modem to switch to router?

I have a friend who is trying to get a direct connection to his internet. the issue is that he and the modem are downstairs, and the router is upstairs. the best option we have to connect (due to wiring going through the walls) is to plug an ethernet switch into the modem, then have one cat 5 go up to the router, and the other one going to his computer. the question here is: will this even work? or do I have to go through the modem first?

 

No, it won't work with a switch, because a modem and the device it is connected to must be on the same collision domain and (almost always) directly connected.

You may be able to get away with using a hub (possibly with an uplink port) as a repeater, if only the router and modem are plugged into it.

 

so how about modem------hub-------router
..........................................\
...........................................computer

will that work at all?

 

Nope. As I said you may be able to get away with using a hub as a repeater with only the modem and the router connected to it. Think of it as a single ethernet cable.

 

Curiosity on my end...why not just move the router downstairs, if that's where your friend is?

 

If you replace the hub with a router it might work. You will have double NAT, but you could set both routers to bridge mode? Then let the modem do all of the assigning of addresses. Otherwise you could get a powerline to connect from upstairs to downstairs. They are pretty cheap.

 

It doesn't solve the problem because an ethernet bridge cannot be used to connect a modem to a router (this includes both powerline and regular bridges).

I have used a setup using a router in the basement next to the cable modem at the cable drop (where it has the strongest signal from the street), and connecting that via powerline to an AP upstairs (since wireless signals propagate better downwards from a wood floor than up from a concrete basement).