Module 6. Wireless Networking Book Questions
What was the first 802.11 standard to implement channel bonding? 802.11n 802.11ax 802.11g 802.11ac
802.11n Explanation: Beginning with 802.11n, two adjacent 20-MHz channels can be combined, or bonded, to make a 40-MHz channel. Because the 5-GHz band contains more channels and is less crowded (at least, for now), it's better suited to channel bonding than the 2.4-GHz band. The newer standards take channel bonding to a higher level by supporting 20-, 40-, and 80-MHz channels, with optional use of 160-MHz channels.
Which standard adapted EAP to WLANs? 802.11g 802.11i 802.1X 802.3
802.1X Explanation: EAP (Extensible Authentication Protocol) was originally designed to work only on point-to-point connections, usually on a WAN. However, it was adapted to work on both wired and wireless LANs in the 802.1X standard, dubbed EAPoL (EAP over LAN). 802.11g is an early Wi-Fi standard. 802.11i was designed as a new wireless security standard to replace WEP and included the subset standard WPA. 802.3 is an Ethernet standard for wired networks.
Which of the following statements is true? A satellite dish receives signals equally from any direction. A fish aquarium full of clear water won't negatively affect a Wi-Fi signal. A Wi-Fi client connects to a range extender that connects to an AP. A smartphone always directs its signal toward the closest cell tower.
A Wi-Fi client connects to a range extender that connects to an AP. Explanation: A Wi-Fi client can connect to a wireless range extender, which can connect to an AP (access point) to further extend the WLAN range. Satellite dishes are shaped to receive directional signals from one direction. Water in a fish aquarium and the glass around it will both refract waves as they travel into and through these different mediums. Cellular towers and cellular devices use omnidirectional antennas to improve mobility of cellular client devices.
Which type of identifier allows wireless clients to roam freely from AP to AP? BSSID IP address ESSID Transmitter address
ESSID Explanation: Within an ESS (extended service set), a client can associate with any one of many APs that use the same ESSID (ESS identifier). This allows users to roam, or change from AP to AP, without losing wireless network service. The identifier for a group of nodes using only one AP is a BSSID (basic service set identifier). The transmitter address field in an 802.11 header identifies the MAC address of the device transmitting a Wi-Fi message. IP addresses function at layer 3 and are not part of the Wi-Fi header.
Which of the following statements is false? Each Wi-Fi channel contains multiple frequency bands. Wi-Fi functions on two different frequency bands. Each Wi-Fi channel contains multiple frequencies. Wi-Fi spreads its data across all available frequencies within a wide channel.
Each Wi-Fi channel contains multiple frequency bands. Explanation: A band covers a frequency range that is further subdivided into channels; therefore, a Wi-Fi channel cannot contain multiple frequency bands. In the United States, the FCC has defined 11 channels within the 2.4-GHz band for Wi-Fi and 24 channels in the 5-GHz band. Wi-Fi uses DSSS, which means its data streams are spread over all available frequencies within one of three, wide channels, all at the same time.
Which problem would a low RSSI level indicate? SHOW ANSWER Mismatched standards Insufficient wireless coverage Incorrect passphrase Encryption protocol mismatch
Insufficient wireless coverage Explanation: You can confirm whether insufficient wireless coverage is the problem by checking the RSSI (received signal strength indicator) level at the client's location. Mismatched standards will prevent a client from detecting an AP's broadcast. An incorrect passphrase or encryption protocol mismatch will prevent the completion of a client's authentication process.
Which off-boarding policy can protect proprietary corporate information if a smartphone is lost? Remote wipe Trusted access OS update requirements Site survey
Remote wipe Explanation: The ability to perform a remote wipe is part of an off-boarding policy that clears a device of important information, permissions, and apps without having physical access to the device. On-boarding gives the device trusted access to certain portions of the network. An on-boarding agent might also scan the device for any needed OS or security updates, required security settings (such as timeouts or sign-in requirements), and any existing malware. A site survey assesses client requirements, facility characteristics, and coverage areas when determining the best placement for APs in a wireless network.
Which device will let you determine all frequencies within a scanned range that are present in a specific environment, not just Wi-Fi? SHOW ANSWER Wi-Fi analyzer Captive portal Wireless LAN controller Spectrum analyzer
Spectrum analyzer Explanation: A spectrum analyzer can assess the quality of a wireless signal by scanning a band of frequencies for signals and noise. A Wi-Fi analyzer can evaluate Wi-Fi network availability as well as help optimize Wi-Fi signal settings or help identify Wi-Fi security threats. 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 wireless LAN controller is used to configure and manage APs in a mesh network.
Which Wi-Fi encryption standard was designed to use AES encryption? WPA WPA2 WEP WEP2
WPA2 Explanation: CCMP, which is short for Counter Mode with CBC (Cipher Block Chaining) MAC (Message Authentication Code) Protocol, improves wireless security for newer devices that can use WPA2 (Wi-Fi Protected Access, version 2). CCMP uses AES (Advanced Encryption Standard) to provide faster and more secure encryption than TKIP for wireless transmissions. WPA incorporates an encryption key generation and management scheme known as TKIP (Temporal Key Integrity Protocol) to improve security for legacy WEP-based devices. WEP (Wired Equivalent Privacy) offered two forms of authentication, neither of which is secure: OSA (Open System Authentication) and SKA (Shared Key Authentication). WEP2 does not exist.
Which device on the network will require the greatest throughput capacity? Smart speaker Wireless LAN controller Wireless bridge Smart thermostat
Wireless bridge Explanation: A wireless bridge connects two networks or two remote portions of one network; the throughput demands of a wireless bridge connected to another AP can be significantly higher than typical Wi-Fi clients. IoT devices, such as a smart speaker and a smart thermostat, generally only need sufficient throughput to process commands, send updated sensor data, or possibly stream music or video—however, even streaming video will require less throughput than a bridge that supports multiple wireless clients. A wireless LAN controller might be used only initially to configure the APs, or the APs might remain connected to the wireless controller for continued management—however, management communication does not require much throughput capabilities.