first Core MIDI only works with iOS which means you need to connect through an ipad/ipod or iphone
you don't need a router to use the coreMIDI, just create a local wifi network with your computer then go to the MIDI setup, choose the Network patch and configure a session then register a controller to this network
actually, i'm no certain that you can connect multiple computers.
if you have the ability to modify a module, you'd rather make a copy of the Network(global) module and route midi signal to your needs.
otherwise, you can try this third part software: ipMidi
http://www.nerds.de/en/ipmidi.html
i never tried it, if you do, please share your experience