CWDP Wireless Network Troubleshooting — Questions and Answers
Question 1: What is the most common cause of sticky client behavior in enterprise WLANs?
- Clients maintaining association with a distant AP instead of roaming to a closer one (Correct answer)
- Clients frequently disconnecting and reconnecting
- Excessive DHCP lease times
- Too many SSIDs configured on the network
Correct answer: Clients maintaining association with a distant AP instead of roaming to a closer one
Sticky clients occur when devices maintain their connection to the original AP even after moving to an area better served by another AP, often due to the client's roaming algorithm threshold being too conservative.
Question 2: How can excessive co-channel interference (CCI) be identified during troubleshooting?
- High retry rates and low throughput despite strong signal levels (Correct answer)
- Complete loss of wireless connectivity
- Clients unable to authenticate
- DHCP server not responding
Correct answer: High retry rates and low throughput despite strong signal levels
CCI manifests as high retry/retransmission rates and degraded throughput even when clients show strong received signal strength, because multiple APs on the same channel contend for airtime.
Question 3: What tool is best suited for identifying non-Wi-Fi interference sources?
- Spectrum analyzer (Correct answer)
- Protocol analyzer (packet capture)
- Wi-Fi scanner application
- Ping utility
Correct answer: Spectrum analyzer
A spectrum analyzer shows all RF energy in the frequency band, including non-Wi-Fi sources like microwave ovens, Bluetooth devices, cordless phones, and video bridges that a Wi-Fi scanner cannot detect.
Question 4: What does a high percentage of management frames indicate in a wireless packet capture?
- Possible network instability with frequent client associations, disassociations, or probe requests (Correct answer)
- A well-optimized network
- High data throughput
- Encrypted traffic that cannot be analyzed
Correct answer: Possible network instability with frequent client associations, disassociations, or probe requests
A disproportionately high percentage of management frames (probe requests, authentication, association, deauthentication) suggests clients are struggling to connect or stay connected, indicating network instability.
Question 5: What is the recommended approach when users report intermittent connectivity issues?
- Correlate the timing with potential interference sources, check client roaming behavior, and verify AP health (Correct answer)
- Immediately replace all access points
- Increase transmit power on all APs to maximum
- Reboot the wireless controller
Correct answer: Correlate the timing with potential interference sources, check client roaming behavior, and verify AP health
Intermittent issues require systematic investigation: correlating occurrence times with potential interference (shift schedules, equipment usage), analyzing client roaming logs, checking AP resource utilization, and reviewing environmental changes.
Question 6: How does transmit power mismatch between APs and clients affect network performance?
- Clients may hear the AP but cannot transmit back reliably, creating asymmetric communication (Correct answer)
- It causes the AP to overheat
- It has no effect on performance
- It only affects battery life on the client device
Correct answer: Clients may hear the AP but cannot transmit back reliably, creating asymmetric communication
When an AP transmits at much higher power than the client device, the client can receive the AP's signal from far away but its lower-power response may not reach the AP, creating an asymmetric link with poor performance.
CWDP Wireless Network Troubleshooting
What is the most common cause of sticky client behavior in enterprise WLANs?