I'm working on an embedded system that will feature a ethernet connection to a PC host. The product contains a DHCP server so the PC can automatically get an IP assigned. In order to not interfere with the host's functions, the 2 IP adresses we assign for that connection (which will always be point-to-point) shouldn't collide with any local networks the PC Host is connected to.
Is there a way to get a range that's guaranteed to be unused? Should I maybe use addresses in 169.254.0.0/16?
EDIT: Some mistakes on my part caused misunderstading. I don't need it to be free as in free beer, what I want is for an user to connect the device to his computer and get a connection automatically set up. If I choose 192.168.43.0/30 for the connection, it might actually interfere with the user if he's using that exact range. That's the problem I'm trying to avoid.
Thank you all for commenting so far!