The Wi-Fi in our house is very weak. So weak that the signal won't reach any far-away rooms. After getting annoyed at my Mi Box dropping the Wi-Fi connection a couple of times, I decided to extend the range of the signal with a Wi-Fi access point.
Most of the tutorials online, however, only mention how to make a Wi-Fi repeater with a Raspberry Pi. Now, for the unaware, a Wi-Fi repeater is terrible because you're essentially cutting the bandwidth in half, and causing more congestion for the network in your area. An AP (access point), on the other hand, is significantly better because the communication between your Raspberry Pi and your router happens through the Ethernet jack.
So let's get started! This guide assumes you have the latest Raspbian Stretch Lite flashed on a SD card with balenaEtcher inside the Raspberry Pi.
- (optional) Create an empty file called
/bootpartition of the USB. Windows will automatically open the drive if you plug it in. Do NOT format the other drive if Windows asks you. Too late, and you've already pressed format? Start over with balenaEtcher.
This asks the Pi to enable SSH on first boot. Useful if you don't have a keyboard, mouse, and a monitor handy to configure the Pi.
- Make sure the Pi is connected to an Ethernet network.
- Start up the Pi and connect to it using SSH. If you don't know the Pi's IP address, download Fing on your phone (Android/iOS) and do a scan on your network. If that doesn't show anything, try running
arp -aon any terminal. If that doesn't work, use
nmap. As a last resort (and potentially the first place you might check if your router is decent), connect to the router's administration page and check the DHCP leases. My router is capable of this but it never showed any devices in the list except the one I was connecting from, so the feature was absolutely useless for me.
- The default username and password is
raspberry. We're going to change the password in a bit.
- Change the password using
sudo apt updateto fetch latest update manifests.
sudo apt upgradeto update the packages.
sudo rpi-updateto update firmware.
sudo rebootto reboot and apply the new firmware.
sudo apt install hostapdto get Wi-Fi hosting tools.
sudo systemctl stop hostapdto stop
hostapd. We don't need it for now and we need it disabled to edit the configuration.
sudo apt install bridge-utilsto install bridging utilities.
sudo brctl addbr br0to create a bridge interface. This is what the Wi-Fi clients will use while connecting.
sudo nano /etc/hostapd/hostapd.confto create configuration for
You must comment out
driver or else it will fail. Once finished, type Ctrl-O, and then Enter to save. Type Ctrl-X to exit.
sudo nano /etc/default/hostapd to apply new configuration. Find the line that says
And uncomment it. Edit like so:
Save and exit.
16. We need to bridge the two connections. Run
sudo brctl addif br0 eth0.
17. Add these lines to
sudo nano /etc/network/interfaces:
18. We need to prevent the Pi from assigning
wlan0 to new network interfaces. Add the following lines to
sudo nano /etc/dhcpcd.conf:
sudo systemctl unmask hostapd sudo systemctl enable hostapd sudo systemctl start hostapd
19. Finally, run
sudo reboot to start your new AP! When rebooting, there might be an error: "Failed to start dhcpcd on all interfaces." This is normal and should be ignored.
So great! Now that you have it set up, you should be good to go, right?
Well, not quite. If it works for you, don't bother reading the rest of the post. If you're curious, read on.
In my testing, the Pi-AP was absolutely great. DHCP requests were all handled by my main router, and Internet access worked great. However, I wondered what the network throughput would be.
To test this, I set up an
iperf3 server and then ran tests between my laptop (a ThinkPad X250) and the server, going through the Pi-AP or directly. The results were disappointing. The direct connection gave me 100Mbps of throughput - very well, seeing as this is Cat.5 cable, but the Pi-AP gave about 20Mbps. What the hell?
I tried using my original, crappy Chinese AP, and it gave me a consistent throughput of 70Mbps. About what I was expecting. I have two theories as to what is going on. Theory number one is that the Pi is underpowered, and therefore suffers from Ethernet/Wi-Fi lag. Theory number two is that the packets first go to the router (or default gateway) for inspection, come back to the Pi and then go to the intended recipient. Then the cycle repeats as the packets make their way back to the client.
I'm betting on the latter, but it could easily be the former. Not too sure what's going on. If you have an idea as to why, please send me an email!