How to Set up a Raspberry Pi as a Wi-Fi extender

Setting up a Raspberry Pi as a Wi-Fi extender can be a cost-effective solution to improve Wi-Fi coverage, its alaso a fun little project if your looking for something to do with a Raspberry Pi.

This involves configuring the Raspberry Pi as both a Wi-Fi receiver (to connect to your main router) and a Wi-Fi access point (to extend the network).

Here’s a step-by-step guide:

Requirements

1. A Raspberry Pi (Raspberry Pi 3, 4,5 or Zero W recommended for built-in Wi-Fi).
2. Raspberry Pi OS (Lite or Desktop version).
3. A suitable power supply for the Raspberry Pi you have.
4. A microSD card (8GB or larger) with Raspberry Pi OS installed.
5. Ethernet cable (optional, for initial setup or bridging).
6. A second USB Wi-Fi adapter (optional, for higher performance).

Step 1: Prepare the Raspberry Pi

Install Raspberry Pi OS

1. Download and install the Raspberry Pi Imager.
2. Use the imager to install Raspberry Pi OS (Lite is sufficient) onto the microSD card.
3. Enable SSH:
   • After flashing, place a file named ssh (no extension) in the boot partition.
4. Enable Wi-Fi (if using Lite version):
   • Add a file named wpa_supplicant.conf to the boot partition with the following content:

     country=US
     ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
     update_config=1
     network={
         ssid="Your_SSID"
         psk="Your_PASSWORD"
     }
     

     Replace Your_SSID and Your_PASSWORD with your Wi-Fi credentials.

5. Insert the microSD card into the Raspberry Pi and power it on.

Access the Pi

1. Find the Raspberry Pi’s IP address using your router or a network scanner.
2. SSH into the Raspberry Pi:

   ssh pi@<IP_ADDRESS>
   

   Default username: pi, password: raspberry.

3. Update the system:

   sudo apt update && sudo apt upgrade -y
   

Step 2: Install Required Software

Now we Install the necessary tools for configuring the Pi as a Wi-Fi extender:

sudo apt install hostapd dnsmasq iptables-persistent

Disable the services until configured:

sudo systemctl stop hostapd
sudo systemctl stop dnsmasq

Step 3: Configure the Access Point

Edit hostapd Configuration

Create and edit the hostapd configuration file:

sudo nano /etc/hostapd/hostapd.conf

Add the following:

interface=wlan0
driver=nl80211
ssid=Pi-WiFi-Extender
hw_mode=g
channel=6
wmm_enabled=1
macaddr_acl=0
auth_algs=1
ignore_broadcast_ssid=0
wpa=2
wpa_passphrase=ExtenderPassword
wpa_key_mgmt=WPA-PSK
rsn_pairwise=CCMP

• Replace ssid with your desired network name.
• Replace wpa_passphrase with a secure password.

Set the hostapd configuration path:

sudo nano /etc/default/hostapd

Uncomment and update:

DAEMON_CONF="/etc/hostapd/hostapd.conf"

Configure dnsmasq

Backup the original configuration:

sudo mv /etc/dnsmasq.conf /etc/dnsmasq.conf.bak

Create a new configuration:

sudo nano /etc/dnsmasq.conf

Add the following:

interface=wlan0
dhcp-range=192.168.4.2,192.168.4.20,255.255.255.0,24h

Step 4: Set Up Network Forwarding

Enable IPv4 forwarding:

sudo nano /etc/sysctl.conf

Uncomment the line:

net.ipv4.ip_forward=1

Apply the changes:

sudo sysctl -p

Add iptables rules for network forwarding:

sudo iptables -t nat -A POSTROUTING -o wlan1 -j MASQUERADE
sudo iptables -A FORWARD -i wlan1 -o wlan0 -m state --state RELATED,ESTABLISHED -j ACCEPT
sudo iptables -A FORWARD -i wlan0 -o wlan1 -j ACCEPT

Save the rules:

sudo sh -c "iptables-save > /etc/iptables/rules.v4"

Step 5: Configure the Wireless Interface

Edit the dhcpcd configuration:

sudo nano /etc/dhcpcd.conf

Add the following:

interface wlan0
    static ip_address=192.168.4.1/24
    nohook wpa_supplicant

Restart dhcpcd:

sudo systemctl restart dhcpcd

Step 6: Start the Services

Enable and start hostapd and dnsmasq:

sudo systemctl unmask hostapd
sudo systemctl enable hostapd
sudo systemctl start hostapd
sudo systemctl restart dnsmasq

Step 7: Test the Wi-Fi Extender

1. Connect to the new network (Pi-WiFi-Extender or your chosen name) using the configured password.
2. Check internet connectivity.

Step 8: Optional Steps

You may want to monitor your network performance, here is an option.

Monitor Performance

• Use tools like nload or htop to monitor network performance.

sudo apt install nload
nload

Improve Coverage

• Use an external Wi-Fi adapter for better range.
• Adjust the channel in hostapd.conf to avoid interference.

Secure the Setup

• Change the default pi password.
• Regularly update the system:

  sudo apt update && sudo apt upgrade -y
  

By following these steps, your Raspberry Pi should now function as a Wi-Fi extender, improving coverage and performance in your home or office.