in order to use Rekordbox in Export Mode (via LINK), each device (CDJ, DJM, etc) and computer running Rekordbox (Export Mode) need to be connected to PRO DJ LINK network. with your current setup, you will always need to use a simjple ethernet hub/switch so that both CDJs and mixer can communicate - and if you want to access Rekordbox (Export Mode) via LINK your computer either needs to connect via ethernet cable or - if your ethernet hub had wireless, - via local wifi network. my advice is to use a simple five port dedicated 'unmanaged' hub/switch with all devices/computer wired. a hardwired PRO DJ LINK setup is probably the most stable thing I've ever encountered in the DJ world (technology or people) and with some creative cable management you can pretty much make it invisible. good luck.