Another related question I keep meaning to ask.
On Windows 10, I occasionally get some odd devices show up. They are often called full-ford (amazon) or Zeta (blackview). They have MAC addresses but no IP address. The router doesn't show them up and I cant access them or ping them. They show up on every Windows 10 machine I have, and I have no devices connected that are of this identification. Furthermore, I have changed the router SSID, password and added access control to a whitelist of machine MACs (not the odd ones), but they still show up...

This is really weird, and I cant find out much about it. I am guessing that it is just a Windows 10 "thing", as it never occurs on any other machine.
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Like, I just rebooted the router, and it disappeared. It is really weird. If there were an IP address I would be panicking but it seems to be a false thing being detected.
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Like, now, I have full_ford by Amazon showing up instead.

Like, seriously, this is very odd.
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It seems other people have the issue too. Turning WPS off seems to fix it, kicks them straight away. Seems to be something like other devices nearby looking for open APs or something, I don't know.
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Actually, seems I still have the issue. I have tracked it down to something called WCN - Wireless Connect-Now (or wtte). It seems it is to do with peer-to-peer device discovery (like WiFi-Direct). Probably the neighbours devices being detected as existing.