Having connected my iMac to a cabled LAN I turned off Wi-Fi for the iMac - not necessary right? And potentially reducing the bandwidth on Wi-Fi for other devices.
I found that using the Apple Watch to auto-logon to the iMac no longer worked. I had a message saying that I needed to turn on Wi-Fi and bluetooth to use the Apple Watch.
Looking deeper, when turning Wi-Fi off it also removed the Apple Watch from the list for bluetooth devices. Having turned Wi-Fi back on the auto-logon feature seems to be working but the bluetooth connection to the Apple Watch is still not showing on the list of devices on the iMac.
Can anyone throw any light on what is happening? Ideally I want to disconnect the Wi-Fi on the iMac but leave the bluetooth working to allow connection for logon.
You need Bluetooth and wireless to be on for this feature to work, but you do NOT need to pair your watch to your iMac. In fact, you don’t even need your devices to be connected to the same wireless network. Just like with AirDrop, all of this takes place in an ad hoc manner.
I wouldn’t worry about having wifi enabled on your iMac while using a wired connection. The OS isn’t going to use any significant amount of your wifi bandwidth if it has a wired connection.
You can also prioritize the connections by dragging them up and down in Network Preferences.
Not sure why both are required, but it could be a safety measure to ensure that both connections are being made in proximity to your iMac, laptop, etc.
Like with AirDrop, it’s the bluetooth connection that provides information about how close the devices are to each other.
And having Wi-Fi turned on is a requirement for ALL Continuity features to work, like Handoff, Universal Clipboard and the rest.