Using Mobile Internet/Data while Connected to a WiFi Network

Installing and Using OpenWrt Network and Wireless Configuration
1

The setup I would like to use is:

  • Local WAN through OpenWRT
  • Some permanent media players attached the WAN over wifi
  • Intermittent cell phones attached to the WAN when people are present
  • Cell phones connect to wifi for local device control, but continue to use their own 4G internet access for everything else

One method for this is described at

However, that method requires that individual phones be specially setup. I'd like something that doesn't require extra setup, so people can just be given the network name/password, and proceed from there.

As a specific example, I have a Raspberry Pi media player that has its own foo.local address. I would like to able to enter 'foo.local' in my cell phone web browser to control it, while maintaining internet access through 4G on the same phone.

Is there a way to do this with OpenWRT settings?

2

Yes you can do it with mwan3. Make or use a non working interface then use it as member, then make a policy for that member but with option blackhole or unreachable, then make a rule that tank the whole subnet.

I recently do this but with different purpose, I have 4G on router that do load balance with cable but didn't want the Pi pulling in XXGB on my 4G.