CWS WLAN Troubleshooting Flashcards
7 cards from real CWS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 CWS WLAN Troubleshooting flashcards as text
What is the hidden node problem in a WLAN?
Answer: Two clients that can hear the AP but cannot hear each other, causing collisions at the AP
The hidden node problem occurs when two clients can both communicate with the AP but are out of range of each other, causing simultaneous transmissions and collisions at the AP.
What is the effect of multipath propagation on WLAN performance?
Answer: Signal copies arriving at different times, causing inter-symbol interference and degraded throughput
Multipath propagation causes the same signal to arrive via multiple reflected paths at slightly different times, resulting in inter-symbol interference (ISI) that degrades performance.
A wireless client is experiencing slow roaming between APs. What is the most likely cause?
Answer: Client clinging to current AP despite poor signal (sticky client)
The 'sticky client' problem occurs when a client holds onto an AP with a declining signal rather than roaming to a better AP, causing degraded performance.
Which 802.11 mechanism is designed to mitigate the hidden node problem?
Answer: RTS/CTS (Request to Send / Clear to Send)
RTS/CTS is a virtual carrier sense mechanism where a client sends an RTS frame to reserve the medium before transmitting, alerting hidden nodes and reducing collisions.
A spectrum analyzer shows a high-amplitude, frequency-hopping signal in the 2.4 GHz band. What is the most likely interference source?
Answer: Bluetooth device using FHSS
Bluetooth uses Frequency Hopping Spread Spectrum (FHSS) in the 2.4 GHz band, appearing as a wide, rapidly hopping signal signature on a spectrum analyzer.
When troubleshooting a WLAN, what does the term 'noise floor' refer to?
Answer: The ambient level of background RF energy in the environment when no desired signals are present
The noise floor is the ambient level of RF energy (in dBm) from all non-signal sources in the environment; a lower noise floor allows weaker signals to be detected reliably.
What troubleshooting information does a WLAN controller provide that standalone APs cannot?
Answer: Centralized logging, client association history, and aggregate statistics across all managed APs
A WLAN controller aggregates logs, client association records, and performance statistics for all managed APs, providing centralized visibility that simplifies large-scale troubleshooting.