I have a Mac mini that I'm using as a Homebridge server. It's connected with fixed Ethernet and also has an active WiFi connection.
The Mac mini has an assigned host name
Jupiter (from 'Sharing' settings) and the router (a Ubiquiti UDM) has assigned
localdomain as a local search suffix (although the host resolves using
local and also without any suffix).
I am using the server's assigned hostname (
jupiter.local) in the Homebridge configuration, which means this is the address used by Apple HomeKit to control devices.
If I ping the host name from another machine on the same network and subnet, the local IP to which it resolves is usually the one assigned to the ethernet interface.
However, when I had problems with Homebridge devices not responding, I found that this coincided with that hostname resolving to the I.P. attached to the WiFi interface.
Of course, I could simply disable WiFi and this would likely solve my problem. But I'm curious to understand what determines which of the network interfaces' I.P. address is returned when another device on the same network attempts to resolve the local hostname.
My knowledge of DNS on a local network is shaky. Is this configuration of the server device, or the DNS service on the router, or both?