Set android as internet gateway to local router (Not mobile hotspot)

**Background** I have a local network and I want to have my mobile serve as an internet gateway when entering the network. What I'm asking is asked here , here and here . An advanced version has also been asked here but all of them have no answers leading me to a conclusion this might not be possible. With this post, trying to list down what I tried, problems faced so as to open a discussion for a possible solution to this problem. Have tried this with relatively recent android 9, 10 and 11. **Some obvious steps** - Have static IP for the mobile which will serve as a gateway. - Setup router to use the gateway. **Problems** - Android connects to wifi and gives a warning that access point doesn't have internet access. We can switch to mobile data but the local network is inaccessible as wifi is disconnected. Changing to always use mobile data in developer options also behaves the same. - Let's suppose android is used as gateway and other devices are able to access internet, how will the device access local network? A probable solution is to make a middleware that decides to send packets to internet or intranet, or perhaps use internet as a fallback. I'm pretty sure mobile will need to be rooted for this kind of control. Is there anything developed which can be used directly?