 B) 2 C) 8 D) 9

Q: What happens if two nearby access points use the same channel? A) They will interfere with each other. B) They will be bonded for joint operation automatically. C) They will be bonded for joint operation automatically if they are on the same ESS. D) They will be bonded for joint operation automatically if they have the same SSID.

Q: The standard for roaming among access points is ________. A) 802.11r B) 802.11s C) 802.11W D) the wireless handoff protocol

Q: Access points in the same ESS communicate via ________. A) wireless transmission B) the distribution system C) a master access point D) routers

Q: In an extended service set, each access point ________. A) must have the same SSID B) must have different SSIDs C) must have coordinated SSIDs D) none of the above

Q: An extended service set (ESS) is a group of BSSs that ________. A) are connected to the same distribution system B) have the same SSID C) both A and B D) neither A nor B

Q: To connect to an access point, you must know its ________. A) SSID B) EUI-48 address C) IP address D) Wi-Fi ID

Q: To use an access point, you need to know its ________. A) SSID B) BSSID C) ESSID D) Wi-Fi ID

Q: ________ have SSIDs. A) Wireless clients B) Wireless access points C) both A and B D) neither A nor B

Q: A single access point and the set of hosts it serves is called a(n) ________. A) BSS B) BSSID C) ESS D) none of the above

Q: A wireless host sends a packet to a server on the company's wired Ethernet LAN via an access point. How many frames will be involved in this one-way transmission? A) 1 B) 2 C) 4 D) There will be one frame for each switch along the way.

Q: Access points take ________ from wireless devices and send them on to devices on the wired LAN. They also do the converse. A) packets B) frames C) both A and B D) neither A nor B

Q: Which of the following uses OFDM? A) 802.11ac B) 802.11n C) both A and B D) neither A nor B

Q: A channel has more bandwidth than is necessary given data transmission speeds requirements in ________ transmission. A) normal radio B) reliable commercial C) spread spectrum D) licensed

Q: In unlicensed bands, ________. A) you can use radios wherever you please B) you can prevent nearby businesses from setting up access points in the same channel C) both A and B D) neither A nor B

Q: WLANs normally use ________. A) licensed bands B) unlicensed bands C) both A and B D) neither A or B

Q: Spread spectrum transmission is used in WLANs for ________. A) higher transmission speed B) more reliable transmission C) greater security D) more efficient transmission

Q: Spread spectrum transmission is used in WLANs because ________. A) it is required by regulators B) it offers strong security C) both A and B D) neither A nor B

Q: The 5 GHz band usually supports about ________ non-overlapping 20 MHz channel(s). A) 1 B) 3 C) 7 D) 12

Q: Companies are moving to the 5 GHz band because there is ________ than in the 2.5 GHz band. A) more bandwidth B) less absorptive attenuation C) both A and B D) neither A nor B

Q: The 2.4 GHz band supports ________ possible non-overlapping 20 MHz channel(s). A) 1 B) 3 C) 7 D) 11

Q: 802.11 standards are being developed to work in the ________ unlicensed band. A) 2.4 GHz B) 5 GHz C) both A and B D) neither A nor B

Q: To transmit data very rapidly, you would want a ________ channel. A) narrowband B) broadband C) single-frequency band D) none of the above

Q: Channels with wide bandwidths are called ________ channels. A) multimode B) full-duplex C) broadband D) parallel

Q: To transmit very rapidly in RADIO, you need ________. A) single-frequency transmission B) single-mode transmission C) wide bandwidth D) narrow bandwidth

Q: A channel extends from 55 MHz to 60 MHz. Its bandwidth is ________. A) 60 MHz B) 55 MHz C) 65 MHz D) none of the above

Q: Signals in a transmission usually ________. A) travel at a single frequency B) spread over a range of frequencies C) spread over the entire frequency distribution D) spread over the entire service band

Q: To handle multiple conversations in radio transmission, you normally use multiple ________. A) channels B) frequencies C) service bands D) wires

Q: 2.4 GHz and 5 GHz are ________. A) frequency spectrums B) broadbands C) channels D) service bands

Q: The frequency spectrum extends ________. A) into the gigahertz range B) into the visible light range C) into the ultraviolet range D) to infinity

Q: What propagation problem becomes worse as frequency increases? A) inverse square law attenuation B) electromagnetic interference C) both A and B D) neither A nor B

Q: The most serious problem with wireless transmission in WLANs is ________. A) inverse square law attenuation B) absorptive attenuation C) shadow zones D) multipath interference

Q: What propagation problem becomes worse as there is a large and dense object between sender and receiver? A) multipath interference B) shadow zones or dead zones C) both A and B D) neither A nor B

Q: What propagation problem is especially bad in moist air? A) absorptive attenuation B) electromagnetic interference C) multipath interference D) inverse square law attenuation

Q: At 10 meters, a signal has a strength of 100 mW. About how strong will it be at 40 meters? A) about 0.5 mW B) about 5 mW C) about 25 mW D) about 6 mW

Q: A cellular telephone uses a(n) ________. A) omnidirectional antenna B) dish antenna C) both A and B D) neither A nor B

Q: The other wireless device is far away in a known direction. It would be better to use ________. A) an omnidirectional antenna B) a dish antenna C) neither A nor B

Q: Radio transmission is measured in terms of ________. A) bytes per second B) wavelength C) frequency D) bits per second

Q: Frequency is measured in terms of ________. A) nanometers B) hertz C) microns D) microseconds

Q: Wireless radio transmission speed is usually measured in terms of ________. A) wavelength B) frequency C) amplitude D) wetness