I cannot work out why you'd want to do this, even if you had access issues. Surely there's two ethernet cables between the Nokia router? Can't you just remove the Nokia router and get an ethernet coupler and connect the Asus router direct to the ONT?
No. I’ll expand (I didn’t go into this detail initially)
TLDR - I can move my Asus router, but I'd rather it was in the cellar. I cant find another ethjernet cable under the floor
Ground floor - I have a bunch of other devices in an alcove that need ethernet (home security etc).
These devices were previously served by a single ethernet cable coming
from the cellar, under floorboards
to a gigabit switch in this alcove (this then served the various devices).
Cellar - previously, a phone line into cellar, my Asus router, another switch that had myriad ethernet going all over the house (including going to that alcove I mentioned above).
It was tidy, it worked.
Now.. Hyperoptic couldnt install the ONT in the cellar. So it's about 4ft from the alcove on the ground floor. Without major hassle, I cannot put a new ethernet cable under floorboard to the Asus router situated in the cellar (which I view as the hub of my network setup).
So... I couldnt work out if I could connect the ground floor ONT directly to the switch, then route the Hyperoptic signal onto my Asus router in the cellar. It didn't work when I tried.
What next? Well, I might have to resite the Asus router in the alcove and connect it to the ONT... then connect all my bits. I just tried this - wifi from the Asus is 500 down/500 up (great) but the only snag now is that my connected unifi wifi access points are now running at half speed and I have no idea why