Uses
Some uses for monitor mode include: geographical packet analysis, observing of widespread traffic; esp. for insecure channels (such as through WEP), and acquiring knowledge of Wi-Fi technology through hands-on experience. This mode is also somewhat useful during the design phase of Wi-Fi network construction to discover how many Wi-Fi devices are already using spectrum in a given area and how busy various Wi-Fi channels are in that area. This helps to plan the Wi-Fi network better and reduce interference with other Wi-Fi devices by choosing the least used channels for a new Wi-Fi network.
Software such as KisMAC or Kismet, in combination with packet analyzers that can read pcap files, provide a user interface for passive wireless network monitoring.
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