CWT Troubleshooting & Maintenance Procedures 2 — Questions and Answers
Question 1: A wireless client shows strong signal strength but experiences frequent disconnections. What should you check first?
- Replace the access point antenna
- Check for RF interference sources near the client (Correct answer)
- Increase the transmit power on the AP
- Change the client's IP address
Correct answer: Check for RF interference sources near the client
Frequent disconnections with strong signal often indicate RF interference rather than signal strength issues.
Question 2: During maintenance, you discover an AP's firmware is two major versions behind. What is the recommended action?
- Leave the firmware as-is if the AP is functioning normally
- Upgrade directly to the latest version without testing
- Review release notes, test in a lab environment, then upgrade during a maintenance window (Correct answer)
- Downgrade to the oldest stable version first
Correct answer: Review release notes, test in a lab environment, then upgrade during a maintenance window
Best practice is to review release notes for breaking changes, validate in a lab, and schedule upgrades during low-traffic windows.
Question 3: A site survey report shows a persistent -85 dBm noise floor in the 5 GHz band in one area. What does this indicate?
- Optimal RF conditions for high-throughput connections
- A significant source of co-channel or adjacent-channel interference (Correct answer)
- The area is outside the AP's coverage zone
- Normal noise floor levels for indoor environments
Correct answer: A significant source of co-channel or adjacent-channel interference
A noise floor of -85 dBm in 5 GHz is elevated and suggests a significant interference source degrading SNR.
Question 4: Users report slow Wi-Fi speeds only during business hours. Which troubleshooting step is most appropriate?
- Replace all APs with newer models
- Analyze channel utilization and client count during peak hours (Correct answer)
- Disable the 2.4 GHz radio on all APs
- Reset all clients to factory defaults
Correct answer: Analyze channel utilization and client count during peak hours
Time-correlated slowdowns point to capacity issues, so analyzing channel utilization and concurrent client load during peak hours is the right first step.
Question 5: After replacing a failed AP, roaming clients do not reconnect to the new AP. The most likely cause is:
- The replacement AP has a different MAC address than the original
- The replacement AP is using a different SSID profile (Correct answer)
- The replacement AP's IP address is on the wrong VLAN
- The replacement AP is broadcasting on the wrong channel
Correct answer: The replacement AP is using a different SSID profile
If the SSID profile or WLAN configuration on the replacement AP does not match the rest of the network, clients will not associate.
Question 6: What does a CRC error counter incrementing rapidly on a wireless interface typically indicate?
- High client throughput and normal operation
- RF signal corruption or interference causing frame errors (Correct answer)
- Excessive multicast traffic on the WLAN
- An overloaded DHCP server
Correct answer: RF signal corruption or interference causing frame errors
Rapidly incrementing CRC errors indicate that frames are being received corrupted, usually due to RF interference or poor signal quality.
Question 7: A technician needs to verify that a newly installed AP is transmitting at the correct power level. Which tool is most appropriate?
- Cable toner
- Spectrum analyzer (Correct answer)
- Optical power meter
- TDR (Time Domain Reflectometer)
Correct answer: Spectrum analyzer
A spectrum analyzer can measure the actual RF transmit power and channel occupancy of an AP in real time.
CWT Troubleshooting & Maintenance Procedures 2
A wireless client shows strong signal strength but experiences frequent disconnections.
What should you check first?