We have a problem in office when a user connects to our LAN without disconnecting from WiFi network he was previously on (a free WiFi provided by building owners). At a minimum, firewall log entries are cluttered with machine attempting to reach WiFi supplied DNS servers via fixed link. More of a threat is scenario when machine is hacked it can be used to bridge networks (public/private).
How to auto-disable wireless or auto-disconnect from it, if physical cable (ethernet) is plugged in?
I dont know of any downloadable software, but many new laptops come with it pre-installed. Dell laptops have something called Dell Control Point, which is mostly a useless hassle, but does have a few redeeming qualities. One of which is the option to disable wireless when docked or plugged in.
You don't need it. Assign different IPs to these interfaces, and set a better metric to the wired connection's routes: it will become preferred, and while Wi-Fi is still online it is not used ;)
