The longer you leave this running (particularly when staff are first entering the office or returning after lunch/meetings), the better sense of what devices are connected to the network you will get. Watch what probes the various devices are sending out (especially when they are deauthenticated, as above). You will see each computer on the network, as identified by their mac addresses, broadcast information about previous networks to which they have connected. BSSID STATION PWR Rate Lost Frames Probe 00:11:22:33:44:55 00:11:22:33:44:55 0F:3E:DF:DA:2D:E2 F8:7E:FC:03:CC:43 -67 0 0 -80 -24 0 234567 234567 SampleOrg,linksys¸John Smith's iPhone,F amygreen,SampleOrg,android-hotspot,Star 00:11:22:33:44:55 00:11:22:33:44:55 F8:19:F3:DF:75:19 38:08:95:EB:7E:0B -58 -54 0 -75 -12 0 234567 234567 SampleOrg HolidayInn,SampleOrg,John Smith's Mac m Recommendation Recommendation: Cleanse wifi network connection history For most devices, deleting networks from the “saved” network list will stop them from being probed. Obviously, this can be an annoyance for networks you regularly connect to, so renaming these networks to non-revealing names would help, as would creating nonname-associated “guest” networks for colleagues connecting to your home network. On iPhones and iPads, it is not possible to selectively remove historical networks unless you are currently in range of that network. It is however possible to remove all history: go to Settings > General > Reset > Reset Network Settings . When you take this step, it is worth going through this reset multiple times – approximately once per year of device ownership, as the first reset appears to only remove recently-connected networks, and older networks will be broadcast. Recommendation: Use innocuous network names Organizations may want to choose innocent or generic network names, and/or not broadcast network names. It is worth noting that devices seeking out hidden networks will "beacon" for the actual network name, so this has extremely limited security use and must be combined with other protective measures. See this Acrylic blog post for further details. It is worth noting that wifi access points are also tracked to assist in location services, and as such the location of a wireless network can be learned from its name or the MAC address of the access point. WiGLE is a community-managed database for such Page 131 of 240