Unfortunately I could not find a concrete answer and maybe even someone with the same hardware can answer the question
Is it possible to use the ethernet port from the D-Link DAP-X1860 to wire it to the internet/network/router (rather than feeding a signal to a client)? It is actually a wireless extender. I want to avoid a repeater which just repeats the wifi signal, I want to use it rather as an access point which gets the network over lan (= more robust) to extent the mesh wifi.
If you're running OpenWrt, you can configure the ethernet port freely, lan, wan or something completely different.
Technicalities aside, using single-ethernet-port devices don't make good routers, as there are many situations where ethernet access is wanted (firstboot and many similar ones, when stuff isn't quite going as planned). Take a look at the covr-x1860 (2* ethernet, defaulting to 1 wan + 1 lan) or wsm20 (1 + 3), same SOC/ wireless, very similar price range.
Thank you very much for the answer! Cool, that the port can be configured freely
I really just want to have a strong wifi signal in my bedroom. I don't plan to connect other wired devices there. What I found really nice is to just plug it into the wall socket which mounts the device automatically. Do you have other recommendations for my needs which are better than the D-Link DAP-X1860?
That would be a plain dumb-AP setup, no need to reconfigure it as wan (just configure lan for dhcp-client and disable dnsmasq && odhcpd as explained in the link).