RPI_Wifi_AP_to_LAN

What is RPI_Wifi_AP_to_LAN ?

In case your ISP can not provide Internet connection, this allows all your computers to connect to Internet via a Wifi AP of your neighbour. (provided that has Internet connection)

The script is based on:

• Article by Instructables.com
• Github repo of Arpit Agarwal (arpitjindal97)

How does it work?

RPI_Wifi_AP_to_LAN makes a connection with the Wifi AP of the neighbour (we assume it has Internet connection) This should be a so-called Guest AP with no access to neighbour's LAN, only connection to Internet
It also create a network with DHCP on the Ethernet port (RJ45) of the Raspberry Pi. Traffic from the ethernet port is forwarded to Wifi vice versa, so all computers will have Internet connection via the Raspberry Pi. You can change your specific settings in the script itself, or in a configuration file on a USB stick and place the USB stick in the Raspberry Pi

Prepare yourself:

• Discus fail-over scenario with neighbour and agree
• Maybe neighbour has to configure a guest AP
• Build the Raspberry Pi as described below
• Enter Wifi AP of neighbour in the script
• Shutdown and store Raspberry Pi.
• Make sure that all computers are on a single switch that has a connection to your ISP's Modem, do connect computers to other ISP's Modem ports

Fail over steps:

• Contact neighbour and agree that fail-over is allowed by neighbour
• Maybe neighbour has to activate Wifi guest AP for you
• power up Raspberry Pi
• Switch off your ISP's Modem
• Take the connection of your switch to your ISP Modem from the ISP Modem and put it in the RJ45 connector of the Raspberry Pi
• Restart your computers

Your fail-over LAN has a DHCP service so your computers should all connect after a reboot.

How to build?

RPI_Wifi_AP_to_LAN consist of:

• A Raspberry PI with Wifi and Ethernet (RJ45 connector)
• Buster OS
• put the script in /home/pi
• edit values of Wifi AP and local LAN config as needed

#  Details Neighbours Wifi Access Point
#  (change as required)
#
nb_ssid="guest_ap"
nb_pass="guest_ap_password"
keymgmt="WPA-PSK"
country="NL"
#
#  Details of the new local network with DHCP 
#  (change as required)
#
ip_address="192.168.2.1"
netmask="255.255.255.0"
dhcp_range_start="192.168.2.2"
dhcp_range_end="192.168.2.100"
dhcp_time="12h"
#
#  Local Network Interfaces
#  (you should be fine with thes values.)
# 
wlan="wlan0"
#
eth="eth0"
#

• Or, create a file named config.txt on a USB stick and enter the parameters in this files
  Example of config.txt

nb_ssid = guest24
nb_pass=formyguests

• add a crontab entry for root sudo crontab -e enter this line at end of file: @reboot /home/pi/rpi_wifi_ap_lan_bridge.sh > /home/pi/rpi_wifi_lan_bridge.log 2>&1

Who will use it?

Anyone with a friendly neighbour that gives access to his/hers Wifi guest AP
This can your home neighbour or (small) office neighbour Talk to them and make arrangments before your ISP connection fails.

Goal , next steps

Adding of a small LCD with status would be nice.