c# - Communicate between computers through Ethernet cable

Question

I want to connect two computers with an Ethernet cable without the user having to set up a LAN through the Control Panel and then transfer data between two instances of my app - one running on each computer.

As soon as I have a connection with an IP address for each computer, I know I can easily transfer a file by using Sockets, Pipes(?), WCF... But both computers are also connected via wifi to a router, so how can I somehow tell the computer that for a specific IP address - please use the cable? (I might be getting all of this wrong. Please feel free to correct me.)

I can use a UWP app or a .net (Winform/WPF) app. Either technology is fine. But this must be done in code, not by the users setting up a LAN through the Control Panel. Also, IPv6 is fine too.

Answer 1

Each network card has its own IP address, so both of the computers will have IP address for the WIFI network and another IP address for the ad-hoc link. The addresses for the ad-hoc link can be set to an address in one IP segment, for example, 10.0.0.1 and 10.0.0.2, if the WIFI addresses are in the range of 192.168.X.X. Your OS will know which card is related to each IP segment.