CCNP Practice Question: Is troubleshooting a wireless network where…

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  Co-channel interference from neighboring access points using the same channel.

  Why this is correct

  Multiple BSSIDs operating on the same 2.4 GHz channel create co-channel contention: when two APs' coverage areas overlap on channel 11, all associated stations must contend for the same RF medium via CSMA/CA. The resulting deferred transmissions, hidden-node collisions, and excessive backoff produce high channel utilization, frame retries, and ultimately client disconnects. This directly matches the spectrum analyzer showing sustained energy on channel 11 and the presence of neighboring APs configured to that same channel.

• ✗

  Adjacent channel interference from access points using channels 10 and 12.

  Why it's wrong here

  The scenario explicitly states that the neighboring APs are using channel 11, not channels 10 or 12. Adjacent-channel interference would require those access points to be transmitting on channels whose sidebands overlap channel 11—like channels 10 and 12—but since they are not, the interference pattern cannot be attributed to those frequencies. Additionally, a spectrum analyzer would show elevated signal energy centered on the adjacent channels themselves, whereas the reported high utilization is centered precisely on channel 11.

• ✗

  Non-WiFi interference from devices like microwaves or cordless phones.

  Why it's wrong here

  Non-WiFi devices such as microwave ovens and cordless phones typically emit broadband energy across a wide swath of the 2.4 GHz spectrum, affecting many channels simultaneously or in an intermittent duty cycle, not a single channel continuously. The spectrum analyzer's finding of high utilization isolated to channel 11 suggests a narrowband, periodic Wi-Fi signal rather than a non-WiFi emitter. Furthermore, modern analyzers often decode 802.11 frame preambles to distinguish Wi-Fi traffic from foreign energy; the report of high utilization alone is more consistent with co-channel contention.

• ✗

  The access point is overloaded with too many clients.

  Why it's wrong here

  Client overload would be an AP-local capacity problem, evidenced by high CPU usage, memory pressure, or airtime consumption driven entirely by associated stations, not by external APs on the same channel. The disconnection pattern caused by excessive client load would typically be random and tied to specific performance thresholds, whereas the scenario links the issue to neighboring APs on the same frequency. The spectrum analyzer showing high RF energy on channel 11 indicates a medium contention problem from an outside source, which client overload cannot explain.