Fundamentals of Wireless LANs Answer_100%

Fundamentals of Wireless LANs (100%)

1 What is the best way to test the line-of-sight path when doing a site-to-site survey? visually with a spectrum analyzer both visually and with a spectrum analyzer visually and with a Global Positioning System 2 Which types of transmission medium are available for use by WLANs? (Select two.) fiber-optic Infrared light UTP radio frequencies STP 3 At which OSI layer or layers does a wireless AP operate? Layer 1 Layers 1 and 2 Layer 2 Layers 2 and 3 4 Which type of antenna connectors are used by the Cisco Aironet Bridges? polarized BNC reverse TNC polarized TNC reverse BNC 5 What is the difference between higher gain antennas and lower gain antennas? antennas? (Select two.) Higher

gain antennas direct energy more precisely. gain antennas have narrower beamwidths. Higher gain antennas have a greater chance of receiving interference. Higher gain antennas have lower bandwidths. Higher

6 Cisco Aironet bridges operate at which layer of the OSI model? physical data-link network transport  7 Why do APs have two antennas attached attached to them? to increase coverage area to provide diversity to provide redundancy redundancy to provide symmetry s ymmetry

When using the site survey tool, a specific mode causes the cl ient adapter to actively send or receive low-level RF packets to and from its associated AP and provides information on the success rate. Which mode accomplishes these functions? 8

repeater mode stand-alone mode passive mode active mode parallel mode 9 Which type of antenna is referenced as a base in a dBd rating? plane yagi dipole isotropic 10 When using high gain omnidirectional antennas, what is helpful in reducing the poor coverage below the antenna? diversity polarization amplifiers downtilt 11 Which open standard operating system is licensed for use in many mobile computing devices?  

ymbian MS DOS Windows XP OS/2 12 Which types of software should be installed on laptops to prevent harmful disruptions while they are operating on public wireless networks? (Select two.) spectrum analyzer antivirus firewall protocol analyzer repair utility 13 Which frequency spectrum do FHSS WLANs use in the United States? 83 Mhz

around the 5 Ghz ISM band Mhz around the 2.4 Ghz ISM band 900 Mhz around the 5 Ghz ISM band 900 Mhz around the 2.4 Ghz IS M band 83

14 dBm is a reference to which unit of measure? milliWatt microWatt 

Watt  kiloWatt  15 What causes the Status LED to blink green in a 1200 series AP? transmitting/receiving packets no devices associated general warning no special meaning 16 What frequency or frequencies does the IEEE 802.11 standard utilize? 900 MHz 3.4 GHz 5.4 GHz 2.4 GHz and 5 GHz 900 MHz, 2.4 GHz and 5.4 GHz 17 What is the WEP key size specified in the 802.11 standard? 256 bit  64 bit and 128 bit  40 bit and 128 bit  40 bit 18 How does an AP behave when the receive antenna is set to diversity? It

will use the antenna that receives the best signal. It will use both antennas at the same time. It will round-robin between the two antennas. The AP will always use one antenna to transmit and the other to receive. 19 When configuring the AP Radio Port Hardware setup page, which settings are recommended in situations where communication is poor and many client devices are associating with the access point? low fragment threshold and high RTS threshold high fragment threshold and high RTS threshold high fragment threshold and low RTS threshold low fragment threshold and low RT S threshold 20 Access points often have two antennas attached to them for diversity in signal reception. What are two purposes of this diversity? (Select two.) helps prevent multipath distortion helps increase signal strength helps eliminate null coverage areas helps prevent diffraction and scattering of the signal 21 Which command is used to set the parent AP for a repeater AP? AP(config)# parent 10.0.0.1 AP(config-if)# parent 1 10.0.0.1

AP(config-if)# parent 1 abcd.1234.ab12 AP(config)# parent abcd.1234.ab12

22 How wide of a band of frequencies is used by 802.11b DSSS? 5 Mhz 11 Mhz 22 Mhz 24Mhz 23 What does a wireless bridge associate with if it is configured as Root=ON? clients and repeaters only other Root=ON devices Master bridge no device since it is in maintenance mode 24 What is the behavior of a wireless bridge when configured as a root bridge? It associates and communicates with any wireless device on the network. It associates and communicates only with other root bridges. It associates and communicates with multiple non-root bridges but only a single root bridge. It associates and communicates with multiple non-root bridges but will not communicate with other root bridges. 25 What are the two methods used by wi reless clients to connect to an AP according to the IEEE 802.11 standard? (Select two.) open authentication shared key authentication private key authorization closed authentication restricted authentication 26 Which type of threats originate from hackers who are more highly motivated and technically competent? external internal structured unstructured 27 When a WLAN is being designed to expand an existing LAN, what should be done during the design phase? (Select three.) Select the carrier. Learn about the current topology and physical structure. Study the actual network performance. Provide an estimation of costs for the new equipment needed. Identify the links that must be replaced.

28 Which topics may be included in the Request for Proposal? (Select three.) prices and payment options workstations and servers specifications an implementation plan a network topology for the new design 29 At which layer of the OSI model do wireless bridges and APs operate? Layer 4 Layer 3 Layer 2 Layer 1 30 What is a good antenna to use with an AP to provide coverage for a long indoor hallway? 5.2 dBi Ground Plane 8.5 dBi Patch Wall 2.15 dBi Rubber Dipole 2.2 dBi Ceiling Mount  31 Bit Flipping, Replay Attacks, and Weak IV collection are all considered attacks against which type of  security? WEP LEAP PEAP IPSec 32 Which of the following statements are correct? (Select two.) Longer

cables lose more power than shorter ones. Thick cables lose more power than thin ones. Higher frequencies lose more power than lower ones. Rigid cables lose more power than flexible ones. 33 In DSSS technology, each data bit becomes a chipping sequence. How many chips per bit are used by the IEEE 802.11 standard? 11 12 13 15 34 Which device decodes the various protocol layers in a recorded frame and presents them as readable abbreviations or summaries? cable tester network analyzer spectrum analyzer time domain reflectometer

35 During a routine wireless benchmark inspection, the IT personnel of the bank discovered that the AP in the lobby was transmitting at 60 mW. The AP connects to a 6-dBi gain omni-directional antenna through a cable with a 3-dB loss. What is the final power output radiated by the antenna element? 30 mW 60 mW 120 mW 180 mW 36 In the graphic, which type of cable s hould be used at the arrow to protect the WLAN against a direct  lightning strike? coax fiber-optic Category 5 UTP 37 Which of the following antenna types could be used for a point-to-multipoint connection? patch wall mast mount Y agi solid dish 38 In the United States, how many nonoverlapping channels are there for the 802.11b standard? three four seven eight  39 In a WLAN, what is the purpose of the common DS? to allow communication between multiple B SSs thereby allowing mobile devices to roam without loss of connectivity to reduce the number of APs needed to provide reliable connectivity while roaming to eliminate the need for connectivity to a wired network to eliminate the need for station addressing when in roaming mode 40 In WLAN data transmission, what is the significance of having four different IFS i ntervals? to increase the amount of data that can be transmitted at one time to prevent collisions when accessing the wireless media to resequence data units at the destination STA to provide priority levels for access to the wireless media 41 Which two spread spectrum modulation techniques are used by WLANs? (Select two.) FDSS ODSS DSSS

DFSS

FHSS

42 The network administrator wants to ensure that his Aironet bridges are transmitting within the 802.11b WLAN power level of 36 dBm established by the United States FCC. Currently the bridges are transmitting at 25 dBm. The omni-directional antenna results in a 12 dBi gain. The cabling results in a loss of 6.8 dBi per 100 feet of cabling. 25 feet of cabling is installed. What is the EIRP in dB? 34.2 35.3 36.1 36.4 43 Which three power modes are available on a Wireless NIC? (Select three.) CAM FastCAM PSP FastPSP FastAPA 44 For a standard survey, how much overlap is sufficient to provide transparent handoffs between APs? 10% 15% 20% 25% 30% 45 The ACU site survey tool can operate in which modes? (Select two.) repeater mode stand-alone mode passive mode active mode parallel mode 46

Most

data collection devices operate at which speed?

1 Mbps 2 Mbps 5 Mbps 11 Mbps 47 What are the keys to maintaining a problem-free network environment and having the ability to isolate and fix a network fault quickly? (Select three). communication data backup documentation planning virus protection fault tolerance

48 Which of the following antenna types are used for wireless bridges? (Select three.) rubber dipole patch wall Yagi Ground Plane solid dish 49 What are the three basic options for configuration on a Cisco Aironet 350 series bridge? (Select  three.) Web-browser interface SNTP CLI CDP SNMP SSID 50 Which statements describe the RF spectrum? (Select two.) It

encompasses both radio waves and microwaves. Most of the frequencies in the spectrum are unlicensed. It extends from about 9 MHz to thousands of GHz. It is used heavily for communications. The acronym stands for radiated frequency (RF). 51 In addition to physically installing the client adapter card into the wireless station, what is needed for functionality of the card? a universal client adapter software driver an interoperability software patch a client adapter driver with its corresponding AP driver a client adapter software driver specific to the O S 52 What are the effects of multipath interference? (Select two.) distorted signals at the receiving end increased coverage range poor signal quality levels enhanced data throughput  incorrect polarization 53 What is the best tool to use if there may be a radio interference problem? cable tester gauss meter spectrum analyzer time domain reflectometer