4. Coniguration of multiple interfaces on OpenWRT.

Place the SD card on board connect the UART-USB to RPI

RPI UART-USB

pin 6 - GND

pin 8 - Rx

pin 10 - Tx

Now connect the USB end of UART-USB to your pc or laptop and in terminal run the following command:

picocom -b 115200 /dev/ttyUSB0

Power on the rpi the openwrt screen should appear.

Now edit the network config file at /etc/config/network

vim /etc/config/network

Remove all the data inside the file and add following interfaces to the file:

config interface 'loopback'

    option ifname 'lo'

    option proto 'static'

    option ipaddr '127.0.0.1'

    option netmask '255.0.0.0'

    config globals 'globals'

    option ula_prefix 'fd93:96c9:5884::/48'

config interface 'wan'

    option type 'bridge'

    option ifname 'eth0'

    option proto 'dhcp'

    option netmask '255.255.255.0'

    option ip6assign '60'

    option metric '10'

    option defaultroute '1'

    #option gateway '192.168.1.1'


 config interface 'wanb'

    option type 'bridge'

    option proto 'dhcp'

    option ifname 'usb0'

    option metric '20'

    option defaultroute '1'


 config interface 'wanc'
    
    option type 'bridge'
    
    option proto 'dhcp'
    
    option ifname 'usb1'
    
    option metric '30'
    
    option defaultroute '1'

Now restart the network setup by:

 /etc/init.d/network restart 

Your Multiwan Openwrt OS is ready to use.

Connect a Ethernet cable to the port and a USB cable to your phone and rpi for usb tethering.

Dont forget to switch on USB-Tethering on your phone it will bw present in settings.