What is best way to extend wifi to 3rd floor of house if have ethernet cable there?

I have internet that is connected on the first floor by a cable modem and on that floor we use a wifi router. The wifi does not reach the third floor but in the past, we ran a logn ethernet cable up there through the floor. Now we want to have wifi access on the third floor by connecting a router (or something else) to that ethernet cable instead of directly to the internet. Can I do this with any router and just plugging that ethernet cable into the spot where the modem would usually plug in? Or would I need a specific type of router or something else?

One option would appear to be a mains ethernet connection to a wi-fi router on the third floor. However, I have no experience of this. Have a look at the manufacturers’ offerings.

Not sure I understand the question - but an example of what my wife and I do to obtain wireless in our outdoor patio -

Our apartment has a wired ethernet connection in every room. We have a small cabinet where the main switch is located for all the apartment’s wired connections. We also have our wireless router located there in the same cabinet. Hence we have both a wired connection, and a wireless signal, in every room in our apartment.

Unfortunately, the wireless signal from the small cabinet, is not strong enough for a good signal on our patio.

What we have done, in the room next to the patio, is plug in a second router (which has a wireless) and we transmit a second wireless signal (with a different channel and different SSID from the 1st wireless), where that second wireless signal is strong in our patio. Thus the 1st router feeds (via an etherent cable) the second router.

Possibly a similar concept would work in your apartment.

Note there may be some complications wrt router firewalls and wireless printing and wireless scanning.

Thank you, that’s 100% what I want to do. Any reason you chose that approach over:

  1. Turn off DHCP on the second router

  2. Give the second router a static IP within the first router’s network

Then it would essentially be a wireless switch and it should eliminate issues with wireless printing/scanning.

I am assuming that your cable to the 3rd floor is plugged into one of the LAN ports of the main router.

In that case, the easiest thing to do is plug that cable into the WAN port of a new access point/router on the 3rd floor. That one should have DHCP turned on, and use a different set of addresses than the main router. For example, if the main one uses 192.168.1.X for its LAN addresses, use 192.168.2.X for the 3rd floor. You should also use a different channel and ESSID than the main one, assuming that you do not want to implement roaming. This simple setup has one disadvantage. Clients of the 3rd-floor router will be able to access any resource attached to the main router, but the reverse is not true. You could not put a wireless printer on the 3rd floor and get to it from the first floor.

If you really need bi-directional access, the setup is more complicated. I will give you that later if you really need it.

All we need is internet access. So, if I understand correctly:

  1. Plug the ethernet cable into the WAN port (the router just has a port called “internet” and 4 ports “ethernet”, do I use the “internet” one or will this not work?)

  2. In setup, change the network address to (my downstairs is

  3. Give it an SSID that is different from downstairs.

Is that all correct?

I simply adopted the easiest approach, which was to plug in a second wireless router. In fact this second router is a very small portable router, and my wife and I take it with us when ever we go travelling (an Edimax 3G-6218N). This second router also has a different set of IP addresses from our main router (I forgot to mention that, and only reading lwfinger’s post reminded me that in fact we also have that setup recommended by lwfinger).

I’m using this portable router right now to access the internet from the rental apartment where we are staying in Quebec city (while on vacation). I brought a short ethernet cable with me, and I plugged our portable Edimax into the rental apartment’s router, giving all the wireless devices that my wife and I use (when traveling) access (2 laptops, 2 tablets, one 1-pod and 1-android-smart-phone).