Employees working in a newly expanded section of an office building report frequent wireless disconnections and degraded network throughput on their laptops connecting via the 2.4 GHz band. A network administrator conducts a site survey and finds that three neighboring access points covering the area are currently configured to use Channels 1, 3, and 5. Which of the following identifies the primary cause of this performance issue and the correct action to resolve it?
- Adjacent-channel interference is occurring because Channels 1, 3, and 5 overlap in frequency; reconfigure the access points to non-overlapping Channels 1, 6, and 11.Answer
- BCo-channel interference is occurring due to identical SSID broadcasting across access points; assign a unique SSID to each individual access point.
- CAn APIPA address assignment issue is causing client packet corruption; deploy a DHCP relay agent on the wireless controller switchport.
- DA Layer 2 native VLAN mismatch exists on the switch trunk ports; reconfigure all switchports to align native VLAN IDs across access points.
Answer
Adjacent-channel interference is occurring because Channels 1, 3, and 5 overlap in frequency; reconfigure the access points to non-overlapping Channels 1, 6, and 11.
In the 2.4 GHz Wi-Fi spectrum, channels have center frequencies separated by 5 MHz, but each channel occupies 20–22 MHz of spectral width. Consequently, channels 1, 3, and 5 partially overlap with one another, causing adjacent-channel interference (ACI) that leads to frame corruption, retransmissions, and latency. The standard mitigation in 2.4 GHz deployments is to assign the three non-overlapping channels: 1, 6, and 11.
Step-by-Step Solution
Key Concept
2.4 GHz Non-Overlapping Channel Selection and Adjacent-Channel Interference (ACI)
Estimated Time:1m 30s