Which interface should I bind to on a robot with mobile internet?
I've currently got a robot running in the wild with a stick for mobile UTMS installed which creates a network interface usb0 with IP 192.168.8.100. Furthermore, I've got a VPN set up which routes any traffic targeted at 192.168.8.100 directly to the robot, so if I set ROS_MASTER_URI to http://192.168.8.100:11311 on my desktop PC, I can see the topics on the robot. So far, so good.
I have however had problems where the stick might spontaneously drop its interface and consequently the ROS system breaks down. While I should of course get to the bottom of why the interface simply drops, it got me thinking that I'd like to have the robot running independently from the stick altogether. Since the robot is not dependent on the internet to run and I'd just like to once and again check on a topic, it would be nice if the stick can just be removed and reinstalled without the system caring much.
Is there any way in which I can have the ROS_MASTER_URI set to a static interface (e.g., localhost), and just extract or insert a message here and there using the VPN connection? Or am I looking at this from the wrong angle?
