I have an open wifi hotspot with usermanager authentication. I was wondering why there are devices with similar names, different IP addresses.
Is this a security threat?
It’s possible that there’s an android app for changing a MAC address, thus making the phone get a new DHCP lease.
Another possibility is, if you have several APs, and their “arp” setting is set to “proxy-arp” (or the vendor equivalent, if it’s not a MikroTik AP), then each AP will present each user with its own MAC, meaning that if the same user accesses your hotspot from different APs, they’ll be seen by the hotspot as all these different MAC addresses.
You can check that second hypothesis by verifying all of your APs, and checking whether they happen to have the same MAC addresses as those.