OpenWrt: How to use wifi as WAN connection?

Question

Situation:

My internet provide only provides wifi / WLAN in my home. I don't have a wired connection to the outside world.

Goal

I'd like to create a LAN in my home that uses the provided wifi connection as WAN port.

Question

How do I configure my OpenWrt router to do that?

Previous research

I've read many questions here on SE and on the internet talking about bridging and how to do it. I ended up with 16 lost hours and no showable result.

Answer 1

I advice you to start from a freshly resetted / installed system.

Introduction

• Open your Web UI (192.168.1.1)
• Go to Network -> Wireless
• It should look something like this:
  • Notice:
    • "radio0" and "radio1" can be interpreted as "wifi device 0" and "wifi device 1"
    • The Radios might show a message "inactive". Don't bother about that
    • A "radio" is nothing you can connect to from your computer. Your computer will connect to a Network.
    • There are already two networks set up - one for each radio. One with SSID OpenWrt2 and one with SSID OpenWrt5.
    • Both of them are disabled. You can test your wifi connections by Enable button and connect to it for another device.

Setup

For the following I presume that

• Your WAN wifi uses 2.4 GHz
• Your LAN wifi uses 5 GHz
• Your Wired LAN and wifi LAN will be on the same network.

Steps:

1. Many tutorials tell you to change the static LAN IP address of your router. Don't. It won't work anyway.

2. Open Network -> Wireless on your OpenWrt web interface

3. Enable your 5 Ghz network by pressing the Enable button. Try to connect to it (Don't worry about the encryption for now). If you cannot connect to it, stop here and go for troubleshooting.

4. Remove the 2.4 Ghz network by clicking the Remove button. (in the picture above this amounts to the OpenWrt2 network)

5. On you 2.4Ghz radio / wifi device, click the Scan button

6. Wifi access points in your vicinity should show up.

7. Press Join this network on the wifi that should become your WAN

8. You should be presented with the Joining Network screen. It looks like this:

9. Leave everything as is. Just enter the password for the wifi you're trying to join (the WAN wifi) into the WPA passphrase field.

10. Press Submit.

11. You should be presented with the Device Conficuration Screen. It should look like this:

12. In the top (Device Configuration), go to Advanced Settings, set Country Code to your country. This will ensure that radio laws of your country are being followed.

13. Go down to the Interface Configuration section, General Setup tab. At Network, click the drop down arrow and add lan to the selection (so you have lan and wwan in that box). It should look something like this:

• This setting is a key component: It connects LAN and WAN.

12. Click Save.
13. You should be back in your Wireless network configuration page. Go to the bottom and click Save & Apply.
14. You should now be able to connect to your internal LAN (OpenWrt5 in my case) and access the internet from there. If not, you need to go for troubleshooting or simply try again after a reset of your device.
15. If your network works as expected, you can now set some additional settings by clicking the Edit button for you LAN wifi (like your security (highly recommended), maximum transmit power or MAC filter, ... )

• After you changed something, don't forget to apply the changes. Otherwise they won't have any effect.

16. And don't forget to set a root password for your OpenWrt system.