BC CompTIA Network+ Mod 6 HW
Which 802.11 standard functions in both the 2.4-GHz and 5-GHz bands? 802.11g 802.11ac 802.11ax 802.11b
802.11ax Explanation: Similar to 802.11n, 802.11ax devices operate in both the 2.4 GHz and 5 GHz frequency ranges. 802.11b and 802.11g both operate in the 2.4 GHz band. 802.11ac operates in the 5 GHz band.
Which protocol replaced TKIP for WPA2? RADIUS WEP RC4 CCMP
CCMP Explanation: Whereas TKIP (Temporal Key Integrity Protocol) was meant to be backward-compatible as much as possible, CCMP (Counter Mode with CBC [Cipher Block Chaining] MAC [Message Authentication Code] Protocol) helps ensure data confidentiality with both encryption and packet authentication. WEP (Wired Equivalent Privacy) was an early option for 802.11 encryption. RADIUS (Remote Authentication Dial-In User Service) is an open source authentication and authorization service. RC4 (Rivest Cipher 4) is an insecure encryption cipher that is still widely used.
Which Carrier Sense technology is used on wireless networks to reduce collisions? SSID CSMA/CD EAPoL CSMA/CA
CSMA/CA Explanation: 802.11 standards specify the use of CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) procedures to access a shared medium. Compared with CSMA/CD (Carrier Sense Multiple Access with Collision Detection), CSMA/CA minimizes the potential for collisions, but it cannot detect the occurrence of a collision and so cannot take steps to recover from the collisions that do occur. EAP (Extensible Authentication Protocol) was adapted to work on both wired and wireless LANs in the 802.1X standard, dubbed EAPoL (EAP over LAN). A wireless network's SSID (service set identifier) is a character string used to identify an access point.
Which function of WPA/WPA2 security ensures data cannot be read in transit? Key distribution Encryption Message integrity Authentication
Encryption Explanation: Encryption algorithms can scramble data transmitted over the airwaves into a format that cannot easily be interpreted if the signal is intercepted. Message integrity ensures incoming packets are, in fact, coming from their declared source. Authentication allows a wireless client to log on to the network. Key distribution assigns every transmission its own key.
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 Guest network Captive portal Brute force attack
Evil twin Explanation: An evil twin is a rogue access point used to trick a device into connecting to the wrong network by broadcasting the same SSID as the authorized network or another SSID that appears just as legitimate to the user. A guest network is an isolated network to give guests access to Internet service without opening the doors to the entire LAN on that router. A captive portal is the first page a new client sees in the browser when connecting to the guest network, and usually requires the user to agree to a set of terms and conditions before gaining further access to the guest network. A brute force attack means trying numerous possible character combinations to find the correct combination for a password or passphrase.
Which one of the following wireless transmission types requires a clear LOS to function? IR Wi-Fi Bluetooth NFC
IR Explanation: Because it's a form of light, IR (infrared) requires a nearly unobstructed LOS (line of sight) between the transmitter and receiver—some devices use a scatter mode that reflects IR signals off nearby surfaces in order to circumvent some obstacles, but IR cannot pass through these obstacles.
What is the lowest layer of the OSI model at which wired and wireless transmissions share the same protocols? Layer 3 Layer 2 Layer 1 Layer 4
Layer 3 Explanation: WLANs define operations at OSI layers 1 and 2. They support the same TCP/IP protocols—such as IP, TCP, and UDP—from layer 3 and up as wired LANs do.
As you're troubleshooting a dead zone in your office, which measurement will help you determine the edges of the dead zone? EIRP Channel Band RSSI
RSSI Explanation: RSSI (received signal strength indicator) measures in dBm the power of the signal on the receiver's end, which can be used to determine areas of stronger or weaker signal reception. EIRP (effective isotropic radiated power) is a measure of the transmission power, minus the cable loss, plus the antenna gain. A band is a range of frequencies on the wireless spectrum. A channel is a subdivision of a band.
You've just completed a survey of the wireless signals traversing the airspace in your company's vicinity, and you've found an unauthorized AP with a very strong signal near the middle of the 100-acre campus. Its SSID is broadcasting the name of a smartphone model. What kind of threat do you need to report to your boss? Evil twin Rogue AP War driving Hidden node
Rogue AP Explanation: A rogue AP offers a connection to the Internet without the authorization of the area's network administrator. An evil twin is a type of rogue access point used to trick a device into connecting to the wrong network by broadcasting the same SSID as the authorized network. War driving is when a hacker searches for unprotected wireless networks by driving around with a laptop or smartphone configured to receive and capture wireless data transmissions. The hidden node problem happens when a wireless node is not visible to other nodes on the other side of the coverage area.
Which of the following wireless technologies does not use the 2.4 GHz band? Wi-Fi Z-Wave ZigBee Bluetooth
Z-Wave Explanation: Z-Wave functions at the fixed frequency 90.842 MHz. Bluetooth, ZigBee, and Wi-Fi all function in the 2.4-2.4835 GHz band.
