Free CWNA-110 practice test: 30 questions with answers

The IEEE publishes the 802.11 amendments, the IETF publishes RFCs such as those for RADIUS and CAPWAP, and the Wi-Fi Alliance certifies interoperability. The FCC sets spectrum rules in the United States rather than defining frame formats, so the other options misassign these roles.

802.11g added ERP-OFDM to the 2.4 GHz band with rates up to 54 Mbps and interoperates with 802.11b. 802.11a is OFDM but only in 5 GHz, 802.11b tops out at 11 Mbps, and 802.11ac is a 5 GHz-only amendment.

802.11ax, marketed as Wi-Fi 6, added OFDMA for multi-user scheduling on resource units. 802.11a introduced OFDM itself, 802.11n added MIMO and channel bonding, and 802.11ac widened channels and added downlink MU-MIMO, so none of those introduced OFDMA.

802.11be introduced 320 MHz channels for use in the 6 GHz band. 160 MHz was already the widest width in 802.11ax, while 80 MHz and 40 MHz are narrower widths that predate Wi-Fi 6.

In the United States, channels 1, 6, and 11 are the common 20 MHz set that does not overlap, and 2.4 GHz is part of the unlicensed ISM spectrum. A default 80 MHz width and mandatory DFS on 2.4 GHz are both wrong, since DFS applies to specific 5 GHz channels shared with radar.

Probe requests are management frames a station sends during active scanning to discover networks. DHCP runs after association, authentication comes after a network is chosen, and QoS data frames carry user payloads, so those three options describe other stages.

An ESS combines multiple BSSs that share an SSID and connect through a distribution system, which is what allows roaming. A BSS is a single AP cell, an IBSS is an ad hoc group with no AP, and Hotspot 2.0 is a Passpoint feature rather than a service set.

The BSSID is the MAC address of the access point radio that forms the BSS, while the SSID is the network name. The passphrase and the channel number are separate settings and do not identify the BSS.

Beacons are management frames that advertise the SSID, supported rates, and TIM information. Control frames such as RTS, CTS, and ACK, including trigger frames, coordinate medium access, and data frames carry user traffic.

The access point's CTS is heard by the hidden client, which sets its network allocation vector and defers transmission, reducing collisions. WMM prioritization, passive scanning, and PS-Poll do not stop simultaneous transmissions from hidden stations.

A spectrum analyzer shows energy across frequency and time regardless of protocol, which reveals non-Wi-Fi interferers. A protocol analyzer only decodes 802.11 frames, and ping results and DHCP lease tables say nothing about RF energy.

A predictive survey models RF coverage in software before deployment, using floor plans and attenuation values for building materials. Recording existing signals is a passive survey, testing live APs is an active survey, and reviewing captures is troubleshooting after the fact.

DFS channels share spectrum with radar, and an AP that detects radar must stop using the channel and move elsewhere. Microwave ovens and Bluetooth are 2.4 GHz sources, and a neighbor on channel 36 is a non-DFS channel that does not force a DFS vacate.

Sticky clients keep a weak association because their driver does not roam when a better AP is available. Hidden node collisions, adjacent-channel interference, and DFS vacating produce other symptoms, such as retries or channel changes, rather than this association pattern.

Verification measures coverage, roaming, throughput, and application behavior against the documented requirements, using representative clients. Comparing hardware with marketing claims and disabling security do not show that the design meets its requirements.

SNR is the received signal level minus the noise floor, both in dBm, so -70 minus -95 gives 25 dB. The negative value reverses the subtraction, 35 dB is an arithmetic slip, and 165 dB adds the two magnitudes, which has no meaning here.

Decibels express a logarithmic ratio, and an increase of about 3 dB roughly doubles power. The first option reverses that, the second treats decibels as a fixed milliwatt addition, and the third reverses the sign of a decrease.

EIRP equals transmit power minus cable loss plus antenna gain, so 20 minus 2 plus 6 gives 24 dBm. The 28 dBm option adds the cable loss, 16 dBm reverses both the loss and the gain, and 12 dBm subtracts the gain as well as the loss.

Diffraction lets a wavefront bend around the edge of an obstacle, delivering weaker energy into shadowed areas. Reflection and refraction redirect energy along other paths, and absorption removes energy, so none of those three explains a signal wrapping around a corner.

Metal racks reflect the transmitted energy, so delayed copies of the same signal reach the receiver along several paths and can interfere with each other. Channel width, power save behavior, and regulatory power limits do not create delayed copies of an RF signal.

Cloud-managed APs get configuration and firmware from an internet-hosted platform, which suits sites with no local IT staff. Autonomous APs must be configured on each device, IBSS has no access point at all, and mesh backhaul links APs to each other rather than providing central management.

In split-MAC designs, time-critical 802.11 tasks such as beacons, probe responses, and acknowledgments run on the AP, while the controller handles policy, configuration, and firmware. The other options describe controller or server duties, such as central policy and credential storage.

Controller-based systems typically run radio resource management, which adjusts channels and power levels across many APs from one place. Mounting, cabling, power injection, and antenna choice are physical installation tasks done at each location regardless of architecture.

Autonomous APs keep their configuration locally, so large deployments take more effort to keep consistent. A controller coordinates configuration and roaming in controller-based designs, and CAPWAP tunnels to a central appliance are a lightweight AP feature rather than an autonomous one.

PoE+ devices need more power than an 802.3af port budget provides, so the AP may boot on partial power and disable radios. SSID visibility, regulatory domains, and VLAN membership do not control how much power a port delivers.

WEP uses RC4 with a 24-bit initialization vector that repeats, and enough captured traffic lets an attacker recover the key. The TKIP, key length, and DHCP options are not the core design flaw of WEP.

SAE is a password-authenticated key exchange, so an attacker cannot test each guess offline against a captured handshake the way WPA2-Personal allows. Encrypting beacons does not protect the passphrase, WPA3-Personal still derives session keys with a 4-way handshake, and key length is not what makes SAE resistant.

The 6 GHz band only allows WPA3-based security, meaning SAE in WPA3-Personal or OWE, with Protected Management Frames required. WPA2 with TKIP, WEP, and open authentication without encryption are not acceptable for 6 GHz networks.

EAP-TLS uses certificates on both the server and the client, which satisfies mutual certificate-based authentication. PEAP typically needs only a server certificate and uses password credentials inside the tunnel, while EAP-MD5 and LEAP rely on passwords and are weak options.

Protected Management Frames, defined by 802.11w, cryptographically protect management frames such as deauthentication so spoofed disconnects are rejected. TKIP protects data frames, hiding the SSID does not protect frames, and MAC filtering is easily spoofed.