When the Pihole DHCP server serves up an address to certain devices the hostname is listed as unknown. I can tell from the MAC what device it is but there's no way to edit the hostname using the GUI and I don't know enough about the file system to know where to edit the table that is created.
It would be great if there was a way to edit the hostname from the interface and to ensure that the name remained with the device should the same device/MAC happen to receive another IP address.
Until an interface change can be made, is there a file that I can edit to set the hostname?