A communication device in a communication network includes at least one processor. The processor is configured to identify a first management information base (MIB) of a first occupied channel in the communication network, and a second MIB of a second occupied channel in the communication network adjacent the first occupied channel. The second occupied channel occupies a frequency band overlapping with an interfering signal band. The processor is further configured to calculate at least one proactive network maintenance (PNM) metric for each of the first and second MIB, and determine, from the calculated PNM metric, that an ingress of the interfering signal is detected on the second occupied channel.