We have three floors, so It might be difficult to use an ethernet cable. I would of course use a CAT6 cable to get the optmial speed. The thing is that it must cross three different doors, as well as the fireplace in secound floor. Mom is not happy about that!
The main router in second floor is very good (300/300 - 2.4Ghz - 5Ghz), so the connection is 5/5 everywhere in the house. I have not yet experienced any problem with the 5Ghz, so our devices are normally at 5/5 on that frequency.
My father bought an ASUS RT-AC66U 11AC AC1750 Router for about a year ago. We have never used it since we upgraded our main router for fiber for 2 months ago.
Should I just plug in this router on the third floor and connect my current ethernet cable? It's not long enough to reach the main router. Well... that reminds me of something. Last time I tried to connect an ethernet cable between this router and mt laptop, every device were slowed down drastically. We got 4 WiFi networks available, 2x 2.4Ghz and 2x 5Ghz.
Hmmm...