Hotspot and a static IP address for the phone

Antagonist

It seems that the hotspot IP-address and even range is changing on a regular basis.

I can see this as a good feature for some people, but in other cases, it provides a challenge. A device connected to my hotspot needs to connect to my phone to deliver files using FTP. This is a embedded device - things like LocalSend or other solutions are not going to work.

It basically is a 'set it and forget it thing', and reconfiguring the IP-address every run would be very, very cumbersome.

Is there a way to make the hotspot IP-range (and phone IP) static? I thought of (m)DNS solutions, but that has drawbacks as well and I don't want to overcomplicate things.

n3t_admin

Antagonist The correct way to go about this, would be to set a static IP on the embedded device, not on the hotspot. You just need to figure out the DHCP range, subnet mask and gateway IP of the hotspot network and enter those details somewhere in the network settings of the embedded device. The easiest way to go about this, is to look at what settings it's currently using and write these down.

There are sadly no ways around that, as the Android hotspot is basically an autonomous system that can't be configured by the end user.

Antagonist

That doesn't help this case, as even the subnet seems to be randomized. That means re-configuring the device each run, which is way too much work.

Also, giving the device a static IP won't work, as it still needs to connect to a fixed FTP server.

Some more flexibility in this would be great.

n3t_admin

Antagonist that's news to me. Are you running purely on mobile data or connected to WiFi when using hotspot? That might explain the different subnets (avoiding conflicts with wifi interface).
I'm afraid there won't be a better solution, since hotspots (or Android in general) were never really designed with routing functionality in mind. Having static IP leases for the hotspot is not something I've seen on Android before - and as you're saying, fixing the random subnets would need to happen first anyway.

Antagonist

Purely mobile data (at least - in the case where I'm going to use it).

Is there some reliable way to at least retrieve the hotspot AP's IP-address (wlan1) using Java? From what I could find, the 'official' options using the SDK are blocked off.