Examples described herein provide multi-band channel scanning. Examples may include transmitting, by a first radio of a first network device operating at a first frequency band below the millimeter-wave (mmWave), a beacon frame indicating a particular scanning channel of a second frequency band within the mmWave, receiving, by a second radio of the first network device operating the second frequency band, a probe request from a second network device via the particular scanning channel, wherein the probe request is in response to the beacon frame received by the second network device, and in response to the probe request, transmitting, by the second radio of the first network device, a probe response in each of one or more sector transmitting directions via the particular scanning channel.