Where could unknown devices appear on the network?

Question

System administration

I use the Archer C6 router at home, all devices are connected to it via Wi-Fi. I recently got myself a white IP, yesterday I set up an IPv6 connection. And right after setting up IPv6, I looked into the home network monitoring from ESET Smart Security and saw that 20 minutes ago some strange devices were noticed in my local network:




And I don’t have anything from ASUS at home, but what is Routerboard.com - I don't even know. The devices appeared there once, and I did not notice them again. They definitely couldn’t get to me on the waffle, because. password strong, WPA2 protection.
What could it be? Features of IPv6? Glitch in the provider's network? I don't believe in the ESET glitch, because Where did he get these devices from? Is there a way to find out now?

Answer 1

Routerboard.com is mikrotik.com (he redirects there).
ASYSTeK is also a manufacturer of wireless network routers.
Once the MAC address of these routers is lit up, they somehow got into your local network. And, it seems, after all, via WiFi - as far as I remember, the MAC address is not transmitted over IP (unless some NetBios-Over-IP is raised).
Or hackers scanned you for vulnerabilities (with a white external IP, your router will be constantly scanned). Check that port 8080 (web-interface of the router) is not open on your router.
Or neighboring WiFi routers "checked in", perhaps the locale was opened during the router setup.
You can scan neighboring WiFi for these router models.

Answer 2

Change your password and reboot try!

Answer 3

Routerboard.com is Mikrotik.
They were definitely from the local network , and not from the external IP? From the side of the external IP, you will be constantly scanned and constantly looking for something to profit from :)