Question Connecting PC via switch with another separate router

Jul 25, 2022
I'm not sure if anyone can help me or if what I'm trying to achieve is even possible without using a powerline ethernet connection or something.

I'm on full fibre and my ONT is downstairs in my office with my desktop PC. The ONT is connected to a switch which then has one port going to the PC and another going to the RJ45 wall socket. This socket then goes to the router that provides WiFi upstairs. Whenever I power on the PC, the router upstairs can't connect to the internet meaning all devices are offline apart from my PC. Now from what I understand, the ONT is designed to supply one IP address only and it's basically giving that one IP address to my PC.

I've tried changing various settings on my PC (Windows 10) to try and obtain IP addresses automatically, giving the default gateway as the that my router uses. However when I do this, the router comes back online and all the other devices can access the internet, but the PC then goes offline and I can't access the routers interface or even ping it. I don't get any WiFi signal downstairs so WiFi isn't an option, I also don't get any WiFi signal upstairs if I move the router downstairs and plug it directly into the ONT (I think this room is heavily insulated or something as I believe the previous owner used it as a recording stupid for his band!) Is there anyway around this problem at all? All I need is the connection to go from the PC, to the switch, to the router and then back down to the switch and to the ONT. Sadly right now it's going from the PC, to the switch and straight to the ONT. I've tried using other devices too such as another router and setting it to the same IP range as the main router upstairs, setting another router up as a repeater etc etc to no avail.

Anyone have any ideas or is it looking likely that powerline ethernet is the way to go?


Jul 20, 2022
At first blush I would say you need to connect your PC to your router instead of your ONT.

I'm not sure but it sounds like your traffic is getting messed up going from your ONT to Switch.
Your path must go


Now technically you can use the same switch to connect ont/router and then router/pc but this requires much more advanced equipment that I suspect you have. This uses VLANS.

What I would do is put another router connected directly to the ONT. Then hook the switch to the router lan and then hook the upstairs router as you currently have. You would want to run the router upstairs as a AP so that all your equipment is on the same network.
You can either leave the wifi on or off or maybe use different SSID for the router directly attached to the ONT.
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