A program I'm developing connects directly over the LAN between 2 computers. Sometimes, a user will have 2 computers on different networks, so the computers won't be able to connect to each other (or ping each other). I want to give the user the possibility of testing this LAN-to-LAN connectivity before downloading and installing the main program.
Is it possible to or connect to (or ping) one computer from another over LAN using Chrome or any other browser? This would also involve detecting the local IP address.
My hunch is that Chrome (and other browsers) won't provide this sort of access to the OS (i.e. with JavaScript or an extension), but maybe there's an alternative (dare I say, a Java Applet, if that's still a thing). A bonus would be if this could work on Windows, macOS, and Linux.
Any ideas?