Networking

Setting Up a Wi-Fi Extender Using a Raspberry Pi

A wifi extender is important in cases where the network is not strong enough past certain ranges. This extender can be used in small areas such as an office or home.  The Raspberry Pi Wi-Fi Extender is a low-cost and high-power device that can help extend your Wi-Fi network range. It mainly establishes its network connection from a Wi-Fi adapter. A Wi-Fi extender is important in cases where the network is not strong enough past certain ranges. This extender can be used in small areas such as an office or home.

Prerequisites
Extending the Wi-Fi using Raspberry
Conclusion
Relevant Sources

Prerequisites

Raspberry Pi 3
Power cable
Wi-Fi adapters
Raspberry Pi Case (optional)

Extending the Wi-Fi using Raspberry

To create a Wi-Fi extender using a Raspberry Pi, the dnsmasq package in Linux is used. This package is important as it takes care of the majority of the technical work for you by functioning as both your DNS and DHCP server, that are needed to form a connection.

You'll also need to install the hostapd package that allows us to create the extender. It is essential to have a Wi-Fi router that is active for you to make a connection as well as an Ethernet device for bridging the connection.

Step One: Updating the Raspberry Pi

Before installing the packages, you should perform an update: sudo apt-get update and sudo apt-get upgrade.

Package Upgrade

Step Two: Installation of the dnsmasq and hostapd packages

Install the dnsmasq and hostapd packages using these commands:

sudo apt-get install dnsmasq

dnsmasq

sudo apt-get install hostapd

hostapd

Step Three: Open the dhcpcd.conf

This can be achieved using this command: sudo nano /etc/dhcpcd.conf

Step Four: Setting up the wlan1 connection

Add the lines below to set up the wlan1 connection as required.

interface wlan1
static ip_address=192.168.5.1/24
static routers=192.168.5.0

Use CTRL + X, press Y then Enter to keep configurations.

Setting Up WLAN Connection

Step Five: Restarting dhcpcd service

Restart your dhcpcd service to ensure all configuration changes are loaded.

sudo service dhcpcd restart

dhcpcd Restart

Step Six: Modification of the hostapd configuration

To modify the hostapd configuration;

sudo nano /etc/hostapd/hostapd.conf

Here we dictate how we can communicate and interact with the WLAN device by changing the following lines:

ssid= " " //here you enter the name of the Wi-Fi

wpa_passphrase=" " //here you enter the password of the Wi-Fi

hostapd.conf

Step Seven: Adjust the hostapd configuration files

Open the following files:

/etc/default/
/etc/init.d/

Using nano editor: sudo nano /etc/default/hostapd

Look for #DAEMON_CONF="" and then substitute it using:

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

Modify Hostapd Config File Part 1

Open the other configuration file in init.d using: sudo nano /etc/init.d/hostapd
Look for #DAEMON_CONF= and replace using DAEMON_CONF=/etc/hostapd/hostapd.conf

Modify Hostapd Config File Part 2

Step Eight: Change directory of the dnsmasq.conf

First, change the directory of the configuration using: sudo mv /etc/dnsmasq.conf /etc/dnsmasq.conf.orig

Step Nine: Creation of a new dnsmasq.conf configuration file

Create a new conf file using: sudo nano /etc/dnsmasq.conf
Type the following into the new file to help communicate with the dnsmasq service and tell it how to deal with all connections being made.

interface=wlan1 # Specification of interface
listen-address = 192.168.5.1 # Specification of listening address
bind-interfaces # Binding interface
server=8.8.8.8 # Setting up Google DNS
domain-needed # Limit forwarding of names that are not domain names
bogus-priv # Drop the non-routed address spaces
dhcp-range=192.168.5.50,192.168.5.150,12h # IP range and lease time

Creating dnsmasq config file

Step Ten: Traffic forwarding configuration

Next, we configure the Raspberry Pi to forward the traffic so that it works like a router. This can be achieved using: sudo nano /etc/sysctl.conf.

Find and eliminate # sign at the beginning (Uncomment): #net.ipv4.ip_forward=1

Enable Packet Forwarding

Step Eleven: Activation of IP forwarding on the Pi

Activate the Raspberry Pi using the command below: sudo sh -c "echo 1 > /proc/sys/net/ipv4/ip_forward"

Note: You may reboot at this point in order to apply the settings:

Step Twelve: NAT configuration

Configure the NAT between the wlan0 and wlan1 interface as a way of forwarding traffic using:

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

To save: sudo sh -c "iptables-save > /etc/iptables.ipv4.nat"

Saving Rules

Now we have to ensure that our configuration is be loaded locally every time the Raspberry Pi boots up First, open rc.local using: sudo nano /etc/rc.local. Then insert iptables-restore < /etc/iptables.ipv4.nat above exit 0

rc.local

Restart the two services:

sudo service hostapd start
sudo service dnsmasq start

Restart Services

Step Thirteen: Restart the Raspberry Pi

Finally, run the following command: sudo reboot to restart the Raspberry Pi. To test it works, use any wireless devices to connect to it using the Wi-Fi network name and password you created.