With a WiFi home network, how to disable it permanently

Hi, all!

I installed Linux Mint 19.3 the other day, and enp9s0 keeps coming up when I type ifconfig. Even though in Network Settings I disabled it. I am able to shut it down in root with “ifconfig enp9s0 down” but that’s only good until I boot up the next time.

Another strange thing, even when disabled in this way, “ethernet” shows up under my WiFi adapter! I’m like, why? I’m really baffled by this. (Again, a connection with an ethernet cable is impossible, so, no, I didn’t once establish an ethernet connection and then forgot about it, lol.)

I’m eager to hear what you think about this. Thanks!

I suspect it’s showing up because it’s there, even though it’s deactivated, I don’t see what harm it’s doing,

If it’s an ethernet card you’re using you could physically remove it or if it’s integrated you may be able to turn it off in the BIOS if it’s troubling you.

Out of curiosity why is an ethernet connection impossible ?