I change the IP address to 192.168.1.1 in IPv4 for the ethernet adapter. However, after I disconnect the device, it still replies from 192.168.1.1 when I ping 192.168.1.1. How can it reply without the connection?enter image description here
It looks like you are pinging your own IP address. You can think of it this way:
The ping gets to your network adapter, and the network adapter looks at it and says "Hey! That's me. I don't need to send this down the wire to anyone else. I can answer the ping myself".
So, it doesn't matter if your network cable is unplugged -- the ping still receives a response.