I have a new router that only has one ethernet port on it, but I want to connect two computers to it. I also have my old router that has 4 ethernet ports on it. Can I somehow use the old one to split the one ethernet connection from my new router?
yes, set the old router as access point or if dont have that, disable the DHCP server.
Put the old router in AP mode, connect the new router to the old router (using 1 of the lan outlets not the one labeled intent) then connect the two pcs to the old router.
What’s the make/model of the new router? It’s not unheard of to only have one Ethernet port on a router but it is a little unusual.
Yes, connect a switch to the one port
You can use an ethernet switch to have more ports, a 5 port one would be plenty for you, something like the Netgear GS305 is perfect and very cheap, typically under £20
I may end up doing something like that. But if I can reuse the equipment I already have, that’d be nice.
Or throw in a simple small switch like this https://store.ui.com/us/en/pro/products/usw-flex-mini. Can’t go wrong for $30