Create a routed Access Point with Raspberry Pi and OpenWrt

 

In this article, I will show you how to configure your Rapberry Pi 3 into a routed WiFi access point. This configuration is a little bit more complicated than the configuration of my previous post that is available under the following link : https://gremaudpi.emf-informatique.ch/create-a-bridged-access-point-with-raspberry-pi-and-openwrt/

In this configuration, the WiFi clients are on a different subnet than the management workstation. The Raspi will act as a router and forward all packets from the clients to the Lan network using Masquerading (Port Address Translation)

Schema

 

 

 

Get the current OpenWrt image

UPDATE : At time of this writing (November 2019), most recent releases of OpenWRT have a known bug preventing the use of the WiFi interface.

The only solution I found to circumvent this problem is to install an old release of OpenWRT (version 18.06.1) that did not have this bug, and afterwards to upgrade to the latest version of OpenWrt directely from the console of OpenWrt.

So, start by downloading the latest release of OpenWRT that works with the WiFi interface

https://downloads.openwrt.org/

 
 

Take the current factory image (openwrt-18.06.1-brcm2708-bcm2710-rpi-3-ext4-factory.img.gz)

Burn the image with etcher

Change LAN IP address of Raspi

 

For this you will need to configure your management workstation IP address to 192.168.1.2 with subnet mask 255.255.255.0.

 

Then open a browser and access to the default IP of the Raspi (http://192.168.1.1)

ATTENTION : BE AWARE OF USING HTTP AND NOT HTTPS

By default, the password is empty.

 

Then, navigate to Network – Interfaces and edit LAN interface

 

Disable DHCP server on this interface

 

To apply this configuration, you will need to first click on "Save & Apply" and then force apply with "Apply unchecked".

 

Your Raspi is now available under 192.168.0.30.

You can revert your management workstation Ip configuration to DHCP.

 

Begin by doing some cleanup

 

Open a browser and access to the new IP address of the Raspi (192.168.0.30)

Navigate to Network – Wireless and remove the default wireless SSID OpenWrt (see below)

 

Navigate to Network – Firewall, and under "General Settings" delete all Zones and click "Save and apply"

 

Under "Traffic Rules", check that all rules are gone

Create a new wireless SSID for Guest

 

Navigate to Network - Wireless and add a new SSID called "Guest" associated with a network called "Guest" too.

 
 

Do not forget to specify you Country Code (in my case Switzerland) in order for your device to comply with established international rules (Advanced settings)

 

Click "Save and Apply" and you should now have a brand new SSID (see below)

 

Click "Enable" to activate the new SSID

 

Set your Contry code

Configure the new Guest Interface

 

Navigate to Network – Interface and edit the newly created Guest Interface

 

Under General Setup, change the protocol from "Unmanaged" to "Static address"

 

Then click "Switch protocol" and configure the IP address and the netmask of the Guest Interface

 

Assign a DHCP server to this interface and click "Save and Apply"