Management of devices without authentication and authorization means anyone can do it. Which is the state of things today (for DNS).

Managing traffic over your network and the devices on your network are very similar tasks that aim to accomplish very similar things. However, they are not equivalent tasks. Relying on traffic management to accomplish device management eventually runs into conflicts. These may stem from unmanaged devices, guest devices, unmanageable devices, or the consequences of the total lack of authentication and authorization.

Ultimately, managing traffic and managing devices are not tasks that replace one another.

Administering devices with network settings is convenient, but rapidly vanishing because there's no technical difference between you administering your local network and a totalitarian ISP administering their users.

My ways of dealing with the modern world, in order of preference:

1. Use Free software, so that devices develop user-empowering features instead of being locked down.

2. Firewall all general Internet access from a device/VM, and let it talk to local network devices only.

3. Firewall the device/VM from accessing most of your network, allow Internet access (ideally through a VPN), and inspect the hardware to make sure there aren't microphones or cameras.

It's sort of like cleaning malware off of an infected PC from within the infected OS.

It was always theoretically impossible, and now we're just seeing the gap of "Well in this case the enemy was imperfect" closing. It was never going to stay open in the first place.