I have EC25 modem and want it to connect to the host system so that it receives a (local) IP address and I could run an application like a web server on the embedded linux system and access it from the host (Windows PC in my case).
On the host system there’s a mobile broadband interface announced that provides internet access through the modem but as an mbn interface it does not have its own IP address.
Bonus question, is it possible for the modem to get internet access via the host system (not the cellular network)?
I think I made a little progress regarding this. I recomposed the modem to the ECM mode using at+qcfg="usbnet",1 (then searched a bit for the ECM windows driver and then manually updated the hardware in windows device manager since everything was recognized as serial ports).
Now there’s a pseudo-ethernet connection in windows (ncpa.cpl) and I can ping the modem and view a webserver running on it. However the issue I face now is that once this connection is up, it is used as default connection in windows (likely the modem pushes a default route) and hence internet access is via the cellular network, which is not the behaviour I want. I want to continue using my cable connection while being able to access services ran on the modem. So the question now is how to avoid the ECM connection becoming the default.
Another issue I noticed is that the modem would get recomposed into usbnet=0 mode on reboot (still not sure if it happens all the time or randomly). Is there a way to make this permanent?
In ps I noticed the following:
dnsmasq -i bridge0 -I lo -z --dhcp-range=bridge0,192.168.225.20,192.168.225.30,255.255.255.0,43200 --dhcp-option-force=6,192.168.225.1 --dhcp-option-force=120,abcd.com
Which I believe is the process responsible for network configuration. But I am struggling to find from which script or config this line comes.