There was a post on a subreddit that I follow (OpenWRT) that was asking for peoples router/network setups and how they are using OpenWRT to accomplish that so I decided to try and make a network diagram of the setup I worked on here at my parents home while I’ve been working remotely (needing stable Internet/WiFi!). There are 2 levels that are covered and the Internet comes into the lower level which then gets sent up via a dedicated 802.11ac radio (separate backchannel). That is then rebroadcasted to the rest of the home with another dedicated, separate 802.11ac AP via the middle relay bridge in between. The relay bridge runs the customized app below that I compiled and it all shares one flat network throughout the home (one /20)! There is also 802.11n sent out for better reach and distance just in case as well 🙂

Edit: You can also add guest networks on each of the radios but with different SSIDs and wlan interfaces which will let them act like wifi-vlans that you can section off with dnsmasq & iptables…

Edit-edit (Updated diagram/layout):

I made this network graph with this site: https://www.lucidchart.com/documents#/dashboard

Historical documentation purposes,
Previous setup with semi-ok results: