I live in Provo, UT and last year we were lucky enough to have our city selected for Google Fiber. Everytime I tell someone this their first question is "So, how amazing is it?"
I'd say it's pretty good ;) (connected via ethernet)
However, there is one caveat. The wireless router/modem that Google gives you is pretty weak. I didn't do extensive benchmarking, but everyone in the house kept experiencing random hiccups and speed tests over wifi were coming back pitiful. Naturally, the non-tech savvy members of the household were starting to doubt the epicness of Google Fiber.
My first instinct was to simply hook up our old router and disable the wireless on the Google Fiber router. Doing that did restore the signal strength we used to have before switching ISPs, but after running speedtests close to the router as well as further away, I realized we still had pretty poor wireless coverage.
I don't know what gave me the idea but I wondered if it was possible to make two wifi access points share the same network. To my surprise, it was extremely easy. Our old Netgear router is on another floor, attached to the Google Fiber router via an extremely long ethernet cable. Both the Netgear router and the Google Fiber router share the same SSID and encryption settings. Everyone's devices in the house seemlessly migrate between access points based on signal strength :D.
This tutorial isn't specific to Google Fiber at all, it just so happens that's what we have and I thought other GFiber customers might have the same issue with their router.
How to Make Two Wireless Routers Share the Same Network
First set aside your secondary router. You're going to need to login to the administrator interface for your Google Fiber router (hereby referred to as GFR). If you're already connected to your GFR then simply open up your web browser and navigate to http://192.168.1.1 (this assumes the default DHCP settings have not been modified on your GFR). You should see a screen like this:
Next click "Continue to Advanced Network Settings" and login using these instructions. You should see a screen like the following.
We're not going to change too much, but one thing we do need to change is the channel your GFR broadcasts on. We want to make your GFR and your secondary router broadcast on channels far enough from each other that they don't interfere with one another.
Click on the "wireless" tab at the top and then "802.11bgn 2.4GHz Wireless" just beneathe the tab.
Change the channel dropdown to either channel 1, 6, or 11. Each of these channels is far enough from the other two that they will not interfere. On your secondary router you'll choose one of the two channels you didn't use on your GFR.
Next we need to change the range of IP addresses that your GFR hands out to connected devices. We need to make room so we can set your secondary router to have a static IP address that your GFR will leave preserved.
Navigate to the "services" tab and then click "IP Address Distribution" just below the tab.
Click the pencil icon under "Action" next to "Dynamic IP Range" and you'll see a screen like this:
Under "LAN DHCP Pool" the "Start IP Address" on your screen should read "192.168.1.1". Change this so that it reads "192.168.1.3". This will allow your secondary router to request a static (unchanging) IP address of "192.168.1.2", but don't worry about that quite yet.
Once you've changed the IP address range and the wireless channel on your GFR, it's time to setup your secondary router. We'll need to login to the administrator interface for your secondary router. Plug the secondary router into the wall and run an ethernet cable between the router and your computer. Be sure you don't plug the cable into the "internet" or "modem" port on the router; plug in the cable as if you were plugging it in to get internet.
If you haven't already, hold down the reset button on the back of your secondary router for about 20-30 seconds. This will factory reset the router and make it way easier for your to configure. If you don't know the default password for your router's administration interface then Google for your router model number followed by "default password" and I'm sure you'll find it.
Once your computer is plugged into your secondary router navigate to http://192.168.2.1 (this may be different depending on your router, hit Google and search for your operating system name followed by "how to find my default gateway").
Once logged in you're going to be looking for a setting that allows your router to act as an "Access Point". This is what it looks like in my Netgear router's administrator interface:
Notice that the address in my browser is http://192.168.1.2 instead of http://192.168.2.1. This is because I've already gone through these steps. Notice also that next to "Specify IP Address" I've changed it to 192.168.1.2 (the static IP we talked about earlier). This puts the secondary router on the same network (see: subnet) as your GFR.
Since we modified your GFR to no longer hand out the 192.168.1.2 address, your secondary router can request it as its static address. Once you've changed the IP your access point will use, enable the setting. Your router will restart but the page won't come back up. That's because the address of the admin interface has changed.
Don't worry about the admin interface just yet, instead plug an ethernet cable into one of the ports on your GFR and then into the internet/modem port on your second router. In most cases you'll want a really long ethernet cable so your second router can be a good distance from your GFR and provide better wireless coverage. Restart your secondary router.
Make sure your computer is connected to your GFR wireless (or via ethernet) and navigate to http://192.168.1.2 to get back to your second router's admin interface. Login again if you need to, then navigate to the "wireless" settings. We need to change them so they match your GFR wireless settings. My router's wireless settings look like this:
Modify your SSID (wifi name) so that it is exactly the same as the SSID on your GFR. Also make sure the wireless mode matches. Mine is in mixed mode, meaning wireless b, g, and n devices are all supported.
Next change the wireless channel to either 1, 6, or 11 (but different from the channel you chose on your GFR). My GFR is channel 11 so I put the secondary router on channel 1. Channel 6 would have worked fine too, but we live in a townhome and we have lots of neighbors; most wireless routers broadcast on channel 6 by default when they are bought from the store (newer ones are smarter and try to choose automatically, but I wouldn't rely solely on that mechanism).
The last thing to change on that screen is your wireless encryption and password. I'll leave that up to you to modify. It should be pretty easy to compare the wireless security settings on your GFR and your secondary router. Just remember that they all have to match, including the wifi password.
That's it! Now just save your settings and restart your secondary router for good measure. You now have two wireless access points for the same home network :D